Quaternary (Holocene and Pleistocene) volcanoes courtesy of the Global Volcanism Program, Smithsonian Institution. Version 5.4.0, 7 August 2026.

Holocene Volcanoes | VOTW 5.4.0, 7 Aug 2026

Antarctic-Scotia Volcanic Regions

Balleny Hotspot Volcano Group

Young Island
Antarctica
Balleny Hotspot Volcano Group
Landform: Composite
Volcano type: Stratovolcano
Elevation: 1340 m
Latitude: 66.42°S
Longitude: 162.47°E
Young Island is the northernmost and second largest of the Balleny Islands off the coast of Antarctica's Victoria Land. Captain Balleny, the discoverer of the islands, reported "smoke" issuing from Freeman Peak on Young Island on 12 February 1839. The island, almost completely mantled by ice, has a broad plateau-like summit reaching 1340 m.
Smithsonian Volcano Information

Sturge Island
Antarctica
Balleny Hotspot Volcano Group
Landform: Composite
Volcano type: Stratovolcano
Elevation: 1167 m
Latitude: 67.4°S
Longitude: 164.83°E
Sturge is the largest and southernmost of the Balleny Islands, which are located just off the coast of Antarctica's Victoria Land. The 44-km-long island is completely mantled by an icecap and has a prominent summit, Russel Peak, at the northern end. "Volcanic activity" was reported on a U.S. Navy chart, but no indications of present or past activity were noted in 1959 (Catalog of Active Volcanoes of the World). No detailed geologic studies have been conducted in the inaccessible Balleny Islands.
Smithsonian Volcano Information

Buckle Island
Antarctica
Landform: Composite
Volcano type: Stratovolcano
Elevation: 1239 m
Latitude: 66.78°S
Longitude: 163.25°E
Buckle Island is in the center of a 160-km-long chain of volcanic islands forming the Balleny Islands off the coast of Antarctica's Victoria Land. The islands are located at the southern end of a submarine ridge system that extends north to New Zealand, but is offset by the Indian-Antarctic ridge system. The elongated, 21-km-long island is capped by an gently sloping icecap that descends steeply to the sea between rocky cliffs. Dark eruption columns were reported during 1839 and 1899, but no detailed geological studies exist for the Balleny Islands volcanoes.
Smithsonian Volcano Information

McMurdo Volcanic Province

The Pleiades
McMurdo Volcanic Province
The Pleiades volcano consists of the small trachytic Mount Pleiones stratovolcano which, along with several lava domes and nested cinder cones with well-preserved craters, rises above the broad Evans Neve plateau. Located in the Melbourne Volcanic Province of Antarctica's northern Victoria Land near the western coast of the Ross Sea, they appear to be among the youngest volcanic centers in Antarctica. A Potassium-Argon age of 3,000 years was obtained from the Taygete cone NNE of Mount Pleiones. Other dates of 12-40,000 years support a youthful age despite the large analytical uncertainties.

Melbourne
McMurdo Volcanic Province
Mount Melbourne is a large undissected stratovolcano along the western coast of the Ross Sea in Antarctica's northern Victoria Land. The glacier-covered edifice lies at the center of a volcanic field containing both subglacial and subaerial vents along a dominantly N-S trend. A large number of scoria cones, lava domes, viscous lava flows, and lava fields are exposed at the summit and upper flanks. A number of very young-looking cones are located at the summit and on the flanks. Tephra layers are found within and on top of ice layers, and the most recent eruption was estimated to have occurred between 1862 and 1922. The volcano displays fumarolic activity that is concentrated along a NNE-SSW line cutting through the summit area and along a line of phreatomagmatic craters on the southern rim of the summit crater. Prominent ice towers and pinnacles were formed from steam condensation around fumarolic vents.

McMurdo Province at 76.8�S
Landform: Caldera
Volcano type: Caldera
Elevation: -500 m
Longitude: 163°E
Magnetic and seismic data suggest that a submarine caldera with a central lava dome is present east of Granite Harbor and north of Ross Island, near the western coast of the Ross Sea and near the southern end of the submarine Victoria Land Basin. Apparent temperatures above the Curie temperature suggested the presence of magma and a Holocene age (Behrendt et al., 1987).

Morning
Landform: Shield
Volcano type: Shield
Mount Morning is a glaciated, undissected, alkalic shield volcano in the Erebus volcanic province SE of the south end of the Royal Society Range. An elongated 4.9 x 4.1 km caldera lies at the summit, and numerous lava domes and cinder cones formed on fissures on the N, NE, and SE flanks. The latest volcanism associated with growth of the phonolitic central volcano was Potassium-Argon dated at about 1.2 to 1 million years, and late-Pleistocene to zero-age Argon-Argon dates were obtained for some of the volumetrically dominant basanitic fissure vents. More than 50 morphologically youthful vents occur on the flanks.

Royal Society Range
Landform: Cluster
Volcano type: Pyroclastic cone(s)
A large number of basaltic cinder cones and lava flows are located in the Royal Society Range of southern Victoria Land. Most vents are of Quaternary age. More than 50 basaltic vents, ranging from tiny scoria mounds to cinder cones up to 300 m high, occupy the foothills. Tephra layers in the ice of Kempe Glacier, K-Ar ages as young as 80,000 years old, and well-preserved geomorphic forms, all argued for young, possibly even Holocene ages (LeMasurier and Thomson, 1990).

Erebus
Mount Erebus overlooks the McMurdo research station on Ross Island and is the largest of three major volcanoes forming the roughly triangular Ross Island. The summit of the dominantly phonolitic volcano has been modified by one or two generations of caldera formation. A summit plateau at about 3,200 m elevation marks the rim of the youngest caldera, which formed during the late-Pleistocene and within which the modern cone was constructed. An elliptical 500 x 600 m, 110-m-deep crater truncates the summit and contains an active lava lake within a 250-m-wide, 100-m-deep inner crater; other lava lakes are sometimes present. The glacier-covered volcano was erupting when first sighted by Captain James Ross in 1841. A persistent lava-lake, with minor explosions punctuated by occasional larger Strombolian explosions that eject bombs onto the crater rim, has been documented since 1972, but nearly continuous activity has probably been occurring for much longer.

Western Antarctica Volcanic Province

Berlin
Western Antarctica Volcanic Province
Landform: Shield
Volcano type: Shield(s)
Longitude: 136°W
Mount Berlin consists of two coalescing shield volcanoes, Berlin Crater and Merrem Peak, each with a 2-km-wide summit caldera. Mount Berlin is located in the Flood Range of Marie Byrd Land, near the eastern coast of the Ross Sea. The two calderas are oriented along an east-west line, characteristic of Flood Range volcanoes. The westernmost and highest volcano, Berlin Crater, reaches 3478 m and is located 3.5 km ESE of Merrem Peak caldera. Berlin Crater displays active fumaroles along its western and northern caldera rims, producing the characteristic Antarctic fumarolic ice towers. The youngest dated tephra of a series of tephra layers in glacial ice at Mount Moulton that was attributed to Mount Berlin had an age of about 14.5 +/- 3.8 thousand years (ka), and a younger undated tephra layer was present. A lava flow at the base of an ice cave below a fumarolic ice tower was dated at about 10.3 +/- 2.7 ka.

Andrus
Western Antarctica Volcanic Province
Landform: Shield
Volcano type: Shield(s)
Longitude: 132.33°W
Three coalescing trachytic shield volcanoes with a combined volume of 252 km3 formed during the Miocene along a N-S line in the Ames Range of western Marie Byrd Land. The youngest and best exposed is Mount Andrus, the southernmost volcano, where late-stage volcanic activity resumed during the late-Pleistocene or Holocene (Gonzalez-Ferran and Gonzalez-Bonorino 1972, LeMasurier and Thomson 1990). A distinct 4.5-km-wide caldera truncates the summit of Mount Andrus. Weak fumarolic activity was observed in 1977 at Mount Kauffman, the northernmost volcano, which also has a morphologically distinct 3-km-wide summit caldera.

Takahe
Volcano type: Shield
Longitude: 112.08°W
Mount Takahe is an isolated shield volcano in eastern Marie Byrd Land with an 8-km-wide summit caldera. The massive 780 km3 volcano displays a conical, youthful morphology, and the oldest dated rocks are only 310,000 years old. Three samples were too young to date by Potassium-Argon, and some tephra layers younger than 30,000 years in the Byrd Station ice core are thought to have originated from Takahe. Two early Holocene phreatomagmatic tephra layers in the Antarctic ice core were attributed to Takahe (Palais et al., 1988). The latest stage of activity constructed cinder cones on the upper southern flanks and tuff cones and cinder cones on the lower SW and NE flanks.

Hudson Mountains
Volcano type: Stratovolcano(es)
Longitude: 99.42°W
The Hudson Mountains, located along the Walgreen Coast in Antarctica's western Ellsworth Land, contain many only slightly eroded cones forming nunataks protruding above the Antarctic icecap. The cinder cones apparently rest on three extensively eroded Miocene stratovolcanoes, Teeters Nunatak, Mount Moses, and Mount Manthe. Subaerial basaltic lava flows dominate, but subglacial or subaqueous tuffs and lava flows are also present. A tephra layer from an eruption of a subglacial volcano in the Hudson Mountains was dated from ice thickness at about 200 BCE. The possible presence of steam was reported at one of the Hudson volcanoes during 1974. Satellite data suggested that an eruption of Webber Nunatak took place during 1985, although this has not been confirmed (LeMasurier and Thomson, 1990).

Antarctic Peninsula Volcanic Province

Paulet
Antarctic Peninsula Volcanic Province
Landform: Minor (Basaltic)
Volcano type: Pyroclastic cone
Paulet is a 1.8 x 2.2 km island located east of the tip of Graham Land Peninsula composed of lava flows capped by scoria cones. The morphology of the younger summit cone suggests activity during the last 1,000 years (LeMasurier and Thomson, 1990).

Mount Haddington Volcanic Field
Antarctic Peninsula Volcanic Province
Volcano type: Shield
The glacier-covered Mount Haddington shield volcano forms the high point of James Ross Island along the Larsen Rift near the northern tip of the Antarctic Peninsula. Effusive eruptions fed large lava deltas with basal hyaloclastite breccias overlain by subaerial lava flows. Tuff cones and pyroclastic cones on the E flank below the summit icecap were considered to be only a few thousand years old (Smellie et al., 2008).

South Shetlands Volcanic Arc

Penguin Island
South Shetlands Volcanic Arc
The 1.4 x 1.7 km Penguin Island is located off the SE coast of King George Island in Antarctica's South Shetland Islands, west of the axis of the Bransfield Rift. The most prominent feature is Deacon Peak, a basaltic scoria cone with a 350-m-wide summit crater on the SW side of the island. A small plug of basaltic lava occupies the 75-m-deep crater. Petrel Crater, a 300-m-wide maar, is located near the east coast. The formation of Deacon Peak was dated by lichenometry at about 300 years ago, and the younger Petrel Crater maar was dated at about 100 years (Birkenmajer, 1979). Some reports of fumarolic activity on nearby Bridgeman Island are attributed to the more youthful Penguin Island.

Deception Island
South Shetlands Volcanic Arc
Landform: Caldera
Volcano type: Caldera
Ring-shaped Deception Island, at the SW end of the South Shetland Islands, NE of Graham Land Peninsula, was constructed along the axis of the Bransfield Rift spreading center. A narrow passageway named Neptunes Bellows provides an entrance to a natural harbor within the 8.5 x 10 km caldera that was utilized as an Antarctic whaling station. Numerous vents along ring fractures circling the low 14-km-wide island have been reported active for more than 200 years. Maars line the shores of 190-m-deep Port Foster caldera bay. Among the largest of these maars is 1-km-wide Whalers Bay, at the entrance to the harbor. Eruptions during the past 8,700 years have been dated from ash layers in lake sediments on the Antarctic Peninsula and neighboring islands.

Bridgeman Island
Bridgeman Island is a small 600 x 900 m remnant of a much larger volcanic edifice that is now largely submerged. It was constructed along the axis of the Bransfield Rift spreading center between the Shetland and Wedell tectonic plates. Bridgeman is located east of King George Island at the NE end of the South Shetland Islands, north of the tip of Graham Land Peninsula. The island has a gently sloping top consisting of truncated lava flows. Steep cliffs surrounding the island expose older lavas and bedded pyroclastic rocks. The extensively eroded volcano does not display youthful volcanic features, although it has been characterized as a now inactive late Pleistocene-Holocene stratovolcano. Several reports of 19th-century fumarolic activity (Catalog of Active Volcanoes of the World) may instead refer to the much younger Penguin Island (Gonz�lez-Ferr�n, 1972).

Melville
Melville Peak is an eroded stratovolcano on NE King George Island with a summit crater. No radiocarbon dates are available, but an ash layer found 30 km away in a NE Bransfield Strait marine sediment core with compositional similarity to Melville Peak suggests possible Holocene activity within the past few thousand years.

South Sandwich Volcanic Arc

Southern Thule
United Kingdom
South Sandwich Volcanic Arc
Volcano type: Stratovolcano(es)
The Southern Thule island group, at the southern end of the South Sandwich island arc bordering the Scotia Sea, consist of three stratovolcanoes constructed along an E-W line. An ice-filled 1.5-2 km wide caldera truncates the summit of andesitic-dacitic Thule, the westernmost island, and a 4.3 x 4.8 km submarine caldera forms Douglas Strait between Thule and basaltic-to-dacitic Cook Island. Another possible submarine caldera lies east of Cook Island and south of basaltic andesite Bellingshausen, the easternmost island. The age of Cook Island is uncertain, but steam was observed at the summit crater of Thule Island in 1962, and ash was seen on the surface of the ice there and on Bellingshausen Island, indicating possible 20th-century eruptions (Baker, 1968). Bellingshausen has a youthful, relatively ice-free profile and an extensive well-preserved lava field on its S flank, where a small explosion crater formed sometime between 1964 and 1986.

Montagu Island
United Kingdom
South Sandwich Volcanic Arc
The largest of the South Sandwich Islands, Montagu consists of a massive shield volcano cut by a 6-km-wide ice-filled summit caldera. The summit of the 11 x 15 km island rises about 3,000 m from the sea floor between Bristol and Saunders Islands. Around 90% of the island is ice-covered; glaciers extending to the sea typically form vertical ice cliffs. The name Mount Belinda has been applied both to the high point at the southern end of the summit caldera and to the young central cone. Mount Oceanite, an isolated peak at the SE tip of the island, was the source of lava flows exposed at Mathias Point and Allen Point. There was no record of Holocene activity until MODIS satellite data, beginning in late 2001, revealed thermal anomalies consistent with lava lake activity. Apparent plumes and single anomalous pixels were observed intermittently on AVHRR images from March 1995 to February 1998, possibly indicating earlier volcanic activity.

Bristol Island
United Kingdom
The 9 x 10 km Bristol Island near the southern end of the South Sandwich arc lies across Fortser's Passage from the Southern Thule Islands and forms one of the largest islands of the chain. Largely glacier-covered, it contains a horseshoe-shaped ridge at the interior extending northward from the highest peak, 1100-m-high Mount Darnley. A steep-sided flank cone or lava dome, Havfruen Peak, is located on the east side, and a young crater and fissure are on the west flank. Three large sea stacks lying off Turmoil Point at the western tip of the island may be remnants of an older now-eroded volcanic center. Both summit and flank vents have been active during historical time. The latest eruption, during 1956, originated from the west-flank crater, and deposited cinder over the icecap. The extensive icecap and the difficulty of landing make it the least explored of the South Sandwich Islands.

Saunders
Saunders Island consists of a large central volcanic edifice intersected by two seamount chains, as shown by bathymetric mapping (Leat et al., 2013). The young Mount Michael stratovolcano dominates the glacier-covered island, while two submarine plateaus, Harpers Bank and Saunders Bank, extend north. The symmetrical Michael has a 500-m-wide summit crater and a remnant of a somma rim to the SE. Tephra layers visible in ice cliffs surrounding the island are evidence of recent eruptions. Ash clouds were reported from the summit crater in 1819, and an effusive eruption was inferred to have occurred from a N-flank fissure around the end of the 19th century and beginning of the 20th century. A low ice-free lava platform, Blackstone Plain, is located on the north coast, surrounding a group of former sea stacks. A cluster of cones on the SE flank, the Ashen Hills, appear to have been modified since 1820 (LeMasurier and Thomson, 1990). Analysis of satellite imagery available since 1989 (Gray et al., 2019; MODVOLC) suggests frequent eruptive activity (when weather conditions allow), volcanic clouds, steam plumes, and thermal anomalies indicative of a persistent, or at least frequently active, lava lake in the summit crater. Due to this observational bias, there has been a presumption when defining eruptive periods that activity has been ongoing unless there is no evidence for at least 10 months.

Candlemas Island
The southern end of Candlemas Island consists of an eroded, glacier-covered basaltic stratovolcano cut by steep cliffs on the east. Lava flows along the cliff dip to the west, suggesting that the original summit vent was beyond the eastern shoreline. The northern end of the irregularly shaped, 6-km-long island consists of an andesitic-to-dacitic complex of scoria cones with radiating lava flows. These initially formed a separate island but now consist of a low attached platform that is estimated to be no more than a few hundred years old (LeMasurier and Thomson, 1990). Dark brown clouds mixed with white steam were reported in 1823 and 1911, but it has not been demonstrated which, if any, of the young north flank lava flows formed since the island was discovered in 1775. Geysers and hot pools have been observed on several occasions during the 20th century. Vindication Island, of possible Holocene age, is located 4.5 km west of Candlemas Island.

Hodson
The largely ice-covered, 5.5 x 7 km Visokoi Island consists of a single stratovolcano, Mount Hodson, whose rounded summit lies west of the center of the island. Numerous basaltic scoria cones were constructed on the lower flanks of the island, which is part of the Traverse Islands in the northern part of the South Sandwich Island chain. The youthful morphology suggests recent volcanism (LeMasurier and Thomson, 1990). Possible eruptive activity was reported during 1830 and 1930.

Leskov Island
The small crescent-shaped Leskov Island lies about 50 km W of the main axis of the South Sandwich Islands, but appears to be comparable in age to volcanoes along the main arc. Only 900 m long and 400 m wide, it is bounded by steep cliffs and is the eroded remnant of a small andesitic stratovolcano. Its arcuate, NE-facing escarpment is concave toward Crater Bay, the site of the main eruptive center. A single Potassium-Argon determination gave an age of 0.5 million years, but fumarolic activity was recorded along the summit ridge in 1911 and 1964 (LeMasurier and Thomson, 1990).

Zavodovski
The 5-km-wide Zavodovski Island, the northernmost of the South Sandwich Islands, consists of a single basaltic stratovolcano with two cones on the east side. Mount Curry, the island's summit, lies west of the center of the island, which is more eroded on that side. Two fissures extend NE from the summit towards the E-flank craters, and a lava platform is located along the eastern coast. The volcano was producing abundant emissions when observed in 1819 by the explorer Bellingshausen. A landing party in 1830 also reported strong emissions along with a fresh lava field on the east side from which pumice was being eroded into the ocean.

Protector Seamounts
Landform: Cluster
Volcano type: Volcanic field
Elevation: -55 m
The Protector Seamounts, located 30 km NW of Zavodovski Island, form the northernmost volcanic region of the South Sandwich volcanic arc. Bathymetry described by Leat et al. (2013) showed that Nimrod Bank forms the central point in the seamount chain. Protector Shoal, on the S end of the bank, is a broad, gently sloping cone that rises to within 55 m of the ocean surface. Large amounts of rhyolitic pumice, first detected by the Royal Navy Ice Patrol Vessel H.M.S. Protector, were ejected during its only recorded eruption in 1962 and formed an extensive pumice raft which drifted as far as New Zealand.

South America Volcanic Regions

Austral Andean Volcanic Arc

Aguilera
Chile
Austral Andean Volcanic Arc
Aguilera, located west of Lake Argentina and NE of Peel Fjord, is part of the Austral Volcanic Zone (AVZ) in the southernmost Chilean Andes. Geochemical evidence indicated that the dacitic volcano was the source of a major late Holocene tephra layer that was erupted around 3,200 years ago (Stern, 2008).

Reclus
Chile
Austral Andean Volcanic Arc
Volcano type: Pyroclastic cone
Reclus, the source of several Patagonian Holocene tephra layers, was recognized to be an independent volcanic edifice in 1987. The volcano consists of a large dacitic pyroclastic cone with a crater about 1 km in diameter. As many as six tephra layers overlie a peat layer dated at 3,780 years before present. Research has also revealed evidence for eruptions in the 19th and early 20th centuries.

Lautaro
Chile
Lautaro is the northernmost volcano of the Austral Volcanic Zone (AVZ) in the southernmost Chilean Andes, and is the closest volcano to the Chile Triple Junction plate boundary. Volcanoes of the AVZ originated from subduction of the Antarctic plate beneath the South American plate. The Catalog of Active Volcanoes of the World synonyms for Lautaro (Cerro Pir�mide, Chalten, and Chaltel) are actually synonyms of the dramatic Patagonian granitic peak of Cerro Fitz Roy (Moreno 1985, pers. comm.). Glacier-covered and rising above the Southern Patagonian Ice Field, this dominantly dacitic volcano has a crater just below its summit on the NW side and a 1-km-wide crater on the NE flank. Ash deposits from eruptions were visible on aerial photos taken during several occasions during the 20th century, and older ash layers form prominent markers on outflow glaciers of the Patagonian icecap.

Monte Burney
Monte Burney, a large ice-covered volcano in the Patagonian region of Chile, lies about 200 km NW of the town of Punta Arenas. It was constructed on the western rim of a 6-km-wide caldera, which is partially filled with and surrounded by an unglaciated pyroclastic-flow deposit. Flank vents produced andesitic-dacitic lava flows and pyroclastic material. Collapse of the edifice produced a major debris avalanche that traveled to the SSW. Two large Plinian eruptions have been documented during the Holocene. The only known historical eruption took place in 1910.

Pali-Aike Volcanic Field
Chile-Argentina
Landform: Cluster
Volcano type: Volcanic field
The 3,000 km2 Pleistocene-to-Holocene Pali-Aike volcanic field straddles the Chile-Argentina border north of the Straits of Magellan, about 150 km NE of the town of Punta Arenas. The southernmost of the Patagonian basaltic plateau lavas, Pali-Aike contains lake-filled maars and basaltic scoria and spatter cones with associated fresh-looking lava flows. The distribution of maars and cones indicates that eruptions occurred along regional fissures oriented E-W and NW-SE. The earliest eruptions produced maars and lava flows that are now exposed only in river valleys. A second stage formed now-eroded spatter cones and soil-covered lava flows. The youngest cones and lava flows are found in the SE part of the field. The most recent volcanic event produced scoria and spatter cones and fresh lava flows not covered by soil. Ejecta covers prehistorical artifacts (Skewes and Stern, 1979).

Fueguino
Landform: Minor (Silicic)
Volcano type: Lava dome(s)
A group of andesitic, columnar-jointed lava domes and pyroclastic cones up to 150 m high on Isla Cook mark the southernmost Holocene volcanoes of the Andes. The volcanoes, known as Volc�n Cook or Volc�n Fueguino, occupy a broad peninsula forming the SE end of the island. One of the cones, S of Bah�a del Volc�n, contains a 150-m-wide crater with a small lake. The lava domes and pyroclastic cones, possibly emplaced along N-S-trending faults, are unaffected by glacial erosion that scoured the underlying plutonic rocks. Passing navigators observed possible eruptive activity in the direction of Cook in 1712 and the eruption of incandescent ejecta in 1820.

Southern Andean Volcanic Arc

Tupungatito
Chile-Argentina
Southern Andean Volcanic Arc
Tupungatito volcano, the northernmost historically active volcano of the central Chilean Andes, is located along the Chile-Argentina border about 90 km E of Santiago and immediately SW of the Pleistocene Tupungato volcano. Tupungatito consists of a group of 12 Holocene andesitic and basaltic andesite craters and a pyroclastic cone at the NW end of the 4-km-wide, Pleistocene dacitic Nevado Sin Nombre caldera, which is filled by glaciers at its southern end and is breached to the NW. Lava flows from the northernmost vent have traveled down the NW flank breach. Tupungatito has produced frequent mild explosive eruptions during the 19th and 20th centuries.

Maipo
Chile-Argentina
Southern Andean Volcanic Arc
Volcano type: Caldera
Maipo, a conical stratovolcano that straddles the Chile-Argentina border SE of Santiago, partially fills the 16 x 20 km Pleistocene Diamante caldera, which formed about 450,000 years ago during an eruption that produced an about 350 km3 of rhyolitic ignimbrite. The Pleistocene cones of Volc�n Don Casimiro and Cerro Listado were formed on the SW rim and SW flank of the caldera, respectively. The post-caldera Maipo rises about 1,900 m above the caldera floor, and has several cones on the E flank along a series of en �chelon NE-trending fractures. Lava flows from one of these cones blocked drainages in 1826 inside the caldera, forming Lake Diamante on the eastern caldera floor.

Palomo
Palomo is a small stratovolcano that is somewhat dissected by glaciers. A NE-flank cone, Andres, is postglacial in age and has produced andesitic lava flows. The volcano lies W of the massive Caldera del Atuel and was constructed within double calderas 3 and 5 km in diameter. The largely ice-covered volcano has erupted basaltic andesite to dacitic lava flows; the double crater indicates migration of activity to the NE. The youthful morphology suggests a very recent, perhaps pre-Hispanic, age.

Caldera del Atuel
Argentina
Landform: Caldera
The 30 x 45 km Caldera del Atuel complex, ~30 km NW-SE and 45 km NE-SW, lies just east of the Argentina-Chile border and 18 km SSW of the rim of the Pleistocene Diamante caldera. The western rim in part follows the international border, and the headwaters of the R�o del Atuel drain to the SE through a wide breach in the caldera rim. The broad floor of the caldera contains with 15 dacitic lava domes and 25 basaltic andesite to andesitic stratovolcanoes and cinder cones. A group of cones known as Las L�grimas overlies the SW rim of the caldera, and Volc�n Guanaqueros on the NE flank of the caldera is a group of young basaltic-to-andesitic cinder cones. The Volc�n Overo complex in the E-central part of the caldera and the Volc�n Sosneado complex in the S part of the caldera contain numerous very youthful basaltic-to-andesitic pyroclastic cones and lava flows. The Overo complex contains 20 centers, and lava flows of the Sosneado complex cover an area of 200 km2.

Risco Plateado
Argentina
The Risco Plateado volcanic complex lies about 10 km S of the Caldera del Atuel and consists of a stratovolcano cut by a 4-km-wide caldera. Two eruptive centers are located on the SW and NE caldera rims along a NE-trending fracture that extends to a cone on the lower NE flank about 8 km from the caldera. Dominantly basaltic andesite lava flows overlie initial dacitic flows. Very youthful-looking basaltic lava flows from the NE-flank center extend NE to the R�o del Atuel. Lava flows from the SW-rim center extend westward beyond the flanks of the complex and those from the NE-rim center flow into the caldera and down its NE flank.

San Jose
Volcano type: Stratovolcano(es)
Volc�n San Jos� lies along the Chile-Argentina border at the southern end of a volcano group that includes the Pleistocene volcanoes of Marmolejo and Esp�ritu Santo. The glaciated 6070-m-high Marmolejo stratovolcano is truncated by a 4-km-wide caldera, breached to the NW, that has been the source of a massive debris avalanche. San Jos� is a 5856-m-high stratovolcano of Pleistocene-Holocene age with a broad 2 km x 0.5 km summit region containing overlapping and nested craters, pyroclastic cones, and blocky lava flows. Volc�n la Engorda and Volc�n Plantat, located SW of Marmolejo and NW of San Jose, have also been active during the Holocene. An 8-km-long lava flow traveled to the SW from the 1-km-wide summit crater of Esp�ritu Santo volcano, which overlaps the southern slope of Marmolejo. Mild phreatomagmatic eruptions were recorded from San Jos� in the 19th and 20th centuries.

Tinguiririca
Tinguiririca is composed of at least seven Holocene scoria cones W of the Chile-Argentina border constructed along a NNE-SSW fissure over an eroded Pleistocene stratovolcano. The complex was constructed during three eruptive cycles dating back to the middle Pleistocene. The latest activity produced a series of youthful small stratovolcanoes and craters, of which the youngest appear to be Tinguiririca and Fray Carlos. Constant fumarolic activity occurs within and on the NW wall of the summit crater. Hot springs and fumaroles with sulfur deposits are found on the W flanks of the summit cones. A single historical eruption was recorded in 1917.

Infiernillo
Argentina
Volcano type: Volcanic field
Infiernillo, a late-Pleistocene to Holocene basaltic andesite volcanic field along the R�o Salado in Argentina lies about 70 km east of the crest of the Andes and NW of the town of Malarg�e. Several vents controlled by extensional tectonics produced lava flows with prominent flow features that reached to the river. A radiocarbon date of about 8840 years before present was obtained from Volc�n Hoyo Colorado.

Calabozos
The composite late-Pleistocene Calabozos caldera (14 x 26 km) produced major rhyodacitic-to-dacitic ashflow sheets of ~200-500 km3 each, collectively referred to as the Loma Seca Tuff, at 800,000, 300,000, and 150,000 years ago. Eruptive activity has continued into the Holocene, forming the 20-25 km3 and the four clustered vents of Descabezado Chico near the western caldera rim. The late-Holocene 2.5 km3 Escorias dacitic lava flow from Descabezado Chico traveled more than 30 km S. Several hot-spring clusters are present along the margin of the central resurgent uplift within the caldera.

Planchon-Peteroa
Planch�n-Peteroa is an elongated complex volcano along the Chile-Argentina border with several overlapping calderas. Activity began in the Pleistocene with construction of the basaltic andesite to dacitic Volc�n Azufre, followed by formation of the basaltic and basaltic andesite Volc�n Planch�n, 6 km N. About 11,500 years ago much of Azufre and part of Planch�n collapsed, forming the massive R�o Teno debris avalanche, which traveled 95 km to reach Chile's Central Valley. Subsequently, Volc�n Planch�n II was formed. The youngest volcano, andesitic and basaltic andesite Volc�n Peteroa, consists of scattered vents between Azufre and Planch�n, and contains a small steaming crater lake. Reported eruptions from the complex have been dominantly explosive, although lava flows were emplaced in 1837 and 1937.

Descabezado Grande
Volc�n Descabezado Grande is a late-Pleistocene to Holocene andesitic-to-rhyodacitic stratovolcano with a 1.4-km-wide ice-filled summit crater. It lies at the center of a 20 x 30 km volcanic complex, 7 km N of the Cerro Azul stratovolcano. A lateral crater, which formed on the upper NNE flank in 1932 shortly after the end of the major 1932 eruption from nearby Quizapu cone on the N flank of Cerro Azul, was the site of the only recorded eruption. The Holocene Alto de las Mulas fissure on the lower NW flank produced young rhyodacitic lava flows. Numerous small late-Pleistocene to Holocene volcanic centers are located N of the volcano. The northernmost of these, Lengua de Vulcano (or Mondaca), produced a very youthful rhyodacitic lava flow that dammed the R�o Lentu�.

Laguna del Maule
The Laguna del Maule volcanic complex includes a 15 x 25 km caldera with a cluster of small stratovolcanoes, lava domes, and pyroclastic cones of Pleistocene-to-Holocene age. The caldera lies mostly on the Chilean side of the border, but partially extends into Argentina. Fourteen Pleistocene basaltic lava flows were erupted down the upper part of the Maule river valley. A cluster of Pleistocene cinder cones was constructed on the NW side of Maule lake in the northern part of the caldera. The latest activity produced an explosion crater on the E side of the lake and a series of Holocene rhyolitic lava domes and blocky lava flows that surround it.

San Pedro-Pellado
The San Pedro-Pellado volcanic complex (also known as San Pedro-Tatara) has been active from the Pliocene to the Holocene. The Tatara-San Pedro edifice overlies the deeply eroded Pellado stratovolcano; both were constructed within the 6 x 12 km R�o Colorado caldera, which formed during an eruption about 0.5 million years ago. The Tatara basaltic andesite shield volcano at the western end of the complex contains stacked sequences of up to 100 or more lava flows forming up to 1500 m of relief. The glacier-filled summit crater of the 3621-m-high dominantly andesitic San Pedro stratovolcano, which overlies the Tatara edifice, contains a young scoria cone that was the site of the most recent eruptions. A major Holocene E-flank debris avalanche filled the R�o de la Puente valley to the south and was followed by eruptions originating within the avalanche scarp low on the east flank that produced lava flows down the Estero Pellado drainage. No historical eruptions have been recorded, but fumaroles are found SE of Pellado.

Nevado de Longavi
The conical Nevado de Longav� is a late-Pleistocene to Holocene, dominantly andesitic stratovolcano constructed over a basement of Tertiary volcaniclastic and granitic rocks. Two edifice-collapse events modified the E and SW flanks of a pre-Holocene edifice, and Holocene activity has been concentrated at the summit and on the E flanks. Andesitic-to-dacitic lava domes occupy the summit region. The latest eruptions produced a lava dome in the upper part of the collapse scarp and summit region that partially collapsed to the E, forming block-and-ash flow deposits. Fumarolic activity has been reported.

Lomas Blancas
Volc�n Lomas Blancas is a small shield-like feature of late-Pleistocene to Holocene age (Moreno and Naranjo, 1991) located about 15 km SE of Nevado de Longav�. An open scarp to the SE side extends about 2.3 km from the summit. The central cone is basaltic. basaltic andesite aa lava flows extend 7 km from the scarp. Much of the volcano is covered by pumice deposits that probably originated from Nevado de Longav�.

Volcan Resago
Landform: Minor (Basaltic)
Volcano type: Pyroclastic cone
Volc�n Resago, in the Linares province of central Chile, is a cinder cone with a double crater. It produced a basaltic andesite lava flow that traveled ~3 km WNW into Laguna Dial. The youthful cone may have been formed during an undocumented Holocene eruption (Gonz�lez-Ferr�n, 1995).

Payun Matru
The Pay�n Matr� volcanic field in Argentina includes a massive hawaiian-style shield volcano that lies 530 km from the oceanic trench. The 8 x 10 km alkaline caldera of Cerro Pay�n Matr� was formed after about 168,000 years ago. The high point of the massif, Cerro Payen stratovolcano, was constructed on the SW flank of the shield. The Pleistocene Pampas Onduladas pahoehoe lava flow traveled 181 km, Earth's longest known Quaternary lava flow. Post-caldera basaltic eruptions produced more than 300 eruptive centers, mostly along E-W fissures that extend across the entire edifice. Fluid lava flows from a concentration of vents on the W flank known as Los Volcanes traveled more than 10 km. Other vent clusters of the 5,200 km2 volcanic field are found on the lower NE and S flanks, and a lava flow from Volc�n Santa Mar�a on the NW flank traveled 15 km NE. At least 30 trachyandesitic lava domes and basaltic lava flows were erupted contemporaneously with the basaltic fissure eruptions. The Puente and Chapua volcanic units east of the main shield and south of the Ondulas flow are considered part of the field. Oral traditions note that indigenous tribes were present at the time of the latest eruption.

Cerro Azul
The Cerro Azul stratovolcano is at the southern end of the Descabezado Grande-Cerro Azul eruptive system. It is a steep-sided edifice with a 500-m-wide summit crater open to the north. The three basaltic andesite "La Resoloma Craters" scoria vents are located below the W flank and the two "Los Hornitos" scoria cones on the lower SW flank. Quizapu, a major vent on the northern flank of Cerro Azul, formed in 1846 during the first historical eruption, accompanied by the emission of voluminous dacitic lava flows that traveled both east into the Estero Barroso valley and west into the R�o Blanquillo valley. Quizapu was later the source of one of the world's largest explosive eruptions of the 20th century in 1932, which created a 600-700 m wide, 150-m-deep crater and ejected 9.5 km3 of dacitic tephra.

Tromen Volcanic Plateau
Tromen is an Argentinian stratovolcano that is the primary structure in an elongated volcanic plateau or field that extends about 70 km from Tilhue in the S to Piujenta in the N, including the Boliviano caldera and Palao dome. The Pleistocene Volc�n Cerro Negro del Tromen lies immediately north. At the SSW end of this chain is Cerro Tilhue, of Pleistocene-Holocene age. The youngest lava flows originated from flank vents and descended the N and NE sides of the andesitic-to-rhyolitic volcanic complex. Holocene vents are also located in the Cerro Michico area on the lower NE flank. Eruptions were reported in the mid-18th century and in 1822. Von Wolff (1929) attributed purported eruptions of Pomahuida in 1820, 1823, 1827, and 1828 as being from Tromen, but these are not confirmed.

Nevados de Chillan
The compound volcano of Nevados de Chill�n is one of the most active of the Central Andes. Three late-Pleistocene to Holocene stratovolcanoes were constructed along a NNW-SSE line within three nested Pleistocene calderas, which produced ignimbrite sheets extending more than 100 km into the Central Depression of Chile. The dominantly andesitic Cerro Blanco (Volc�n Nevado) stratovolcano is located at the NW end of the massif. Volc�n Viejo (Volc�n Chill�n), which was the main active vent during the 17th-19th centuries, occupies the SE end. The Volc�n Nuevo lava-dome complex formed during 1906-1945 on the NW flank of Viejo. The Volc�n Arrau dome complex was then constructed on the SE side of Volc�n Nuevo between 1973 and 1986, and eventually exceeded its height. Smaller domes or cones are present in the 5-km valley between the two major edifices.

Antuco
Antuco volcano, constructed NE of the Pleistocene Sierra Velluda stratovolcano, rises dramatically above the SW shore of Laguna de la Laja. It has a complicated history beginning with construction of the basaltic-to-andesitic Sierra Velluda and Cerro Condor stratovolcanoes of Pliocene-Pleistocene age. Construction of the Antuco I volcano was followed by edifice failure at the beginning of the Holocene that produced a large debris avalanche which traveled down the R�o Laja to the west and left a large 5-km-wide caldera breached to the west. The steep-sided modern basaltic-to-andesitic cone has grown 1,000 m since then; flank fissures and cones have also been active. Moderate explosive eruptions were recorded in the 18th and 19th centuries from both summit and flank vents, and lava flows have traveled into the R�o Laja drainage.

Callaqui
The late-Pleistocene to Holocene Callaqui stratovolcano has a profile of an overturned canoe, due to its construction along an 11-km-long, SW-NE fissure above a 1.2-0.3 million year old Pleistocene edifice. The ice-capped, basaltic andesite volcano contains well-preserved cones and lava flows, which have traveled up to 14 km. Small craters 100-500 m in diameter are primarily found along a fissure extending down the SW flank. Intense solfataric or fumarolic activity occurs at the southern portion of the summit; in 1966 and 1978, red glow was observed in fumarolic areas (Moreno, 1985 pers. comm.). An explosive eruption was reported in 1751 CE, there were uncertain accounts of eruptions in 1864 and 1937, and a small phreatic ash emission was noted in 1980.

Tolhuaca
Tolhuaca (or Tolguaca) is a late-Pleistocene to Holocene stratovolcano located immediately NW of Lonquimay volcano. A NW-SE zone of aligned summit craters is youngest to the NW. Another group of vents cutting the south and east flanks is oriented SW-NE, parallel to the zone of flank vents on Lonquimay, and is of post-glacial age (Moreno and Gardeweg 1989). Reports of eruptions in 1876 and on 7 January 1933 are not confirmed; the latter date probably refers to an eruption of Lonquimay or Llaima (Petit-Breuilh 1994, pers. comm.). Polanco et al. (2000) stated that explosive activity consisted of three VEI 3-4 eruptions between 8050 and 6590 BP. The Pemehue volcanic trend on the NW flank was noted by Naranjo (pers. comm. 2010) in Melosh et al. (2012) as having post-glacial lava flows dated at less than 6,000 years old. Only fumarolic activity has occurred from this basaltic-andesitic volcano during historical time. Fumaroles and hot springs are common across the NW flank where there is an active geothermal reservoir (Melosh et al., 2012).

Copahue
Volc�n Copahue is an elongated composite cone constructed along the Chile-Argentina border within the 6.5 x 8.5 km wide Trapa-Trapa caldera that formed between 0.6 and 0.4 million years ago near the NW margin of the 20 x 15 km Pliocene Caviahue (Del Agrio) caldera. The eastern summit crater, part of a 2-km-long, ENE-WSW line of nine craters, contains a briny, acidic 300-m-wide crater lake (also referred to as El Agrio or Del Agrio) and displays intense fumarolic activity. Acidic hot springs occur below the eastern outlet of the crater lake, contributing to the acidity of the R�o Agrio, and another geothermal zone is located within Caviahue caldera about 7 km NE of the summit. Infrequent mild-to-moderate explosive eruptions have been recorded since the 18th century. Twentieth-century eruptions from the crater lake have ejected pyroclastic rocks and chilled liquid sulfur fragments.

Laguna Blanca
A group of cinder cones and associated lava flows SW of the town of Zapala at the southern end of the Loncopue graben form the Laguna Blanca volcanic field. A morphologically pristine cinder cone on the northern shore of Laguna Blanca is a prominent feature of the Laguna Blanca National Park, noted for its aquatic bird fauna, including black-necked swans and flamingos. The youthful-looking basaltic to trachyandesitic cinder cones and small shield volcanoes are considered to be of Holocene age, although no radiometric ages are available.

Lonquimay
Lonquimay is a small, flat-topped, symmetrical stratovolcano of late-Pleistocene to dominantly Holocene age immediately SE of Tolguaca volcano. A glacier fills its summit crater and flows down the S flank. It is dominantly andesitic, but basalt and dacite are also found. The prominent NE-SW Cord�n Fissural Oriental fissure zone cuts across the entire volcano. A series of NE-flank vents and scoria cones were built along an E-W fissure, some of which have been the source of voluminous lava flows, including those during 1887-90 and 1988-90, that extended out to 10 km.

Sollipulli
The 4-km-wide, glacier-filled Sollipulli caldera lies E of the Pleistocene Nevados de Sollipulli complex. Major silicic pyroclastic rocks associated with caldera formation have not been found; it may have a non-explosive origin. Post-caldera eruptions have been focused along the caldera walls and have increased its height. A series of dacitic lava domes lines the E and S caldera rims. The 1-km-wide Alpehu� crater, which cuts the SW rim, was the source of a large Plinian eruption 2900 years before present (BP). Explosion craters and scoria cones are found on the outer flanks. Two N-flank cones produced lava flows during the latest documented activity about 700 years BP (Naranjo et al., 1993). This low-profile volcano is less prominent than its neighbors Llaima and Villarrica, but its explosive history makes it a potentially hazardous volcanic center.

Caburgua-Huelemolle
Four groups of basaltic cinder cones lie east of Lago Villarrica and NE of Villarrica volcano. The northernmost and southernmost groups, the Volcanes de Caburgua and Volc�n Huelemolle, respectively, lie along the major regional Liquine-Ofqui fault zone. Volcanes de Caburgua lies at the south end of Lago Caburgua and consists of six early Holocene basaltic cinder cones. Lava flows from these cones contributed to blockage of river drainages that formed the lake. The southernmost group, Volc�n Huelemolle, consists of three early Holocene basaltic cinder cones between the Liucura and Puc�n (or Minetu�) rivers. The two other cone groups, Cerro Redondo and Pichares, lie to the east of Caburgua and Huelemolle. Stratigraphic evidence indicates that these basaltic cone groups were active between about 8,000 and 6,000 years ago.

Llaima
Llaima, one of Chile's largest and most active volcanoes, contains two main historically active craters, one at the summit and the other, Pichillaima, to the SE. The massive, dominantly basaltic-to-andesitic, stratovolcano has a volume of 400 km3. A Holocene edifice built primarily of accumulated lava flows was constructed over an 8-km-wide caldera that formed about 13,200 years ago, following the eruption of the 24 km3 Curacaut�n Ignimbrite. More than 40 scoria cones dot the volcano's flanks. Following the end of an explosive stage about 7200 years ago, construction of the present edifice began, characterized by Strombolian, Hawaiian, and infrequent subplinian eruptions. Frequent moderate explosive eruptions with occasional lava flows have been recorded since the 17th century.

Quetrupillan
The late-Pleistocene to Holocene Quetrupill�n Volcanic Complex is at the center of a group of three volcanoes, with Villarrica and Lanin, trending transverse to the Andean chain. Constructed within a large 7 x 10 km caldera, this glacier-covered volcano contains a 3.5-km-wide caldera and a truncated central cone. Work by Simmons et al. (2020) identified sixteen Holocene vents and their associated lavas around the lower flanks; compositions were dominantly trachyte, with one basaltic andesite eruption and two of trachyandesite. While each vent could represent a distinct eruption, and no absolute dates are available, Simmons et al. (2020) suggested that there had been about 10 eruptive periods associated with the vents, and that evidence of Holocene activity that had constructed the main cone had been removed by ice advances and retreats during the Little Ice Age. Four Holocene pumice lapilli deposits were identified by Fontijn et al. (2016) as originating from Quetrupill�n, with compositions ranging from rhyolite to dacite. Other nearby volcanic features include a basaltic scoria cone 12 km NE, a rhyolitic lava dome on the S flank of the caldera, and both scoria cones and basaltic andesite lava flows about 15 km S. An eruption was reported in 1872 (Petit-Breuilh, pers. comm. 2004; Petit-Breuilh Sep�lveda, 2004), but Simmons et al. (2020) noted that there was no corroboration from multiple independent sources for such an event.

Lanin
Lan�n is a large conical late-Pleistocene to Holocene stratovolcano along the Chile-Argentina border. The dominantly effusive basaltic-to-trachydacitic volcano lies at the eastern end of a NW-SE-trending volcanic group beginning with Villarrica that is transverse to the Andean chain. The beautifully symmetrical, 3776-m-high Lan�n rises 2500 m above its base; shoulder areas on the upper flanks hint at a buried caldera. The volcano was formed in four eruptive stages dating back to the early Pleistocene or late Pliocene. The last two stages occurred during the late-Pleistocene and Holocene. A small lava dome at the summit fed blocky lava flows to the north about 2200 years ago. Lan�n was reported active after an earthquake in 1906, but Sapper (1917) stated that newspaper accounts are strongly disputed, and no historical eruptions are known. A postglacial tuff ring (Volc�n Arenal) is located below the SW flank in Argentina. A younger lava flow from Lan�n covers deposits of Volc�n Arenal and extends south into Lago Paim�n.

Huanquihue Group
A group of young basaltic volcanoes lies in Argentina near the Chilean border, south of Lan�n volcano. The Huanquihu� volcano group consists of a NNE-SSW-trending chain of stratovolcanoes of Pleistocene age, some of which lie along the border. A Holocene compound cinder cone with three nested craters up to 400 m in diameter that occupied a valley NE of Cerro Huanquihu� and a tuff cone constructed within glacial Lake Epulafquen lies at the northern end of the chain. Growth of this Holocene tuff cone, La Angostura ("The Narrowing"), created a peninsula that formed a narrow channel connecting Lake Epulafquen and Lake Huechulafquen. A very recent lava flow from the base of the Ach�n-Niellu cinder cone (also known as Cerro Escorial) traveled north into glacial Lago Epulafquen, forming a prominent lava delta. The Escorial lava flow is an extremely youthful flow that diverted local drainages and formed new lakes. A radiocarbon date of about 200 years before present was obtained from this flow, and local residents recount oral histories of the eruption, which was observed by their grandparents.

Villarrica
The glacier-covered Villarrica stratovolcano, in the northern Lakes District of central Chile, is ~15 km south of the city of Pucon. A 2-km-wide caldera that formed about 3,500 years ago is located at the base of the presently active, dominantly basaltic to basaltic andesite cone at the NW margin of a 6-km-wide Pleistocene caldera. More than 30 scoria cones and fissure vents are present on the flanks. Plinian eruptions and pyroclastic flows that have extended up to 20 km from the volcano were produced during the Holocene. Lava flows up to 18 km long have issued from summit and flank vents. Eruptions documented since 1558 CE have consisted largely of mild-to-moderate explosive activity with occasional lava effusion. Glaciers cover 40 km2 of the volcano, and lahars have damaged towns on its flanks.

Mocho-Choshuenco
The compound Mocho-Choshuenco volcano is composed of two glacier-covered stratovolcanoes, located east of Lago Rinihu� and SE of Lago Panguipulli and post-dating a 4-km-wide basaltic caldera. The small Choshuenco stratovolcano, constructed on the NW rim of the caldera, is late-glacial in age. A major Plinian eruption produced the Neltume Pumice about 10,300 years ago. The larger andesitic-to-dacitic El Mocho volcano, constructed within the caldera, is postglacial and has reported eruptions from 1864 and 1937. Additional craters and basaltic scoria cones are located on the flanks of Mocho-Choshuenco, primarily on the NE and SW sides.

Carran-Los Venados
Volcano type: Pyroclastic cone(s)
The Carr�n-Los Venados volcano group includes about 50 basaltic to basaltic andesite scoria cones, maars, and a small stratovolcano that are broadly aligned along a 17-km-long ENE-WSW trend ESE of Lago Ranco. The volcanic features occupy a low-lying area N of the more topographically prominent Puyehue-Cord�n Caulle volcanic chain, and many of the vents are postglacial in age. The Mirador scoria cone and two maars, Ri�inahue and Carr�n, were formed during eruptions in the 20th century. These historical eruptions were concentrated where the regional Liquine-Ofqui fault zone intersects the alignment of volcanic vents.

Antillanca Volcanic Complex
The Antillanca Volcanic Complex is a cluster of late-Pleistocene to Holocene basaltic-to-andesitic scoria cones, maars, and small stratovolcanoes covering an area of 380 km2 SE of Lago Puyehue and NE of Lago Rupanco. The most prominent edifice is the Holocene Casablanca stratovolcano, which has a truncated conical profile and produced major explosive eruptions about 2,910 and 2,260 radiocarbon years ago. Older late-Pleistocene stratovolcanoes, such as Sarnoso to the SW and Fiuch� to the NW, are extensively dissected by glaciers. Fissures oriented in four major directions influence the orientation of the cones. Thermal areas are found in scattered locations on the NW side of the complex.

Puyehue-Cordon Caulle
The Puyehue-Cord�n Caulle volcanic complex (PCCVC) is a large NW-SE-trending late-Pleistocene to Holocene basaltic-to-rhyolitic transverse volcanic chain SE of Lago Ranco. The 1799-m-high Pleistocene Cordillera Nevada caldera lies at the NW end, separated from Puyehue stratovolcano at the SE end by the Cord�n Caulle fissure complex. The Pleistocene Mencheca volcano with Holocene flank cones lies NE of Puyehue. The basaltic-to-rhyolitic Puyehue volcano is the most geochemically diverse of the PCCVC. The flat-topped, 2236-m-high volcano was constructed above a 5-km-wide caldera and is capped by a 2.4-km-wide Holocene summit caldera. Lava flows and domes of mostly rhyolitic composition are found on the E flank. Historical eruptions originally attributed to Puyehue, including major eruptions in 1921-22 and 1960, are now known to be from the Cord�n Caulle rift zone. The Cord�n Caulle geothermal area, occupying a 6 x 13 km wide volcano-tectonic depression, is the largest active geothermal area of the southern Andes volcanic zone.

Puntiagudo-Cordon Cenizos
The Puntiagudo-Cord�n Cenizos volcanic chain lies between Lago Rupanco and Lago Todos Los Santos in the Chilean lake district. Volc�n Puntiagudo is a late-Pleistocene andesitic stratovolcano with a prominent sharp-peaked summit that results from glacial dissection. An 18-km-long fissure system with more than 40 late-Pleistocene to Holocene basaltic scoria cones and small stratovolcanoes extends to the NE. Lava flows from these centers descend to the NW and SE, in some cases reaching to the shores of the two lakes, forming irregular peninsulas. The only historical eruption occurred in 1850, when ashfall was reported from the Cord�n Cenizos chain.

Tronador
The Tronador volcanic group straddles the Chile-Argentina border east of scenic Lake Todos los Santos. Activity dates back to the early Pleistocene, and the most prominent part of the dominantly basaltic-to-andesitic complex is the prominent, glacier-covered Monte Tronador volcano, which formed in three stages during the mid-Pleistocene. The only possible Holocene activity took place SSE of Monte Tronador, where the Fonck cinder cone (also known as Cerro Volcanico) overlies rocks of the Steffen volcano group. The well-preserved cone was the source of a single andesitic lava flow that postdates the last glacial cycle dating back to 70,000-14,000 years ago and has variously been inferred to be of latest Pleistocene or Holocene age.

Cayutue-La Vigueria
The Cayutu�-La Viguer�a volcanic field consists of about 20 basaltic maars and cinder cones of Holocene age along the N-S-trending Liqui�e-Ofqui fault zone. The field occupies a low-lying area between the southern end of Ensenada Cayutu� (the southern extension of Lake Todos los Santos) and the northern end of the Estuario Reloncav�. La Viguer�a and Volc�n Cayutu� are the principal cones. Formation of La Viguer�a and associated lava flows temporarily dammed the R�o Petrohu� about 3,000 years ago, forming an ephemeral lake that was filled with deposits from Calbuco and Osorno volcanoes. Pyroclastic cones and lava flows filled the Ensenada de Cayutu� depression, separating Lake Todos los Santos from Ral�n Bay.

Osorno
The symmetrical, glaciated, Osorno volcano towers above Todos los Santos and Llanquihu� lakes. It was constructed over the SW part of a roughly 250,000-year-old eroded stratovolcano, La Picada, that has a mostly buried 6-km-wide caldera. The dominantly basaltic to basaltic andesite volcano includes two small dacitic lava domes on the NW and SSE flanks. Flank scoria cones and fissure vents, primarily on the W and SW sides, have produced lava flows that reached Lago Llanquihu�. Frequent explosive eruptions including pyroclastic flows and surges have occurred during the past 14,000 years. Recorded eruptions have originated from summit and flank vents, producing basaltic and andesitic lava flows that have entered both Llanquihu� and Todos los Santos lakes.

Yate
Yate volcano is a late Pleistocene, glacially dissected basaltic andesite stratovolcano with Holocene flank vents. One of these flank vents is labeled Volc�n Yate on the Volc�n Hornopir�n 1:50,000 quadrangle map. This isolated feature, NNE of Volc�n Hornopir�n and S of the Relancav� strait, shows evidence of Holocene eruptions. Elongated, it contains six eruptive centers localized along a NW-trending fissure ~7.5 km long. The most recent activity originated from basaltic andesite pyroclastic cones on the NW and W flanks. No reported eruptions are known, although the fresh morphology of its flank cones suggests recent activity (Gonz�lez-Ferr�n, 1995). A non-eruptive landslide in 1965 produced a debris flow that reached Lake Cabrera, causing a tsunami that destroyed a settlement and caused 27 fatalities.

Hornopiren
Volc�n Hornopir�n, located SSW of Yate volcano, is a morphologically youthful basaltic andesite stratovolcano that is mostly forested. The volcano, whose name means "snow oven," lies along a graben defined by the major regional Liqui�e-Ofqui fault zone, N of the Hornopir�n strait and immediately S of Lago Cabrera. Prominent lava flows descend beyond the SW base of the volcano and overlie the graben floor. The volcano was said to be in eruption in 1835, although no details are known.

Apagado
Landform: Minor
Volc�n Apagado, also known as Hualiaque, is located W of Hornopir�n volcano and SW of Yate on the peninsula between the Gulf of Ancud and the Reloncav� estuary. The sparsely vegetated pyroclastic cone contains a well-preserved summit crater; scoria deposits have a calibrated age of about 2,500 years BP. A 6-km-wide depression open to the SW mentioned by Gonz�lez-Ferr�n (1995), and a small lava flow passing through that breach, are not prominent on satellite imagery.

Crater Basalt Volcanic Field
The Crater Basalt volcanic field in the northern Patagonia region of Argentina covers an area of about 700 km2. The field lies about 400 km E of the Peru-Chile trench along the broad regional Gastre fault system. Nine cinder cones and spatter cones produced blocky lava flows of alkali basaltic, basanitic, and trachybasaltic composition. One of the largest features is Cerro Ferm�n, a cinder cone that produced multiple lava flows. The highest cone, Cerro Negro, fed lava flows that traveled to the W, E, and then NE, where its distal margin is cut by a provincial road. Some of the lava flows, such as those from Cerro Ventana and Cerro Contreras, cover Holocene shorelines of playa lakes.

Calbuco
Calbuco is one of the most active volcanoes of the southern Chilean Andes, along with its neighbor, Osorno. The late-Pleistocene to Holocene andesitic volcano is immediately SE of Lake Llanquihu� in the Chilean lake district. Guanahuca, Guenauca, Huanauca, and Huanaque, all listed as synonyms of Calbuco (Catalog of Active Volcanoes of the World), are actually synonyms of nearby Osorno volcano (Moreno 1985, pers. comm.). The edifice is elongated in a SW-NE direction and is capped by a 400-500 m wide summit crater. The complex evolution included collapse of an intermediate edifice during the late Pleistocene that produced a 3-km3 debris avalanche that reached the lake. It has erupted frequently during the Holocene, and one of the largest historical eruptions in southern Chile took place from Calbuco in 1893-1894 that concluded with lava dome emplacement. Subsequent eruptions have enlarged the lava-dome complex in the summit crater.

Huequi
Landform: Minor
Volcano type: Lava dome(s)
Volc�n Huequi is a small, glacier-free lava-dome complex in the center of the Huequi Peninsula in Ancud Bay. The basaltic andesite to dacitic volcano consists of a complex of lava domes within an arcuate collapse depression with debris-avalanche deposits extending to the NW. Explosive eruptions were recorded during the 19th and 20th centuries, initially in 1890 and most recently in about 1920.

Chaiten
Chait�n is a small caldera (~3 km in diameter) located 10 km NE of the town of Chait�n on the Gulf of Corcovado. Multiple explosive eruptions throughout the Holocene have been identified. A rhyolitic obsidian lava dome occupies much of the caldera floor. Obsidian cobbles from this dome found in the Blanco River are the source of artifacts from archaeological sites along the Pacific coast as far as 400 km from the volcano to the N and S. The caldera is breached on the SW side by a river that drains to the bay of Chait�n. The first recorded eruption, beginning in 2008, produced major rhyolitic explosive activity and building a new dome and tephra cone on the older rhyolite dome.

Michinmahuida
The glacier-covered basaltic-to-andesitic Volc�n Michinmahuida, located west of Lago Re�ihue, has a saddle-shaped summit with an elongated 3-km-wide caldera. The massive edifice is elongated in a NE-SW direction, and a youthful eruptive center is located on the ENE side of the complex. A major explosive eruption at the beginning of the Holocene produced the Amarillo Ignimbrite that may have created the now ice-filled summit caldera, and Holocene tephra deposits from summit and flank vents have been identified. An eruption was reported in 1742, and Charles Darwin observed activity in 1834. The latest known eruption, February-March 1835, produced a lava flow from a flank crater and lahars that reached the coast at Punta Chana.

Yanteles
Little-known glacier-covered Yanteles volcano in southern Chile is at the corner of a volcanic massif located 60 km S of the city of Chaiten, with higher eroded peaks about 5 km E and along a ridge extending 10 km SW. Several Holocene tephra layers have been attributed to this volcano. There were reports of an eruption at the time of the 20 February 1835 Chile earthquake, and Sapper (1917) stated that previously unseen black areas were observed there after the 1835 earthquake, but the nature of this activity is not clear.

Melimoyu
Melimoyu is a stratovolcano with an 8-km-wide, largely buried caldera located ~40 km NW of the town of Puyuhuapi. The ice-filled caldera is drained by a glacier through a notch in the NE caldera rim. The basaltic andesite volcano is elongated 10 km in an E-W direction and has several cinder cones. A 1-km-wide crater is located at its summit, and two late-Holocene tephra layers have been documented.

Puyuhuapi
Landform: Minor
Volcano type: Pyroclastic cone(s)
A chain of dominantly basaltic cinder cones erupted along two NE-SW-trending fissures at the head of Puyuhuapi fjord comprise the Volcanes de Puyuhuapi. The larger group of four cones lies on the W side of the fjord and fed lava flows that traveled SE to the sea. The second lineament formed a chain of four smaller cones between the head of the fjord and Lake Risopatr�n to the N. The two fractures are related to the regional Liqui�e-Ofqui fault zone. The cinder cones are extremely well preserved, suggesting a very young age.

Mentolat
Volc�n Mentolat is an ice-filled 6-km-wide caldera in the central part of Magdalena Island across the Puyuhuapi strait from Puerto Cisnes. An eruption about 7,000 years ago produced a pumice and scoria layer that extends to the SE. A young-looking andesitic lava flow on the SW flank may be its most recent product. Reports by Serrano describe an eruption at the beginning of the 18th century that could refer to this lava flow.

Cay
Volc�n Cay, located E of Mac� volcano and NW of the town of Puerto Ais�n, is a basaltic to dacitic stratovolcano. An explosion crater is open to the E, and about a half dozen explosion craters and pyroclastic cones lie along a fissure trending SW of the summit. Another 10 basaltic pyroclastic cones are located along a second parallel fissure 5 km SE that is part of the major regional Liqui�e-Ofqui fault zone. These cones were considered to be Holocene by Gonz�lez-Ferr�n (1995), but Naranjo and Stern (2004) found no evidence for Holocene tephra deposits.

Maca
The glacier-covered, basaltic-to-dacitic Volc�n Mac� stratovolcano lies within a caldera and contains a summit lava dome. Five flank cinder cones and lava domes lie along a NE-trending fissure that extends 15 km from the summit SW to Bah�a P�rez. The volcano lies along the regional Liqui�e-Ofqui fault zone, and a lava flow from a cinder cone at Bah�a P�rez erupted as recently as between 1450 and 1670 CE.

Cerro Hudson
The ice-filled, 10-km-wide caldera of Cerro Hudson volcano was not recognized until its first 20th-century eruption in 1971. It is the southernmost volcano in the Chilean Andes, related to subduction of the Nazca plate beneath the South American plate. The massive volcano covers an area of 300 km2. The compound caldera is drained through a breach on its NW rim, which has been the source of mudflows down the R�o de Los Huemeles. Two cinder cones occur N of the volcano and others occupy the SW and SE flanks. This volcano has been the source of several major Holocene explosive eruptions. An eruption about 6,700 years ago was one of the largest known in the southern Andes during the Holocene; another eruption about 3,600 years ago also produced more than 10 km3 of tephra. An eruption in 1991 formed a new 800-m-wide crater in the SW portion of the caldera.

Corcovado
Little is known of this isolated volcano that was seen in eruption by Darwin in 1834, and an eruption was reported to have occurred in November 1835. Corcovado, probably of late-Pleistocene age, is eroded by glaciers and surrounded by Holocene cinder cones. A series of lakes flank the eastern side of the basaltic to basaltic andesite structure. Eruptions in historical time were considered likely from these postglacial volcanoes (Moreno 1985, pers. comm.).

Meullin
The Meull�n volcanic field consists of a chain of well-preserved cinder cones along the Lago Meull�n, Lago Yulton, R�o Cuervo, and Quitralco fault segments of the regional Liquine-Ofqui fault zone. The cones straddle both sides of the Ais�n (Ays�n) Fjord and were considered to be of Holocene age (Vargas et al., 2013). The cinder cones, a few of which are sub-aquatic, extend to the south along NE-SW, NNE-SSW, and N-S lines from Yulton Lake. The largest concentration of cones lies between Meull�n Lake and the older Pleistocene Meull�n volcano located west of the volcanic field, and additional forested cinder cones were constructed along the R�o Pescado valley south of Ais�n Fjord.

Central Andean Volcanic Arc

Quimsachata-Oroscocha
Peru
Central Andean Volcanic Arc
Landform: Minor (Silicic)
Volcano type: Lava dome
The Quimsachata-Oroscocha group consists of two late Pleistocene and Holocene monogenetic volcanoes at the foot of the Cordillera Oriental, far east of the main volcanic front. Quimsachata is a high-potassium andesitic scoria cone surrounded by a lava shield that was erupted in flat terrain along the Vilcanota River about 11,500 years ago. Oroscocha is a rhyolitic lava dome with a short, thick lava flow erupted from a N-S-trending fissure about 6,400 years ago.

Cerro Auquihuato
Peru
Central Andean Volcanic Arc
The Cerro Auquihuato cinder cone lies ~30 km NE of Sara Sara volcano. Along with older cones, it was constructed along the southern rim of an isolated high plateau east of the R�o Ocona. The cone fed a lava flow with very prominent levees that traveled southward down a river valley dissecting the margins of the plateau. The Instituto Geof�sico del Per� lists it as having undated Holocene activity (as of June 2025).

Coropuna
Peru
Nevado Coropuna is a massive ice-covered volcanic complex with multiple summit cones built over a 12 x 20 km area. The summit of the andesitic-to-dacitic complex is a cone at the NW end, north of a line of E-W-trending cones. Deep, steep-walled, canyons surrounding the volcano have produced topographic relief of more than 4,000 m over a horizontal distance of 15 km. Dark-colored younger lava flows descend the NE, SE, and W flanks, but the age of the most recent eruptions are not known. Solfataric activity has been reported.

Andahua-Orcopampa
The Andahua-Orcopampa volcanic field in the Andahua (or Andagua) valley area, 20 km ENE of Nevados de Coropuna, is a large 60 x 60 km scoria cone and lava field. Known locally as the "Valley of the Volcanoes," the field lies in a series of deep NNW-SSE-trending, en-echelon valleys: Orcopampa, Andahua, and Ayo. The field contains youthful dominantly trachyandesitic cinder cones and lava flows that have destroyed buildings and may be only a few hundred years old. The area was reported to have been active during the time of the Incas and to have "become active again" in 1913. Lava flows have repeatedly dammed the R�o Andagua valley, and an existing small lake was impounded by the youngest lavas.

Huambo
The monogenetic Huambo volcanic field lies SSE of the Andahua-Orcocampo volcanic field, west of Sabancaya volcano. The field is divided into two segments. The southern area contains several cinder cones and associated lava flows, some of which are inferred to be of early to late-Holocene age on the basis of morphological criteria. The northern part contains a single vent, the Cerro Keyocc cinder cone, which produced an extensive lava field that covered a plateau to the north during an eruption radiocarbon dated at about 2,650 years ago.

Sabancaya
Sabancaya, located in the saddle NE of Ampato and SE of Hualca Hualca volcanoes, is the youngest of these volcanic centers and the only one to have erupted in historical time. The oldest of the three, Nevado Hualca Hualca, is of probable late-Pliocene to early Pleistocene age. The name Sabancaya (meaning "tongue of fire" in the Quechua language) first appeared in records in 1595 CE, suggesting activity prior to that date. Holocene activity has consisted of Plinian eruptions followed by emission of voluminous andesitic and dacitic lava flows, which form an extensive apron around the volcano on all sides but the south. Records of observed eruptions date back to 1750 CE.

El Misti
El Misti is a symmetrical andesitic stratovolcano with nested summit craters immediately NE of the city of Arequipa, Peru. Eruptions from the active cone began about 13,700 and 11,300 years ago, within a 1.5 x 2 km caldera that underwent collapse about 50,000 years ago. A large scoria cone has grown with the 830-m-wide outer summit crater. At least 20 tephra-fall deposits and numerous pyroclastic-flow deposits have been documented during the past 50,000 years, including a pyroclastic flow that traveled 12 km S about 2,000 years ago. The most recent activity has been dominantly pyroclastic, and strong winds have formed a parabolic dune field of volcanic ash extending up to 20 km downwind. An eruption in the 15th century affected nearby Inca inhabitants. Some reported eruptions may represent increased fumarolic activity.

Ubinas
The truncated appearance of Ubinas, Per�'s most active volcano, is a result of a 1.4-km-wide crater at the summit. It is the northernmost of three young volcanoes located along a regional structural lineament about 50 km behind the main volcanic front. The growth and destruction of Ubinas I was followed by construction of Ubinas II beginning in the mid-Pleistocene. The upper slopes of the andesitic-to-rhyolitic Ubinas II stratovolcano are composed primarily of andesitic and trachyandesitic lava flows and steepen to nearly 45�. The steep-walled, 150-m-deep summit crater contains an ash cone with a 500-m-wide funnel-shaped vent that is 200 m deep. Debris-avalanche deposits from the collapse of the SE flank about 3,700 years ago extend 10 km from the volcano. Widespread Plinian pumice-fall deposits include one from about 1,000 years ago. Holocene lava flows are visible on the flanks, but activity documented since the 16th century has consisted of intermittent minor-to-moderate explosive eruptions.

Ticsani
Landform: Minor (Silicic)
Volcano type: Lava dome(s)
Ticsani is a dacitic lava dome complex in the Ichuna district of Peru, about 30 km SE of Huaynaputina volcano. Volc�n Ticsani resembles Huaynaputina in its dacitic composition and explosive eruptive style. Both lie about 50 km behind the main volcanic front of the Peruvian Andes. A fresh-looking lava field lies at the NW base of the youthful-looking, unglaciated edifice. A major debris avalanche partially filled the R�o Tambo to the south. Emplacement of three lava domes since the end of the Pleistocene was accompanied by explosive eruptions. No historical eruptions are known, but fumarolic activity continues, and pumice from the crater containing the youngest lava dome overlies tephra from the 1600 CE Huaynaputina eruption.

Huaynaputina
Huaynaputina (whose name means "new volcano") was the source of the largest historical eruption of South America in 1600 CE. It has no prominent topographic expression and lies within a 2.5-km-wide collapse depression and further excavated by glaciers within a Tertiary to Pleistocene edifice. Three overlapping ash cones with craters up to 100 m deep were constructed during the 1600 CE eruption on the floor of the older crater, whose outer flanks are heavily mantled by ash deposits from the 1600 eruption. This powerful fissure-fed eruption may have produced nearly 30 km3 of dacitic tephra, including pyroclastic flows and surges that traveled 13 km to the E and SE. Lahars reached the Pacific Ocean, 120 km away. The eruption caused substantial damage to the major cities of Arequipa and Moquengua.

Tutupaca
Tutupaca consists of two dissected volcanic edifices, of which the southern appears more youthful. Collapse of the northern edifice produced a debris avalanche that traveled 7 km N. Postglacial lava flows are present, the largest of which originated from the saddle between the two edifices. Solfataric activity was noted in the Catalog of Active Volcanoes of the World. Based on morphological evidence, de Silva and Francis (1990) suggested that reported historical eruptions in the 18th and 19th centuries (listed in the Catalog of Active Volcanoes of the World) more likely originated from the more youthful-looking Yucamane volcano. Work by Samaniego et al. (2015) showed that activity in 1787-89 and 1802 CE originated at Tutupaca, and they considered the 1780, 1862, and 1902 reports to be valid as well.

Yucamane
Volc�n Yucamane lies at the south end of a group of three volcanoes known as the Caliente-Yucamane Volcanic Complex; both it and Cerro Caliente to the north display evidence of postglacial lava flows, which overlie thick moraines. The andesitic Yucamane has a youthful, well-preserved summit crater. Late-Pleistocene and Holocene eruptions have produced airfall deposits, pyroclastic flows and surges, and block-and-ash flows produced by growth and collapse of lava domes. The most recent confirmed eruption, a subplinian event, took place about 3000-3300 radiocarbon years ago. Historical eruptions originally attributed to the more dissected Tutupaca during the 18th-20th centuries (Catalog of Active Volcanoes of the World) were considered by de Silva and Francis (1990) to have more likely been from Yucamane, but later authors (eg. Samaniego et al. 2015) assigned them to Tutupaca, including an eruption of uncertain character reported in 1787 (Volcanological Society of Japan, 1971). Ongoing fieldwork has not found deposits younger than the 3000 BP event (Samaniego, 2015).

Nevados Casiri
The Nevados Casiri compound volcano in Peru, also known as Paugarani, lies near the Chilean border ~25 km N of Tacora volcano. The trachytic and trachyandesitic complex consists of four volcanic edifices, with the youngest cone on the SE side. Two dark younger lava flows are SE of the most recently active cone, which has a well-defined summit crater. An older lava dome is located to the west. Sulfur has been mined on the NW and SE flanks.

Taapaca
Volcano type: Complex
The Taapaca volcanic complex, lying W of the main Andean chain, rises NE of the small town of Putre, the principal settlement of the northern Chilean Altiplano. The elongated volcanic massif, known locally as Nevados de Putre, consists of an andesitic stratovolcano and a dacitic lava-dome complex. It overlies Pleistocene ignimbrite deposits and trends roughly E-W, with activity migrating generally to the SW during four principal periods of activity dating back at least 1.5 million years. At least three major edifice collapse events have produced debris-avalanche deposits, the youngest of which underlies Putre. Studies have shown that explosive activity with dome growth and associated block-and-ash flows and lahars continued into the late Holocene. The youngest volcanic stage, beginning about 9000 years ago, produced the summit lava dome of the Putre Unit at the E and S ends of the complex. The latest documented activity produced an ash layer dated ~2000 years ago.

Parinacota
Chile-Bolivia
The symmetrical Volc�n Parinacota is the southernmost and youngest of a pair of volcanoes forming the Nevados de Payachata group along the Chile-Bolivia border. The dominantly Pleistocene Pomerape volcano towers above a low saddle to the NE. Collapse of Parinacota about 8,000 years ago produced a 6 km3 debris avalanche that traveled 22 km W and blocked drainages, forming Lake Chungar�. Holocene eruptive activity has subsequently reconstructed the stratovolcano, which contains a pristine, 300-m-wide summit crater and youthful lava flows on the W flanks. Although no historical eruptions are known, Helium surface-exposure dates have been obtained for eruptions during the past two thousand years both from the main cone and the Ajata group of satellite cones and lava flows on the S and SW flanks.

Guallatiri
One of northern Chile's most active volcanoes, Volc�n Guallatiri is a symmetrical ice-clad stratovolcano at the SW end of the Nevados de Quimsachata volcano group. It lies just W of the border with Bolivia and is capped by a central dacitic dome or lava complex, with the active vent situated on its S side. Thick lava flows are prominent on the lower N and W flanks of the andesitic-to-rhyolitic volcano. Minor explosive eruptions have been reported since the beginning of the 19th century. Intense fumarolic activity with "jet-like" noises continues, and numerous solfataras extend more than 300 m down the W flank.

Tata Sabaya
Bolivia
The symmetrical Tata Sabaya towers above the northern end of the Salar de Coipasa in the Altiplano of Bolivia. A pyroclastic shield capped by lava domes was topped by effusive eruptions that formed the unglaciated andesitic stratovolcano. Collapse of this edifice produced a large late-Pleistocene debris avalanche that swept into the Salar de Coipasa and covered an area of more than 300 km2 S of the volcano, traveling up to 30 km. Tufa deposits on avalanche hummocks correspond to a ~12,000 year old high stand of the lake. Renewed eruptions during the Holocene constructed lava domes and flows that have restored much of the original edifice. Youthful lava flows extend down the NW and W flanks, and pyroclastic-flow deposits from partial collapse of the summit dome extend to the lower SW flank.

Isluga
The broad Isluga volcano lies 7 km W of the Chile/Bolivia border at the W end of a group of volcanoes extending to Tata Sabaya volcano in Bolivia. A stratovolcano, it contains a well-preserved, 400-m-wide summit crater at the W end of the elongated, snow-covered summit region. Numerous postglacial lava flows, many showing distinct levees, are most prominent along a broad front on the lower S flank. Activity from the summit crater was reported in the 19th and 20th centuries. A lava flow in 1878 destroyed several towns.

Irruputuncu
Chile-Bolivia
Irruputuncu is a small stratovolcano that straddles the Chile/Bolivia border. It is the youngest and most southerly of a NE-SW-trending chain of volcanoes. It was constructed within the collapse scarp of a Holocene debris avalanche whose deposit extends to the SW. Subsequent eruptions filled much of this scarp and produced thick, viscous lava flows down the W flank. The summit complex contains two craters, the southernmost of which is fumarolically active. The first unambiguous historical eruption took place in November 1995, when phreatic explosions produced dark ash clouds.

Olca-Paruma
Chile-Bolivia
A 15-km-long E-W ridge forming the border between Chile and Bolivia is comprised of several stratovolcanoes with Holocene lava flows. Andesitic-dacitic lava flows extend as far as 5 km N from the active crater of Volc�n Olca and to the north and west from vents farther to the west. Olca is flanked on the west by Cerro Michincha and on the east by Volc�n Paruma, which is immediately west of the higher pre-Holocene Cerro Paruma volcano. Volc�n Paruma has been the source of conspicuous fresh lava flows, one of which extends 7 km SE, and has displayed persistent fumarolic activity. The only reported historical activity from the complex was a flank eruption of unspecified character between 1865 and 1867, which SERNAGEOMIN notes is based on unconfirmed records.

Sairecabur
This chain of andesitic-dacitic volcanoes along the Chile-Bolivia border contains at least 10 postglacial centers and stretches from Escalante volcano in the N to Sairec�bur volcano in the S. Nomenclature reflecting local usage results in conflicting names applied to these features on Chilean and Bolivian topographic maps. The highest peak, Sairec�bur, is located on the northern margin of a 4.5-km-wide caldera. Postglacial activity began S of the summit, but most recently produced a pristine lava flow to the NW. An active sulfur mine is located N of the volcano. Escalante, slightly older than Sairec�bur, has a crater lake at its summit and youthful lava flows on its flanks, and other eruptive centers have also produced Holocene lava flows. The Pleistocene-Holocene Curinquinca volcano lies at the NE end of the complex; Cerro Colorado volcano lies at the NW end.

Licancabur
The symmetrical steep-sided Licancabur stratovolcano was constructed primarily during the Holocene and contains a lake in its 400-m-wide summit crater. The Pleistocene Juriques volcano is located immediately to the SE and is capped by a 1.5-km-wide summit crater. Archaeological ruins were found on the crater rim. The shallow freshwater summit lake is 70 x 90 m and has a measured temperature of 6�C, supporting growth of planktonic fauna at nearly 6,000 m elevation. Young blocky andesitic lava flows with prominent levees extend up to 6 km down the NW-to-SW flanks; older flows reach up to 15 km from the summit crater and are covered by pyroclastic-flow deposits that extend 12 km. The most recent activity produced flank lava flows.

Guayaques
The Cerros de Guayaques group of N-S-trending rhyodacitic lava domes straddles the Chile-Bolivia border. The 10-km-long chain is located immediately E of the Purico pyroclastic shield. There is some evidence for Holocene activity, and the youngest domes appear to be N of the summit crater of the dome complex (de Silva and Francis, 1991). A well-defined summit crater was the source of the largest lava flows, which traveled 3 km to the SW. There are no records of historical activity.

Purico Complex
Volcano type: Shield(pyroclastic)
Latitude: 23°S
The Purico volcanic complex consists of two ignimbrite sheets, separated by a short erosional interval, that were erupted about 1.3 million years ago, along with several stratovolcanoes and lava domes that define a postulated 10 x 20 km ring fracture. Cerro Toco volcano overlies the vent area of the Caj�n Ignimbrite. A sulfur mine on its SE flank was mined until the early 1990s. The youngest lava domes, Cerro Chasc�n de Purico and Cerro Aspero are of Holocene age (de Silva and Francis, 1991). Both domes differ morphologically from many other flat-topped silicic Andean volcanic domes and have conical profiles. The Cerro Chasc�n de Purico dacitic dome was formed by a series of viscous lava flows and has a well-preserved summit crater and lava flows that show no evidence of glacial modification. The Cerro Aspero appears to be a single Pelean-type dome. The dacitic-to-andesitic Macon stratovolcano of Holocene age lies at the southern end of the complex, and the Alitar maar at the SE end displays constant solfataric activity.

Colachi
Colachi is a andesitic-dacitic stratovolcano that was constructed on an uplifted block of welded ignimbrites. The most recent activity produced pristine silicic lava flows of probable Holocene age, the largest of which covers a 7 km2 area on the saddle between Colachi and the neighboring volcano of Acamarachi (de Silva and Francis, 1991). A smaller flow was erupted on the W flank. The closely spaced Colachi and Acamarachi volcanoes represent different magmatic systems (Gardeweg 1993, pers. comm.).

Acamarachi
Acamarachi, a steep-sided andesitic-dacitic volcano, forms the highest peak in this part of the northern Andes. Also known as Cerro Pili, it is at the SSE end of a small volcanic complex that extends from the neighboring volcano Colachi to the NNW. A large lava dome is located on its N flank. A poorly preserved summit crater and the absence of youthful flank lava flows suggest that the volcano was largely constructed in pre-Holocene times, although the summit lava flows draping the upper cone were considered to be of Holocene age (Gonz�lez-Ferr�n, 1995).

Chiliques
Volc�n Chiliques is a structurally simple stratovolcano located immediately south of Laguna Lej�a. The summit contains a 500-m-wide crater. Several youthful lava flows, some of which are considered to be of possible Holocene age (de Silva, 2007 pers. comm.), descend its flanks. The largest of these extends 5 km NW. Older lava flows reach up to 10 km from the summit on the N flank. This volcano had previously been considered to be dormant; however, in 2002 a NASA nighttime thermal infrared satellite image from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) showed low-level hot spots in the summit crater and upper flanks.

Putana
Volc�n Putana, also known as Jorgencal or Machuca, is part of a large, roughly N-S-trending volcanic complex that covers an area of 600 km2. Vigorous fumarolic activity is visible at the summit from long distances. The main edifice, which formed primarily by lava effusion, consists of accumulated postglacial dacitic lava domes and flows mantling an older pre-Holocene volcano. The youngest basaltic andesite lava flows are viscous and rarely extend more than 3 km. A major eruption of unspecified character was reported in the early 19th century (Rudolph, 1955; Guest 1981, pers. comm.), although Gonz�lez-Ferr�n (1995) indicated that no historical eruptions had occurred.

Cordon de Puntas Negras
Two intersecting volcanic chains, the Cord�n de Puntas Negras and Cord�n Chalviri, trend roughly SE from Chiliques volcano to Volc�n Puntas Negras stratovolcano and SW from there to Cerro Tuyajto, respectively. The chain of small cones, lava domes, lava flows, and maars covers an area of about 500 km2 and contains at least 25 different vents. The Cord�n de Puntas Negras is situated along the southern margin of the 35 x 70 km Pliocene La Pacana caldera. The pristine morphology of many of the volcanic features indicates a Holocene (de Silva and Francis, 1991) or historical (Gonz�lez-Ferr�n, 1995) age. Small cones such as Cerros Cenizas, Aguas Calientes, Laguna Escondida, and Chinchilla have well-preserved summit craters and produced short lava flows. A distinct maar-type vent is present, as well as a 13 km2 silicic lava flow and dome complex. A volcanic center immediately SE of Cerro Laguna Escondida appears to be the youngest vent of the complex.

Miniques
Volc�n Mi�iques is a large basaltic andesite to dacitic volcanic complex S of Laguna Miscanti and Laguna Mi�iques. The summit is cut by three overlapping craters. Larger craters, partially filled by lava domes and flows, are located W and NE of the summit. The stratovolcano and lava-dome complex was considered to have been active from the Pliocene to the Holocene (Gonz�lez-Ferr�n, 1995); de Silva (2007 pers. comm.) assigned it a possible Holocene age. A prominent lava flow extends NW from the summit to the lower flanks, separating Laguna Mi�iques from Laguna Miscanti.

Cerro Tujle
Volcano type: Maar
The Cerro Tujle maar (also known as Cerro Tucle or Cerro Tugle) in the Cord�n de Tujle has a 60-m-deep crater (de Silva and Francis, 1991). The maar is located SE of the Salar de Atacama, N of Cerro Toloncha.

Caichinque
Caichinque is a relatively small Pleistocene-Holocene volcanic complex that forms a topographic high dividing Salar Capur from Salar Talar. More than a half-dozen vents produced andesitic-to-dacitic lava flows, with young flows descending to the NE and SE from the summit. One prominent flow traveled 6 km to the E, forming two lobes extending into the Salar Talar. The youthful morphology of the flows suggested a prehistorical age (Gonz�lez-Ferr�n, 1995), but de Silva (2007 pers. comm.) considered the volcanic complex to perhaps be as old as late Pleistocene.

Tilocalar
Volcano type: Lava cone(es)
Two small eruptive vents that produced lava flows lie about 3 km apart in the Callej�n de Tiloc�lar area. Lava flows overlie Pliocene ignimbrites and were considered to be of Pleistocene-Holocene age by Gonz�lez-Ferr�n (1995). The larger feature, Tiloc�lar Sur, lies about 3.5 km SW of Tiloc�lar Norte. Four basaltic andesite to andesitic lava flows originated from Tiloc�lar Sur, and an explosion crater lies a kilometer to the south. The Tiloc�lar Norte lies near the eastern wall of the Callej�n de Tiloc�lar and produced lava flows that traveled primarily to the north.

Pular
Cerro Pular on the NE end and Cerro Pajonales on the SW form a 12-km-long volcanic ridge NE of Socompa volcano that is mostly pre-Holocene, but may have experienced some more recent activity. The chain lies NW of the Salar de Pular, about 15 km W of the Argentinian border. Extensive andesitic lava flows reach the lower flanks of the volcanoes, and about 10 craters are present. A major satellite vent W of the ridge appears to be the youngest feature of the volcanic complex. An uncertain small explosive eruption was reported in 1990, but the vent location was not known.

La Negrillar
The basaltic andesite La Negrillar cone and lava flow complex (also known as Aguas Perdidas) covers a roughly 50 km2 area along the SW margin of the Atacama basin about 35 km WNW of Socompa volcano between the small Sierra San Juan and Sierra Almeida ranges. It was interpreted to be Holocene by de Silva and Francis (1991), though Gardeweg (1993, pers. comm.) did not consider it to be of Holocene age. Additionally, de Silva (2007, pers. comm.) noted that it was not as youthful looking as the El Negrillar complex to the N, although it did show leveed lava flows and pristine craters.

Socompa
Straddling the Chile-Argentina border, Volc�n Socompa is a massive dacitic stratovolcano that lies immediately north of the only railway line between the two countries. It is the youngest and southernmost of a NE-SW-trending chain of volcanoes including Pular and Pajonales. In contrast to the latter two volcanoes, no glacial moraines have been observed on the relatively uneroded Socompa. Collapse of the NW portion of the volcano about 7200 years ago produced a 600 km2 debris-avalanche deposit that extends about 40 km from the summit and is one of the world's largest and best exposed. Undated post-collapse eruptions constructed dacitic lava domes that have filled much of the head of the collapse scarp. No historical eruptions are known.

Lascar
L�scar is the most active volcano of the northern Chilean Andes. The andesitic-to-dacitic stratovolcano contains six overlapping summit craters. Prominent lava flows descend its NW flanks. An older, higher stratovolcano 5 km E, Volc�n Aguas Calientes, displays a well-developed summit crater and a probable Holocene lava flow near its summit (de Silva and Francis, 1991). L�scar consists of two major edifices; activity began at the eastern volcano and then shifted to the western cone. The largest eruption took place about 26,500 years ago, and following the eruption of the Tumbres scoria flow about 9000 years ago, activity shifted back to the eastern edifice, where three overlapping craters were formed. Frequent small-to-moderate explosive eruptions have been recorded since the mid-19th century, along with periodic larger eruptions that produced ashfall hundreds of kilometers away. The largest historical eruption took place in 1993, producing pyroclastic flows to 8.5 km NW of the summit and ashfall in Buenos Aires.

Corrida de Cori Volcanic Field
Cerro Escorial, a small andesitic-dacitic stratovolcano, has young-looking lava flows and a well-preserved crater. It is the youngest volcanic center of the NW-SE-trending Corrida de Cori range that marks the Chile/Argentina border. Escorial is located 4 km NE of an active sulfur mine in older, extensively hydrothermally altered rocks. Very youthful-looking lava flows extend westward 3-4 km over an ignimbrite deposit on the Chilean side. A 1-km-wide crater caps the summit. Escorial was considered by de Silva and Francis (1991) to be of probable Holocene age based on morphological evidence, but Richards and Villeneuve (2002) obtained an Ar/Ar age of about 0.342 million years on a lava flow. Most of the lava flows extend to the SW into Chile, but a few small lobes traveled NE on the Argentinian side of the volcano. De Silva (2007 pers. comm.) noted that the well-preserved summit crater postdates the lava flow and could be of Holocene age.

Llullaillaco
The world's highest historically active volcano, Llullaillaco sits astride the Chile-Argentina border. The summit is formed by a smaller well-preserved cone that was constructed on an older Pleistocene edifice. A major debris-avalanche deposit produced by collapse of the older volcano about 150,000 years ago extends eastward into Argentina and diverges around the N and S sides of the older Cerro Rosado stratovolcano 17 km to the E. Construction of several lava domes and flows was associated with growth of the modern cone. The two most prominent flows contain distinct flow levees and ridges and extend down the N and S flanks. These two extremely youthful-looking dacitic flows were initially considered to be of Holocene age, but more recent Ar/Ar dating indicates that they are of late Pleistocene age (Richards and Villeneuve, 2001). Two explosive eruptions and another that may have included lava effusion were reported in the 19th century.

Cordon del Azufre
Volcano type: Complex
Cord�n del Azufre is a small volcanic complex straddling the Chile-Argentina border. The complex consists of a cluster of lava flows from vents on the NE side, wholly within Argentina, and a 5-km-long chain of vents along the border with Chile. An older andesitic-dacitic edifice with a 1.3-km-wide crater was mostly covered by younger Holocene andesitic lava flows. The youngest cone, 300-m-high Volc�n la Moyra, was the source of fresh-looking blocky andesitic lava flows that descended 6 km into Chile and 3 km into Argentina.

Cerro Bayo Gorbea
Volcano type: Complex
Cerro Bayo is a complex volcano of partial Holocene age located along the Chile-Argentina border. An older center to the south contains a poorly preserved, 800-m-wide crater. A younger northern center along the national border has a well-preserved 400-m-wide crater and produced lava flows to the north and NE. The summit of the complex, located west of the border in Chile, is the source of two viscous dacitic lava flows that traveled to the north and represent the most recent activity of the complex.

Sierra Nevada
The Sierra Nevada volcanic complex, located in one of the most inaccessible parts of the Central Andes, covers an area of about 225 km2 astride the Chile-Argentina border. The complex is of partial Holocene age and includes at least 12 volcanic vents with associated lava flows (de Silva and Francis, 1991). Craters up to 400 m in diameter and large andesitic lava flows that extend up to 7 km with well-developed flow ridges are present. The oldest part of the complex, at its eastern end in Argentina, includes two stratovolcanoes, one with a 1-km-wide summit crater.

Falso Azufre
The Falso Azufre volcanic complex is a 15-km-long, E-W trending group of overlapping craters, lava domes, and composite cones extending from Chile into Argentina. The western portion includes the high point and principal edifice of the complex, Cerro Falso Azufre, and consists of overlapping craters that produced dominantly pyroclastic products. The eastern portion, located wholly in Argentina, contains two small composite cones and two lava domes that appear to represent the most recent activity of the complex and may be of Holocene age (de Silva, 2007 pers. comm.).

Nevado de Incahuasi
Nevado de Incahuasi is a complex volcanic massif that straddles the Chile-Argentina border ENE of Nevados Ojos del Salado volcano. Two stratovolcanoes occupy a compound 3.5-km-wide caldera, and Pleistocene lava domes are located on the W and SW flanks. The youngest stratovolcano is capped by a 1-km-wide crater, and dacitic lava flows radiate down the flanks. The fresh-looking morphology of the youngest products suggest a Holocene (Gonz�lez-Ferr�n, 1995) or possible Holocene (de Silva 2007, pers. comm.) age. A dacitic lava dome partially fills an arcuate crater on the E flank of Incahuasi (which means "House of the Inca" in Quechua). Four pyroclastic cones are located 7 km to NE and produced basaltic andesite lava flows that cover an area of 10 km2.

Lastarria
The NNW-trending edifice of 5706-m-high Lastarria volcano along the Chile-Argentina border contains five nested summit craters. The youngest feature is a lava dome that overlaps the northern crater rim. The large andesitic-dacitic Negriales lava field on the western flanks was erupted from a single SW-flank vent. A large debris-avalanche deposit is found on the SE flank. Recent pyroclastic-flow deposits form an extensive apron below the northern flanks of the volcano. Although no historical eruptions have been recorded, the youthful morphology of deposits suggests activity during historical time. Persistent fumarolic activity occurs at the summit and NW flank, and sulfur flows have been produced by melting of extensive sulfur deposits in the summit region.

El Solo
El Solo is large stratovolcano composed of nine eruptive centers located west of Nevados del Ojos de Salado and SE of Tres Cruces volcano. The 6205-m-high volcano was the source of major rhyodacitic pyroclastic-flow deposits erupted during the Holocene that thickly fill adjacent valleys (Gonz�lez-Ferr�n, 1995).

Nevados Ojos del Salado
The world's highest active volcano, Nevados Ojos del Salado, rises to 6,879 m along the Chile-Argentina border. The volcano lies about 20 km south of the road that crosses the international border at Paso de San Francisco. The summit complex, which is elongated in a NE-SW direction and overlies a largely buried caldera, contains numerous craters, pyroclastic cones and andesitic-to-rhyolitic lava domes and has been the source of Holocene lava flows. A major rhyodacitic explosive eruption about 1000-1500 years ago produced pumiceous pyroclastic flows. The most recent eruptive activity appears to have originated along a NNE-trending rift along the summit complex. It involved formation of a thick, viscous lava flow and at least a dozen small cones, lava domes, and explosion craters. No confirmed historical eruptions have been recorded, but the volcano has displayed persistent fumarolic activity, and there was an unconfirmed report of minor gas-and-ash emission in 1993.

Aracar
Aracar is a steep-sided stratovolcano with a youthful-looking summit crater 1-1.5 km in diameter that contains a small lake. It is located just east of the Argentina-Chile border. The volcano was constructed during three eruptive cycles dating back to the Pliocene. The andesitic stratovolcano overlies dacitic lava domes. Lava flows found at the base of the volcano below 4500 m elevation are relatively well preserved, but upper-flank lavas, often an indication of youthful activity, are not present (de Silva, 2007 pers. comm.). There were reports of possible ash columns from the summit in 1993, but it is not known whether these were rockfall dust or eruption plumes.

Central Andean Arc at 25.1�S
An isolated basaltic andesite cinder cone was constructed on top of Miocene ignimbrites and lava flows between the Corrida de Cori range on the Chile/Argentina border and the Salar R�o Grande in Argentina. Blocky lava flows from the cone descended in a broad lobe to the SE and in a narrow tongue to the E nearly to the Salar R�o Grande. A second smaller vent lies about 800 m NW of the cinder cone. The relatively fluid lava flows display surficial breadcrust textures and were considered by Richards and Villeneuve (2002) to be very young, possibly of Holocene age.

El Condor
The compound volcano of Cerro el C�ndor, one of the few large stratovolcanoes located wholly in Argentina, lies within a 2.5-km-wide caldera. The complex lies to the north of Falso Azufre volcano, which straddles the Chile/Argentina border. The summit contains several ash cones and craters that have been the source of a number of pristine lava flows, one of which traveled 10 km to the west. Satellitic centers also abound; one on the east flank produced a fresh-looking lava flow that traveled 8 km to the east. The morphologically youthful lava flows and pristine summit crater imply a Holocene age (de Silva and Francis, 1991).

Peinado
The symmetrical Cerro Peinado stratovolcano in Argentina is the source of well-preserved Holocene lava flows from summit and flank vents (de Silva and Francis, 1991). The upper part of the cone is covered by pyroclastic material. Possible pyroclastic-flow lobes extend to the NW and N. An apron of pristine lava flows that extends to 6 km were erupted from the main cone and from flank vents, including a prominent ESE-flank vent. It is surrounded by small fields of older cinder cones, maars, and lava flows, located along N-S-trending faults, which are related to the Salar de Antofalla and Antofagasta volcanic fields.

Cerro Blanco
The Cerro Blanco volcanic complex contains the 5-km-diameter Cerro Blanco (or Robledo) caldera in NW Argentina, 80 km SW of the Cerro Gal�n caldera. Cerro Blanco was the site of the largest known Holocene eruption in the Central Andes about 4,200 years BP (Fernandez-Turiel et al., 2013). The rhyolitic Plinian eruption produced ashfall over about 110 km3 and widespread ignimbrite deposits. The large Cerro Blanco del Robledo lava dome overgrew the SW rim of the caldera and is surrounded by extensive rhyolitic pumice-fall deposits. Satellite geodetic surveys in the central Andes (Pritchard and Simons, 2002) showed subsidence of the caldera in the 1990s.

Tipas
This massive volcanic complex is the world's third highest active volcano, but remains largely unknown. Cerro Tipas (also known as Walter Penk or Cazadero), is located immediately SSW of its better known neighbor, Nevados Ojos del Salado, Earth's highest volcano. The summit of Tipas lies within Argentina, immediately south of the Chilean border. This complex of craters, cones, lava domes and lava flows covers an area of 25 km2. It displays a youthful morphology, and its latest eruptions were considered by de Silva and Francis (1991) to be of Holocene age.

Northern Andean Volcanic Arc

Romeral
Colombia
Northern Andean Volcanic Arc
Latitude: 5.203°N
The andesitic-to-dacitic Romeral stratovolcano lies at the northern end of the Ruiz-Tolima volcanic chain, NW of Cerro Bravo volcano, and east of the towns of Neira and Aranzazu. It has produced two young Plinian pumice deposits covering areas to the NW. The pumice deposits are separated by a soil layer radiocarbon dated at about 8,460 and 7,340 years BP.

Cerro Bravo
Colombia
Northern Andean Volcanic Arc
Latitude: 5.091°N
Cerro Bravo is a relatively low dominantly dacitic lava-dome complex north of Nevado del Ruiz that was constructed within the Pleistocene Quebrada Seca caldera. A series of moderate plinian eruptions during the Holocene were accompanied by pyroclastic flows and lava dome growth. Although historical records of the roughly 4000-m-high Cerro Bravo eruptions have not been found, stratigraphic evidence indicates that it last erupted sometime between the 1595 and 1845 eruptions of Ruiz.

Santa Isabel
Colombia
Latitude: 4.818°N
Santa Isabel is a small andesitic shield volcano that is dwarfed by its neighbors to the NE (Nevado del Ruiz) and SE (Tolima). Three lava domes occupy the elongated, N-S-trending glaciated summit region, which has two main peaks. Holocene lava flows fill valleys to the SW and SE. A small Holocene lava dome was emplaced at the center of a circular depression about 10 km SW. No historical eruptions are known.

Nevado del Ruiz
Nevado del Ruiz is a broad, glacier-covered volcano in central Colombia that covers more than 200 km2. Three major edifices, composed of andesitic and dacitic lavas and andesitic pyroclastics, have been constructed since the beginning of the Pleistocene. The modern cone consists of a broad cluster of lava domes built within the caldera of an older edifice. The 1-km-wide, 240-m-deep Arenas crater occupies the summit. The prominent La Olleta pyroclastic cone located on the SW flank may also have been active in historical time. Steep headwalls of massive landslides cut the flanks. Melting of its summit icecap during historical eruptions, which date back to the 16th century, has resulted in devastating lahars, including one in 1985 that was South America's deadliest eruption.

Nevado del Tolima
The steep-sided, glacier-covered Nevado del Tolima volcano contrasts with the broad profile of Nevado del Ruiz to the north. The andesitic-dacitic younger Tolima formed during the past 40,000 years, rising above and largely obscuring a 3-km-wide late-Pleistocene caldera. The summit consists of a cluster of late-Pleistocene to Holocene lava domes associated with thick block-lava flows on the N and E flanks, and extensive pyroclastic-flow deposits. The summit contains a funnel-shaped crater 200-300 m deep. Holocene activity has included explosive eruptions ranging in size from moderate to Plinian, and the last major eruption took place about 3,600 years ago. Lava dome growth has produced block-and-ash flows that traveled primarily to the NE and SE. Minor explosive eruptions have been recorded in the 19th and 20th centuries.

Machin
The small Cerro Mach�n stratovolcano lies at the southern end of the Ruiz-Tolima massif about 20 km WNW of the city of Ibagu�. A 3-km-wide caldera is breached to the south and contains three forested dacitic lava domes. Voluminous pyroclastic flows traveled up to 40 km away during eruptions in the mid-to-late Holocene, perhaps associated with formation of the caldera. Late-Holocene eruptions produced dacitic block-and-ash flows that traveled through the breach in the caldera rim to the west and south. The latest known eruption of took place about 800 years ago.

Nevado del Huila
Nevado del Huila, the highest peak in the Colombian Andes, is an elongated N-S-trending volcanic chain mantled by a glacier icecap. The andesitic-dacitic volcano was constructed within a 10-km-wide caldera. Volcanism at Nevado del Huila has produced six volcanic cones whose ages in general migrated from south to north. The high point of the complex is Pico Central. Two glacier-free lava domes lie at the southern end of the volcanic complex. The first historical activity was an explosive eruption in the mid-16th century. Long-term, persistent steam columns had risen from Pico Central prior to the next eruption in 2007, when explosive activity was accompanied by damaging mudflows.

Sotara
Volc�n Sotar�, also known as Cerro Azafatudo, is an andesitic-dacitic stratovolcano about 25 km SSE of Popay�n city in southern Colombia, SW of Purac� volcano. Three calderas, 4.5, 2.5, and 1 km in diameter, give the summit an irregular profile. No historical eruptions are known, though there is current fumarolic and hot spring activity.

Purace
Purac� is an active andesitic volcano with a 600-m-diameter summit crater at the NW end of the Los Coconucos Volcanic Chain. This volcanic complex includes nine composite and five monogenetic volcanoes, extending from the Purac� crater more than 6 km SE to the summit of Pan de Az�car stratovolcano. The dacitic massif which the complex is built on extends about 13 km NW-SE and 10 km NE-SW. Frequent small to moderate explosive eruptions reported since 1816 CE have modified the morphology of the summit crater, with the largest eruptions in 1849, 1869, and 1885.

Dona Juana
The forested Do�a Juana stratovolcano contains two calderas, breached to the NE and SW. The summit of the andesitic-dacitic volcano is comprised of a series of post-caldera lava domes. The older caldera, open to the NE, formed during the mid-Holocene, accompanied by voluminous pyroclastic flows. The younger caldera contains the active central cone. The only historical activity took place during a long-term eruption from 1897-1906, when growth of a summit lava dome was accompanied by major pyroclastic flows.

Galeras
Galeras, a stratovolcano with a large breached caldera located immediately west of the city of Pasto, is one of Colombia's most frequently active volcanoes. The dominantly andesitic complex has been active for more than 1 million years, and two major caldera collapse eruptions took place during the late Pleistocene. Long-term extensive hydrothermal alteration has contributed to large-scale edifice collapse on at least three occasions, producing debris avalanches that swept to the west and left a large open caldera inside which the modern cone has been constructed. Major explosive eruptions since the mid-Holocene have produced widespread tephra deposits and pyroclastic flows that swept all but the southern flanks. A central cone slightly lower than the caldera rim has been the site of numerous small-to-moderate eruptions since the time of the Spanish conquistadors.

Azufral
Azufral stratovolcano in southern Colombia, also known as Azufral de T�querres, is truncated by a 2.5 x 3 km caldera containing a Holocene rhyodacitic lava-dome complex. A crescent-shaped lake, Laguna Verde, occupies the NW side of the caldera. Nearly a dozen lava domes are present, the latest of which were formed about 3600 years ago and have active fumaroles. Azufral rocks are more silicic than those of nearby Colombian volcanoes; an apron of rhyodacitic pyroclastic-flow deposits rings the volcano. The last known eruption took place about 1000 years ago.

Cumbal
Many youthful lava flows extend from the glacier-capped Cumbal volcano, the southernmost historically active volcano of Colombia. The volcano is elongated in a NE-SW direction and is composed primarily of andesitic-dacitic lava flows. Two fumarolically active craters occupy the summit ridge: the main crater on the NE side and Mundo Nuevo crater on the SW. A young lava dome occupies the 250-m-wide summit crater, and eruptions from the upper E flank produced a 6-km-long lava field. The oldest crater lies NNE of the summit crater, suggesting SW-ward migration of activity. Explosive eruptions in 1877 and 1926 are the only known historical activity. Thermal springs are located on the SE flanks.

Chiles-Cerro Negro
Colombia-Ecuador
The Chiles-Cerro Negro volcanic complex includes both the Pleistocene Chiles and the Cerro Negro de Mayasquer stratovolcanoes astride the Colombia-Ecuador border. Cerro Negro has a caldera open to the west, with andesitic and dacitic lava flows of possible Holocene age (Hall 1992, pers. comm.) and solfataras on the shore of a small crater lake. An eruption reported in 1936 may have been from Reventador (Catalog of Active Volcanoes of the World). The higher, glacier-covered summit of Chiles, about 4 km ESE of Cerro Negro, last erupted about 160,000 years ago, but it has a caldera open to the north with hot springs and an active hydrothermal system on its eastern flank.

Soche
Ecuador
Volc�n el Soche, a small stratovolcano near the Colombia border, is the northernmost of a chain of Ecuadorian volcanoes east of the principal volcanic axis. This dominantly dacitic volcano was constructed over Paleozoic rocks and has a summit caldera open to the E. A major explosive eruption took place during the early Holocene at about 8600 years BP, depositing tephra NW into Colombia. The ejection of voluminous dacitic airfall pumice and pyroclastic flows was followed by the formation of two lava domes in the caldera.

Chachimbiro
Ecuador
The Chachimbiro volcanic complex lies about 25 km NW of the city of Ibarra. Late Pleistocene collapse of the andesitic Huanguillaro stratovolcano produced a 6.8 km3 debris-avalanche deposit and a 4-km-wide avalanche caldera open to the east that has largely been filled by lava domes, including the rhyodacitic Hug� dome. The avalanche deposit is overlain by three large ignimbrites and pyroclastic-flow deposits related to dome growth. The late Pleistocene-to-Holocene, NNE-trending, dacitic Chachimbiro-Pucar� line of lava domes includes the Pitzantzi dome, which erupted about 5,700 years ago, producing an ash deposit that extends to the NW. Hot springs and thermal areas are present in the complex.

Cuicocha
Ecuador
The scenic lake-filled Cuicocha caldera is located at the southern foot of the sharp-peaked Pleistocene Cotacachi stratovolcano about 100 km N of Quito. Both Cotacachi and Cuicocha were constructed along the Otavalo-Umpal� fracture zone. Eruptive activity began about 4500 years ago and continued until about 1300 years ago. The 3-km-wide, steep-walled caldera was created during a major explosive eruption about 3100 years ago that produced nearly 5 km3 of pyroclastic-flow and fall deposits. Four intra-caldera lava domes form two steep-sided forested islands in the 148-m-deep lake. A pre-caldera lava dome is situated on the outer E side of the caldera. Pyroclastic-flow deposits cover wide areas around the low-rimmed caldera, primarily to the east. Gas emission continues from several locations in the caldera lake.

Imbabura
Volcano type: Compound
Imbabura volcano rises to the north above scenic Laguna de San Pablo in the Interandean valley about 60 km N of Quito. The main edifice, Taita Imbabura ("Father Imbabura") forms the summit, with Huarmi Imbabura ("Imbabura's Son") forming a lateral lava-dome complex on the SW flank. Activity at the Pleistocene Imbabura I edifice constructed a large andesitic stratovolcano and ended prior to about 43,000 years ago with a major collapse that produced a debris avalanche that traveled 16 km N. Subsequent growth of the Imbabura II stratovolcano continued at least into the early Holocene and typically consisted of growth and collapse of large-volume dacitic lava domes. A major eruption about 25,000 years ago produced a debris avalanche and possible lateral blast and was followed by growth of the Huarmi Imbabura lava dome. Historical reports of eruptions consisted of only mudflows and rock slides.

Mojanda
Mojanda, one of the largest volcanoes of Ecuador's northern Interandean Depression, rises SW of the historic town of Otavalo. Volc�n Mojanda has a complex geologic history involving two adjacent simultaneously active volcanoes. An earlier edifice contains remnants of a larger earlier caldera and a smaller summit caldera occupied by two lakes. The andesitic-to-rhyolitic Fuya Fuya volcano was constructed contemporaneously immediately to the west of Mojanda and produced two major rhyolitic plinian explosive eruptions, possibly associated with caldera formation. Fuya Fuya underwent edifice collapse less than 165,000 years ago, leaving a large horseshoe-shaped caldera open to the west. Subsequently, a new composite cone and dacitic lava domes were extruded inside the caldera. The youngest domes are unglaciated and of possible Holocene age.

Cayambe
Volcano type: Compound
The massive compound andesitic-dacitic Cayambe stratovolcano is located on the western edge of the Cordillera Real, east of the Inter-Andean Valley. The volcano, whose southern flank is on the equator, is capped by extensive glaciers. The modern Nevado Cayambe, constructed to the east of older Pleistocene volcanic complexes, contains two summit lava domes about 1.5 km apart. Several other lava domes on the upper flanks have been the source of pyroclastic flows that reached the lower flanks. A prominent Holocene pyroclastic cone on the lower E flank, La Virgen, fed thick andesitic lava flows that traveled about 10 km E. Nevado Cayambe has also produced frequent explosive eruptions beginning about 4,000 years ago, with the most recent known activity during 1785-86.

Pululahua
Pululahua is a relatively low, forested volcano about 15 km N of Quito. The 5-km-wide summit caldera is narrowly breached to the west and partially filled by a group of dacitic lava domes. Pre-caldera lava domes of different ages are found outside the caldera to the E, SE, and S. Four post-caldera domes rise up to 450 m above the caldera floor. Large explosive eruptions producing pyroclastic flows took place during the late Pleistocene and Holocene. Caldera formation took place during a series of eruptions lasting 150-200 years beginning about 2,650 radiocarbon years ago. The latest dated eruption occurred from the post-caldera lava domes about 1,670 years ago and produced lava flows and pyroclastic flows.

Reventador
Volc�n El Reventador is the most frequently active of a chain of Ecuadorian volcanoes in the Cordillera Real, well east of the principal volcanic axis. The forested, dominantly andesitic stratovolcano has 4-km-wide avalanche scarp open to the E formed by edifice collapse. A young, unvegetated, cone rises from the amphitheater floor to a height comparable to the rim. It has been the source of numerous lava flows as well as explosive eruptions visible from Quito, about 90 km ESE. Frequent lahars in this region of heavy rainfall have left extensive deposits on the scarp slope. The largest recorded eruption took place in 2002, producing a 17-km-high eruption column, pyroclastic flows that traveled up to 8 km, and lava flows from summit and flank vents.

Atacazo
Atacazo, located about 25 km SW of Quito, consists of a large Pleistocene andesitic stratovolcanoes truncated by a late-Pleistocene to Holocene caldera. Growth of the La Carcacha edifice was followed by construction of Atacazo, a stratovolcano with flank lava domes. The 6-km-wide caldera, which is breached to the SW, is partially filled by three dacitic Holocene lava-dome complexes. Two andesitic lava domes are also found on the SE flank. Several plinian eruptions have occurred at the Atacazo-Ninahuilca complex during the Holocene, accompanied by growth of lava domes. The latest dated eruption took place about 2300 years ago, forming the Ninahuilca Chico lava domes within the summit caldera. Dome formation was accompanied by Plinian explosive eruptions and pyroclastic flows that traveled 35 km down valleys to the west.

Chacana
Chacana is a massive, eroded caldera complex of Pliocene-Holocene age that forms one of the largest rhyolitic centers of the northern Andes. The caldera is 32 km long N-S and 18-24 km wide E-W. It was constructed during three cycles of andesitic-to-rhyolitic volcanism, with major eruptions about 240,000, 180,000, and 160,000 years ago. Dacitic lava flows were erupted from caldera-floor fissures between about 30,000 and 21,000 years ago. Numerous lava domes were constructed within the caldera, which has been the source of frequent explosive eruptions throughout the Holocene as well as historical lava flows during the 18th century. The massive Antisana stratovolcano is immediately to the SE.

Guagua Pichincha
Guagua Pichincha and the older Pleistocene Rucu Pichincha stratovolcanoes form a broad volcanic massif that rises immediately W of Ecuador's capital city, Quito. A lava dome grew at the head of a 6-km-wide scarp formed during a late-Pleistocene slope failure ~50,000 years ago. Subsequent late-Pleistocene and Holocene eruptions from the central vent consisted of explosive activity with pyroclastic flows accompanied by periodic growth and destruction of the lava dome. Many minor eruptions have been recorded since the mid-1500's; the largest took place in 1660, when ash fell over a 1,000 km radius and accumulated to 30 cm depth in Quito. Pyroclastic flows and surges also occurred, primarily to then W, and affected agricultural activity.

Aliso
Longitude: 78°W
The Aliso volcanic complex lies at the eastern foot of the Ecuadorian Andes, east of Antisana volcano and SW of the town of Baeza. The largely unexplored complex contains an arcuate summit ridge on the west with older andesitic lava flows and tundra-like vegetation, and rhyolitic and dacitic lava domes in a wet cloud-forest environment on the lower eastern flanks. The Pumayacu center on the SE flank contains several lava domes along a NNE axis parallel to the Andean Thrust Fault System (TFZ). Morphologically young andesitic lava flows occur along the flat-topped ridge above Baeza town. The Pumayacu center erupted pyroclastic-flow deposits of late Pleistocene and Holocene age. One pyroclastic-flow deposit was dated at about 4,400 BP, and a pumice lapilli layer overlies a ceramic-rich cultural horizon thought to be about 2,000 years old.

Antisana
Antisana is a massive, glacier-covered stratovolcano NE of Cotopaxi, along the western margin of the Eastern Cordillera, 50 km SE of Quito. An older edifice forming the east side of the volcano was constructed over granitic and metasedimentary rocks and is itself overtopped on its NW side by the current edifice. Viscous lava flows have issued from radial fissures on the flanks. A lava flow was erupted from a vent NNE of the summit during 1801-1802.

Iliniza
The two glacier-covered peaks of Iliniza volcano are prominent landmarks west of the Interandean Valley. The smaller Iliniza Norte is a remnant of the main volcanic edifice located 1.8 km NNW of the younger Iliniza Sur, an andesitic-dacitic stratovolcano surrounded by thick pyroclastic-flow deposits. The edifice is mainly Pleistocene, though the Tishigcuchi (Rasuyacu) lava dome on the S flank was active during the Holocene. Iliniza itself, which is substantially eroded, may also have had relatively young eruptions (Hall, 1987, pers. comm.). A lava dome forms the summit of Iliniza Sur, and two more lava domes are found on the southern and NE flanks of the complex.

Sumaco
The forested Sumaco stratovolcano rises above the jungles of the western Amazon basin, east of Antisana volcano, and occupies an isolated position far to the east of the main Andes volcanic axis. Constructed over Cretaceous sedimentary rocks, it forms a relatively symmetrical cone in an area of heavy rainfall and erosion. Sumaco has produced alkaline tephritic, basanitic, and phonolitic rocks distinct from those of the main Andean chain. The volcano has a broad summit crater, 300 x 400 m wide, containing a central cone. Reports of historical eruptions are somewhat ambiguous; an eruption is inferred in the 18th or early-19th century on the basis of changes in crater morphology.

Cotopaxi
The symmetrical, glacier-covered, Cotopaxi stratovolcano is Ecuador's most well-known volcano and one of its most active. The steep-sided cone is capped by nested summit craters, the largest of which is about 550 x 800 m in diameter. Deep valleys scoured by lahars radiate from the summit of the andesitic volcano, and large andesitic lava flows extend to its base. The modern edifice has been constructed since a major collapse sometime prior to about 5,000 years ago. Pyroclastic flows (often confused in historical accounts with lava flows) have accompanied many explosive eruptions, and lahars have frequently devastated adjacent valleys. Strong eruptions took place in 1744, 1768, and 1877. Pyroclastic flows descended all sides of the volcano in 1877, and lahars traveled more than 100 km into the Pacific Ocean and western Amazon basin. Smaller eruptions have been frequent since that time.

Quilotoa
Quilotoa is a truncated, dacitic cone in the Western Cordillera of Ecuador, 35 km WNW of the city of Latacunga, that contains a 3-km-wide caldera with steep-sided walls that rise 400 m above the surface of 240-m-deep caldera lake. Multiple lava domes are present along the caldera's perimeter. This small volcano has produced eight major explosive eruptions during the past 200,000 years. Its most recent major eruption about 800 radiocarbon years ago produced voluminous pyroclastic flows, lahars that reached the Pacific Ocean, and one of the largest airfall-tephra deposits of the northern Andes. Formation of the caldera was followed by extrusion of a small lava dome. Reports of observed eruptions from the caldera lake are somewhat ambiguous. Fumaroles are present on the lake floor and hot springs occur on the E flank.

Chimborazo
Glacier-clad Chimborazo, Ecuador's highest volcano, anchors the southern end of the country's "Avenue of Volcanoes" 30 km NW of the city of Riobamba. The dominantly andesitic-to-dacitic structure is mostly of Pliocene-to-Pleistocene age. The volcano collapsed about 35,000 years ago, producing a major debris avalanche, whose deposits underlie Riobamba and temporarily dammed the R�o Chambo, producing an ephemeral lake. Subsequent mainly been andesitic activity constructed three edifices along an E-W line, the youngest and westernmost of which forms the current summit. Although activity was at one time thought to have ceased during the very latest Pleistocene, recent work indicates that it erupted more than a half dozen times during the Holocene, producing pyroclastic surges that reached down to 3,800 m elevation.

Licto
Landform: Minor (Basaltic)
The Licto group of scoria cones lies along the R�o Chambo ~25 km SE of the city of Riobamba and just north of the town of Licto. These three basaltic andesite to andesitic cones form the southernmost area of Quaternary volcanism in the Interandean valley of Ecuador. The Cerro Tulabug cone is the largest, with Loma Bellavista ~2 km SE and Licto, the smallest, ~1 km down the WNW flank. The group was considered to be of late Pleistocene or Holocene age (Hall, 1987, pers. comm; Eissen, 2006, pers. comm.) based on the relatively youthful morphology of the cones.

Tungurahua
Tungurahua, a steep-sided andesitic-dacitic stratovolcano that towers more than 3 km above its northern base, is one of Ecuador's most active volcanoes. Three major edifices have been sequentially constructed since the mid-Pleistocene over a basement of metamorphic rocks. Tungurahua II was built within the past 14,000 years following the collapse of the initial edifice. Tungurahua II collapsed about 3,000 years ago and produced a large debris-avalanche deposit to the west. The modern glacier-capped stratovolcano (Tungurahua III) was constructed within the landslide scarp. Historical eruptions have all originated from the summit crater, accompanied by strong explosions and sometimes by pyroclastic flows and lava flows that reached populated areas at the volcano's base. Prior to a long-term eruption beginning in 1999 that caused the temporary evacuation of the city of Ba�os at the foot of the volcano, the last major eruption had occurred from 1916 to 1918, although minor activity continued until 1925.

Sangay
The isolated Sangay volcano, located east of the Andean crest, is the southernmost of Ecuador's volcanoes and its most active. The steep-sided, glacier-covered, dominantly andesitic volcano grew within the open calderas of two previous edifices which were destroyed by collapse to the east, producing large debris avalanches that reached the Amazonian lowlands. The modern edifice dates back to at least 14,000 years ago. It towers above the tropical jungle on the east side; on the other sides flat plains of ash have been eroded by heavy rains into steep-walled canyons up to 600 m deep. The earliest report of an eruption was in 1628. Almost continuous eruptions were reported from 1728 until 1916, and again from 1934 to the present. The almost constant activity has caused frequent changes to the morphology of the summit crater complex.

Middle America-Caribbean Volcanic Regions

Lesser Antilles Volcanic Arc

Saba
Netherlands
Lesser Antilles Volcanic Arc
Saba, the northernmost active volcano of the West Indies, is a 5-km-diameter island forming the upper half of a large stratovolcano that rises 1,500 m above the sea floor. Its eruptive history is characterized by the emplacement of lava domes and associated pyroclastic flows. The summit, known as Mount Scenery (or The Mountain), is a Holocene lava dome that overtops a major collapse scarp that formed about 100,000 years ago. Flank domes were constructed on the SW, SE, E, and NE sides of the island near the coast. A large andesitic lava flow entered the sea on the NE flank, forming the Flat Point Peninsula. The village of The Bottom overlies pyroclastic-surge deposits that contain European pottery fragments and were radiocarbon dated at 280 +/- 80 years before present. The village was settled in 1640 CE on grassy meadows on the volcano's flanks reflecting initial vegetation recovery following destruction of tropical rainforests by pyroclastic flows and surges. Lava dome growth may also have occurred during this SW-flank eruption.

The Quill
Netherlands
Lesser Antilles Volcanic Arc
The Quill is a large dominantly andesitic stratovolcano that forms the SE end of St. Eustatius (Statia) Island. It was formed about 32,000-22,000 years ago by rhyolitic eruptions on a shallow-water limestone bank 3 km offshore of a 200,000 year old volcanic center exposed at the NW end of the island. The interaction of rhyolitic magma with seawater produced pyroclastic-surge deposits, rich in limestone fragments, that joined the two islands and cover the entire slopes of the volcano. The surges also swept across the older island and incorporated carbonized plant remains, shell fragments, and remains of fossil hermit crabs. A likely cryptodome tilted up limestones at Sugarloaf on the southern coast. A steep-sided crater, 760 m wide and more than 300 m deep, caps The Quill; a notch on the western crater rim has directed the youngest pyroclastic flows towards the island's capital, Orangestad. The last dated eruption produced pyroclastic flows about 1,600 years ago.

Liamuiga
Saint Kitts and Nevis
Mount Liamuiga volcano, comprising the NW end of St. Kitts Island, contains a steep-walled, 1-km-wide summit crater, which contained a shallow lake until 1959. Two lava domes are located on the upper W flank, and intrusion of a 3rd dome, Brimstone Hill, on the lower SW flank uplifted a Pleistocene limestone block. Liamuiga, sometimes referred to as Mount Misery, is the youngest of three NW-migrating volcanic centers on St. Kitts. Its most recent major eruptions less than 2,000 years ago produced pyroclastic flows and mudflows whose deposits underlie populated coastal areas. Reports of possible eruptions in 1692 and 1843 are considered uncertain. An earthquake swarm from late 1988 to early 1989 caused small landslides in the summit crater; another earthquake swarm took place in 1999-2000. Active fumaroles are found in the summit crater.

Nevis Peak
Saint Kitts and Nevis
The conical island of Nevis, lying across a narrow channel from St. Kitts (St. Christopher) Island, is a composite cone with overlapping summit craters. An unnamed lava dome is located NE of the rims of the two craters. The high point of the island is located on the outer crater rim. The inner crater truncates the W rim of the earlier crater and is widely breached on the west side. A small lava dome was emplaced within the inner crater in recent pre-Columbian time, and pyroclastic flows and mudflows were deposited on the lower slopes of the cone. Four lava domes were constructed on the flanks: Madden's Mount (NE flank), Butlers Mountain (E flank), Mount Lily (NW coast), and Saddle mountain (S coast). No historical eruptions are known, and the youngest dated eruption was about 100,000 years ago. Active fumaroles and hot springs are found on the island (the most recent of these formed in 1953 and remains active), and seismic swarms have occurred on several occasions during the 20th century.

Soufriere Hills
The complex, dominantly andesitic Soufri�re Hills volcano occupies the southern half of the island of Montserrat. The summit area consists primarily of a series of lava domes emplaced along an ESE-trending zone. The volcano is flanked by Pleistocene complexes to the north and south. English's Crater, a 1-km-wide crater breached widely to the east by edifice collapse, was formed about 2000 years ago as a result of the youngest of several collapse events producing submarine debris-avalanche deposits. Block-and-ash flow and surge deposits associated with dome growth predominate in flank deposits, including those from an eruption that likely preceded the 1632 CE settlement of the island, allowing cultivation on recently devegetated land to near the summit. Non-eruptive seismic swarms occurred at 30-year intervals in the 20th century, but no historical eruptions were recorded until 1995. Long-term small-to-moderate ash eruptions beginning in that year were later accompanied by lava-dome growth and pyroclastic flows that forced evacuation of the southern half of the island and ultimately destroyed the capital city of Plymouth, causing major social and economic disruption.

Soufriere Guadeloupe
France
La Soufri�re de la Guadeloupe volcano occupies the southern end of Basse-Terre, the western half of the island of Guadeloupe. Construction of the Grand D�couverte volcano about 200,000 years ago was followed a Plinian eruption and caldera formation about 100,000 years later, and then by construction of the Carmicha�l volcano within the caldera. Two episodes of edifice collapse and associated large debris avalanches formed the Carmicha�l and Amic craters about 11,500 and 3,100 years ago, respectively. The present volcano subsequently grew within the Amic crater. The summit consists of a flat-topped lava dome, and several other domes occur on the southern flanks. Six phreatic explosive eruptions since 1690 opened radial fractures across the summit lava dome. The phreatic eruptions in 1976-77 caused severe economic disruption when Basse-Terre, the island's capital city immediately below the volcano, was evacuated.

Morne aux Diables
Dominica
The lava dome complex of Morne aux Diables (Devils Peak) forms the northern tip of the island of Dominica. Several nested craters and a 90-m-high, 335-m-wide lava dome are located within a larger 1.2-km-wide crater. The complex overall includes seven andesitic lava domes with a central depression where a cold soufriere is located. A chain of lava domes, two of which form a peninsula on the SW flank, form an E-W belt across the S flank. Bathymetry shows a double-peaked lava dome off the northern coast, truncated by a 4-km-long fault-bounded cliff. No eruptions have been recorded, but the most recent lava domes may be late Pleistocene to Holocene. The youngest (NW) summit crater contains an active thermal area with bubbling springs. Severe earthquake swarms in 1841 and 1893 were associated with either Morne aux Diables or Morne Diablotins to the south. Shallow volcano-tectonic seismicity was detected 2009-2010.

Morne Diablotins
Dominica
Morne Diablotins, in northern Dominica, is the largest and highest on the island. A complex of at least five coalescing lava domes forms the broad summit, and other domes are found to the SE. Pyroclastic-flow deposits emplaced ~22,000-40,000 years ago, known as the Grand Savanne Ignimbrite, extend in five radial lobes around the volcano as far as the coast. Pre-Columbian block-and-ash flow aprons on the NW flank are relatively unmodified by erosion. No recent eruptions are known, although numerous hot springs, both onshore and submarine, are found near Glanvillia, on the NW flank. Severe earthquake swarms in 1841 and 1893 originated either from Morne Diablotins or Morne aux Diables to the N.

Morne Watt
Dominica
Morne Watt (Watt Mountain) volcano lies SE of the Trois Piton/Micotrin lava-dome complex in SE Dominica, E of the capital city of Roseau. The two best-known volcanic features on Dominica, the Valley of Desolation and the Boiling Lake thermal areas, lie on the flank; both are major tourist attractions within the national park. Morne Anglais stratovolcano lies 4 km SW of Morne Watt. Soufri�re Hills volcano, with dated pyroclastic-flow producing eruptions ~10,000 years ago, lies 3 km E. A major eruption from Morne Watt producing pyroclastic flows occurred ~1300 years ago. A moderately large phreatic explosion took place at the Valley of Desolation thermal area NE of Morne Watt in 1880, when ash fell over a 4-km-wide sector at the coast, 10 km from the vent. A smaller phreatic explosion occurred in July 1997, when ashfall was confined to the Valley of Desolation area. These mark the only known historical eruptions on the island.

Morne Trois Pitons
Two large lava-domes complexes, Morne Trois Pitons and Micotrin, rise NE of the capital city of Roseau in central Dominica. Micotrin (Morne Macaque) dome lies immediately south of the larger 1387-m-high Morne Trois Pitons; small lakes are located in the saddle between the two domes and on the eastern flank of Micotrin. The domes are located along the margin of a large semi-circular depression on the western coast of central Dominica, whose origin has been variously attributed to caldera collapse, gravity sliding, or the juxtaposition of several independent volcanic centers. The area is the source of the voluminous, mostly submarine Roseau Tuff, a thick sequence of pyroclastic flows erupted between about 40,000 and 25,000 years ago. It is considered to have originated from calderas at Morne Trois Piton and Wotten Waven, the latter an elliptical NE-SW-trending caldera containing Microtin at its NE end. Explosive eruptions at the Trois Piton-Microtin complex producing pyroclastic flows continued into the late Pleistocene and Holocene. The youngest dated eruption took place about 800 CE, but other smaller eruptions may have occurred since.

Morne Plat Pays
The Morne Plat Pays volcanic complex occupies the southern tip of the island of Dominica and has been active throughout the Holocene. An arcuate caldera that formed about 39,000 years ago as a result of a major explosive eruption and flank collapse is open to Soufri�re Bay on the west. This depression cuts the SW side of Morne Plat Pays stratovolcano and extends to the southern tip of Dominica. At least a dozen small post-caldera lava domes were emplaced within and outside this depression, including one submarine dome south of Scotts Head. The latest dated eruptions occurred from the Morne Patates lava dome about 1270 CE, although younger deposits have not yet been dated. The complex is the site of extensive fumarolic activity, and at least ten swarms of small-magnitude earthquakes, none associated with eruptive activity, have occurred since 1765 at Morne Patates.

Pelee
France
Montagne Pel�e forms the northern end of the island of Martinique. Three major edifice failures since the late Pleistocene, the last about 9,000 years ago, have left large scarps open to the SW inside which the modern volcano has been constructed. More than 20 large eruptions have occurred here during the past 5,000 years. Extensive pyroclastic-flow deposits, incised by steep-walled ravines, mantle the slopes of the volcano. The l'Etang Sec summit crater is filled by two lava domes emplaced during the 1902 and 1929 eruptions. Moderate phreatic or phreatomagmatic eruptions in the Upper Rivi�re Claire valley were recorded in 1792 and 1851-52. The catastrophic 1902 eruption, which destroyed the city of St. Pierre, became the type-example of Pelean eruptions and marked the onset of modern volcanological studies of pyroclastic density currents.

Qualibou
Saint Lucia
The Qualibou caldera on the SW side of St. Lucia provides the setting for the Pitons, two steep-sided pre-caldera lava domes that form one of the scenic highlights of the West Indies. The 3.5 x 5 km caldera formed about 32-39,000 years ago in conjunction with the eruption of the Choiseul Tuff. A larger depression has been interpreted to have formed by edifice collapse, and bathymetry has identified large submarine debris-avalanche deposits off the west coast of the island. This depression and associated volcanic vents and geothermal areas is also known as the Soufri�re volcanic centre. Numerous resurgent post-caldera lava domes fill the caldera floor. The latest dated magmatic eruptions took place about 20,000 years ago, but younger undated lava domes and explosion craters are present. The only known Holocene eruptive activity was a minor phreatic eruption in the Sulfur Springs geothermal area in 1766 CE that ejected a thin ash layer over a wide area. A volcanic earthquake swarm centered 6 km ESE of the caldera occurred in 1990.

Soufriere St. Vincent
Saint Vincent and the Grenadines
Soufri�re St. Vincent is the northernmost and youngest volcano on St. Vincent Island. The NE rim of the 1.6-km wide summit crater is cut by a crater formed in 1812. The crater itself lies on the SW margin of a larger 2.2-km-wide caldera, which is breached widely to the SW as a result of slope failure. Frequent explosive eruptions after about 4,300 years ago produced pyroclastic deposits of the Yellow Tephra Formation, which cover much of the island. The first historical eruption took place in 1718; it and the 1812 eruption produced major explosions. Much of the northern end of the island was devastated by a major eruption in 1902 that coincided with the catastrophic Mont Pel�e eruption on Martinique. A lava dome was emplaced in the summit crater in 1971 during a strictly effusive eruption, forming an island within a lake that filled the crater. A series of explosive eruptions in 1979 destroyed the 1971 dome and ejected the lake; a new dome was then built.

Kick 'em Jenny
Grenada
Elevation: -185 m
Kick 'em Jenny, an active submarine volcano 8 km off the N shore of Grenada, rises 1,300 m from the sea floor. Recent bathymetric surveys have shown evidence for a major arcuate collapse structure, which was the source of a submarine debris avalanche that traveled more than 15 km W. Bathymetry also revealed another submarine cone to the SE, Kick 'em Jack, and submarine lava domes to its S. These and subaerial tuff rings and lava flows at Ile de Caille and other nearby islands may represent a single large volcanic complex. Numerous eruptions have occurred since 1939, mostly documented by acoustic signals. Prior to the 1939 eruption, when an eruption cloud rose 275 m above the ocean and was witnessed by a large number of people in northern Grenada, there had been no written mention of the volcano. Eruptions have involved both explosive activity and the quiet extrusion of lava flows and lava domes in the summit crater; deep rumbling noises have sometimes been heard onshore. Recent eruptions have modified the morphology of the summit crater.

St. Catherine
Grenada
The island of Grenada is composed of five Pliocene-to-Pleistocene volcanic centers, the youngest and highest of which is Mount St. Catherine on the northern end of the island. A complex of lava domes is located within a crater breached to the east at the summit. Pyroclastic-flow deposits extend NW from the extensively weathered volcano. The most recent activity on Grenada originated from a group of young maars, tuff rings, and scoria cones that extend SSW-NNE across the length of the 30-km-long island. Kick 'em Jenny, the historically active submarine volcano 8 km N of Grenada, is listed separately in this compilation along with adjacent submarine and subaerial cones that may represent a single volcanic complex. The most recent eruption, along a NE-SW-trending fault cutting across the island, produced a scoria cone near Radix village that could be less than 1,000 years old. Hot springs and fumaroles are present at several locations.

Central America Volcanic Arc

Tacana
Mexico-Guatemala
Central America Volcanic Arc
Tacan� is a 4064-m-high composite stratovolcano that straddles the M�xico/Guatemala border at the NW end of the Central American volcanic belt. The volcano rises 1800 m above deeply dissected plutonic and metamorphic terrain. Three large calderas breached to the south, and the elongated summit region is dominated by a series of lava domes intruded along a NE-SW trend. Volcanism has migrated to the SW, and a small adventive lava dome is located in the crater of the youngest volcano, San Antonio, on the upper SW flank. Viscous lava flow complexes are found on the north and south flanks, and lobate lahar deposits fill many valleys. Radial drainages on the Guatemalan side are deflected by surrounding mountains into the Pacific coastal plain on the SW side of the volcano. Historical activity has been restricted to mild phreatic eruptions, but more powerful explosive activity, including the production of pyroclastic flows, has occurred as recently as about 1950 years ago.

Tajumulco
Guatemala
Central America Volcanic Arc
Tajumulco is Guatemala's highest peak and the highest volcano in Central America. Two summits, one with a 50-70 m wide crater, lie along a NW-SE line. A lava flow from the ~4200-m-high NW summit traveled down a deep valley on the NW flank. The andesitic-dacitic volcano was constructed over the NW end of a large arcuate SW-facing escarpment of uncertain origin. Tajumulco has had several unconfirmed reports of historical eruptions. Sapper (1917) considered it to have erupted during historical time, but without accurate dates. The volcano was reported to eject many rocks, destroying houses on 24 October 1765, but this may have been a rock avalanche. Juarros reported some eruptions before 1808, and there are unlikely reports of eruptions in 1821 (or 1822), 1863, and 1893 (Incer 1988, unpublished manuscript).

Santa Maria
Guatemala
Symmetrical, forest-covered Santa Mar�a volcano is part of a chain of large stratovolcanoes that rise above the Pacific coastal plain of Guatemala. The sharp-topped, conical profile is cut on the SW flank by a 1.5-km-wide crater. The oval-shaped crater extends from just below the summit to the lower flank, and was formed during a catastrophic eruption in 1902. The renowned Plinian eruption of 1902 that devastated much of SW Guatemala followed a long repose period after construction of the large basaltic andesite stratovolcano. The massive dacitic Santiaguito lava-dome complex has been growing at the base of the 1902 crater since 1922. Compound dome growth at Santiaguito has occurred episodically from four vents, with activity progressing E towards the most recent, Caliente. Dome growth has been accompanied by almost continuous minor explosions, with periodic lava extrusion, larger explosions, pyroclastic flows, and lahars.

Almolonga
Guatemala
Volc�n de Almolonga is an andesitic stratovolcano with a 3.3-km-wide late-Pleistocene central caldera that is located along the Zunil fault zone. The caldera is surrounded by a ring-dike configuration of dacitic and rhyolitic lava domes. The youngest and only historically active dome complex is Cerro Quemado (whose name means Burned Peak), located immediately south of Guatemala's second largest city, Quezaltenango. About 1200 radiocarbon years ago, part of the andesitic-to-dacitic Cerro Quemado dome collapsed, producing a debris avalanche and an associated lateral explosion that swept across the valley to the west as far as the flanks of Siete Orejas volcano. The latest eruption in 1818 produced a blocky 2.5-km-long lava flow. Hot springs are located on the northern and eastern flanks of Cerro Quemado, and the Zun�l geothermal field, the site of a geothermal exploration project, lies on the SE flank of Cerro Quemado.

Atitlan
Volc�n Atitl�n is one of several conical stratovolcanoes in the Guatemalan highlands. Along with Tolim�n to the north, it forms a dramatic backdrop to Lake Atitl�n. The summit directly overlies the inferred margin of the Pleistocene Atitl�n III caldera and is the highest of three large post-caldera stratovolcanoes constructed near the southern caldera rim. The volcano consequently post-dates the eruption of the voluminous, roughly 85,000-year-old rhyolitic Los Chocoyos tephra associated with formation of the Atitl�n III caldera. The andesitic Volc�n Atitl�n is younger than Tolim�n 3 km away on the N flank, although their earlier activity overlapped. In contrast to Tolim�n, Atitl�n displays a thick pyroclastic cover. The northern side of the volcano is wooded to near the summit, whereas the upper 1,000 m of the southern slopes are unvegetated. Predominantly explosive eruptions have been recorded since the 15th century.

Toliman
Volc�n Tolim�n is a large andesitic stratovolcano that rises above the S shore of Lake Atitl�n. It was constructed within the Pleistocene Atitl�n III caldera, near its inferred southern margin. A shallow elliptical crater truncates the summit, and a subsidiary peak to the SSW also has a shallow crater. In contrast to the tephra-covered surface of Volc�n Atitl�n immediately to the S, the surface is covered by thick lava flows. Many of the flows were erupted from vents on the flanks and form a highly irregular shoreline on the S side of Lake Atitl�n. A lava flow that entered Lake Atitl�n from the Cerro de Oro lava dome on the N flank was considered by Newhall et al. (1987) to be less than a few thousand years old based on the thickness of sediment accumulated on the sublacustral part of the flow.

Acatenango
Acatenango is ~15 km SW of the city of Antigua, Guatemala, and 3 km N of Fuego volcano. Both edifices were constructed during three eruptive periods post-dating the roughly 85,000-year-old Los Chocoyos tephra from Atitl�n caldera. An older Acatenango edifice collapsed to the south sometime prior to 43,000 years ago, forming La Democracia debris-avalanche deposit, which covers a wide area of the Pacific coastal plain. Construction of the Yepocapa cone, ~900 m N of the main crater, was completed about 20,000 years ago, after which growth of the larger southern cone, Pico Central (also known as Pico Mayor), began. The first well-documented eruptions took place from 1924 to 1927 CE. Francisco Vasquez, writing in 1690 CE, noted that in 1661 a volcano that lay aside of Fuego "opened a smoking mouth and still gives off smoke from another three, but without noise."

Fuego
Volc�n Fuego, one of Central America's most active volcanoes, is also one of three large stratovolcanoes overlooking Guatemala's former capital, Antigua. The scarp of an older edifice, Meseta, lies between Fuego and Acatenango to the north. Construction of Meseta dates back to about 230,000 years and continued until the late Pleistocene or early Holocene. Collapse of Meseta may have produced the massive Escuintla debris-avalanche deposit, which extends about 50 km onto the Pacific coastal plain. Growth of the modern Fuego volcano followed, continuing the southward migration of volcanism that began at the mostly andesitic Acatenango. Eruptions at Fuego have become more mafic with time, and most historical activity has produced basaltic rocks. Frequent vigorous eruptions have been recorded since the onset of the Spanish era in 1524, and have produced major ashfalls, along with occasional pyroclastic flows and lava flows.

Agua
The symmetrical, forested Volc�n de Agua stratovolcano forms an impressive backdrop to the city of Antigua, Guatemala, opposite from the Fuego and Acatenango volcanoes. The isolated basaltic andesite to andesite edifice makes it a prominent landmark visible from all directions. A circular 280-m-wide crater is breached on the NNE, six small pit craters are located on the NW flank, and two small cones lie on the S flank. No dated Holocene tephra deposits or recorded eruptions are known from Agua, but its name (the water volcano) originates from a devastating mudflow on 11 September 1541. The mudflow destroyed Ciudad Vieja, the first Guatemalan capital city established by the Spanish Conquistadors, prompting the establishment of a new capital at nearby Antigua.

Cuilapa-Barbarena
The Cuilapa-Barbarena volcanic field contains approximately 70 Quaternary cinder cones, generally less than 100 m high. Many of the mostly basaltic cones are located along the strike of the major regional Jalpatagua fault, which extends SE from Guatemala City, north of the chain of stratovolcanoes stretching across Guatemala. The cones were erupted from fracture systems related to the intersection of the Jalpatagua fault with the southern and western margins of the Miocene Santa Rosa de Lima caldera, and overlie pyroclastic-flow deposits from Amatitl�n caldera to the NW. The age of the most recent eruptions is not known, although the youngest cones post-date the last phase of eruptive activity at Tecuamburro volcano and could be Holocene (Reynolds, 1987). Williams (1960) considered the most recent eruptions to have occurred within the last few thousand years.

Pacaya
Eruptions from Pacaya are frequently visible from Guatemala City, the nation's capital. This complex basaltic volcano was constructed just outside the southern topographic rim of the 14 x 16 km Pleistocene Amatitl�n caldera. A cluster of dacitic lava domes occupies the southern caldera floor. The post-caldera Pacaya massif includes the older Pacaya Viejo and Cerro Grande stratovolcanoes and the currently active Mackenney stratovolcano. Collapse of Pacaya Viejo between 600 and 1,500 years ago produced a debris-avalanche deposit that extends 25 km onto the Pacific coastal plain and left an arcuate scarp inside which the modern Pacaya volcano (Mackenney cone) grew. The NW-flank Cerro Chino crater was last active in the 19th century. During the past several decades, activity has consisted of frequent Strombolian eruptions with intermittent lava flow extrusion that has partially filled in the caldera moat and covered the flanks of Mackenney cone, punctuated by occasional larger explosive eruptions that partially destroy the summit.

Jumaytepeque
Jumaytepeque is a small basaltic stratovolcano located NNE of the city of Cuilapa, north of the major NW-SE-trending Jalpatagua fault that cuts diagonally across SE Guatemala. The volcano was constructed near the SE rim of the large Miocene Santa Rosa de Lima caldera. It is not overlain by a ca. 23,000-year-old tephra unit from nearby Ayarza caldera, and its erosionally unmodified form suggests that Holocene activity is possible (Reynolds 2007, pers. comm.). Two older cinder cones to the north are covered with Ayarza tephra.

Tecuamburro
Tecuamburro is a small forested stratovolcano, or large lava-dome complex, about 50 km ESE of Guatemala City and 20 km S of the main volcanic chain. An older andesitic stratovolcano, Miraflores, was formed about 100,000 years ago. Tecuamburro and other lava domes were constructed during the late Pleistocene or early Holocene within an open E-facing scarp produced by structural failure of Miraflores more than 38,000 years ago. One of the largest of these domes, Pe�a Blanca, overtops the NW rim of the collapse scarp. Two nested craters, the larger of which is Chupadero, lie at the NW end of the complex. The smaller crater is a phreatic tuff ring, Laguna Ixpaco, that was formed about 2,900 years ago during the latest dated eruption of the complex. Numerous fumaroles, hot springs, and boiling mud pots are found in the area around the acidic lake.

Moyuta
Moyuta is the easternmost of a chain of large stratovolcanoes extending along the volcanic front of Guatemala. Like Tecuamburro volcano, it is offset about 20 km S of the main volcanic chain and lies south of the Jalpatagua Fault, overlying the southern boundary of the Jalpatagua Graben. The volcano is capped by a cluster of at least three forested, steep-sided, coalescing andesitic lava domes that from some distant perspectives give the summit a flat-topped appearance. Numerous cinder cones in various stages of erosion are located on the flanks of the complex. The age of the latest eruption is not known, although the summit domes were considered to have been emplaced in relatively recent times (Williams et al., 1964). Small fumaroles are found on the N and S flanks, and hot springs are located near Azulco at the NE base and along rivers on the SE side.

Flores
Volc�n de Flores is one of the largest of a cluster of small stratovolcanoes located in SE Guatemala behind the volcanic front. Also known as Volc�n Amayo, it lies ~10 km W of the city of Jutiapa, at the SW end of the SE Guatemala volcanic platform. The summit rises ~600 m above a basement of Cretaceous and Tertiary sedimentary rocks and contains a shallow crater breached on its eastern side. Satellitic cones occur at the southern and eastern base of the dominantly basaltic volcano, and youthful lava flows occur at the NE base, near El Aguacite.

Tahual
Deeply dissected Volc�n Tahual rises ~700 m above plains S of the town of Monjas. The summit of the forested stratovolcano is cut by a broad erosional crater that extends to the base of the volcano and is narrowly breached to the NE. A Holocene pyroclastic cone near the NE base fed a short basaltic lava flow (Williams et al., 1964). The scenic lake-filled Laguna de Hoyo lies to the N. This steep-walled crater and the NE-flank cinder cone lie along faults bordering a graben that extends across the eastern base of the volcano to neighboring Retana caldera on the SE.

Cerro Santiago
A cluster of cinder cones and low shield volcanoes surrounds the city of Jutiapa in SE Guatemala. The most prominent is Cerro Santiago, one of two coalescing cinder cones capping a shield SE of the city. Youthful flows from the two Los Cerritos cones NE of Jutiapa cross the Interamerican Highway. Volc�n Culma forms a steep-sided basaltic lava mound immediately E of the city. To the W lies Cerro Gordo (referred to as Amayo by Williams et al., 1964), a craterless cinder cone surrounded by basaltic lava flows. It is one of several cinder cones to have produced lava flows that cover the area between Jutiapa and Tertiary volcanic hills to the S.

Suchitan
The summit of the andesitic-to-basaltic Volc�n Suchit�n stratovolcano, NE of the city of Jutiapa, is elongated N-S. Several large canyons cut the slopes of the dominantly andesitic edifice. A large cone, Cerro Mataltepe, is located on the upper N flank; two smaller cones are located on the lower N flank. Two Holocene basaltic lava flows are also present on the N and NW flanks (Williams et al., 1964), and many flank vents are basaltic. The volcano was constructed immediately E of the 5-km-wide basaltic-to-dacitic Retana caldera, formed in part in association with the eruption of a dacitic pumice deposit. Steep walls 60-250 m high rise above the flat caldera floor. One of the latest basaltic lava flows went through a low notch in the eastern caldera rim. Several lava cones and a maar are located along a N-S line N of Retana caldera. A reported eruption in 1469 CE is considered to have actually been from Atitl�n volcano in the Guatemalan highlands.

Chingo
Guatemala-El Salvador
Volc�n Chingo is a symmetrical stratovolcano that straddles the Guatemala/El Salvador border. A shallow, oval-shaped summit crater is breached on the W side. Other small stratovolcanoes and cinder cones are located on both sides of the volcano along a major N-S-trending fault. Youthful cones, such as Cerro de Olla, lie across the Salvadorian border to the S. To the N in Guatemala, Volc�n las Viboras, a cinder cone that caps a basaltic shield volcano, is the most prominent of several fault-controlled cones near Laguna Atescatempo. Flank fissures have fed many youthful lava flows, particularly on the W flank of Chingo and the N flank of Volc�n las Viboras.

Ixtepeque
Ixtepeque volcano, which takes its name from the Aztec word for obsidian, is perhaps the largest obsidian field in North America. A 4 x 5 km rhyolitic obsidian lava field was erupted within the Ipala graben from a craterless vent along a NE-trending fissure that passes through adjacent rhyolitic lava domes and basaltic cinder cones. Obsidian from Ixtepeque has shown up at archaeological sites across Central America. Flat-lying pumice beds produced by explosive eruptions preceding lava effusion are found locally around the volcano. Other obsidian flows originated from lava domes NE of Ixtepeque. These rhyolitic vents are interspersed with basaltic cinder cones and lava flows. Laguna de Obrajuelo is a complex cone cut by a large crater more than a km in diameter. Initial basaltic eruptions were followed by the extrusion of obsidian flows and the eruption of rhyolitic pumice that were considered by Williams et al. (1964) to be only a few thousand years old.

Cerro Singuil
El Salvador
The most prominent feature of a volcanic field in the interior valley of El Salvador near the Guatemalan border SE of Volc�n Chingo is Cerro Sing�il. This scoria cone, also known as El Cerron, has a well-preserved summit crater and is part of a group of cinder cones and explosion craters mapped as Holocene in age by Weber and Wiesemann (1978). A young basaltic lava flow extends to the NNE down the valley of the Quebada La Presa, the headwaters of the R�o Guajoyo. The volcanic field includes a line of three NNE-trending explosion craters N of the city of Chalchuapa, the highest of which is Cerro Tablas.

Apaneca Range
El Salvador
The Apaneca Range (also known as the Cuyanausul Range) consists of a group of basaltic-to-andesitic Pleistocene and Holocene stratovolcanoes in western El Salvador between the Santa Ana complex and the Guatemala border. The Pleistocene dacitic-rhyolitic Concepci�n de Ataco caldera (5 x 3.5 km) lies at the W end of the complex, along with post-caldera late-Pleistocene to Holocene andesitic-dacitic lava domes. The post-caldera cones of Cerro el Aguila (the highest peak of the complex) and Cerro los Naranjos at the E end of the chain were mapped as Holocene by Weber and Weisemann (1978). Young craters on the basaltic Cerro Laguna Verde stratovolcano may also have been active during the Holocene. Numerous fumarole fields are located on the N flank of the range, and the Ahuachap�n geothermal field has been producing since 1975. Several small hydrothermal explosions have occurred in historical time, including one in October 1990 at the Agua Shuca thermal area in which 26 people were killed.

Santa Ana
El Salvador
Santa Ana (also known as Ilamatepec), is a massive, dominantly andesitic-to-trachyandesitic stratovolcano in El Salvador immediately W of Coatepeque Caldera. Collapse during the late Pleistocene produced a voluminous debris avalanche that swept into the Pacific Ocean, forming the Acajutla Peninsula. Reconstruction of the volcano subsequently filled most of the collapse scarp. The broad summit is cut by several crescentic craters, and a series of vents and cones have formed along a 20-km-long fissure system that extends from near the town of Chalchuapa NNW of the volcano to the San Marcelino and Cerro la Olla cinder cones on the SE flank. Small to moderate explosive eruptions from both summit and flank vents have been documented since the 16th century. The San Marcelino cinder cone on the SE flank produced a lava flow in 1722 that traveled 13 km E.

Izalco
Volc�n de Izalco began growing in 1770 CE on the southern flank of Santa Ana volcano, eventually building a steep 650-m-high stratovolcano truncated by a 250-m-wide summit crater. Frequent Strombolian eruptions during the two centuries prior to the cessation of activity in 1966 provided a night-time beacon for ships, causing it to be known as El Faro, the "Lighthouse of the Pacific." The dominantly basaltic andesite tephra and lava flows are geochemically distinct from those of both Santa Ana and its fissure-controlled flank vents. Lava flows have primarily erupted from flank vents, traveling as far as about 7 km south down the slopes of Santa Ana.

Coatepeque Caldera
Coatepeque is a 6.5 x 11.5 km collapse caldera ~50 km W of San Salvador that is largely occupied by a lake with hot springs near the margins. The height of the caldera rim increases on its W side, where it intersects the E flank of Santa Ana. The caldera was formed during a series of major rhyolitic explosive eruptions between ~72,000 and 51,000 years ago. Post-caldera eruptions included the formation of basaltic cinder cones and lava flows near the western margin of the caldera and the extrusion of rhyodacitic lava domes along a NE-SW line near the caldera lake margins. The highest dome forms Isla de Cabra, or Cerro Grande. The age of the domes is not known precisely, but the youngest dome, Cerro Pacho, was estimated to have formed less than 10,000 years ago. No verified eruptions have been recorded.

Cerro Cinotepeque
Cerro Cinotepeque is the largest and most prominent of a group of four pyroclastic cones mapped as Holocene by Weber and Weismann (1978) in low-lying areas on either side of the R�o Lempa, ~40 km N of San Salvador. Cinotepeque lies south of the river; Cerro Colorado, Cerro Santiago, and Cerro Mosquito lie immediately north of the river. Two additional cones are about 10 km farther north, just beyond the town of Nuevo Concepcion. A large group of small Pleistocene stratovolcanoes and pyroclastic cones constructed along NW-SE-trending faults is located west and south of Cinotepeque and west of Guazapa volcano.

San Salvador
The massive compound San Salvador volcano dominates the landscape W of El Salvador's capital city of San Salvador. The dominantly andesitic Boquer�n stratovolcano has grown within a 6-km-wide caldera whose rim is partially exposed at Picacho and Jabal� peaks, which themselves were formed by collapse of an older edifice about 40,000 years ago. The summit of Boquer�n is truncated by a steep-walled crater 1.5 km wide and ~500 m deep that formed during a major eruption around 800 years ago. It contained a crater lake prior to an eruption during 1917 that formed a small cinder cone on the crater floor; a major N-flank lava flow also erupted in this year. Three fracture zones that extend beyond the base of the volcano have been the locus for numerous flank eruptions, including two that formed maars on the WNW and SE sides. Most of the four historical eruptions recorded since the 16th century have originated from flank vents, including two in the 17th century from the NW-flank cone of El Play�n, during which explosions and a lava flow damaged inhabited areas.

Ilopango
The 8 x 11 km Ilopango caldera, filled by one of El Salvador's largest lakes, has a scalloped 150-500 m high rim. The caldera, which lies immediately east of the capital city of San Salvador, is strongly controlled by regional faults of the central Salvador graben. Four major dacitic-rhyolitic explosive eruptions during the late Pleistocene and Holocene produced pyroclastic-flow and pyroclastic-fall deposits that cover much of El Salvador. The latest collapse resulted from the massive 5th century CE Tierra Blanca Joven (TBJ) eruption, which produced widespread pyroclastic flows and devastated early Mayan cities. Post-caldera eruptions formed a series of glassy dacitic and andesitic lava domes within the lake and near its shore. The Islas Quemadas, a group of low islets in the center of the lake that mark the summit of a largely submerged lava dome, were formed during an eruption in 1879-80.

Taburete
Taburete volcano rises above the Pacific coastal plain E of the R�o Lempa at the SW end of a cluster of volcanoes between San Vincente and San Miguel volcanoes. Basaltic to basaltic andesite, it is elongated in a NW-SE direction and overlaps with Tecapa volcano to the NE. Its summit forms a prominent peak that rises above the southern crater rim. A well-preserved, 150-300 m deep summit crater has a low point on its eastern rim. A fairly recent lava flow descends the S flank (Williams and McBirney, 1955). Loma Pacha cone on the lower SE flank fed a thick lava flow that traveled 1 km SE. The age of the most recent eruption is not precisely known, and Weber and Wiesemann (1978) did not map its Holocene deposits.

San Vicente
San Vicente stratovolcano, also known as Chichontepec, is ~20 km SE of Lake Ilopango. The andesitic edifice with two summit peaks was constructed within the Pleistocene La Carbonera caldera, whose rim is visible only on its SW side. The N and S flanks are covered by lava flows from the central vent, but lava flows on the eastern side originated from a vent on the upper flank. Volcanism has continued into the Holocene, but the latest lava flows are covered by deposits from the major Tierra Blanca eruption from Ilopango around 450 CE. Reports of eruptions in 1643 CE and 1835 CE are false (Catalog of Active Volcanoes of the World; Sapper, 1917), but numerous hot springs and fumaroles are found on the N and W flanks.

Usulutan
Usulut�n volcano anchors the SE end of a cluster of basaltic to basaltic andesite stratovolcanoes between San Vicente and San Miguel volcanoes. The flanks of the forested volcano are dissected, but youthful lava flows are present on its southern flanks. The younger summit rocks of Usulut�n and the Cerro Nanzal pyroclastic cone on the lower SE flank were mapped as Holocene (Weber and Wiesemann, 1978). A broad 1.3-km-wide crater is breached to the E from the summit to its lower flank.

El Tigre
Cerro el Tigre is the highest, NE-most, and oldest of the cluster of coalescing basaltic to basaltic andesite Quaternary volcanoes between the R�o Lempa and San Miguel volcano. Its summit crater has been destroyed by erosion, and its flanks are deeply dissected. Two large NNW-trending valleys, parallel to other regional fissures, cross the volcano, which lies about 7 km SE of Tecapa volcano and a similar distance NE of Usulut�n volcano. Although the volcano itself is Pleistocene in age, two young cones on its flanks were mapped as Holocene by Weber and Wiesemann (1978). Cerro Oromontique and Cerro la Manita were erupted on the W and S flanks, respectively, along a NW-SE-trending fissure extending towards Tecapa.

Tecapa
Tecapa is a complex basaltic-to-andesitic stratovolcano at the NW end of a cluster of volcanoes E of the R�o Lempa between San Vicente and San Miguel volcanoes. The Berl�n caldera, whose rim is visible on the W side of the complex, was formed during the eruption of the Blanca-Rosa dacitic pumice in the late Pleistocene. Following caldera formation, the cones of Cerro Las Palmas, Cerro Pel�n, Tecapa-Laguna de Alegria, and Cerro Alegria were constructed along a WSW-ENE line. The crater of Tecapa-Laguna de Alegria contains a deep notch on the eastern rim and is filled by Laguna de Alegria crater lake. The volcanic complex currently displays fumarolic activity, and a producing geothermal plant is located at the Berl�n geothermal field.

Chinameca
The small Chinameca stratovolcano (also known as El Pacayal) lies across a low saddle about 7 km NW of the large San Miguel volcano. A 2-km-wide, steep-sided caldera, Laguna Seca el Pacayal, truncates the summit, whose flanks are covered with coffee plantations. The Holocene cone of Cerro el Limbo on the W flank rises above the level of the caldera rim, and a Holocene lava flow extends from a NNW-flank vent into the lowlands to the N beyond the town of Chinameca (Weber and Weisemann, 1978). A group of fumarole fields on the N flank surrounds the city of Chinameca, and the volcano has been the site of a geothermal exploration program.

Laguna Aramuaca
Volcano type: Maar
A solitary, 1-km-wide, lake-filled maar, Laguna Aramuaca, occupies a low-lying area about 10 km SE of the city of San Miguel. The Pan-American highway swings around the S side of the maar, immediately N of the R�o Grande de San Miguel. It was mapped as Holocene by Weber and Wiesemann (1978), but has not been studied in detail. The low rim of the maar rises above the countryside but is only slightly above sea level; spectacular pyroclastic-surge deposits are exposed by quarries near the rim.

San Miguel
The symmetrical cone of San Miguel, one of the most active volcanoes in El Salvador, rises from near sea level to form one of the country's most prominent landmarks. A broad, deep, crater complex that has been frequently modified by eruptions recorded since the early 16th century caps the truncated unvegetated summit, also known locally as Chaparrastique. Flanks eruptions of the basaltic-andesitic volcano have produced many lava flows, including several during the 17th-19th centuries that extended to the N, NE, and SE. The SE-flank flows are the largest and form broad, sparsely vegetated lava fields crossed by highways and a railroad skirting the base of the volcano. Flank vent locations have migrated higher on the edifice during historical time, and the most recent activity has consisted of minor ash eruptions from the summit crater.

Isla del Tigre
Honduras
Isla del Tigre is a small, 5-km-wide island located across a narrow 2-km-wide strait S of Isla Zacate Grande in the Gulf of Fonseca. The conical basaltic stratovolcano is the southernmost volcano of Honduras. It is less dissected than neighboring Zacate Grande on the mainland to the N, and is of probable Holocene age (Carr 1992, pers. comm.). A single satellitic cone, El Vig�a, overlooks the village of Amapala on the NW flank.

Isla Zacate Grande
Honduras
Zacate Grande volcano forms a low island 7 x 10 km wide across a narrow strait from the end of a peninsula surrounded on three sides by the Gulf of Fonseca and Chismuyo bay. At least seven satellitic cones, some of which form small islands offshore, are located from the NE to SE base of the broad basaltic stratovolcano. Some of these, including the symmetrical cone of Isla Gueguensi in the tidal flats about 3 km E of the base of Zacate Grande, are of probable Holocene age (Carr 1992, pers. comm.). In contrast to neighboring Isla El Tigre volcano to the S, Zacate Grande itself is extensively eroded, and deep valleys extend from the summit ridges to the base of the volcano.

Lago Yojoa
Honduras
The Lago Yojoa volcanic field consists a group of Pleistocene-to-Holocene scoria cones and collapse pits (Williams and McBirney, 1969). The principal NE-trending chain of cones cuts through Cerro Babilonia, the high point of this field N of Lake Yojoa, along the same fault pattern that bounds the limestone mountains bordering the lake. Most of the pyroclastic cones, consisting of basaltic scoria and agglutinate, are 100-200 m high, and some contain craters. Lava flows radiate in all directions from the cones. The longest flow traveled N to the village of R�o Lindo, where a waterfall cascades over the terminus of the flow. A few Quaternary lava flows occur in the Sulu graben along the Carretara del Norte N of Lake Yojoa. The rocks range from tholeiitic basalts to trachybasalts, trachyandesites, and trachytes. Two trachyandesitic tephra beds attributed to local eruptions and sampled by Mehringer et al. (2005) from cores within the volcanic field, were found to have fallen shortly before 11,000 and about 8,600 14C years BP.

Cosiguina
Nicaragua
Cosig�ina (also spelled Coseg�ina) is a low basaltic-to-andesitic composite volcano that is isolated from other eruptive centers in the Nicaraguan volcanic chain. The stratovolcano forms a large peninsula extending into the Gulf of Fonseca at the western tip of the country. It has a pronounced somma rim on the northern side; a young summit cone rises 300 m above the northern somma rim and buries the rim on other sides. The younger cone is truncated by a large elliptical prehistorical summit caldera, 2 x 2.4 km in diameter and 500 m deep, with a lake at its bottom. Lava flows predominate in the caldera walls, although lahar and pyroclastic-flow deposits surround the volcano. A brief but powerful explosive eruption in 1835 is Nicaragua's largest during historical time. Ash fell as far away as M�xico, Costa Rica, and Jamaica, and pyroclastic flows reached the Gulf of Fonseca.

San Cristobal
Nicaragua
The San Crist�bal volcanic complex, consisting of five principal volcanic edifices, forms the NW end of the Marrabios Range. The symmetrical 1745-m-high youngest cone, named San Crist�bal (also known as El Viejo), is Nicaragua's highest volcano and is capped by a 500 x 600 m wide crater. El Chonco, with several flank lava domes, is located 4 km W of San Crist�bal; it and the eroded Moyotepe volcano, 4 km NE of San Crist�bal, are of Pleistocene age. Volc�n Casita, containing an elongated summit crater, lies immediately east of San Crist�bal and was the site of a catastrophic landslide and lahar in 1998. The Plio-Pleistocene La Pelona caldera is located at the eastern end of the complex. Historical eruptions from San Crist�bal, consisting of small-to-moderate explosive activity, have been reported since the 16th century. Some other 16th-century eruptions attributed to Casita volcano are uncertain and may have been from other Marrabios Range volcanoes.

Telica
Nicaragua
Telica, one of Nicaragua's most active volcanoes, has erupted frequently since the beginning of the Spanish era. This volcano group consists of several interlocking cones and vents with a general NW alignment. Sixteenth-century eruptions were reported at symmetrical Santa Clara volcano at the SW end of the group. However, its eroded and breached crater has been covered by forests throughout historical time, and these eruptions may have originated from Telica, whose upper slopes in contrast are unvegetated. The steep-sided cone of Telica is truncated by a 700-m-wide double crater; the southern crater, the source of recent eruptions, is 120 m deep. El Liston, immediately E, has several nested craters. The fumaroles and boiling mudpots of Hervideros de San Jacinto, SE of Telica, form a prominent geothermal area frequented by tourists, and geothermal exploration has occurred nearby.

Cerro Negro
Nicaragua's youngest volcano, Cerro Negro, was created following an eruption that began in April 1850 about 2 km NW of the summit of Las Pilas volcano. It is the largest, southernmost, and most recent of a group of four youthful cinder cones constructed along a NNW-SSE-trending line in the central Marrabios Range. Strombolian-to-subplinian eruptions at intervals of a few years to several decades have constructed a roughly 250-m-high basaltic cone and an associated lava field constrained by topography to extend primarily NE and SW. Cone and crater morphology have varied significantly during its short eruptive history. Although it lies in a relatively unpopulated area, occasional heavy ashfalls have damaged crops and buildings.

Las Pilas-El Hoyo Complex
Las Pilas-El Hoyo volcanic complex, overlooking Cerro Negro volcano to the NW, includes a diverse cluster of cones within about a 3-km-diameter area. A N-S-trending fracture system cutting across the edifice is marked by numerous flank vents, including maars, that are part of a 30-km-long volcanic massif. The Cerro Negro chain of cinder cones is listed separately in this compilation because of its extensive historical eruptions and possible distinct magmatic system. The lake-filled Asososca maar is located adjacent to the Cerro Asososca cone on the southern side of the fissure system, south of the axis of the Marrabios Range. Two small maars west of Lake Managua are located at the southern end of the fissure. Aside from a possible eruption in the 16th century, eruptions of Las Pilas took place in the 1950s from a fissure that cuts the eastern side of the 700-m-wide crater and extends down the N flank.

Apoyeque
The Apoyeque volcanic complex occupies the broad Chiltepe Peninsula, which extends into south-central Lake Managua. The peninsula is part of the Chiltepe pyroclastic shield volcano, one of three large ignimbrite shields on the Nicaraguan volcanic front. A 2.8-km wide, 400-m-deep, lake-filled caldera whose floor lies near sea level truncates the low Apoyeque edifice, which rises only about 500 m above the lake shore. The caldera was the source of a thick deposit of dacitic pumice that covers the surrounding area. The 2.5 x 3 km lake-filled Xilo� (Jilo�) maar is located immediately SE of Apoyeque. The Talpetatl lava dome was constructed between Laguna Xilo� and Lake Managua. Pumiceous pyroclastic flows from Laguna Xilo� were erupted about 6,100 years ago and overlie deposits of comparable age from the Masaya Plinian eruption.

Nejapa-Miraflores
Volcano type: Fissure vent(s)
The Nejapa-Miraflores alignment (also known as Nejapa-Ticoma), ~10 km S of Apoyeque near the western margin of the Nicaraguan graben, cuts through the western part of the capital city of Managua and marks the right-lateral offset of the volcanic arc in Nicaragua. This group of features has erupted tholeiitic basaltic rocks similar to those from mid-ocean ridges, with about 40 eruptions during the past 30,000 years, the most recent of which (from Asososca maar) occurred about 1,250 years ago. A series of pit craters and fissure vents extends into Lake Managua and is continuous with the volcanic vents on the Chiltepe peninsula. An area of maars and tuff cones perpendicular to the N-S trend of the alignment forms the scalloped shoreline of Lake Managua. Laguna Tiscapa crater is located several kilometers to the east near the central part of the city of Managua. The elongated Nejapa and Ticoma pit craters are surrounded by small basaltic cinder cones and tuff cones.

Momotombo
Momotombo is a young stratovolcano that rises prominently above the NW shore of Lake Managua, forming one of Nicaragua's most familiar landmarks. Momotombo began growing about 4500 years ago at the SE end of the Marrabios Range and consists of a somma from an older edifice that is surmounted by a symmetrical younger cone with a 150 x 250 m wide summit crater. Young lava flows extend down the NW flank into the 4-km-wide Monte Gal�n caldera. The youthful cone of Momotombito forms an island offshore in Lake Managua. Momotombo has a long record of Strombolian eruptions, punctuated by occasional stronger explosive activity. The latest eruption, in 1905, produced a lava flow that traveled from the summit to the lower NE base. A small black plume was seen above the crater after a 10 April 1996 earthquake, but later observations noted no significant changes in the crater. A major geothermal field is located on the south flank.

Granada
Volcano type: Fissure vent(s)
The Granada lineament, also known as the La Joya alignment, is an arcuate fissure extending from about 2 km SE of the Apoyo caldera rim around to N of the city of Granada. Small cinder cones are present about 8 km NNW from the Mombacho summit, and the N-S oriented La Joya maar explosion crater chain stretches over 1 km just SW of Granada city. This feature is structurally distinct from the Apoyo caldera and is analogous to the Nejapa-Miraflores alignment north of Masaya volcano. The lineament, characterized by the eruption of basaltic lavas and tephras compositionally similar to mid-ocean ridge basalts, originated about 12,000 years ago, and the latest eruptions may have occurred as recently as about 2,000 years ago.

Masaya
Masaya volcano in Nicaragua has erupted frequently since the time of the Spanish Conquistadors, when an active lava lake prompted attempts to extract the volcano's molten "gold" until it was found to be basalt rock upon cooling. It lies within the massive Pleistocene Las Sierras caldera and is itself a broad, 6 x 11 km basaltic caldera with steep-sided walls up to 300 m high. The caldera is filled on its NW end by more than a dozen vents that erupted along a circular, 4-km-diameter fracture system. The Nindir� and Masaya cones, the source of observed eruptions, were constructed at the southern end of the fracture system and contain multiple summit craters, including the currently active Santiago crater. A major basaltic Plinian tephra erupted from Masaya about 6,500 years ago. Recent lava flows cover much of the caldera floor and there is a lake at the far eastern end. A lava flow from the 1670 eruption overtopped the north caldera rim. Periods of long-term vigorous gas emission at roughly quarter-century intervals have caused health hazards and crop damage.

Zapatera
Zapatera is a small low shield volcano that forms a 7 x 10 km wide island on the western side of Lake Nicaragua just offshore from Mombacho volcano. The island contains some of the most significant archaeological sites in Nicaragua. The small, roughly circular 2-km-wide El Llano caldera is located near the center of the island, which is cut by a series of NE-trending faults that continue into Lake Nicaragua. The conical 305-m-high Cerro El Llano lava dome occupies the center of the caldera, and other lava domes are found on the southern and NE flanks. Numerous low-rimmed tuff rings and maars, of which Laguna de Zapatera on the NW flank is the best-preserved, are found on the northern and western sides of the densely forested 629-m-high island and across a narrow strait on the adjacent mainland.

Mombacho
Mombacho is an andesitic and basaltic stratovolcano on the shores of Lake Nicaragua south of the city of Granada that has undergone edifice collapse on several occasions. Two large breached craters formed by edifice failure cut the summit on the NE and S flanks. The NE-flank scarp was the source of a large debris avalanche that produced an arcuate peninsula and a cluster of small islands (Las Isletas) in Lake Nicaragua. Two small, well-preserved cinder cones are located on the lower N flank. The only reported activity was in 1570, when a debris avalanche destroyed a village on the south side of the volcano. Although there were contemporary reports of an explosion, there is no direct evidence that the avalanche was accompanied by an eruption. Fumarolic fields and hot springs are found within the two collapse scarps and on the upper N flank.

Concepcion
Volc�n Concepci�n is a symmetrical basaltic-to-dacitic stratovolcano that forms the NW half of the dumbbell-shaped island of Ometepe in Lake Nicaragua and is connected to neighboring Madera volcano by a narrow isthmus. A steep-walled summit crater is 250 m deep and has a higher western rim. N-S-trending fractures on the flanks have produced chains of spatter cones, cinder cones, lava domes, and maars located on the NW, NE, SE, and southern sides extending in some cases down to Lake Nicaragua. It was constructed above a basement of lake sediments, and the modern cone grew above a largely buried caldera, a small remnant of which forms a break in slope about halfway up the N flank. Frequent explosive eruptions during the past half century have increased the height of the summit significantly and have kept the upper part of the volcano unvegetated.

Orosi
Costa Rica
Oros� is one of a cluster of four eroded and vegetated cones in the Guanacaste Range at the NW corner of Costa Rica. Volc�n Oros� itself has a conical shape as viewed from the north or west, but its flanks are heavily eroded. The complex includes Oros�, Orosilito, Volc�n Pedregal, and Cacao. The highest peak of the volcanic complex is 1659-m-high Volc�n Cacao, 5.5 km SE of Oros�. The summit of Cacao is cut by two large horseshoe-shaped calderas breached to the SW and east related to edifice collapse. The age of the latest activity of the complex is not known. Historical eruptions were reported from Oros� in 1844 and 1849, but even at the time of the first volcanological observations at the end of the 19th century, Oros� was overgrown with large trees, and the eruptions may actually have been from neighboring Rinc�n de la Vieja. The latest documented volcanic activity produced mudflows (perhaps secondary) about 3500 years ago.

Rincon de la Vieja
Costa Rica
Rinc�n de la Vieja is a volcanic complex in the Guanacaste Range of NW Costa Rica. Sometimes referred to as the Rincon de la Vieja-Santa Mar�a Volcanic Complex, it consists of a slightly arcuate 20-km-long ridge of 12 craters and pyroclastic cones constructed within the 15-km-wide early Pleistocene Guachipel�n caldera, whose rim is exposed on the south side. Sometimes known as the "Colossus of Guanacaste," it has an estimated volume of 130 km3 and contains at least nine major eruptive centers. The Santa Mar�a cone, the highest peak of the complex, is located on the E side of the ridge and has a lake within the 400-m-diameter crater. A Plinian eruption producing the 0.25 km3 R�o Blanca tephra about 3,500 years ago was the last major magmatic eruption. All subsequent eruptions, including numerous reported eruptions possibly dating back to the 16th century, have been from the active crater, near the center of the complex, with an acidic 300-m-diameter lake.

Tenorio
Costa Rica
The 225 km2 dominantly andesitic Tenorio volcanic massif anchors the SE end of the Guanacaste Range and consists of a cluster of densely forested NNW-SSE-trending volcanic cones. Overlapping lava flows from the principal peak, Tenorio, cover the NW-to-SW flanks and descend the NE flank. The NW-most of three craters on the central cone is sparsely vegetated and appears to be the most recently active. Volc�n Montezuma to the north has two craters, the northern of which was the source of a lava flow to the NE. Additional pyroclastic cones are found to the NE and SW of the central complex, and the Bijagua lava domes were constructed on the N flank. A major debris avalanche covered about 100 km2 below the S flank. A legend exists of an eruption in 1816 CE, but the volcano was densely forested at the time of an 1864 visit by Seebach and no documented eruptions are known. Fumarolic activity is present on the NE flank.

Arenal
Conical Volc�n Arenal is the youngest stratovolcano in Costa Rica and one of its most active. The 1670-m-high andesitic volcano towers above the eastern shores of Lake Arenal, which has been enlarged by a hydroelectric project. Arenal lies along a volcanic chain that has migrated to the NW from the late-Pleistocene Los Perdidos lava domes through the Pleistocene-to-Holocene Chato volcano, which contains a 500-m-wide, lake-filled summit crater. The earliest known eruptions of Arenal took place about 7000 years ago, and it was active concurrently with Cerro Chato until the activity of Chato ended about 3500 years ago. Growth of Arenal has been characterized by periodic major explosive eruptions at several-hundred-year intervals and periods of lava effusion that armor the cone. An eruptive period that began with a major explosive eruption in 1968 ended in December 2010; continuous explosive activity accompanied by slow lava effusion and the occasional emission of pyroclastic flows characterized the eruption from vents at the summit and on the upper western flank.

Platanar
The Platanar volcanic center is the NW-most volcano in the Cordillera Central of Costa Rica. The massive complex covers about 900 km2 and is dominated by two largely Pleistocene stratovolcanoes, Platanar and Porvenir. These volcanoes were constructed within the Pleistocene Chocosuela caldera, which may have formed during a major slope failure. The Cerro Platanar volcano (known locally as Volc�n Congo) on the N side of the complex has prehistorical lava flows on its W flanks and is the youngest volcanic center. The highest peak is Porvenir, whose summit crater lies 3 km S of Platanar. A thin layer of phreatic ash suggested that an eruption from Platanar occurred within the past few thousand years (Stine and Banks, 1991). The Aguas Zarcas group of nine basaltic cinder cones, located on the N flank of the Platanar-Porvenir complex to as low as 160 m altitude is, in part, Holocene in age.

Miravalles
Miravalles is an andesitic stratovolcano that is one of five post-caldera cones along a NE-trending line within the broad 15 x 20 km Guayabo (Miravalles) caldera. The caldera was formed during several major explosive eruptions that produced voluminous dacitic-rhyolitic pyroclastic flows between ~1.5 and 0.6 million years ago. Growth of post-caldera volcanoes in the eastern part of the caldera that overtopped much of the eastern and southern caldera rims was interrupted by edifice collapse which produced a major debris avalanche to the SW. Morphologically youthful lava flows cover the W and SW flanks of the post-caldera Miravalles complex, which rises above the town of Guayabo on the flat western caldera floor. A small steam explosion on the SW flank was reported in 1946. High heat flow remains, and it is the site of a large developed geothermal field.

Poas
The broad vegetated edifice of Po�s, one of the most active volcanoes of Costa Rica, contains three craters along a N-S line. The frequently visited multi-hued summit crater lakes of the basaltic-to-dacitic volcano are easily accessible by vehicle from the nearby capital city of San Jos�. A N-S-trending fissure cutting the complex stratovolcano extends to the lower N flank, where it has produced the Congo stratovolcano and several lake-filled maars. The southernmost of the two summit crater lakes, Botos, last erupted about 7,500 years ago. The more prominent geothermally heated northern lake, Laguna Caliente, is one of the world's most acidic natural lakes, with a pH of near zero. It has been the site of frequent phreatic and phreatomagmatic eruptions since an eruption was reported in 1828. Eruptions often include geyser-like ejections of crater-lake water.

Barva
One of three massive volcanoes close to the capital city of San Jos�, Volc�n Barva (Barba) is a complex volcano with multiple peaks and flank vents. Three peaks visible from the Central Valley give it the common local name of Las Tres Mar�as. The voluminous andesitic-to-dacitic Tirib� Tuff, exposed in the Central Valley, was erupted about 322,000 years ago. The summit area is dominated by a 2 x 3 km crater open to the ESE. One of the cones on the upper N flank contains a crater lake. Cones are also found on the S flanks, along with lava flows. The Los Angeles flow, one of the most recent, descends nearly to the city of Heredia. A large Plinian eruption occurred during the early Holocene. Eruptions were reported in 1760 or 1766, 1776? (also a mudflow), and 1867, but later visits to the summit did not provide evidence for recent activity.

Irazu
The massive Iraz� volcano in Costa Rica, immediately E of the capital city of San Jos�, covers an area of 500 km2 and is vegetated to within a few hundred meters of its broad summit crater complex. At least 10 satellitic cones are located on its S flank. No lava effusion is known since the eruption of the Cervantes lava flows from S-flank vents about 14,000 years ago, and all known Holocene eruptions have been explosive. The focus of eruptions at the summit crater complex has migrated to the W towards the main crater, which contains a small lake. The first well-documented eruption occurred in 1723, and frequent explosive eruptions have occurred since. Ashfall from the last major eruption during 1963-65 caused significant disruption to San Jos� and surrounding areas. Phreatic activity reported in 1994 may have been a landslide event from the fumarolic area on the NW summit (Fallas et al., 2018).

Turrialba
Turrialba, the easternmost of Costa Rica's Holocene volcanoes, is a large vegetated basaltic-to-dacitic stratovolcano located across a broad saddle NE of Iraz� volcano overlooking the city of Cartago. The massive edifice covers an area of 500 km2. Three well-defined craters occur at the upper SW end of a broad 800 x 2200 m summit depression that is breached to the NE. Most activity originated from the summit vent complex, but two pyroclastic cones are located on the SW flank. Five major explosive eruptions have occurred during the past 3500 years. A series of explosive eruptions during the 19th century were sometimes accompanied by pyroclastic flows. Fumarolic activity continues at the central and SW summit craters.

Baru
Panama
The westernmost volcano in Panam�, Bar�, is a complex dominantly andesitic stratovolcano in the Talamanca Range near the Costa Rica border. The forested volcano (also referred to as Volc�n de Chiriqui) is the highest peak in Panam�, and the summit hosts many communication towers. A large 6-km-wide summit caldera breached to the west was formed by a large volcanic landslide, which created a massive debris-avalanche deposit about 9,000 years ago that extends onto the Pacific coastal plain, largely overlying a late-Pleistocene avalanche deposit. Post-collapse eruptions have constructed lava domes inside the caldera that have grown to a height exceeding that of the caldera rim. A strong explosive eruption at about 700 CE ended human occupation at the Cerro Punta archaeological site NW of the volcano. Montessus de Ballore (1884) reported a strong eruption in the mid-16th century; Sapper (1917) considered this report to be uncertain, but radiocarbon dates subsequently implied tephra deposits younger than about 500 years. Volc�n Bar� is the youngest major volcano in Panam�, and geothermal exploration projects have been undertaken to determine its energy potential.

Chiapanecan Volcanic Arc

El Chichon
Mexico
Chiapanecan Volcanic Arc
El Chich�n is a small trachyandesitic tuff cone and lava dome complex in an isolated part of the Chiapas region in SE M�xico. Prior to 1982, this relatively unknown volcano was heavily forested and of no greater height than adjacent non-volcanic peaks. The largest dome, the former summit of the volcano, was constructed within a 1.6 x 2 km summit crater created about 220,000 years ago. Two other large craters are located on the SW and SE flanks; a lava dome fills the SW crater, and an older dome is located on the NW flank. More than ten large explosive eruptions have occurred since the mid-Holocene. The powerful 1982 explosive eruptions of high-sulfur, anhydrite-bearing magma destroyed the summit lava dome and were accompanied by pyroclastic flows and surges that devastated an area extending about 8 km around the volcano. The eruptions created a new 1-km-wide, 300-m-deep crater that now contains an acidic crater lake.

Trans-Mexican Volcanic Arc

Sanganguey
Mexico
Trans-Mexican Volcanic Arc
Volc�n Sangang�ey, the highest volcano of the NW-SE-trending Tepic-Zacoalco graben, is an eroded andesitic and dacitic stratovolcano that contains a prominent lava spine at its summit. The NW and SE flanks of the Pleistocene edifice have 45 cinder cones that erupted during the past 300,000 years along five parallel lines. Some of the cinder cones appear morphologically similar to cones on nearby Ceboruco volcano that are known to be less than 1,000 years old. There are no confirmed historical eruptions from Sangang�ey. An incorrect report of an eruption in 1859 from San Juan (a synonym of Sangang�ey) refers to the nearby Pleistocene San Juan volcano. An native tradition records an eruption in 1742 (Sapper, 1917), which may refer to activity from one of the flank cinder cones.

Mascota Volcanic Field
Mexico
Trans-Mexican Volcanic Arc
A group of calc-alkaline andesitic and lamprophyre cinder cones and lava domes, along with associated lava flows, is located near the town of Mascota about 50 km E of Puerto Vallarta. Mascota is the youngest of a group of potassic volcanic fields in extensional grabens of the Jalisco block south of the R�o Ameca. Most volcanism here is confined to two NNW-SSE-trending grabens cutting Cretaceous ash-flow tuffs. The youngest eruption was a basaltic andesite lava flow at Volc�n Malpa�s, north of Mascota; the lack of soil development and sparse vegetation suggest that it may be only a few thousand years old (Carmichael et al., 1996). The field is noted for its unusual diversity of volcanic rocks, and contains Earth's youngest known minettes (lamprophyres).

Ceboruco
Volc�n Ceboruco is the only volcano in the NW part of the Mexican Volcanic Belt with observed eruptions. The complex stratovolcano rises above the floor of the Tepic graben and is truncated by two concentric summit calderas. Eruption of the voluminous rhyodacitic Jala Pumice formed the initial 4-km-wide caldera about 1,000 years ago. The second caldera, 1.5 km wide, was formed by collapse of part of the large Dos Equis dacitic lava dome, which partly filled the earlier caldera. About 15 basaltic and andesitic cinder cones and lava flows have erupted along a NW-SE-trending line cutting across Ceboruco. The massive, sparsely vegetated El Norte lava flow, probably erupted in the past few hundred years, covers the entire N flank. The last eruption took place during 1870-1875 CE. Explosive eruptions from a vent on the upper W flank accompanied extrusion of a 1.1 km3 dacitic lava flow that covers a large area on the lower W flank.

Colima
The Colima complex is the most prominent volcanic center of the western Mexican Volcanic Belt. It consists of two southward-younging volcanoes, Nevado de Colima (the high point of the complex) on the north and the historically active Volc�n de Colima at the south. A group of late-Pleistocene cinder cones is located on the floor of the Colima graben west and east of the complex. Volc�n de Colima (also known as Volc�n Fuego) is a youthful stratovolcano constructed within a 5-km-wide scarp, breached to the south, that has been the source of large debris avalanches. Major slope failures have occurred repeatedly from both the Nevado and Colima cones, producing thick debris-avalanche deposits on three sides of the complex. Frequent recorded eruptions date back to the 16th century. Occasional major explosive eruptions have destroyed the summit (most recently in 1913) and left a deep, steep-sided crater that was slowly refilled and then overtopped by lava dome growth.

Zitacuaro-Valle de Bravo
The Zit�cuaro-Valle de Bravo volcanic field in the central part of the Trans-Mexican Volcanic Belt consists of a broad region of shield volcanoes, lava domes, and cinder cones surrounding the city of Heroica de Zit�cuaro. The Zit�cuaro volcanic complex itself, located SE of the city, was constructed within the 30-km-wide Las Tres Chicas caldera of Miocene age, which later underwent three post-caldera episodes of intra-caldera lava dome resurgence and included the intrusion of dacitic central lava domes, the emplacement of pyroclastic flows, and the eruption of andesitic lava flows. The youngest dated activity at the complex produced La Dieta airfall deposit about 31,000 years ago, and persistent local seismicity continues at Zit�cuaro. The Valle de Bravo area to the south contains dominantly andesitic lava domes and flows, many of which were erupted along regional faults. The youngest flows were erupted at the bottom of a fault-controlled canyon; the most recent of these, west of the Valle de Bravo lake, has been Ar-Ar dated at about 5,200 +/- 2,300 years, and morphology suggests a Holocene age for other cones.

Jocotitlan
The composite Jocotitl�n volcano, which rises above the Toluca basin 60 km WNW of Mexico City, was constructed during the Pleistocene of andesitic-to-dacitic lava flows. A major obsidian-bearing dacitic Plinian eruption was followed by the emplacement of a dacitic lava-dome complex, accompanied by lava effusion, pumice-fall eruptions, and pyroclastic surges. The most prominent feature is an escarpment open to the NE that formed as a result of gravitational failure during the early Holocene. The resulting debris-avalanche deposit covers an 80 km2 area to the NE. Lava dome emplacement accompanied by pyroclastic flows and surges subsequently filled much of the avalanche scarp. The latest known eruption occurred about 750 years ago and produced block-and-ash flows and pyroclastic surges.

Michoacan-Guanajuato
The widespread Michoac�n-Guanajuato volcanic field contains over 1,400 vents, including the historically active cinder cones of Par�cutin and Jorullo, covering a 200 x 250 km wide area of Michoac�n and Guanajuato states in west-central M�xico. Cinder cones are the predominant volcanic form, but small shield volcanoes, lava domes, maars and tuff rings (many in the Valle de Santiago area), and coneless lava flows are also present. The volcanoes with shield-type morphologies are mostly Pleistocene in age, although the Michoac�n-Guanajuato centers have higher slope angles and smaller basal diameters. Jorullo, which was constructed in the 18th century, and Par�cutin, which grew above a former cornfield during 1943-52, are the two best known volcanic features scattered throughout the field.

Nevado de Toluca
Nevado de Toluca, M�xico's fourth highest peak, rises above the Toluca basin about 80 km W of Mexico City. The broad, complex andesitic-dacitic stratovolcano, also known by the Nahuatl Indian name Xinant�catl, has a 1.5-km-wide summit crater open to the east. A large dacitic lava dome in the crater separates two lakes, known as the lakes of the Sun and Moon. At least three major edifice collapses during the Pleistocene produced large debris avalanche and lahar deposits that affected broad areas below the volcano. Four major explosive eruptions during the late Pleistocene produced widespread ashfall and pyroclastic-flow deposits at about 36,000, 21,700, 12,100, and 10,500 years ago (uncalibrated 14C), producing the Ochre and the Lower, Middle, and Upper Toluca Pumice deposits, respectively. Recent work has revealed evidence for at least one Holocene eruption, about 3,300 years ago, that produced pyroclastic flows and surges.

Iztaccihuatl
Iztacc�huatl (the "Woman in White") presents the profile of a sleeping woman as seen from the Valley of Mexico. A series of overlapping cones constructed along a NNW-SSE line to the south of the Pleistocene Llano Grande caldera forms the summit ridge of the massive 450 km3 volcano. Andesitic and dacitic Quaternary volcanism has taken place from vents at or near the summit. Valley headwalls near the summit vent (El Pecho) have lava flows and tuff deposits post-dating a glaciation about 11,000 years ago. The youngest vents are located at the summit and a depression at 5,100 m along the summit ridge midway between El Pecho and Los Pies (White, 1986). Nixon (1989) considered all summit lavas to be Pleistocene, but noted a postglacial dacitic vent on the S flank of Iztacc�huatl, north of the saddle between it and Popocat�petl.

Chichinautzin
The massive Chichinautzin volcanic field extends over an 88 km E-W area immediately south of Mexico City. The Sierra Chichinautzin, formed primarily of overlapping small cinder cones and shield volcanoes, creates a broad topographic barrier at the southern end of the Basin of Mexico that extends from the E flank of Nevado de Toluca to the W flank of Iztacc�huatl. The volcanic field contains more than 220 Pleistocene-to-Holocene monogenetic vents. The best-known eruption occurred about 1,670 radiocarbon years ago (400 CE) from the Xitle scoria cone, NE of the Volc�n Ajusco lava dome complex, which forms the highest peak of the Sierra Chichinautzin. The Xitle eruption produced a massive basaltic tube-fed lava flow that covered agricultural lands as well as pyramids and other structures of Cuicuilco and adjacent prehispanic urban centers. The southern part of Mexico City and the National University of M�xico lie atop the distal end of the 13-km-long lava flow.

La Malinche
La Malinche is an eroded stratovolcano, cut by deep canyons, NE of the city of Puebla. It occupies an isolated position between the Popocat�petl-Iztacc�huatl and Orizaba-Cofre de Perote volcanic ranges. Much of the andesitic-dacitic volcano was constructed during the Pleistocene, and the summit exhibits evidence of glacial erosion. Although relatively unstudied, research has identified Holocene tephra layers that originated from Volc�n la Malinche. Several cones and explosion craters, at least one of Holocene age, are found on the flanks; one of the most prominent of these is the Xalapaxco maar complex on the lower ENE flank. Holocene lahars associated with an eruption about 3,100 years ago reached the Puebla basin and affected communities there.

Serdan-Oriental Volcanic Field
The Serd�n-Oriental Volcanic Field, covering an area 35-40 km E-W and 60 km N-S, includes numerous late Pleistocene to Holocene rhyolitic lava domes, tuff cones, tuff rings, lava flows, and scoria cones. Most of the volcanic features are within or adjacent to the a broad closed Serd�n-Oriental Basin at the eastern end of the Mexican Altiplano, bounded by the Cofre de Perote-Orizaba range on the east and Los Humeros caldera to the north. A major explosive eruption from a vent inferred to be buried within the basin produced the Quetzalapa Plinian pumice-fall deposit roughly 20,000 years ago. The most prominent features of the volcanic field are the two Las Derrumbadas lava domes surrounded by debris avalanche deposits, and the sharp-peaked Cerro Pizarro lava dome at the northern end of the basin. Several of the tuff rings contain lakes, such as Laguna Atexcac and Laguna Alchichica. Although often associated with Las Cumbres, obsidian domes to the N and SW are included here as part of the Serd�n-Oriental regional distributed volcanism. The rhyolitic Yolotepec lava dome, between Las Cumbres and La Gloria, is also included here; it has been radiocarbon dated to ~3900 BCE (5,900 years BP).

Los Humeros
Volcano type: Caldera(s)
Los Humeros is the easternmost of a series of silicic volcanic centers with active geothermal systems located north of the axis of the Mexican Volcanic Belt. The first major silicic eruption produced the 230 km3 X�ltipan Ignimbrite about 460,000 years before present (BP), which covered about 3,500 km2 and resulted in formation of the 15 x 21 km Los Humeros caldera. The emplacement of post-caldera lava domes and eruption of the 40 km3 Faby Tuff about 240,000 years BP was followed by eruption of the Zaragoza Tuff about 100,000 years BP and formation of the nested 10-km-wide Los Potreros caldera. A third and much smaller caldera (El Xalapazco) was formed about 40,000-20,000 years BP. The most recent eruptions include the production of extensive morphologically youthful basaltic lava flows that are undated, but are younger than a 20,000 BP rhyolitic lava flow and could be in part of early Holocene age. A major explosive eruption about 6,400 years ago produced the bimodal Plinian Cuilcuiltic Member tephra.

Naolinco Volcanic Field
The Naolinco Volcanic Field in the Sierra de Chiconquiaco range north of Jalapa (Xalapa), Veracruz, consists of a broad area of scattered Quaternary pyroclastic cones and associated dominantly basaltic lava flows. These cones cover an E-W-trending area on both sides of the town of Naolinco de Victoria; the largest is Cerro Acatl�n, located NE of the town. This and other nearby cones produced voluminous lava flows that traveled S and SE. The Coacoatzintla lava flow from the Rinc�n de Chapultepec scoria cone was erupted about 1200 BCE. A cluster of basaltic cinder cones S of the town of Las Vigas de Ramirez produced lava flows have traveled eastward to beyond the city of Xalapa (Jalapa). A flow from the El Volcancillo vent was radiocarbon dated at about 1150 CE.

Popocatepetl
Volc�n Popocat�petl, whose name is the Aztec word for smoking mountain, rises 70 km SE of Mexico City to form North America's 2nd-highest volcano. The glacier-clad stratovolcano contains a steep-walled, 400 x 600 m wide crater. The generally symmetrical volcano is modified by the sharp-peaked Ventorrillo on the NW, a remnant of an earlier volcano. At least three previous major cones were destroyed by gravitational failure during the Pleistocene, producing massive debris-avalanche deposits covering broad areas to the south. The modern volcano was constructed south of the late-Pleistocene to Holocene El Fraile cone. Three major Plinian eruptions, the most recent of which took place about 800 CE, have occurred since the mid-Holocene, accompanied by pyroclastic flows and voluminous lahars that swept basins below the volcano. Frequent historical eruptions, first recorded in Aztec codices, have occurred since Pre-Columbian time.

Pico de Orizaba
Pico de Orizaba (Volc�n Citlalt�petl), M�xico's highest peak and North America's highest volcano, lies at the southern end of a volcanic chain extending north to Cofre de Perote volcano, east of the Serdan-Oriental Basin. The edifice was formed in three stages beginning during the mid-Pleistocene. Construction of the initial Torrecillas and Espol�n de Oro volcanoes was contemporaneous with growth of Sierra Negra volcano on the SW flank, and was followed by edifice collapses that produced voluminous debris avalanches and lahars. The modern volcano was constructed during the late Pleistocene and Holocene of viscous andesitic and dacitic lavas, forming the current steep-sided cone. Repetitive explosive eruptions beginning during the early Holocene accompanied lava dome growth and lava effusion. Recorded eruptions have consisted of moderate explosive activity and the effusion of dacitic lava flows. The last known observations of activity were in 1846 CE.

San Martin
Volc�n de San Mart�n, part of the Tuxtla Volcanic Field, is a broad alkaline shield volcano that rises above the Gulf of Mexico. The massive volcano, also known as San Mart�n Tuxtla, is elongated NW-SE and is capped by a 1-km-wide summit crater. The upper part of the volcano is covered with dense tropical rain forests. The summit and flanks contain more than 250 pyroclastic cones and maars. Well-preserved cinder cones are abundant between the summit and Laguna Catemaco on the SE flank. Holocene cones in this area produced ash deposits that buried stone pyramids. The two largest recorded eruptions took place in 1664 and 1793. The 1793 eruption occurred from two cinder cones in the summit crater and produced widespread ashfall and lava flows that extended 3.5 km down the NE flank.

Eastern Pacific Volcanic Regions

Galapagos Rift Volcanic Province

Galapagos Rift at 86�W
Galapagos Rift Volcanic Province
Volcano type: Fissure vent(s)
The Gal�pagos Rift is an oceanic spreading ridge between the Cocos plate to the north and the Nazca plate to the south. A large area of hydrothermal vents along the crest of the ridge ENE of the Gal�pagos Islands was discovered in 1977. The location listed here is the position of Clambake vent, which was surrounded by very youthful sediment-free flows of basaltic sheet lava. This position is at the northern limit of the location error circle for a 1972 earthquake swarm and only a few kilometers south of a concurrent fish kill (Macdonald and Mudie, 1974) that may have been associated with extrusion of lava flows. Very fresh, glassy, sediment-free sheet-flow lavas observed during dives near this site in February and March 1977 (Corliss et al., 1979); the morphology of the flows suggested that they were less than 5 years old (Chadwick and Embley, 1994). The rift at this point consists of a small rift valley 3-4 km wide with walls 200-250 m high. A low axial ridge formed by the youngest sediment-free lava flows rises about 20 m above the valley floor, flanked by older marginal ridges. A 2002 expedition discovered evidence for new lava flows covering markers emplaced in 1990.

Northern Galapagos Volcanic Province

Pinta
Northern Galapagos Volcanic Province
The elongated island of Pinta is a shield volcano with numerous cones and lava flows originating from NNW-trending fissures. A steep sea cliff truncates the W flank. The unvegetated lava flows that cover the SE and N flanks appear to have been erupted during the past few thousand or few hundred years (McBirney and Williams, 1969). Although an eruption was reported in 1928 (U.S. Hydrographic Office, 1938), no description or source of that event is given, so it is considered uncertain; no confirmed or dated eruptions are known.

Genovesa
Northern Galapagos Volcanic Province
The small, very low island of Genovesa is the top of a shield volcano. The surface of a summit crater lake is near sea level. A larger 2-km-wide caldera on the S side forms an embayment that is filled by Darwin Bay. Sediment filling Arctulus Lake, a crater in the center of the island, is less than 6,000 years old. Youthful flows erupted from flank fissures cover much of the island and very fresh, glassy spatter has been found (Simkin 1976, pers. comm.). No recorded eruptions are known, although the fresh-looking lava flows suggest a very youthful age. Basaltic rocks on the island are noted for their abundant coarse plagioclase crystals.

Marchena
The low shield volcano forming Marchena Island contains one of the largest calderas of the Gal�pagos Islands. The 6 x 7 km caldera and its outer flanks have been largely buried by a cluster of pyroclastic cones and associated lava flows. Its first historical eruption occurred in 1991. Other young lava flows, some of which may be only a few thousand, or even a few hundred years old, filled the caldera and flowed down its outer forested flanks, in some cases to the sea.

Galapagos Hotspot Volcano Group

Galapagos Hotspot Volcano Group
Volc�n Ecuador straddles the equator at the NW end of Isabela Island. The western side of the volcano, the smallest of the six large shield volcanoes on the island, is broadly breached by edifice collapse, and youthful lava flows cover much of the caldera floor. Two large pyroclastic cones were constructed along the coast, and several chains of spatter cones and small scoria cones cross the caldera floor, which has a prominent bench on its southern side. A single dark-colored aa lava flow covers about half of the caldera floor. A number of young lava flows reach the coast to form Cape Berkeley, W of a large youthful-looking tuff cone. Extending from the outer eastern flanks of the main edifice is a line of NE-trending fissure-fed vents that connect Volc�n Ecuador (also known as Cape Berkeley volcano) with Volc�n Wolf. The only Isabela Island volcano without historical eruptions, the youthful morphology of its most recent lava flows nevertheless resembles those of very recent flows on other Isabela Island volcanoes.

Fernandina
Galapagos Hotspot Volcano Group
Fernandina, the most active of Gal�pagos volcanoes and the one closest to the Gal�pagos mantle plume, is a basaltic shield volcano with a deep 5 x 6.5 km summit caldera. The volcano displays the classic "overturned soup bowl" profile of Gal�pagos shield volcanoes. Its caldera is elongated in a NW-SE direction and formed during several episodes of collapse. Circumferential fissures surround the caldera and were instrumental in growth of the volcano. Reporting has been poor in this uninhabited western end of the archipelago, and even a 1981 eruption was not witnessed at the time. In 1968 the caldera floor dropped 350 m following a major explosive eruption. Subsequent eruptions, mostly from vents located on or near the caldera boundary faults, have produced lava flows inside the caldera as well as those in 1995 that reached the coast from a SW-flank vent. Collapse of a nearly 1 km3 section of the east caldera wall during an eruption in 1988 produced a debris-avalanche deposit that covered much of the caldera floor and absorbed the caldera lake.

Wolf
Volc�n Wolf, the highest volcano of the Gal�pagos Islands, straddles the equator at the north end of the archipelago's largest island, Isabela. The edifice has steeper slopes than most other Isabela volcanoes, reaching angles up to 35�. The summit caldera is 6 x 7 km across and 700 m deep. A prominent bench on the west side of the caldera rises 450 m above the caldera floor, much of which is covered by a lava flow erupted in 1982. Radial fissures concentrated along diffuse rift zones extend down the N, NW, and SE flanks, and submarine vents lie beyond the N and NW fissures. Similar unvegetated flows originating from a circumferential chain of spatter and scoria cones on the eastern caldera rim drape the forested flanks to the sea. The proportion of aa lava flows exceeds that of other Gal�pagos volcanoes. An eruption in 1797 was the first observed and documented in the Gal�pagos Islands.

Darwin
Volc�n Darwin, named after the renowned naturalist, contains a symmetrical 5-km-wide, 200-m-deep summit caldera whose floor is nearly covered by youthful lava flows. A broad terrace occupies the SW part of the caldera. Unvegetated lava flows descend all flanks and reach both the eastern and western coasts. The most recent summit activity produced several small lava flows from vents on the east caldera floor and NE and SE caldera rims. Radial fissures descend the flanks, and one reaches beyond its base to the SW coast and cuts Tagus tuff cone. The sheltered anchorage of Tagus Cove breaches the southern side of the cone and was visited by Darwin and others. This prominent tuff cone and its neighbor Beagle (also breached to the south) are located on the SW-flank coastline and were a prominent part of Darwin's geological studies in the Gal�pagos Islands.

Alcedo
Alcedo is one of the lowest and smallest of six shield volcanoes on Isabela Island. Much of the flanks and summit caldera are vegetated, but young lava flows are prominent on the N flank near the saddle with Darwin volcano. It is the only Galapagos volcano known to have erupted rhyolite as well as basalt, producing about 1 km3 of late-Pleistocene rhyolitic tephra and lava flows from several vents late in its history. Recent faulting has produced a moat around part of the 7-8 km caldera floor, which is elongated N-S and appears to be migrating to the south. Fewer circumferential fissures occur on Alcedo than on other western Gal�pagos volcanoes. An eruption attributed to Alcedo in 1954 (Richards, 1957) is more likely to have been from neighboring Sierra Negra (Simkin 1980, pers. comm.). Photo-geologic mapping by K.A. Howard (pers. comm.) revealed only one flow on 30 October 1960 photographs that does not appear on 30 May 1946 photos. That is near Cartago Bay, low on the SE flank, rather than the 610-m, NE-flank elevation listed for the 1954 eruption. An active hydrothermal system is located within the caldera.

Sierra Negra
The broad shield volcano of Sierra Negra at the southern end of Isabela Island contains a shallow 7 x 10.5 km caldera that is the largest in the Gal�pagos Islands. Flank vents abound, including cinder cones and spatter cones concentrated along an ENE-trending rift system and tuff cones along the coast and forming offshore islands. Although it is the largest of the five major Isabela volcanoes, it has the flattest slopes, averaging less than 5� and diminishing to 2� near the coast. A sinuous 14-km-long, N-S-trending ridge occupies the west part of the caldera floor, which lies only about 100 m below its rim. The Volc�n de Azufre fumarolic area lies within a graben between this ridge and the west caldera wall. Lava flows from a major eruption in 1979 extend all the way to the north coast from circumferential fissure vents on the upper northern flank.

Cerro Azul
Located at the SW tip of the J-shaped Isabela Island, Cerro Azul contains a steep-walled 4 x 5 km nested summit caldera complex that is one of the smallest diameter, but at 650 m one of the deepest in the Gal�pagos Islands. The shield volcano is the second highest of the archipelago. A conspicuous bench occupies the SW and west sides of the caldera, which formed during several episodes of collapse. Youthful lava flows cover much of the caldera floor, which has also contained ephemeral lakes. A prominent tuff cone located at the ENE side of the caldera is evidence of episodic hydrovolcanism. Numerous spatter cones dot the western flanks. Fresh-looking lava flows, many erupted from circumferential fissures, descend the NE and NW flanks. Historical eruptions date back only to 1932, but Cerro Azul has been one of the most active Gal�pagos volcanoes since that time. Solfataric activity continues within the caldera.

Santa Cruz
The highlands of the broad Santa Cruz shield volcano rise to the N above the Charles Darwin Research Station at Academy Bay. The oval-shaped, 32 x 40-km-wide island is capped by youthful pit craters and cinder cones with well-preserved craters that largely bury a shallow summit caldera. Older uplifted submarine lava flows are found on the NE part of the island and at the fault-delimited offshore island of Baltra. The highland scoria cones are grouped along an E-W belt parallel to recent fault scarps that border Academy Bay. The youngest lava flows were erupted from vents along the summit fissure and on the N flank. Their fresh morphology and sparsely vegetated surfaces suggest they may be only a few thousand years old, although their ages are not known precisely.

Santiago
The elongated shield volcano of Santiago Island, also known as San Salvador Island or James Island, has numerous scattered Holocene pyroclastic cones. Fresh-looking lava flows from these cones cover the flanks. The summit ridge, lined with a chain of NW-trending cinder and spatter cones, is located at the NW end of the island. Prominent flank tuff cones occur at the western and eastern coasts. The most recent activity has been concentrated at the NW and SE ends of the island. The pahoehoe lava flows at James and Sullivan Bays, on opposite ends of the island, were erupted in the past few hundred years. The James Bay flows were dated by fragments of marmalade pots left by buccaneers in 1684 that were subsequently embedded in the lava flows described by Charles Darwin in 1835.

San Cristobal
San Crist�bal Island consists of a densely vegetated western part and a lower, younger eastern part with many unvegetated lava flows. The morphology on the SW side of the resembles low-angle Hawaiian shields more than the steep-sided shields of Fernandina and Isabela Island. Most lava flows on the NE part of the island originated from SW-NE-trending fissures. Some of the flows have reached the sea, where littoral cones formed. The dates of the latest eruptions are unknown, but possibly less than 1,000 years old. Kicker Rock, two small islands about 5 km off the NW coast, is an eroded remnant of a tuff cone.

Northern East Pacific Rise Volcanic Province

Northern EPR at 17�N
Northern East Pacific Rise Volcanic Province
This second-order segment of the northern East Pacific Rise, also called Segment RO2, lies between the Orozco and Rivera transform faults, south of the Rivera transform. The segment displays a typical small rifted axial crest, about 2-3 km wide and 20-50 m deep. At some locations the summit trough almost disappears, suggesting high rates of volcanism. A seamount lies just east of the axial crest at about 16�33'N. Magnetic paleointensity measurements on basaltic glasses dated a lava flow at about 2,000 +/- 1,000 years and another at "contemporary" age, perhaps decades to a few hundred years old.

Northern EPR at 16�N
Northern East Pacific Rise Volcanic Province
This second-order segment of the northern East Pacific Rise, also called Segment RO3, lies between the Orozco and Rivera transform faults, immediately north of the Orozco transform. This segment displays a broad, shallow profile that is the widest and shallowest of a 5,000-km-long area of the East Pacific Rise between 23�S and 23�N. The flat axial crest ranges from 3-4 to about 10 km wide, and is about 2,300-2,350 m deep; the axis morphology suggests a high magma supply rate. Magnetic paleointensity measurements on basaltic glasses dated several lava flows at about 2,000 +/- 1,000 years, suggesting a major volcanic episode that produced lava flows flooding much of the axial plateau and extended on to its flanks. Several other lava flows were dated at "contemporary" ages, perhaps less than 100 years.

Northern EPR at 10.7�N
Undersea Features
Divers in the submersible Alvin discovered an extremely fresh lava flow in an unexpected location at 10�44'N on the East Pacific Rise during an expedition in November 2003. The young flow was covered by bacterial mats, had large amounts of bacterial floc ("snow-blowers") issuing from diffuse vents, and was sparsely populated by small animals. Uranium-series dating indicated that the eruption had taken place within a time window only a few months to weeks prior to the observations. This segment of the East Pacific Rise, located just north of the Clipperton Transform Fault, is an area with an estimated low magma production rate.

Northern EPR at 9.8�N
Undersea Features
A series of dives with the submersible Alvin in 1991 on the East Pacific Rise at about 9�50'N detected evidence for a very recent, possibly ongoing, eruption. Hot-vent animal communities documented during November-December 1989 had been buried by fresh basaltic lava flows, and the scorched soft tissues of partially buried biota had not yet attracted bottom scavengers. Fresh black smoker chimneys and new lava flows were present. This site is south of the Clipperton Fracture Zone at a depth of about 2,500 m, and about 1,000 km SW of Acapulco, M�xico; the south end of the Lamont Seamount chain is about 10 km NW. This is also the location where lava flows previously estimated as being less than roughly 50 years old had been found. Later dating using very short half-life radionuclides from dredged samples confirmed the young age of the eruption and indicated that another eruptive event had taken place in late 1991 and early 1992. An eruption in 2005-2006 produced lava flows that entrapped previously emplaced seismometers.

Mathematicians Ridge Volcanic Province

Socorro
Mathematicians Ridge Volcanic Province
Socorro, the SE-most of the Revillagigedo Islands south of Baja California, is the summit of a massive, predominately submarine basaltic shield volcano capped by a largely buried, 4.5 x 3.8-km-wide summit caldera. A large tephra cone and lava dome complex, Cerro Evermann, forms the summit, and along with other cones and vents, fills much of the Pleistocene caldera. Rhyolitic lava domes have been constructed along flank rifts oriented to the N, W, and SE, and silicic lava flows from summit and flank vents have reached the coast and created an extremely irregular shoreline. Late-stage basaltic eruptions produced cones and flows near the coast. Only minor explosive activity, some of which is of uncertain validity, has occurred from flank vents in historical time dating back to the 19th century. In 1951 a brief phreatic eruption ejected blocks, and the gas column reached 1200 m altitude. A submarine eruption occurred during 1993-94 from a vent 3 km W of the island during which large scoriaceous blocks up to 5 m in size floated to the surface without associated explosive activity.

Barcena
Mathematicians Ridge Volcanic Province
Volc�n B�rcena, formed by eruptions during 1952-53, is the most prominent feature of the 4.5-km-long Isla San Benedicto, the NE-most of the Revillagigedo Islands, 350 km S of the tip of Baja California. Pleistocene trachytic lava domes form the north end of the island, with B�rcena and Mont�culo Ciner�tico at the southern end. Mont�culo Ciner�tico is a smaller tephra cone that preceded and was largely overtopped by B�rcena, and may also have been constructed during the past few hundred years. Growth of the 300-m-high B�rcena tephra cone beginning in August 1952 was accompanied by strong explosive eruptions and pyroclastic flows. The eruption concluded the following year with the emplacement of two small lava domes in the crater and extrusion of a coastal lava delta at the SE base of the cone.

Gulf of California Rift Volcanic Province

Salton Buttes
United States
Gulf of California Rift Volcanic Province
The Salton Buttes consist of five small rhyolitic lava domes extruded onto Quaternary sediments of the Colorado River delta at the SE margin of the Salton Sea. Their age has variously been considered to be late Pleistocene or early Holocene based on different dating techniques. Recent paleomagnetic dating calibrated by radiocarbon ages suggests that the domes were erupted during an interval of about 500 years between about 2,300 and 1,800 years ago, with the possible exception of Mullet Island at the northern end of the field, which could be as much as 5,000 years older. The present-day saline Salton Sea was formed in the early 20th century by unintended flooding into the basin formerly occupied by Pleistocene Lake Cahuilla Lake during diversion of the Colorado River for irrigation purposes. The Salton Sea geothermal field produces saline brines.

Isla San Luis
Gulf of California Rift Volcanic Province
Volcano type: Tuff cone
Isla San Luis is the largest of the seven Encantada islands at the NW end of the Guaymas lineament in the northern part of the Gulf of California. The 4.5 km2 island (also known as La Encantada Mayor, or Salvatierra) is located 3 km off the eastern shore of Baja California north of Punta Bufeo, and has an irregular shoreline with a narrow peninsula forming its SW tip. Initial basaltic andesite and andesitic submarine eruptions producing palagonite tuffs were followed by effusion of subaerial dacitic lava flows and the formation of dacitic tuff rings. The latest eruptions formed two rhyolitic obsidian domes, the younger in a tuff cone at the center of the island and at the older at the NW tip of the island. In their detailed study of the island, Paz Moreno and Demant (1999) did not specifically suggest Holocene activity, but noted that the "well-preserved morphology of the volcanic structures clearly support a late Quaternary age for all the eruptive activity" and that the northern lava dome may have been emplaced during the 110-130 ka interglacial period. Hausback aet al. (2003) 14C dated marine mollusk shells associated with three eruptions in the last 5,000 years.

Jaraguay Volcanic Field
The Jaraguay Volcanic Field is the northernmost of a group of large young alkalic volcanic fields in Baja California. Located primarily on the Pacific Ocean side of northern Baja between Jaraguay and Arroyo San Jos�, the field contains numerous youthful-looking cinder cones and associated basaltic and basaltic andesite lava flows. Some lava flows are less vegetated than flows of the San Quint�n Volcanic Field to the north. Several lava flows were erupted near the south side of Arroyo San Jos� at the SW end of the Jaraguay volcanic field.

San Borja Volcanic Field
The San Borja (or El Rosarito) volcanic field, is located in central Baja California NE of the Vizcaino Peninsula. Holocene lava flows occur at Rosarito and Morro San Domingo at the western end of the field along the coast north of the Vizcaino Peninsula. Some lava flows are less vegetated than flows of the San Quint�n volcanic field to the north that overlie 5,000-6,000 year-old midden deposits (Rogers et al., 1985). The Holocene lava flows in the western part of this alkalic volcanic field are of basaltic andesite and andesitic composition.

Isla Tortuga
A youthful shield volcano forms Isla Tortuga, which lies in the Gulf of California, 40 km off the Baja coast. There is a circular, 1-km-wide caldera, west of the center of the oval 4-km-long island. Circumferential faults cut the rim of the more than 100-m-deep caldera, which is floored by a solidified lava lake and contains youthful-looking spatter cones. The volcano was constructed during two north-migrating periods of activity that began with submarine eruptions and included formation of a circular tuff-ring complex enclosing the caldera. The sides of a small volcanic horst in the center of the caldera display lava flows overlying a 2-m-thick halite bed, formed when sea water filled the caldera, creating an evaporite basin. Recent lava flows cover most of the flanks, and fumarolic activity has continued into historical time. A submarine cone with a 2-km-wide summit caldera lies about 5 km ESE of the island on the flanks of the edifice.

Comondu-La Purisima
Latitude: 26°N
The Comond�-La Pur�sima volcanic field, located in southern Baja California, west of the Sierra de la Giganta, dates back to the Miocene. However, the youthful morphology of some cinder cones suggested possible Holocene ages (Sawlan, 1991). The youngest lavas form blocky flows with flow ridges and are mostly located in the area between Comond� and the La Pur�sima river. Vents usually occur along NNW-trending faults, and many lava flows are offset, sometimes repeatedly, along grabens. Both basaltic and andesitic lava flows are present. The former are typically 5-10 m thick, and the latter are up to 60-80 m thick and form dense, glassy flows with subhorizontal fractures.

Hawaiian-Emperor Hotspot Volcano Group

Kama'ehuakanaloa
United States
Hawaiian-Emperor Hotspot Volcano Group
The Kama?ehuakanaloa seamount, previously known as Loihi, lies about 35 km off the SE coast of the island of Hawaii. This youngest volcano of the Hawaiian chain has an elongated morphology dominated by two curving rift zones extending north and south of the summit. The summit region contains a caldera about 3 x 4 km and exhibits numerous lava cones, the highest of which is about 975 m below the ocean surface. The summit platform also includes two well-defined pit craters, sediment-free glassy lava, and low-temperature hydrothermal venting. An arcuate chain of small cones on the western edge of the summit extends north and south of the pit craters and merges into the crests prominent rift zones. Seismicity indicates a magmatic system distinct from that of Kilauea. During 1996 a new pit crater formed at the summit, and lava flows were erupted. Continued volcanism is expected to eventually build a new island; time estimates for the summit to reach the ocean surface range from roughly 10,000 to 100,000 years.

Kilauea
United States
Hawaiian-Emperor Hotspot Volcano Group
Kilauea overlaps the E flank of the massive Mauna Loa shield volcano in the island of Hawaii. Eruptions are prominent in Polynesian legends; written documentation since 1820 records frequent summit and flank lava flow eruptions interspersed with periods of long-term lava lake activity at Halemaumau crater in the summit caldera until 1924. The 3 x 5 km caldera was formed in several stages about 1,500 years ago and during the 18th century; eruptions have also originated from the lengthy East and Southwest rift zones, which extend to the ocean in both directions. About 90% of the surface of the basaltic shield volcano is formed of lava flows less than about 1,100 years old; 70% of the surface is younger than 600 years. The long-term eruption from the East rift zone between 1983 and 2018 produced lava flows covering more than 100 km2, destroyed hundreds of houses, and added new coastline.

Mauna Loa
Massive Mauna Loa is a basaltic shield volcano that rises almost 9 km from the ocean floor to form the world's largest Holocene volcano. Flank eruptions typically occur from the lengthy NE and SW rift zones, and from the Moku`aweoweo summit is caldera, which is within an older and larger 6 x 8 km caldera. Two of the youngest large debris avalanches documented in Hawaii traveled nearly 100 km from Mauna Loa; the second of the Alika avalanches was emplaced about 105,000 years ago (Moore et al., 1989). Almost 90% of the surface of the volcano is covered by lavas less than 4,000 years old (Lockwood and Lipman, 1987). Beginning about 1,500 years ago, a series of voluminous overflows from a summit lava lake covered about 25% of the volcano's surface. Over the last 750 years, from shortly after the formation of Moku`aweoweo caldera until the present, an additional 25% of the volcano has been covered with lava flows, mainly from summit and NW rift zone vents.

Mauna Kea
Mauna Kea, Hawaii's highest volcano, reaches 4205 m, only 35 m above its neighbor, Mauna Loa. In contrast to Mauna Loa, Mauna Kea lacks a summit caldera and is capped by a profusion of cinder cones and pyroclastic deposits. It's rift zones are less pronounced than on neighboring volcanoes, and the eruption of voluminous, late-stage pyroclastic material has buried much of the early basaltic shield volcano, creating a steeper and more irregular profile. This transition took place about 200,000 to 250,000 years ago, and much of Mauna Kea, whose Hawaiian name means "White Mountain," was constructed during the Pleistocene. Its age and high altitude make it the only Hawaiian volcano with glacial moraines. A road that reaches a cluster of astronomical observatories on the summit also provides access to seasonal tropical skiing. The latest eruptions produced a series of cinder cones and lava flows from vents on the northern and southern flanks during the early- to mid-Holocene.

Hualalai
The basaltic Hualalai, at the western end of the island, is the third youngest shield volcano on Hawaii. Three rift zones, with numerous cinder cones and spatter cones, trend N, NW, and SE, and converge about 5 km E of the summit. Detailed mapping has shown that 95% of the surface area is of Holocene age, more than half is less than 3,000 years old, and a quarter is less than 1,000 years old. Eruptions at the end of the 18th century and in 1801 produced lava flows from vents on the NW rift zone that reached the sea and buried villages; the 1801 Huehue lava flow underlies part of the airport at Kona. The earlier of the two flows, the Kaupulehu lava flow, is notable for its large quantities of lava-encrusted mafic and ultramafic nodular xenoliths.

Haleakala
The massive Haleakala shield volcano forms the eastern portion of the island of Maui. The summit is at the NW end of a volcanic ridge and at the head of a large scarp that opens to the ENE, interrupting the ridge which continues 7 km across the valley, formed as a result of the coalescence of headward erosion of the Koolau and Kaupo valleys. Subsequently the valley has been partially filled by a chain of young cinder cones and lava flows erupted along the rift zone that extends across the basaltic volcano from the SW to the E flanks. The most recent eruption was thought to have occurred between the exploring voyages of La Perouse in 1786 and Vancouver in 1793, but uncertainty surrounds the date of this event, which could have occurred in about 1750 CE (anthropological evidence) or several centuries earlier (radiocarbon dates).

Northeast Pacific Rifts Volcanic Province

Endeavour Segment
Canada
Northeast Pacific Rifts Volcanic Province
The Endeavour Segment (or Ridge) lies near the northern end of the Juan de Fuca Ridge, W of the coast of Washington and SW of Vancouver Island. The northern end is offset to the east with respect to the West Valley Segment, which extends north to the triple junction with the Sovanco Fracture Zone and the Nootka Fault. The 90-km-long, NNE-SSW-trending segment lies at a depth of more than 2,000 m and is the site of vigorous high-temperature hydrothermal vent systems that were discovered in 1981. Five major vent fields that include sulfide chimneys and black smoker vents are spaced at about 2-km intervals in a 1-km-wide axial valley at the center of the ridge. Preliminary uranium-series dates of Holocene age were obtained on basaltic lava flows, and other younger "zero-age" flows were sampled. Seismic swarms were detected in 1991 and 2005.

Cobb Segment
Canada
Northeast Pacific Rifts Volcanic Province
The Cobb Segment is in the northern part of the Juan de Fuca Ridge, south of the Endeavour Ridge segment. This 150-km-long segment, also known as the Northern Symmetrical or NSymm Segment, is the longest of the Juan de Fuca Ridge. It has a narrow axial crest, 1-2 km wide, with a shallow graben that has a high point at about 2,300 m depth. A prominent seamount with hydrothermal deposits at its summit lies just west of the axis high and was the source of a broad area of young, mostly sediment-free lava flows. As with other Juan de Fuca Ridge segments, a shallow magma source is thought to underlie the Cobb Segment, and a preliminary Uranium-series date of Holocene age was obtained on a basaltic lava flow.

CoAxial Segment
Undersea Features
The CoAxial segment of the Juan de Fuca Ridge is about 435 km W of the Oregon coast, NE of Axial volcano. A submarine eruption along the CoAxial segment that produced thermal plumes and a new lava flow was detected by acoustic hydrophones in June 1993, just days after installation of the hydrophone system. This was the first deep-sea volcanic eruption detected as it was happening. The location of the eruption was at a depth of about 2,400 m, about 37 km NE of Axial volcano. Bathymetric surveys indicated that one or more additional sea-floor lava extrusions took place immediately east of the 1993 lava flow sometime between 1981-82 and 1991.

Axial Seamount
Longitude: 130°W
Axial Seamount rises 700 m above the mean level of the central Juan de Fuca Ridge crest about 480 km W of Cannon Beach, Oregon, to within about 1,400 m of the ocean surface. It is the most magmatically and seismically active site on the Juan de Fuca Ridge between the Blanco Fracture Zone and the Cobb offset. The summit is marked by an unusual rectangular-shaped caldera (3 x 8 km) that lies between two rift zones and is estimated to have formed about 31,000 years ago. The caldera is breached to the SE and is defined on three sides by boundary faults of up to 150 m relief. Hydrothermal vents with biological communities are located near the caldera fault and along the rift zones. Hydrothermal venting was discovered north of the caldera in 1983. Detailed mapping and sampling efforts have identified more than 50 lava flows emplaced since about 410 CE (Clague et al., 2013). Eruptions producing fissure-fed lava flows that buried previously installed seafloor instrumentation were detected seismically and geodetically in 1998 and 2011, and confirmed shortly after each eruption during submersible dives.

Cleft Segment
The Cleft Segment, the southernmost of the Juan de Fuca Ridge, lies immediately north of the Blanco Fracture Zone. The 80-km-long segment is named for a nearly continuous 10-km-long, 30-50 m wide cleft at its southern end. Two episodes of seafloor spreading were documented along the northern part of the segment in the 1980's. Bathymetric surveys indicated that a series of discontinuous pillow-lava mounds were extruded along a 17-km-long fissure between 1981 and 1987. The eruption possibly coincided with emission of a large plume of hot mineral-laden water in 1986. The location is at a depth of about 2,300 m near the northern edge of the Cleft segment and the southern end of the Vance segment of the Juan de Fuca Ridge, about 500 km W of the central Oregon coast. Youthful sheet-lava flows immediately south of the pillow lavas were estimated to be only a few years older.

North Gorda Ridge Segment
The northernmost of five segments of the Gorda Ridge lies immediately south of the Blanco Transform Fault that offsets the Gorda and Juan de Fuca oceanic spreading ridges. The 65-km-long segment is located about 200 km W of the southern Oregon coast and has deep 5- 10-km-wide valleys at either ends with a shallower narrow axial valley at the center. This morphology, which in plan view resembles an hourglass, is typical of magmatically active spreading segments. A submarine lava flow was erupted in late February and early March 1996, near the center of the segment. The eruption was initially detected through acoustic T-waves from a seismic swarm and the emission of large thermal plumes. In April submarine cameras revealed new lava flows about 100-200 m wide along a fissure that was at least 3.5 km long. A seismic swarm of uncertain origin also occurred at this location in January 1998.

Escanaba Segment
The linear, N-S-trending Escanaba Segment, the southernmost of the Gorda Ridge, lies immediately north of the Mendocino Fracture Zone off the coast of northern California. The axial crest of the 130-km-long segment, also known as the Escanaba Trough, is about 3-5 km wide at the northern end and increases to 18 km to the south near the junction with the Mendocino FZ. The rift valley floor of the slow-spreading segment lies at about 3,200 m depth, bounded by faulted walls about 1,500 m high with unusual gold-bearing massive sulfide deposits in sediment hills at the base of the scarps uplifted by volcanic sills or laccoliths. Thick sediment deposits from the continental margin enter the axial trough from the fracture zone and thin to the north. A preliminary uranium-series date of Holocene age was obtained from a basaltic lava flow in the axial valley in the less-sedimented northern part.

Jackson Segment
The Jackson Segment of the Gorda Ridge more than 200 km off the coast of Oregon lies immediately SSW of the North Gorda Ridge, the northernmost of five segments forming the Gorda Ridge spreading center. The first recorded activity took place in April 2001, when volcanic seismicity was detected by hydroacoustic monitoring. The seismicity indicated possible dike propagation to the south and was similar to that which was documented at the time of the eruption of a submarine lava flow from the adjacent North Gorda Ridge segment in 1996. The 2001 activity originated from the central axial valley of the Jackson Segment, near the "narrowgate" on the southern part of the segment. Later surveys, however, revealed no evidence for submarine eruptive activity in April 2001.

West Valley Segment
Canada
Volcano type: Fissure vent
The West Valley Segment is the northern-most part of the Juan de Fuca Ridge, intersecting the Sovanco Fracture Zone and offset from the Endeavour Segment to the south.

East Blanco Depression
Volcano type: Fissure vent
The East Blanco Depression (EBD) is a pull-apart basin within the western Blanco Transform Fault Zone, a right-lateral transform fault that links the Juan de Fuca Ridge and Gorda Ridge (Dziak et al., 1996). In January 1994 a T-wave swarm suggested eruptive activity. Investigations later that year were inconclusive regarding an associated eruption, but found an active hydrothermal mound on the flanks of a pillow-lava volcano. Dziak et al. (1996) considered the EBD to have been the site of recent seafloor eruptions.

North America Volcanic Regions

Basin and Range Volcanic Province

Mono Lake Volcanic Field
Basin and Range Volcanic Province
Latitude: 38°N
The Mono Lake volcanic field east of Yosemite National Park and north of the Mono Craters consists of vents within Mono Lake and on its north shore. The most topographically prominent feature, Black Point, is an initially sublacustral basaltic cone that rises above the NW shore and was formed about 13,300 years ago when Mono Lake was higher. Holocene rhyodacitic lava domes and flows form Negit and parts of Paoha islands off the northern shore and center of the lake, respectively. The most recent eruptive activity in the Long Valley to Mono Lake region took place 100-230 years ago, when lake-bottom sediments forming much of Paoha Island were uplifted by intrusion of a rhyolitic cryptodome (Stine, in Bailey et al., 1989). Spectacular tufa towers line the shores of Mono Lake.

Mono-Inyo Craters
Basin and Range Volcanic Province
The Mono-Inyo Craters chain, on the eastern side of the Sierra Nevada between Mono Lake and Long Valley caldera, form a sickle-shaped, 25-km-long group of 35 dominantly rhyolitic lava domes, lava flows, and tephra rings. The partially overlapping dike-fed domes of the Mono Craters at the north end were erupted near the margin of a pull-apart basin. Explosive eruptions began more than 50,000 years ago from now-buried vents, but almost all of the exposed domes and flows are of Holocene age. Activity propagated both north and south from the center of the chain during the late Holocene. The latest eruptions occurred nearly contemporaneously about 600 years ago from the Panum Crater area at the northern end of the Mono Craters and from the Inyo Craters to the south, producing a series of tephra rings and obsidian lava domes and flows accompanied by deposition of locally extensive tephra layers and the formation of several phreatic explosion craters at the southern end of the Inyo Craters. The latest eruptions at Inyo Craters about 600 years ago produced explosive eruptions accompanied by formation of the South Deadman, Obsidian Flow, and Glass Creek rhyolitic lava domes and lava flows. The Inyo Crater Lakes are small phreatic craters that formed during this eruption on the south flank of the Pleistocene Deer Mountain rhyolite dome of the Long Valley caldera.

Mammoth Mountain
Mammoth Mountain, a trachydacitic lava-dome complex, lies on the SW topographic rim of Long Valley caldera. It is west of the structural rim of the caldera and considered to represent a magmatic system distinct from other nearby volcanic regions (Hildreth, 2004). The latest magmatic eruptions took place about 57,000 years ago. Mammoth Mountain is surrounded by at least 35 mafic vents that are part of the same magmatic system and include Red Cones, two closely spaced basaltic cinder cones SW of Mammoth Mountain and SE of Devils Postpile National Monument. The cones, whose name derives from colorful scoria deposits, are unglaciated and were radiocarbon dated at about 8,500 years ago. Phreatic eruptions, distinct from those at South Inyo Craters, took place about 700 years ago from vents on the north side of Mammoth Mountain. Recent unrest, including seismicity, gas emission, and tree kill, is thought to be related to dike intrusion in 1989.

Ubehebe Craters
Volcano type: Maar(s)
The Ubehebe Craters (pronounced you-bee-HEE-bee) consist of an isolated group of overlapping maars formed during eruptions of alkali basalt along a fault cutting alluvial fan deposits on the flanks of Tin Mountain in Death Valley National Park. Ubehebe Crater is a 0.8-km-wide, 235-m-deep maar surrounded by a tuff ring. Little Hebe Crater, the second youngest vent located immediately south, is a small tuff cone with a 100-m-wide crater overlain by pyroclastic-surge deposits. At least a dozen craters are located within an area of 3 km2, and bedded pyroclastic-surge deposits cover an area of 15 km2. Early scoria cone formation was followed by hydrovolcanic explosions that formed two clusters of explosion craters and tuff rings. Field work and revised dating (Calzia et al., 2016; Fierstein et al., 2016) based on paleomagnetic and 10Be evidence has shown that the craters were formed during a single short-lived phreatic, phreatomagmatic, and magmatic eruptive episode about 2,100 years ago.

Soda Lakes
Volcano type: Maar(s)
Two lake-filled maars, Soda Lake and Little Soda Lake, lie NW of the town of Fallon. The basaltic maars were formed subaerially, post-dating the Pleistocene glacial Lake Lahontan, and were estimated to be less than 10,000 years old and perhaps even less than 1,500 years old (Garside and Schilling, 1979; Price and LaPointe, 1998). Soda Lake is about 1.3 x 2 km elongated NE-SW. The 300-m-wide Little Soda Lake lies south of Soda Lake. The late-Pleistocene Upsal Hogback cones lie to the NNE of Soda Lakes. The maars are the site of a geothermal prospect that may have discharged hot springs through the end of the 19th century.

Markagunt Plateau
The Markagunt Plateau volcanic field, covering 3,000 km2 east of Cedar Breaks National Monument in SW Utah, includes basaltic cinder cones, lava vents, and sparsely vegetated lava flows. Products of an older episode of volcanism producing trachytic, andesitic and rhyolitic lavas that were succeeded by basaltic lavas of two different ages. Several lines of NE-SW-trending cinder cones occur within the volcanic field, with the youngest flows being located near Panguitch Lake on the north and Navajo Lake on the south. Navajo Lake formed when a thick blocky flow dammed Duck Creek. Young lava flows, many of which are fissure fed, have distinct margins and covered or diverted stream drainages, which have for the most part not been reestablished across the flows. Although the precise age of the lava flows is not known, the oldest trees on the youngest flows at Panguitch Lake date to about 1050 CE (Gregory, 1949), consistent with legends of the Southern Paiute (who arrived in the area about 1000 CE) noting ejection of fiery rocks and molten lava flows (Palmer, 1957).

Black Rock Desert
The Black Rock Desert volcanic field consists of a group of closely spaced small Pleistocene-to-Holocene volcanic fields in the Black Rock and Sevier deserts of south-central Utah, at the eastern margin of the Great Basin. The Black Rock Desert field contains both Utah's youngest known rhyolite dome (400,000 years old) and its youngest eruptive vent, which produced the roughly 660-year-old Ice Springs lava flows. The broader volcanic field includes the smaller Deseret, Pavant, Kanosh, Tabernacle, Ice Spring, and northern Black Rock Desert fields. The Pavant Butte and Tabernacle Hill tuff cones were erupted about 16,000 and 14,000 years ago through the waters of glacial Lake Bonneville. Lava flows from the Ice Springs crater complex traveled about 4 km west and north, overlapping late-Pleistocene flows from Pavant Butte.

Dotsero
Volcano type: Maar
A small maar and scoria cone complex at Dotsero is located near the junction of the Colorado and Eagle Rivers west of the Gore Range. Highway I-70 cuts across a lava flow, but the most prominent feature of the complex is a 700 m wide and 400 m deep maar that was erupted about 4,150 radiocarbon years ago along a ridge consisting of evaporites and reddish oxidized sandstones of Pennsylvanian age. Small scoria cones were constructed along a NNE-SSW line on either side of the maar. Small lahars preceded eruption of a basaltic lava flow that traveled 3 km down two narrow V-shaped valleys and spread out onto the floodplain of the Eagle River, diverting the river to the south side of the valley. Older Pleistocene basaltic lava flows occur nearby at Willow Peak, McCoy, and Triangle Peak.

Uinkaret Field
The Uinkaret volcanic field straddling the Grand Canyon contains cinder cones that have produced lava flows that repeatedly cascaded into the Grand Canyon, forming temporary lava dams up to 200 m high. Two of the most prominent landmarks are Vulcan's Throne, a cinder cone on the north rim, and Vulcan's Forge, a small volcanic neck erupted within the Colorado River, 1000 m below. Most of the field lies north of the Grand Canyon on the Uinkaret Plateau between the Toroweap and Hurricane faults. It is largely Pleistocene in age, and Vulcan's Throne has a cosmogenic helium age of about 73,000 years. Volcanic activity has continued into the Holocene. One lava flow, from Little Springs, south of Pliocene Mount Trumbull, has a cosmogenic helium age of 1300 +/- 500 years BP. Pottery sherds dated at between 1050 and 1200 CE were found within the Little Springs lava flow, which occurred about the same time as the Sunset Crater eruption in the San Francisco volcanic field to the SE.

San Francisco Volcanic Field
The vast San Francisco Volcanic Field in northern Arizona has more than 550 vents, the youngest of which is Sunset Crater, named for its brilliantly colored scoria deposits on the cone. The eruptions forming the 340-m-high Sunset Crater cinder cone were initially considered from tree-ring dating to have begun between the growing seasons of 1064-1065 CE; however, more recent paleomagnetic evidence places the activity between about 1080 and 1150 CE. The largest vent, Sunset Crater itself, was the source of the Bonito and Kana-a lava flows that extended about 2.5 km NW and 9.6 km NE, respectively. Additional vents along a 10-km-long fissure extending SE produced small spatter ramparts and a 6.4-km-long lava flow to the east. Ash and lapilli covered an area of more than 2,100 km2 and forced the abandonment of settlements of the indigenous Sinagua Indians.

Carrizozo
The massive Carrizozo lava flow, which traveled 75 km down the Tularosa Basin of south-central New Mexico, is one of Earth's longest known Holocene lava flows. The youthful-looking flow originated from a broad low basaltic shield on the floor of the Tularosa Basin, east of the Rio Grande Rift, topped by Little Black Peak, a small cinder cone. The 4.2 km3 tube-fed pahoehoe flow covered 330 km2 and has a width that ranges from 1 km in the central neck region to 5 km in the proximal and distal portions. The flow was inferred to have been emplaced during a single long-duration eruption estimated to have lasted 2-3 decades. A surface exposure age of about 5,200 BP was obtained for the Carrizozo flow. An older lava flow traveled 16 km S and 11 km E from Broken Back crater.

Zuni-Bandera
The Zuni-Bandera volcanic field covers 2,460 km2 along the Jemez lineament west of the Rio Grande Rift. An older volcanic episode, mostly from vents along the Chain of Craters, took place about 3.8-3.7 million years ago (Ma); the younger episode began about 1.7 Ma and formed an extensive area of lava flows known as El Malpais. The youngest lava flow, the McCartys flow, traveled 60 km NE, fed by lava tubes up to 29 km long. The McCartys flow was recorded in native legends and was thought to have been erupted about 1,000 years ago, but radiocarbon dating indicates an age of about 3,000 years before present. The only other dated flow of Holocene age originated from Bandera Crater about 9,000-10,000 radiocarbon years ago. An earlier flow, the massive Pleistocene Fence Lake lava flow, traveled as far as 90 km W.

Red Hill-Quemado
The Red Hill-Quemado volcanic field in western New Mexico is across the border from the Springerville volcanic field in Arizona and contains more than 40 cinder cones and maars that were active from the late Miocene to early Holocene. The volcanic field lies along the NE-trending Jemez Lineament that extends from SE Colorado to east-central Arizona. Dating by Onken and Forman (2017) showed that three eruptive events took place during the early Holocene, and that the 2-km-wide Zuni Salt Lake maar with its late-stage nested cinder cones was formed about 11,000-11,800 calibrated 14C years ago.

Pinacate
Pinacate is a roughly 55 x 60 km volcanic field in the Sonoran desert of NW M�xico. It contains numerous maars, tuff rings, and cinder cones of late-Pleistocene to Holocene age. The 2,000 km2 field is a prominent feature in this arid, sparsely populated region between the Arizona border and the head of the Gulf of California. An older volcanic period constructed the Santa Clara basaltic-to-trachytic shield volcano. This was followed by the eruption of more than 500 basaltic cinder cones and lava flows that cover the slopes of Santa Clara and the surrounding desert. Among the principal features of the field are two maars: Elegante crater (1.6 km wide) and Cerro Colorado (1 km wide). Legends from the Tohono O'odham people tell of eruptions, though accounts of ash-and-steam eruptions in the 20th century are questionable.

Durango Volcanic Field
The broad Durango volcanic field covers 2,100 km2 at the NW corner of the Meseta Central near the eastern edge of the Sierra Madre Occidental of north-central M�xico. The expansive undissected lava plain lies within the Mexican Basin and Range province and is NE of the city of Durango. The field includes about 100 Quaternary basanitic cinder and lava cones as well as several xenolith localities. La Bre�a-El Jag�ey maar complex consists of two intersecting maars, the largest of which (La Bre�a) contains a series of nested cinder cones. The maar complex is one of the youngest eruptive centers and was considered by Aranda-G�mez et al. (1992) to be only a few thousand years old.

Yellowstone-Snake River Hotspot Volcano Group

Black Butte Crater Lava Field
Yellowstone-Snake River Hotspot Volcano Group
The Black Butte Crater lava field is the westernmost of the young lava fields of the Eastern Snake River Plain. It lies north of Twin Falls, Idaho, and created an L-shaped lava flow 2-5 km wide that extends 60 km S and then west. A single radiocarbon age of 10,130 +/- 350 years BP was obtained for lava flows here (Kuntz et al., 1986). Black Butte Crater caps a lava shield at the NE end of the flow field. The vent area contains a complex lava lake that forms a six-part flower-petal like depression with steep walls up to 30 m high that covers an area of 2 km2. A lava tube and channel system extending 5 km SE of the crater displays both roofed and collapsed portions. The Big Wood and Little Wood rivers follow the northern and southern margins of the distal part of the lava flow, respectively. The voluminous flow diverted the river channels so that they now join 40 km W of their former confluence.

Craters of the Moon
Yellowstone-Snake River Hotspot Volcano Group
Craters of the Moon, the largest lava field of the Snake River Plain (SRP), covers about 1,600 km2 with more than 60 mapped lava flows erupted from eight fissure systems. About 25 cinder cones up to 250 m high formed primarily along a 45-km-long segment of the Great Rift, the principal 2-8 km wide fissure system that trends NW-SE through Craters of the Moon National Monument. Craters of the Moon lies at the NW part of the eastern SRP, with White Knob and the Pioneer Mountains along the northern boundary. The lava field was formed during eight eruptive episodes between about 15,000 and 2,000 years ago separated by quiescent periods up to about 3,000 years in duration. This contrasts with other SRP lava fields, which were formed during single eruptive episodes of relatively short duration. A complex assemblage of basaltic volcanic features is present, and cinder cones are common.

Wapi Lava Field
The Wapi Lava Field, SE of the Craters of the Moon, covers about 325 km2, and consists of a low shield volcano formed during an eruption around 300 BCE that produced ~6 km3 of pahoehoe lava flows. The mass of layered lava flows and agglutinates forming the high point of the lava shield is named Pillar Butte. The vent area lies along the Great Rift of the Craters of the Moon and consists of five major and six minor vents covering an area of 0.5 km2. The largest of the vents contains several pit craters truncating lava lakes that filled the crater. The small King's Bowl rift immediately to the north formed at about the same time along a central eruptive fissure flanked by two parallel non-eruptive fissures. This eruption also produced a phreatic explosion that created Kings Bowl, an 80-m-long, 30-m-deep explosion crater. Split Butte maar to the west is partially overlapped by Wapi flows.

Hell's Half Acre
Hell's Half Acre, the easternmost of the young basaltic lava fields of the Snake River Plain, covers an area of about 400 km2 SW of Idaho Falls. Basaltic lavas forming the broad, low shield are dominantly pahoehoe flows that were erupted from a 3-km-long, NW-SE trending vent system at the NW part of the field during a brief eruptive episode about 5,200 years ago. The summit vent area contains an irregular, elongate 300 x 800 m central depression where a former lava lake fed late-stage flows. About 10 circular pit craters are present in the lava lake surface, and two prominent lava tube systems are located near the summit vent complex. Two major flow lobes, each about 5 km wide and 10 km long, extend to the S and SW along the flood plain of the Snake River and surround Morgans Pasture, a large kipuka.

High Lava Plains Volcanic Province

Devils Garden
High Lava Plains Volcanic Province
The Devils Garden lava field, the NW-most of a group of three youthful-looking basaltic lava fields SE of Newberry volcano, east of the Cascade Range, contains 117 km2 of overlapping pahoehoe lava flows erupted from fissure vents at the NE part of the field. Inflated pahoehoe flows were erupted from spatter ramparts and spatter cones onto a nearly flat-lying surface surrounding several large kipukas of older rocks. The extremely fluid and inflated lavas left flows that typically increased from about a half meter thickness near the vent to about 5 m in more distal areas and have a volume of 1.2 km3. The flows are older than the Mazama Ash (6,800 years old) but are fresh-looking and relatively unvegetated. The precise age of Devils Garden is not known, but was considered to be either Holocene (Smith et al. 1978; Sarna-Wojciki et al. 1983) or about 20,000 years old (Chitwood 1994).

Diamond Craters
High Lava Plains Volcanic Province
Diamond Craters volcanic field consists of a 70 km2 area of basaltic lava flows along with numerous cinder cones and maars located between the SE Oregon town of Burns and Steens Mountain. A basaltic pahoehoe lava field is overlain by deposits from phreatomagmatic and Strombolian eruptions that formed a late-stage central vent complex of about 20 craters and cones that densely fill a 1.1 x 1.6 km caldera. The age is constrained to within 7,320-7,790 calibrated years Before Present by radiocarbon-dated floodplain deposits below the lava flows and paleomagnetic evidence (Sherrod et al., 2012). Doming has created a series of six overlapping topographic highs. The highest of these is known as Graben Dome; its summit is cut by a NW-SE graben 0.4 x 2.1 km long and 30 m deep. Lava flows on the E side of the field, scattered cinder cones, and maars formed during the last stage of activity.

Jordan Craters
Jordan Craters volcanic field consists of well-preserved basaltic lava flows and scoria cones that are the youngest and northernmost of a group of three Quaternary lava fields covering an area of 250 km2 in SE Oregon. The Pleistocene Clarks Butte shield volcano and Rocky Butte (Lava Butte) lava fields lie to the south, along the trend of regional Basin and Range faulting. Jordan Craters lie on the Owyhee-Oregon plateau at the SE end of a series of widely scattered young volcanic fields extending SE from Bend, Oregon. Coffeepot Crater at the NW end of the field was the source, about 3,200 years ago or later, of one of Oregon's youngest lava flows. The flows covered 75 km2 with 1.6 km3 of olivine-basalt pahoehoe and dammed local drainages, forming the two small Upper and Lower Cow Lakes at the SE end of the lava field. Jordan Craters is renowned for its excellent exposures of a wide variety of youthful lava-flow features and has similarities to Holocene basaltic flows of Idaho's Snake River Plain to the east.

California Coast Ranges Volcano Group

Clear Lake Volcanic Field
California Coast Ranges Volcano Group
The late-Pliocene to early Holocene Clear Lake Volcanic Field in the northern Coast Ranges contains lava dome complexes, cinder cones, and maars of basaltic-to-rhyolitic composition. The westernmost site of Quaternary volcanism in California, this volcanic field is in a complex geologic setting within the San Andreas transform fault system. Mount Konocti, a composite dacitic lava dome on the south shore of Clear Lake, is the largest volcanic feature. Volcanism has been largely non-explosive, with only one major airfall tuff. The latest eruptive activity, forming maars and cinder cones along the shores of Clear Lake, continued until about 9,000 years ago. A large silicic magma body provides the heat source for the Geysers, a geothermal field with a complex of electrical power plants.

High Cascades Volcanic Arc

Rainier
High Cascades Volcanic Arc
Mount Rainier is a heavily glaciated andesitic volcano in the Puget Sound region. Large Holocene mudflows from collapse have reached as far as the Puget Sound lowlands. The present summit was constructed within a large crater breached to the NE, formed by collapse during a major explosive eruption about 5,600 years ago that deposited the widespread Osceola Mudflow. Rainier has produced eruptions throughout the Holocene, including about a dozen during the past 2,600 years; the largest of these occurred about 2,200 years ago. The present summit cone is capped by two overlapping craters. Extensive hydrothermal alteration of the upper portion of the volcano has contributed to its structural weakness; an active thermal system has caused periodic melting on flank glaciers and produced an elaborate system of steam caves in the summit icecap. Reported uncertain 19th-century eruptions, including a possible but not confirmed phreatic eruption in 1894, have not left identifiable deposits.

Adams
High Cascades Volcanic Arc
The andesitic-dacitic Mount Adams stratovolcano is second in volume only to Mount Shasta in the Cascade Range. The volcanic complex is elongated along a NNW-SSE line, and includes more than 60 flank vents over 200 km2. Volcanism began about 940 ka, with three main cone-building stages occurring at about 500, 450, and 30 ka. It was active throughout the Holocene, producing two dozen minor explosive eruptions from summit and flank vents. Six Holocene lava flows are located on the flanks between 2,100 and 2,600 m elevation. The most voluminous Holocene lava flows, some of which traveled 10 km or more, were emplaced between about 7,000 and 4,000 years ago. The latest eruption about 1,000 years ago produced a minor tephra layer and possibly a small lava flow down the E flank.

St. Helens
Prior to 1980, Mount St. Helens was a conical volcano sometimes known as the Fujisan of America. During the 1980 eruption the upper 400 m of the summit was removed by slope failure, leaving a 2 x 3.5 km breached crater now partially filled by a lava dome. There have been nine major eruptive periods beginning about 40-50,000 years ago, and it has been the most active volcano in the Cascade Range during the Holocene. Prior to 2,200 years ago, tephra, lava domes, and pyroclastic flows were erupted, forming the older edifice, but few lava flows extended beyond the base of the volcano. The modern edifice consists of basaltic as well as andesitic and dacitic products from summit and flank vents. Eruptions in the 19th century originated from the Goat Rocks area on the N flank, and were witnessed by early settlers.

West Crater
West Crater, a small andesitic lava dome with associated lava flows, is part of a Quaternary volcanic field in southern Washington consisting primarily of small basaltic and basaltic andesite cinder cones and shield volcanoes, oriented along a NW-SE zone to the SE of St. Helens. This 20-km-wide zone extends from Marble Mountain, north of Swift Reservoir, to south of Trout Creek Hill. The Pleistocene basaltic Trout Creek Hill shield volcano produced a lava flow about 340,000 years ago that traveled 20 km SE, temporarily damming the Columbia River. At least three vents in this field are of Holocene age: West Crater, a small cone at Hackamore Creek, and a phreatic crater at the summit of Bare Mountain. The latest eruptions at these locations have been dated at about 8,000 years before present, and have included emplacement of an andesitic lava dome and associated lava flow at West Crater and formation of a phreatic explosion crater at Bare Mountain.

Indian Heaven
The Pleistocene-to-Holocene Indian Heaven volcanic field, located midway between St. Helens and Adams, is an area of low overlapping shield volcanoes with flank vents primarily oriented N-S. Small shield volcanoes topped by cinder and spatter cones dominate the field, which also contains subglacial vents. The shield volcanoes extend from Sawtooth Mountain on the north to Red Mountain on the south; the high point of the field is Lemei Rock shield volcano. Basaltic-to-andesitic lava flows cover much of the field; individual lava flows, many with extensive lava tubes, traveled up to 46 km. The youngest eruption, about 8,200 years ago, produced the voluminous Big Lava Bed, a 0.9 km3 basaltic lava flow that traveled nearly 25 km S of its source from an unnamed cinder cone SE of Red Mountain, to within 8 km of the Columbia River.

Hood
Mount Hood, Oregon's highest peak, forms a prominent backdrop to the city of Portland. The eroded summit area consists of several andesitic or dacitic lava domes. Major Pleistocene edifice collapse produced a debris avalanche and lahar that traveled north down the Hood River valley and crossed the Columbia River. The glacially eroded volcano has had at least three major eruptive periods during the past 15,000 years. The last two occurred within the past 1,800 years from the central vent high on the SW flank and produced deposits that were distributed primarily to the south and west along the Sandy and Zigzag rivers. The last major eruptive period took place beginning in 1781 CE, when growth of the Crater Rock lava dome was accompanied by pyroclastic flows and lahars down the White and Sandy rivers. The Sandy River lahar deposits extended to the west as far as the Columbia River and were observed by members of the 1804-1805 Lewis and Clark expedition shortly after their emplacement. Minor 19th-century eruptions were witnessed from Portland.

Jefferson
Mount Jefferson, Oregon's second highest peak, is a deeply eroded stratovolcano. The glacier-clad landmark prominent from both sides of the Cascade Range was named by Lewis and Clark for the president that sponsored their expedition. Jefferson was constructed in two episodes interrupted by extensive glacial erosion. The first of these, beginning about 290,000 years ago, produced an andesitic-to-dacitic volcano possibly higher than the current summit. Dacitic lava domes were emplaced during a second cycle beginning about 70,000 years ago which included ash flows that traveled 15 km E and W. Several Holocene cinder cones near the Cascade crest south of Jefferson have produced lava flows that traveled down glacially carved valleys, including those from Forked Butte and North Cinder Peak. The most recent eruption, from a cinder cone on the flank of the South Cinder Peak cone, produced a lava flow that traveled west into Marion Lake about 1,000 years ago.

Blue Lake Crater
Blue Lake Crater is a series of at least three overlapping explosion craters along a NE trend slightly east of the crest of the Cascade Range in the state of Oregon. Explosions through pre-existing bedrock about 1,300 years ago deposited basaltic bombs and cinders, and spread tephra to the E and SE during perhaps the youngest eruption in the Santiam and McKenzie Passes region. The eruption created an elongated, steep-walled crater with a low rim that rises about 50 m above adjacent topography. The crater is now filled by the 300 x 800 m Blue Lake, immediately west of the glacial moraine dammed Suttle Lake. A chain of spatter cones, 6 km to the SSW and about 4 km NE of Mount Washington, is aligned with Blue Lake Crater and has ejecta that are petrographically similar and may have been erupted at the same time.

Sand Mountain Field
The Sand Mountain volcanic field consists of 23 basaltic and basaltic andesite cinder cones along a N-S line immediately west of the Cascade crest NW of Mount Washington. Two cone alignments trending NNW and NNE intersect near the largest cinder cone, Sand Mountain. Although previous radiometric dates spanned a range of more than a thousand years, tightly constrained paleomagnetic ages imply that at least 13 eruptive units were emplaced in a relatively short period of time about 2,950 years ago lasting at most a few decades. The Jack Pine vent at the northern end of the field is compositionally distinct from the rest of the volcanic field and is considered to have been erupted about 4,000 years earlier. Lava flows traveled predominately to the west, blocking local drainages and forming several small lakes.

Belknap
Volcano type: Shield(s)
The Belknap Crater area near McKenzie Pass in Oregon, north of the Three Sisters volcanoes, was the source of one of the largest concentrations of youthful volcanism in the Cascade Range. The basaltic to basaltic andesite Belknap shield volcano, topped by the Belknap Crater pyroclastic cone and the Little Belknap shield volcano immediately to the east, have produced widespread late Holocene lava flows on all sides, much of which took place between about 3,000 and 1,500 years ago. Eruptions from the NE base of Belknap crater produced lava flows that traveled 15 km W into the McKenzie River valley.

Three Sisters
The north-south-trending Three Sisters volcano group dominates the landscape of the Central Oregon Cascades. All Three Sisters stratovolcanoes ceased activity during the late Pleistocene, but basaltic-to-rhyolitic flank vents erupted during the Holocene, producing both blocky lava flows north of North Sister and rhyolitic lava domes and flows south of South Sister volcano. Glaciers have deeply eroded the Pleistocene andesitic-dacitic North Sister stratovolcano, exposing the volcano's central plug. Construction of the main edifice ceased at about 55,000 yrs ago, but north-flank vents produced blocky lava flows in the McKenzie Pass area as recently as about 1600 years ago. Middle Sister volcano is located only 2 km to the SW and was active largely contemporaneously with South Sister until about 14,000 years ago. South Sister is the highest of the Three Sisters. It was constructed beginning about 50,000 years ago and was capped by a symmetrical summit cinder cone formed about 22,000 years ago. The late Pleistocene or early Holocene Cayuse Crater on the SW flank of Broken Top volcano and other flank vents such as Le Conte Crater on the SW flank of South Sister mark mafic vents that have erupted at considerable distances from South Sister itself, and a chain of dike-fed rhyolitic lava domes and flows at Rock Mesa and Devils Chain south of South Sister erupted about 2000 years ago.

Bachelor
This volcanic system extends from Mount Bachelor on the N to Lookout Mountain about 20 km S, with a chain of scoria cones and small shield volcanoes between and additional volcanic features to the E. The basaltic andesite and basaltic volcanoes formed during four eruptive periods dating back to about 18,000-15,000 years before present (BP). Construction of the main scoria cone chain was completed by about 12,000 years BP, and Bachelor (formerly known as Bachelor Butte) is one of its youngest features. The latest activity produced lava flows on the E side of Sparks Lake from scoria cones on the NNE flank of Bachelor, and lava flows from Egan scoria cone on the N flank that slightly preceded the eruption of the Mazama ash from Crater Lake about 7,000-8,500 years ago.

Davis Lake
The Davis Lake area contains three andesitic Holocene cinder cones and associated fresh-looking lava flows along a N-S line at the base of a group of Pleistocene basaltic andesite shield volcanoes east of the crest of the Cascade Range, south of the Mount Bachelor volcanic chain. The northernmost lava flow created a natural barrier forming Davis Lake and lies at the western base of the Pleistocene Davis Mountain shield volcano and at the SW end of Wickiup Reservoir. The two southern flows are in a flat-lying area straddling Crescent Creek between Hamner and Odell Buttes. The middle lava flow was erupted from a small breached cinder cone on the lower southern flank of Hamner Butte and was radiocarbon dated at 4,740 years before present. The southernmost lava flow originated from a cone at the ENE base of Odell Butte. All three lava flows were probably erupted at about the same time.

Newberry
Newberry volcano, situated east of the Cascade Range, covers an area of about 1,600 km2. The low-angle basaltic to basaltic andesite shield volcano includes more than 400 cinder cones, but has also produced major silicic eruptions associated with formation of a 6 x 8 km summit caldera containing two lakes. The earliest eruptive products (less than 0.73 Ma) consist of a sequence of ash-flow and airfall tuffs. Caldera collapse is thought to be associated with major ash deposits from about 0.5 and 0.3-0.5 Ma. These eruptions were preceded by the emplacement of numerous mafic cones and vents, and silicic lava domes and flows, many of which are aligned NNW and NNE parallel to regional fault zones. Six major eruptions from the early Holocene to about 1,300 years ago have included both basaltic lava flows from flank vents, the explosive ejection of rhyolitic pumice and pyroclastic flows, and the extrusion of obsidian flows within the caldera.

Cinnamon Butte
Cinnamon Butte, Thirsty Point, and Kelsay Point are forested cinder cones along a WNW-ESE line immediately west of the Cascade crest and NE of Diamond Lake. The cones have well-preserved summit craters, and lava flows appear to be unglaciated, suggesting they are younger than 11,000 years (Sherrod, 1991). Lava flows from Cinnamon Butte pass through gaps of late-Pleistocene moraines, although all three cones are covered by the roughly 6,845-year-old Mazama Ash associated with the formation of Crater Lake caldera (~30 km S). Other Pleistocene cinder cones and a lava dome are located nearby, mostly west of the Cascade Range crest.

Crater Lake
The spectacular 8 x 10 km Crater Lake caldera in the southern Cascades of Oregon formed about 7,700 years ago as a result of the collapse of a complex of overlapping shield and stratovolcanoes known as Mount Mazama. The cone-building stage, during which at least five andesitic and dacitic shields and stratovolcanoes were constructed, took place between about 420 and 40 thousand years ago (ka). A series of rhyodacitic lava domes and flows and associated pyroclastic rocks were erupted between about 30 ka and the climactic eruption. The explosive eruptions triggering collapse of the 8-10 km wide caldera about 7500 years ago were among Earth's largest known Holocene eruptions, distributing tephra as far away as Canada and producing pyroclastic flows that traveled 40 km from the volcano. A 5-km-wide ring fracture zone is thought to mark the original collapse diameter. The deep blue waters of North America's second deepest lake, at 600 m, fill the caldera to within 150-600 m of its rim. Post-caldera eruptions within a few hundred years of caldera formation constructed a series of small lava domes on the caldera floor, including the partially subaerial Wizard Island cinder cone, and the completely submerged Merriam Cone. The latest eruptions produced a small rhyodacitic lava dome beneath the lake surface east of Wizard Island about 4,200 years ago.

Shasta
The most voluminous of the Cascade volcanoes, northern California's Mount Shasta is a massive compound stratovolcano composed of at least four main edifices constructed over a period of at least 590,000 years. An older edifice was destroyed by a large debris avalanche which filled the Shasta River valley to the NW. The Hotlum cone, forming the present summit, the Shastina lava dome complex, and the SW flank Black Butte lava dome, were constructed during the early Holocene. Eruptions from these vents have produced pyroclastic flows and mudflows that affected areas as far as 20 km from the summit. Eruptions from Hotlum cone continued throughout the Holocene.

Medicine Lake
Medicine Lake is a large Pleistocene-to-Holocene, basaltic-to-rhyolitic shield volcano east of the main axis of the Cascade Range. Volcanism, similar in style to that of Newberry volcano in Oregon, began less than one million years ago. A roughly 7 x 12 km caldera truncating the summit contains a lake that gives the volcano its name. A series of young eruptions lasting a few hundred years began about 10,500 years before present (BP) and produced 5 km3 of basaltic lava. Nine Holocene eruptions clustered during three eruptive episodes at about 5000, 3000, and 1000 years ago produced a chemically varied group of basaltic lava flows from flank vents and silicic obsidian flows from vents within the caldera and on the upper flanks. The last eruption produced the massive Glass Mountain obsidian flow on the E flank about 900 years BP. Lava Beds National Monument on the N flank of Medicine Lake shield volcano contains hundreds of lava-tube caves displaying a variety of spectacular lava-flow features, most of which are found in the voluminous Mammoth Crater lava flow, which extends in several lobes up to 24 km from the vent.

Lassen Volcanic Center
The Lassen Volcanic Center consists of the andesitic Brokeoff stratovolcano SW of Lassen Peak, a dacitic lava dome field, peripheral small andesitic shield volcanoes, and large lava flows, primarily on the Central Plateau NE of Lassen Peak. A series of eruptions from Lassen Peak from 1914 to 1917 is the most recent eruptive activity in the southern Cascade Range. Activity spanning about 825,000 years began with eruptions of the Rockland caldera complex and was followed beginning about 590,000 years ago by construction of Brokeoff. Beginning about 310,000 years ago activity shifted to the N flank of Brokeoff, where episodic, more silicic eruptions produced the Lassen dome field, a group of 30 dacitic lava domes including Bumpass Mountain, Mount Helen, Ski Heil Peak, and Reading Peak. At least 12 eruptive episodes took place during the past 100,000 years, with Lassen Peak being constructed about 27,000 years ago. The Chaos Crags dome complex, ~3 km NNW of Lassen Peak, was constructed about 1,100-1,000 years ago. The Cinder Cone complex 17 km NE of Lassen Peak was erupted in a single episode several hundred years ago and is considered part of the volcanic center (Clynne et al., 2000). The 1914-1917 eruptions of Lassen Peak began with phreatic eruptions and included emplacement of a small summit lava dome, subplinian explosions, mudflows, and pyroclastic flows.

Garibaldi Volcanic Arc

Silverthrone
Garibaldi Volcanic Arc
The Silverthrone volcanic complex lies near the coast in SW British Columbia, 55 km N of Kingcome Inlet and 60 km NW of Knight Inlet. The roughly circular, 20-km-wide, deeply dissected caldera complex contains rhyolitic, dacitic and andesitic lava domes, lava flows, and breccia. The bulk of the complex appears to have been erupted between 100,000 and 500,000 years ago, but postglacial andesitic and basaltic andesite cones and lava flows are also present. Anomalously old Potassium-Argon (K-Ar) dates of 1.0 and 1.1 Ma were obtained from a lava flow in the postglacial Pashleth and Machmel Creek valleys (Green et al., 1988). This flow is clearly much younger than the K-Ar date, and high-energy glacial streams have only begun to etch a channel along the margin. A radiocarbon date from barnacles 8.5 km upstream from the mouth of Machmel River, and buried by the flow, yielded an age of 12,200 +/- 140 years (Blake, 1985). This is a maximum age for the flow, which could be much younger (Hickson and Edwards, 2001).

Bridge River Cones
Garibaldi Volcanic Arc
The Bridge River Cones volcanic field consists of a group of small basaltic and trachybasaltic eruptive centers at the extreme northern end of the Garibaldi volcanic belt in SW British Columbia. Pleistocene volcanic necks and cones were Potassium-Argon dated at 0.97 and 0.59 million years ago in the Salal Creek area and display ice-contact features (Lawrence et al., 1984). Tuber Hill is a small subaerial 600,000-year-old basaltic stratovolcano to the N that was constructed on the Bridge River upland when neighboring valleys were filled with ice. Lava flows that overlie poorly consolidated glacial till and appear to post-date the latest glaciation are found immediately N of Bridge River. The youngest flow may be less than 1500 years old (Souther; in Wood and Kienle, 1990).

Meager
Mount Meager volcanic complex, of Pliocene-to-Holocene age, forms a dissected andesitic-to-rhyodacitic stratovolcano with multiple eroded summit lava domes and volcanic necks. It lies in the Garibaldi volcanic belt and is the northernmost volcano of the Cascade arc that extends to northern California. The summit of the complex consists of overlapping piles of andesitic lava flows and younger dacitic lava domes and flows. Quaternary basalts underlying the uppermost 22 km of the Elaho valley originated at the 1375 m level in the South Fork Meager River. The most recent activity, about 2350 years ago, produced Canada's largest known Holocene explosive eruption and an associated welded block-and-ash flow and a lava flow from a vent on the NE flank of Plinth Peak. Two clusters of hot springs occur within the complex, which has been investigated for potential geothermal power.

Garibaldi Lake
A group of nine small andesitic stratovolcanoes and basaltic andesite vents in the scenic Garibaldi Lake area immediately north of Mount Garibaldi was formed during the late Pleistocene and early Holocene. The oldest stratovolcano, The Black Tusk, formed between about 1.3 and 1.1 million years ago (Ma). Following glacial dissection, renewed volcanism (0.21-0.17 Ma) produced the lava dome and flow forming its summit. Other Pleistocene vents are located along and to the west of the Cheakamus River. The Cinder Cone, to the east of The Black Tusk, produced a 9-km-long lava flow during the late Pleistocene or early Holocene (0.04 +/- 0.04 Ma). Mount Price, west of Garibaldi Lake, was formed in three stages dating back to 1.1 million years, the latest of which produced two large lava flows from Clinker Peak during the early Holocene that ponded against the retreating continental ice sheet and formed the barrier containing Garibaldi Lake. The Table, a steep-sided subglacial tuya south of Garibaldi Lake, was also formed during the early Holocene.

Garibaldi
Mount Garibaldi at the head of Howe Sound north of Vancouver is a Pleistocene dacitic stratovolcano capped by a lava dome complex. An initial period of volcanism 0.51-0.22 million years ago was followed after a period of quiescence by construction of a conical plug dome and breccia pile at the south summit, Atwell Peak. Retreat of the ice cap left the W flank unsupported, and it collapsed in a series of landslides, exposing the core of the volcano. Lava flows from Dalton Dome north of Atwell Peak subsequently flowed down the scarp. Subglacial flank centers such as Eanastick (Enostuck) Meadow, Glacier Pike, and Paul Ridge were also formed during the late Pleistocene. The final activity formed the Opal Cone on the SE flank and the lengthy Ring Creek lava flow, which filled a glaciated valley on the S flank during the early Holocene (Mathews, 1958; Brooks and Friele, 1992).

Cayley Volcanic Field
The Cayley volcanic field is a deeply dissected basaltic andesite to rhyodacitic complex that covers a broad area between the Cheakamus and Squamish river valleys in the central Garibaldi volcanic belt. Mount Cayley itself was formed during at least three periods of activity primarily during the Pliocene and Pleistocene, but activity at satellitic dominantly subglacial vents along a N-S line both north and south of Mount Cayley continued in the late Pleistocene and Holocene. Vents in the Cheakamus Valley formed a 22-km-long lava flow sequence prior to 50,000 years before present that was topped by esker-like flows of late Pleistocene age. The youngest lava flows from Pali Dome West and from the subglacial Slag Hill volcano north of Mount Cayley were not impounded by ice at low elevations, implying that they erupted after the end of the Fraser Glaciation (less than 10,000 years ago). Large volcanic landslides have occurred at heavily eroded Mount Cayley during the Holocene. At least five hot springs are present in valleys adjacent to the volcano, and shallow earthquakes have occurred in the vicinity.

Baker
Mount Baker is a glacier-covered andesitic stratovolcano constructed above the E flank of the eroded mid-Pleistocene Black Buttes volcano and SW of the early Pleistocene 4.5 x 8 km rhyodacitic Kulshan caldera. With the exception of the Schreibers Meadow cinder cone on the SE flank, which formed about 9,800 years ago, Holocene volcanism has been confined to the central conduit. A major eruption about 6,500 years ago, its largest eruptive event during the Holocene, was accompanied by a collapse that sent lahars down the Nooksack drainage. Residents in the Puget Sound region as far away as Victoria, British Columbia, observed 19th-century activity, all of which consisted of relatively minor phreatic eruptions. Sherman Crater, the crater immediately south of the summit, has been the site of increased steam emission since 1975. The Nooksack Indian Tribe referred to the volcano as Kweq Smaenit (the White Mountain), while the Lummi Nation knows it as Koma Kulshan.

Glacier Peak
Glacier Peak, the most isolated of the Cascade volcanoes, rises above the rugged forested terrain of the Glacier Peak Wilderness Area in the North Cascades. This dacitic-andesitic stratovolcano with summit and flank lava domes resembles St. Helens in its explosive vigor. More than a dozen glaciers descend its flanks, prompting its name. Although its summit towers above surrounding valleys, the volcano was constructed above a high ridge and is itself less than 1,000 m high. Repeated major explosive eruptions associated with lava dome growth during the late Pleistocene and Holocene deposited tephra over wide distances to the east. Voluminous pyroclastic flows and mudflows extended into the Puget Sound lowlands to the west and diverted several river courses into adjacent valleys. The latest eruption only a few hundred years ago was noted by indigenous Pacific Northwest Indians, and hot springs occur on its flanks.

Interior Western Canada Volcanic Province

Nazko
Interior Western Canada Volcanic Province
Nazko Cone, the easternmost and youngest volcano of the Anahim Volcanic Belt in the Chilcotin-Nechako Plateau, central British Columbia, rests on glacial till. It was formed in three episodes of activity, the first of which took place during a Pleistocene interglacial stage about 340,000 years ago (Souther et al., 1987). The second stage produced a large hyaloclastite scoria mound erupted beneath the Cordilleran ice sheet during the late Pleistocene. The final activity occurred about 7,200 years ago, forming a compound subaerial basanitic cinder cone that overtopped the hyaloclastite mound and produced two small lava flows that traveled about 1 km W. An airfall tephra deposit extends several kilometers to the N and E. Mining of the red cinder and scoria deposits began in the early 1990s.

Wells Gray-Clearwater
Interior Western Canada Volcanic Province
The Wells Gray-Clearwater volcanic field in the Quesnel Highland of east-central British Columbia contains basaltic cones and lava flows of early Pleistocene to Holocene age. Pleistocene deposits include plateau-capping lava flows, subglacial mounds and tuyas, and hyaloclastites. Buck Hill Cone was erupted during the latest Pleistocene during the waning stages of the Fraser glaciation. Holocene eruptions took place in the Spanish Creek, Ray Lake, and Kostal Lake areas (Hickson and Souther, 1984), forming cinder cones and producing lava flows that traveled up to 14 km. A lava flow from Dragon cone was radiocarbon dated at about 7,600 years ago, and flows from Flourmill, Kostal, and Spanish Lake Cones rest on glaciated bedrock without an intervening paleosol, suggesting an early Holocene age. The latest eruption took place from Kostal cone about 400 years ago (Hickson and Edwards, 2001).

Queen Charlotte Volcano Group

Edgecumbe
Queen Charlotte Volcano Group
The Edgecumbe volcanic field covers about 260 km2 of Kruzov Island west of Sitka in SE Alaska. The basaltic-to-dacitic field is dominated by the large composite cones of Mount Edgecumbe, Crater Ridge, and Shell Mountain. This Pleistocene-to-Holocene system is 16 km E of the Queen Charlotte-Fairweather transform fault separating the North American and Pacific plates. Mount Edgecumbe is a stratovolcano with a well-defined crater, and is the largest edifice of the field. Crater Ridge is truncated by a 1.6-km-wide, 240-m-deep caldera. These and other vents are oriented along a SW-NE line. Volcanic activity originated about 600,000 years ago along fissures cutting Kruzof Island. A series of major silicic explosive eruptions took place about 9,000-13,000 radiocarbon years ago. The latest dated eruptions were phreatomagmatic explosions during the mid-Holocene, and all postglacial activity has been pyroclastic. Reports of observed eruptions are unsubstantiated.

Duncan Canal
Queen Charlotte Volcano Group
Basaltic flows in the Duncan Canal area of the central SE Alaska panhandle are both subaerial and submarine. Pahoehoe and aa lava flows overlie glacial till at Kupreanof Island. Quaternary basaltic lava flows up to 10 m thick form several broad peninsulas and scattered outcrops on the shores of Sumner Strait at the southern end of Kupreanof Island (Brew et al., 1985). On a peninsula in Kah Sheets Bay a basaltic flow depositionally overlies till of the youngest glaciation, and youthful-looking flows are exposed along a broad 12-km-wide front westward toward Douglas Bay. Two probable vents are found to the north within Mesozoic and Paleozoic rocks at the northern end of the Castle Islands in the Duncan Canal fault zone, and at Indian Point the flows contain inclusions of picrite. At High Castle Island, the basaltic flows are columnar-jointed and overlie planar to cross-bedded coarse sandstone and poorly sorted volcaniclastic conglomerate.

Tlevak Strait-Suemez Island
Scattered flat-lying lava flows with pahoehoe surfaces occur near Tlevak Strait and on the SW end of Suemez Island near the southern end of the SE Alaska panhandle. Outcrops are located on western Prince of Wales Island, along Bobs Bay on the NW side of Dall Island, and at Trocadero Bay on Suemez Island. The flows overlie Paleozoic sedimentary rocks and are associated with Tertiary rhyolitic and dacitic lava flows on Suemez Island. The younger alkaline olivine basaltic flows were considered by Brew (in Wood and Kienle, 1990) to be of probable postglacial age. The Alaska Volcano Observatory notes that "Many of the vents are located close to Cape Felix, on the southwest portion of Suemez Island. (Kate Bull, personal communication, 2009)."

Milbanke Sound Group
Swindle, Lake, and Lady Douglas Islands in the Milbanke Sound area of the Fiord Ranges in west-central British Columbia contain cinder cones of Holocene age. Kitasu Hill on the western side of Swindle Island is a young basaltic cone that produced lava flows that extend to the north. Other postglacial vents identified by Dolmage (1921, 1924) are correlated by lithology only and may be as old as Tertiary (Baer, 1973; Holland, 1976). Basaltic tuff breccias on Lake Island and Lady Douglas Island originated from Helmet Peak on Lady Island. Basaltic lava flows from Price and Dufferin Islands overlie adjacent beach deposits (Souther; in Wood and Kienle, 1990).

Northern Cordilleran Volcanic Province

Behm Canal-Rudyerd Bay
Northern Cordilleran Volcanic Province
Numerous basaltic cinder cones and lava flows occur in the panhandle of SE Alaska on both sides of Behm Canal, which divides Revillagigedo Island from the mainland. The lava flows, which are locally columnar-jointed and overlie glacial-fluvial sediments and granitic gneisses of the Coast Mountains, are located on the E and SE sides of Revillagigedo Island and at Rudyerd Bay across Behm Canal to the east. Most exposures are on SE Revillagigedo Island, but outcrops also occur on the mainland east of Behm Canal at the southern end of Punchbowl Cove at Rudyerd Bay. Undisturbed cinder cones and lava-flow surfaces at Painted Peak on SE Revillagigedo Island and elsewhere indicate that most of the activity was post-glacial (Brew, in Wood and Kienle, 1990). Pumice, lapilli, and ash deposits locally cover parts of glaciated ridge tops. Lava flows at the outlet of Lake Grace near Behm Canal on the eastern side of Revillagigedo Island were considered to be of late-Pleistocene or Holocene age (Wanek and Callahan, 1971). Minor andesitic and trachyandesitic flows are also present.

Fort Selkirk
Northern Cordilleran Volcanic Province
The Fort Selkirk volcanic field near the junction of the Yukon and Pelly rivers in central Yukon is the northernmost Holocene volcanic field in Canada. It consists of a sequence of valley filling alkaline olivine basalt and basanitic lava flows succeeded by construction of three nephelinitic pyroclastic cones and lava flow aprons. The Ne Ch'e Ddhawa pyroclastic cone (Wootten's Cone) is composed primarily of hyaloclastite tuffs, breccias, and pillow breccias erupted subglacially during the late Pleistocene (Jackson, 1989). The youngest cone, Volcano Mountain, produced young nephelinitic lava flows that remain unvegetated and appear to be only a few hundred years old. However, dating of sediments in a lake impounded by the lava flows indicated that the youngest flows could not be younger than mid-Holocene and could be early Holocene or older (Jackson and Stevens, 1992).

Alligator Lake
A group of basaltic cones and lava flows (the Miles Canyon basalts) in south-central Yukon near the capital city of Whitehorse was considered to be of Pleistocene age (Wheeler, 1961). The upper part of the Alligator Lake volcanic complex, consisting of two well-preserved cinder cones capping a small shield volcano, probably post-dates local Holocene glaciation (Eiche et al., 1987). Lava flows from both cones traveled to the N and were erupted simultaneously. Their compositions range from alkali olivine basalt to basanitic. Flows from the NE cone are the largest, extending 6 km from the cone and expanding to a width of 10 km at the terminus. Portions of the flows contain spinel lherzolite and granitoid xenoliths and megacrysts of olivine, pyroxene, and spinel.

Atlin Volcanic Field
The Surprise Lake volcanic field in the Atlin volcanic district is a group of late-Pleistocene to Holocene cinder cones on the Teslin Plateau in NW-most British Columbia, between Atlin Lake on the W and Surprise Lake on the E. The largest volcanic feature is Ruby Mountain (named for the brilliantly colored tephra deposits on the summit and flanks), which has been partially dissected by Pleistocene and post-Wisconsin glaciation. Two basaltic cinder cones at the heads of Cracker and Volcanic Creeks lie within glacially dissected U-shaped valleys and were considered to be post-glacial (Edwards et al., 1996). Placer miners working in the region at the end of the 19th century reported an eruption from the Ruby Mountain area about 80 km S of Gladys Lake (Hickson et al., 1994; Edwards et al., 1996) during which ash fell for several days and the miners were able to work at night due to incandescent glow. However, no field evidence has been found to support any activity from that time, and the report is considered uncertain.

Tuya Volcanic Field
A broad region with numerous formerly subglacial volcanic cones known as tuyas forms the Tuya Volcanic Field near Tuya Lake and a broad area to the N. Although tuyas, the products of Pleistocene subglacial eruptions, are perhaps better known in Iceland, these predominantly flat-topped basaltic table mountains derive their name from the Tuya region in the Cassiar Mountains and Tanzilla Plateau area of northern British Columbia. Tuya Butte itself, immediately N of Tuya Lake, has no summit crater or obvious vent, suggesting fissure-fed eruptions, although several indications suggest a vent location near a large cirque on the N face. Other tuyas lie in the High Tuya Lake, Iverson Creek, Rancheria River, and Klinkit Lake areas. Several small subaerial shield volcanoes, and postglacial lapilli cones and lava flows have been reported in this area. At least one of these, Grabrielse Cone near the headwaters of Iverson Creek, is of Holocene age.

Heart Peaks
The late-Cenozoic Heart Peaks shield volcano, located NW of Level Mountain in NW British Columbia, is capped by rhyolitic lava domes. The basal shield rises above local topography and is composed of flat-lying basaltic and trachybasaltic lava flows and pyroclastics. The most recent eruptive activity is of dominantly Pleistocene age; late-stage Holocene activity is uncertain (Edwards and Russell, 2000; Edwards 2004, pers. comm.). The volcano rises above the Heart Peaks Plateau, which is sculpted on all sides by tributaries of the Inklin River. The colorful bright green and pink, steep-sided lava domes of the Heart Peaks Formation are formed of porphyritic rhyolitic and minor trachytic rocks and occupy the western side of the plateau.

Level Mountain
Level Mountain is the most voluminous eruptive center of the Stikine volcanic belt in NW British Columbia. The massive volcano covers an area of 1,800 km2 SW of Dease Lake and N of Telegraph Creek. An 860 km3 bimodal Miocene-to-Pliocene stratovolcano with several eruptive centers caps a Miocene basaltic shield. Following extensive glacial dissection and emplacement of late-Pliocene silicic lava domes, lesser activity continued into the Quaternary. More than 20 Tertiary-to-Holocene eruptive centers have been identified in the central portion of Level Mountain and on its flanks. The broad dissected summit region consists of trachytic and rhyolitic lava domes and was considered to have several minor basaltic vents of postglacial age (Hamilton and Scafe, 1977), although Edwards and Russell (2000) considered Holocene activity to be uncertain.

Edziza
The composite felsic stratovolcano Mount Edziza and associated satellitic lava domes and pyroclastic cones were constructed over the past 7.5 million years during five magmatic cycles beginning with eruption of alkali basalts and ending with felsic and basaltic eruptions as late about 1,000 years ago. The 7.5 million-year-old (Ma) Armadillo Peak stratovolcano at the south end of the complex is overlapped by the Ice Peak central volcano, which was formed during the early Pleistocene, and contains a caldera largely destroyed by glaciers. The Mount Edziza stratovolcano on the north was formed about 1.0-0.9 Ma. A 2-km-wide, ice-filled caldera truncates its summit; lava domes were subsequently emplaced around its periphery and lava lakes ponded within the caldera and overflowed its rim. Numerous ice-contact features and products of subglacial eruptions are found in the Mount Edziza complex. More than 30 Holocene pyroclastic cones, primarily of basaltic composition, are located on Mount Edziza and the adjacent Spectrum Range, some of which are younger than about 1,300 years before present. Large areas of Holocene lava flows of the postglacial Big Raven Formation are located north of Mount Edziza, forming the Desolation Lava Field, and south and SW of Ice Peak, forming the Snowshoe Lava Field.

Spectrum Range
The Spectrum Range, named for its extensive colorful solfataric alteration, is one of four large composite volcanoes that make up the Mount Edziza-Spectrum Range volcanic complex, in which a predominately rhyolitic lava dome complex overlies a basal basaltic shield volcano. The Pliocene center contains Pleistocene subglacial and subaerial cones on the SW flank and Holocene pyroclastic cones and lava flows on the NW and SW sides. The Mess Lake Lava Field on the NW flank consists of young lava flows and tephra from three pyroclastic cones, including The Ash Pit, which may be the youngest volcanic feature of this complex.

Hoodoo Mountain
Hoodoo Mountain is a flat-topped Pleistocene-to-Holocene volcano in the Boundary Ranges of NW British Columbia near the Alaska border that is composed of both subglacial and subaerial volcanic products. Valley glaciers surround the volcano on all except the south side. The Pleistocene Little Bear Mountain basaltic tuya adjoins Hoodoo Mountain on the immediate north. Most of the volcano formed beneath glacial ice; all flank flows appear to have originated from beneath the current 4-km-wide summit icecap. More than 90% of the volcano, which dates back to at least 100,000 years, consists of interlayered peralkaline phonolitic and trachytic lava flows and hyaloclastites. At least one subaerial explosive eruption produced a welded and unwelded ignimbrite sequence on the north side. The most recent stage of volcanic activity produced subaerial unglaciated lava flows with well-preserved lava channels that originated from summit and flank vents about 9,000 years ago.

Iskut-Unuk River Cones
Eight small basaltic centers at the southern end of the Stikine volcanic belt near the Alaska border comprise the Iskut-Unuk River Cones group. Lava flows date back 70,000 years, but the subaerial vents produced cinder cones and lava flows that were probably all active between about 9,000 and a few hundred years ago. Five of the centers produced lava flows that traveled up to ~20 km down the Iskut and Unuk River valleys and their tributaries. The three remaining centers are products of ice-contact volcanism that formed pillow lava, hyaloclastite breccias, and scoria. The flows are similar in mineralogy and contain abundant crustal xenoliths. Vents in the Iskut River Canyon area produced at least 10 lava flows, and the Lava Fork vents at least three lava flows, the latest of which erupted within the past few hundred years.

Tseax River Cone
The basaltic Tseax River cinder cones (Aiyansh volcano) at the southern end of the Stikine volcanic belt have been the site of some of the youngest volcanic eruptions in Canada. Nested cinder cones lying along a tributary of the Nass River were the source of a lava flow that traveled into the Tseax River, damming it and forming Lava Lake. The flow subsequently traveled 11 km N to the Nass River, where it filled the flat valley floor for an additional 10 km. Native legends of the Nisga'a People tell of a prolonged period of disruption by the volcano, including the destruction of their village on the Nass River and the death of some people from "poison smoke." The vent was active at least twice (625 and 220 radiocarbon years ago) and other remnants of lava flows exist in the area, which was designated the Nisga'a Memorial Lava Beds Provincial Park in 1993 (Hickson and Edwards, 2001).

Crow Lagoon
Thick deposits of Holocene basaltic tephra originating from an unknown volcanic center have been found near Crow Lagoon, ~40 km N of Prince Rupert near the southern tip of the SE Alaskan panhandle. The deposits are located along the S side of the Khutzeymateen Inlet. Ballistically emplaced bombs imply a nearby source, which remains unidentified (Souther and Weiland, 1993).

Northern Alaska-Bering Sea Volcanic Province

St. Paul Island
Northern Alaska-Bering Sea Volcanic Province
The largest of the Pribilof Islands, St. Paul contains numerous young cinder cones. It consists of a 110 km2 area of coalescing small basaltic-to-trachybasaltic shield volcanoes capped by cinder cones. The most widely exposed lava flows originated from vents in the Bogoslof Hill area in the center of the island and a row of cinder cones in the Rush Hill area on the west side. Subaerial activity began about 540,000 years ago and produced a basaltic lava platform. Later eruptions produced a series of monogenetic vents and two small shield volcanoes. Bogoslof Hill and Hutchinson Hill, forming isolated Northeast Point connected by a low narrow isthmus to the rest of the island, were formed during the Pleistocene. The youngest vent is the Fox Hill cinder cone on the western side of the island that produced a lava flow about 3,200 years ago that traveled into the sea at Southwest Point.

Ingakslugwat Hills
Northern Alaska-Bering Sea Volcanic Province
The Ingakslugwat Hills consist of at least 32 small cinder cones and eight larger craters covering more than 500 km2 in the Yukon-Kuskokwin delta area of SW Alaska. Numerous small spatter cones and cinder cones range from 8 to 190 m in height; many are concentrated in the NW side of the volcanic field. The latest activity was considered to have occurred during the Holocene (Moll-Stalcup, in Wood and Kienle, 1990). One low cone containing a 400-m-wide lake may be a maar. This dominantly alkali olivine basaltic field also contains basanitic and nephelinitic rocks, some with inclusions of lherzolite and layered gabbro.

St. Michael
The St. Michael volcanic field, at the south end of Norton Sound, includes more than 55 cones and craters on St. Michael and Stuart islands. Broad low shield volcanoes underlie the younger cones, and maars are located at the SW part of the field, which covers over 3,000 km2 and extends inland along the Golsovia and Kogok rivers. The youngest activity is of Holocene age, and native tradition says that a village was submerged by lava three times (Dall, 1870).

Imuruk Lake
The Oligocene-to-Holocene Imuruk monogenetic volcanic field in the central Seward Peninsula north of the Bendeleben Mountains contains around 75 small basaltic vents surrounded by voluminous lava flows. The largest and most recent vent is the Lost Jim cone, a 30-m-high cinder cone near Imuruk Lake that produced the only Holocene lava flow in the field. The massive Lost Jim lava flow, erupted about 1,655 years ago, extends 35 km W and 9 km N of the vent, and covers about 230 km2. The next youngest flow, the late-Pleistocene Camille lava flow, traveled 39 km from its vent.

Wrangell Volcanic Arc

Wrangell
Wrangell Volcanic Arc
Mount Wrangell is one of the world's largest continental-margin volcanoes, with a diameter of 30 km at 2,000 m elevation. The andesitic shield volcano has produced fluid lava flows as long as 58 km and contains an ice-filled caldera 4-6 km in diameter and 1 km deep, located within an older 15-km-wide caldera. Most of the edifice was constructed during eruptions between about 600,000 and 200,000 years ago. Formation of the summit caldera followed sometime between about 200,000 and 50,000 years ago. Three post-caldera craters are located at the broad summit, along the northern and western caldera rim. A steep-sided flank cinder cone, Mount Zanetti, is located 6 km NW of the summit. The westernmost cone has been the source of infrequent eruptions beginning in the 18th century. Increased heat flux in recent years has melted large volumes of ice in the northern crater.

Churchill
Wrangell Volcanic Arc
The Bona-Churchill massif in the St. Elias Mountains has a 2.7 x 4.2 km summit caldera which was the source of the White River Ash, produced by two of the largest explosive eruptions in North America during the past 2,000 years (McGimsey et al., 1992). The summit of Mount Bona lies 4 km across a high saddle from the younger Churchill. The source vent of the widespread bi-lobate White River Ash deposit, which covers more than 340,000 km2 of eastern Alaska and NW Canada, was initially thought to be a pumice mound that is mostly buried beneath the Klutlan Glacier NE of Churchill volcano. Later work revealed thick young pumice deposits along the caldera rim that are mineralogically and chemically similar to the White River Ash deposits.

Alaska Peninsula Volcanic Arc

Black Peak
Alaska Peninsula Volcanic Arc
The highly eroded stratovolcano and lava dome complex of Black Peak was constructed within an ice-free mid-Holocene caldera with two small caldera lakes on the N and E sides. The pre-caldera volcano consists of andesitic-dacitic lava domes, lava flows, and volcaniclastic rocks that were constructed over a basement of Pliocene volcanogenic sediments. Ash-flow tuffs and block-and-ash-flow deposits from the more than 10 km3 caldera-forming eruption, which occurred less than about 4000 years ago, fill the Ash Creek and Bluff Creek valleys to the west and north to depths of as much as 100 m. Most of the 3.5-km-wide caldera floor is occupied by a complex of nested dacitic lava domes and associated lava flows centered in the southern part of the caldera.

Aniakchak
Alaska Peninsula Volcanic Arc
One of the most dramatic calderas of the Aleutian arc, the 10-km-wide Aniakchak caldera formed around 3,400 years ago during a voluminous eruption in which pyroclastic flows traveled more than 50 km N to the Bering Sea and also reached the Pacific Ocean to the south. At least 40 explosive eruptions have been documented during the past 10,000 years, making it the most active volcano of the eastern Aleutian arc. A dominantly andesitic pre-caldera volcano was constructed above basement Mesozoic and Tertiary sedimentary rocks that are exposed in the caldera walls to elevations of about 610 m. The ice-free caldera floor contains many pyroclastic cones, tuff cones, maars, and lava domes. Surprise Lake on the NE side drains through The Gates, a steep-walled breach on the east side of the 1-km-high caldera rim that was the site of catastrophic draining of a once larger lake about 1850 years BP. Vent Mountain and Half Cone are two long-lived vents on the south-central and NW caldera floor, respectively. The first and only confirmed historical eruption took place in 1931 from vents on the west and SW caldera floor.

Yantarni
Yantarni is a small andesitic stratovolcano located between Aniakchak caldera and Chiginadak volcanoes that was not discovered until 1979. A large breached crater on the NE side, formed by collapse of the summit about 2000-3500 years ago, contains a lava dome that marks the summit. This eruption, which resembled that of Mount St. Helens in 1980, began with a debris avalanche produced by the edifice collapse that was accompanied by a possible lateral blast and followed by the emplacement of 1 km3 of pyroclastic flows related to growth of the summit lava dome.

Chiginagak
The symmetrical, glaciated Chiginagak stratovolcano located on the Alaska Peninsula ~15 km NW of Chiginagak Bay contains a small summit crater, which is breached to the south, and one or more summit lava domes. Lava domes occur high on the NW and SE flanks of the calc-alkaline volcano. An unglaciated lava flow and an overlying pyroclastic-flow deposit extending E from the summit are the most recent eruption products, which most likely originated from a lava dome on the SE flank, 1 km from the summit. Brief ash eruptions were reported in July 1971 and August 1998. Fumarolic activity has been reported on the NE flank, and two areas of hot-spring travertine deposition are located at the NW base near Volcano Creek.

Kialagvik
Kialagvik is a small, poorly known glacier-mantled stratovolcano NE of Chiginagak volcano with a Holocene central lava dome and associated pyroclastic-flow deposits (Riehle, in Wood and Kienle 1990). The central dome rises 350 m above an ice field that mantles the upper part of the volcano. Andesitic lava flows and overlying dacitic block-and-ash-flow deposits are exposed broadly on the SW flank and in a small area on the NE flank. No historical activity is known.

Ugashik-Peulik
The Ugashik-Peulik volcanic complex lies south of Becharof Lake and east of Upper Ugashik Lake. Late-Pleistocene caldera formation was followed by the emplacement of at least five Holocene lava domes within the 4.5-km-wide caldera. Most of the caldera walls consist of basement sandstones of Jurassic age. Following caldera formation the small, 3 km3 Peulik stratovolcano grew 2.5 km to the N. Lava flows from Peulik cover the caldera rim to the south and extend to Becharof Lake, 6 km N. A small lava dome on the E flank of Peulik was the source of a small block-and-ash flow. The summit of Peulik contains a 1.5-km-wide crater breached to the west that is partially filled by a lava dome. Debris-avalanche deposits cover a 75 km2 area to the NW. A single documented historical eruption took place from Peulik in 1814.

Ukinrek Maars
Volcano type: Maar(s)
Ukinrek Maars are two explosion craters that were created in an area without previous volcanic activity during a 10-day phreatomagmatic eruption March-April 1977. The basaltic maars were erupted through glacial deposits in the Bering Sea lowlands 1.5 km S of Becharof Lake and 12 km W of Peulik volcano; their location is related to the regional Bruin Bay fault. The elliptical West Maar, which was the first to form, is 105 x 170 m and 35 m deep. The other maar, 600 m to the east, is 300 m wide and 70 m deep. Both maars are now filled by crater lakes; the eastern lake encircles a 49-m-high lava dome that was emplaced at the end of the eruption. Base surges were directed primarily to the NW. Juvenile material from the Ukinrek eruptions was of mantle-derived olivine basaltic composition. The dacitic Gas Rocks lava domes, of Quaternary age, are located on the shores of Becharof Lake, 3 km N of Ukinrek maars and were the site of a phreatic eruption about 2,300 years ago.

Alaska Peninsula Arc at 155.4�W
Volcano type: Lava dome
A small unnamed lava dome and an associated lava flow about 30 km E of Becharof Lake and 8 km NW of Alinchak Bay are not significantly modified by glacial erosion. Detterman et al. (1987) suggested a Holocene age for the small dome. Lava flows traveled a short distance to the north.

Martin
The mostly ice-covered Mount Martin stratovolcano lies at the SW end of the Katmai volcano cluster in Katmai National Park. The volcano was named for George C. Martin, the first person to visit and describe the area after the 1912 eruption. It is capped by a 300-m-wide summit crater, which is ice-free because of an almost-constant steam plume; it also contains a shallow acidic lake. The edifice was constructed entirely during the Holocene, and overlies glaciated lava flows of the adjacent mid- to late-Pleistocene Alagoshak volcano to the WSW. Martin consists of a small fragmental cone that was the source of ten thick overlapping blocky dacitic lava flows, largely uneroded by glaciers, that descend 10 km to the NW, cover 31 km2, and form about 95% of the eruptive volume of the volcano. Two reports of historical eruptions that originated from uncertain sources were attributed by Muller et al. (1954) to Martin.

Mageik
Mount Mageik is a broad ice-capped stratovolcano at the head of the Valley of Ten Thousand Smokes across Katmai Pass from Trident volcano. Four small overlapping peaks form the broad summit, three of which lie along a NE-SW trend south of the northern peak. The central summit consists of a lava dome, while the E, SW, and N volcanoes are capped by fragmental cones with ice-filled craters. The three westernmost summits are glaciated and of primarily Pleistocene age, but the East Mageik summit cone was the source of at least six Holocene eruptive episodes and fed Holocene lava flows that descended toward Katmai Pass and cover the NE-to-SE flanks of the volcano. A 300-m-wide explosion crater between the east and central summits that formed about 2,400-2,500 years ago contains a shallow, acidic lake and many superheated fumarole jets. Three Holocene debris avalanches from S-flank failures descended into the Martin Creek drainages, one perhaps reaching the coast. Reports of observed eruptions during 1927-1946 CE are considered uncertain (Miller et al., 1998; Hildreth and Fierstein, 2000).

Trident
The Trident stratovolcano cluster was named for the three prominent peaks that were the most visible features at the summit prior to 1953. The andesitic-dacitic group consists of four overlapping stratovolcanoes and numerous flank lava domes, including Falling Mountain and Mt. Cerberus on the far west flank. The summit complex is located 3-5 km SE of Novarupta volcano, and merges along a ridge to the NE with Katmai. The three oldest Trident volcanoes are glaciated and Pleistocene in age, while the youngest, Southwest Trident, was formed during historical time. Eruptions migrated through time from the NE to the SW. In 1953 a new lava dome began growing on the SW flank of Trident I volcano. A series of thick andesitic lava flows were erupted between 1953 and 1968, forming a cone with 400-800 m of local relief. Periodic explosions took place until 1974, and the current summit contains a 350-m-wide crater. Some of the distal lava flows from West Trident stratovolcano collapsed into the Novarupta vent during its 1912 eruption.

Katmai
Katmai was initially considered to be the source of the Valley of Ten Thousand Smokes ash flow in 1912. However, the 3 x 4 km caldera of 1912 is now known to have formed as a result of the voluminous eruption at nearby Novarupta volcano. The edifice had four NE-SW-trending summits, most of which were truncated by the 1912 collapse. Two or more large explosive eruptions took place during the late Pleistocene. Most of the two overlapping pre-1912 Katmai volcanoes are Pleistocene, but Holocene lava flows from a flank vent descend the SE flank of the SW edifice into the Katmai River canyon. The steep walled young caldera has a jagged rim that rises 500-1,000 m above the caldera floor and contains a deep lake. Lake waters have covered a small post-collapse lava dome (Horseshoe Island) that was seen on the caldera floor at the time of the initial ascent to the caldera rim in 1916.

Novarupta
Novarupta, the least topographically prominent volcano in the Katmai area, was formed during a major eruption in 1912. This eruption was the world's largest during the 20th century and produced a voluminous rhyolitic airfall tephra and the renowned Valley of Ten Thousand Smokes (VTTS) ash flow. At the end of the eruption a small, 65-m-high, 400-m-wide lava dome grew within the source vent of the VTTS ashflow, a 2-km-wide area of subsidence NW of Trident volcano. The NE side of the Falling Mountain lava dome of the Trident volcanic cluster, as well as Broken Mountain and Baked Mountain, was removed by collapse of the Novarupta depression, which is marked by radial and scalloped arcuate fractures. Much larger collapse took place at Katmai volcano, 10 km E, where a 3 x 4 km caldera formed in response to magma reservoir drainage toward Novarupta.

Griggs
The summit of Mount Griggs towers above Knife Creek on the NE side of the Valley of Ten Thousand Smokes. The volcano is offset west of the NE-trending alignment of volcanoes in the Katmai area. The broad stratovolcano, formerly known as Knife Peak, consists of a late-Pleistocene edifice with glacial valleys on the north that was truncated on its SW side by an early Holocene collapse. A Holocene volcano was subsequently constructed within the 1.5-km-wide scarp left following a large SW-flank debris avalanche. Nested cones with three concentric craters mostly fill the scarp, and thick, blocky lava flows cover the SW flanks below the collapse scarp. In contrast to the more silicic centers of the Katmai area along the crest of the range, lava flows from Griggs are dominantly andesitic in composition, and dacitic lava flows are uncommon. No eruptions have been observed, but noisy fumarolic jets near the summit can be heard from the valley floor.

Snowy Mountain
Snowy Mountain, located 15 km NE of Mount Katmai, is the SW-most of a chain of closely spaced volcanoes extending NE along the crest of the Alaska Range. More than 90% of the volcano is covered by glacial ice, which prompted the naming of the volcano by members of the 1917 Katmai Expedition. Two small andesitic-dacitic stratovolcanoes, SW Snowy and NE Snowy, originated about 200,000 years ago. Collapse of NE Snowy during the Holocene produced a large debris avalanche that traveled to the north and left a large breached crater inside which a blocky lava dome was constructed. Peat beneath an ash layer thought to be associated with the lava dome was radiocarbon dated at about 250 +/- 70 years ago. No eruptive activity has been observed and documented. Wood and Kienle (1990) noted that an active fumarole field at the summit had melted holes through the ice, and there was a zone of shallow seismicity beneath that mountain that is probably due to the hydrothermal system.

Denison
Mount Denison lies near the head of the Serpent Tongue, Hook, and Hallo glaciers NE of Snowy volcano. This poorly known section of Katmai National Park contains a line of four closely spaced and mostly ice-covered volcanic peaks. Denison lies at the SW end of this chain, which also includes Steller, Kukak, and Devils Desk volcanoes. Orientation of lava flows and a thick cross-bedded tephra deposit suggest that a vent is located near Mount Denison (Swanson, in Wood and Kienle 1990). The precise age of the most recent activity at Denison is not known.

Steller
Mount Steller is part of a chain of closely spaced volcanic peaks oriented NE-SW in Katmai National Park and lies between Mount Denision and Kukak volcanoes. Uncertainty surrounds the number and location of vents in this heavily glaciated area. The precise age of the most recent activity at Steller is not known, but the volcano was considered to have been active during the Holocene by Nye et al. (1998).

Kukak
The almost completely ice-covered Kukak volcano lies west of Hallo Bay near the end of a glacier-covered range extending NE from Mount Katmai. A vigorous fumarole field at the southern base of the hydrothermally altered northern summit and is the only one of the Denison-Steller-Kukak chain of volcanoes to display geothermal activity. Two reports eruptions noted by Hantke (1959) appear to be erroneous. The report of a 1951 eruption is an apparent reference to a 22 July 1951 ashfall at Kukak Bay, which was attributed by Muller et al. (1954) to Martin volcano. A 1953 explosive "eruption" was single large puff of steam followed by steaming from caverns in Hook Glacier (Muller et al., 1954).

Kaguyak
The 2.5-km-wide Kaguyak caldera in the NE part of Katmai National Park is filled by a lake more than 180 m deep whose surface lies 550 m below the caldera rim. The volcano rises directly from lowland areas near sea level south of the Big River. Initially considered to be a typical stratovolcano truncated by a caldera, the pre-caldera edifice has been shown to consist of nine contiguous late-Pleistocene lava dome clusters, most of which lie east of the present caldera. A large post-caldera lava dome extends into the lake on the SW side and another dome forms a small island in the center of the lake. The caldera is unglaciated, and distal tephras from the caldera-forming eruption have been radiocarbon dated at about 5,800 years before present. Voluminous dacitic pyroclastic-flow deposits surround the caldera and reached Shelikof Strait to the SE.

Fourpeaked
Poorly known Fourpeaked volcano in NE Katmai National Park consists of isolated outcrops surrounded by the Fourpeaked Glacier, which descends eastward almost to the Shelikof Strait. The orientation of andesitic lava flows and extensive hydrothermal alteration of rocks near the present summit suggest that it probably marks the vent area. Eruptive activity during the Holocene had not been confirmed prior to the first historical eruption in September 2006. A N-trending fissure extending 1 km from the summit produced minor ashfall.

Douglas
Glacier-covered, dissected Mount Douglas stratovolcano is located at the N end of the Alaska Peninsula south of Kamishak Bay, and is the NE-most in Katmai National Park. It was constructed above Cretaceous and Jurassic sedimentary rocks, and contains a small, ice-free summit crater lake and an active fumarole field. A lake temperature of 25�C and a pH of 1 were measured in 1982. Fumaroles are located on the NE wall of the 160 x 200 m wide crater lake; some are subaqueous and produce turbulence on the surface of the blue-green lake. The fumaroles, which are actively depositing sulfur, were all at the pressure boiling point in 1982 and heated up to 114-118�C in 1991. Unglaciated and relatively uneroded lava flows are found on the NW flank. The age of the most recent eruptions is not known, but Nye et al. (1998) considered activity to have occurred during the Holocene.

Augustine
Augustine volcano, rising above Kamishak Bay in the southern Cook Inlet about 290 km SW of Anchorage, is the most active volcano of the eastern Aleutian arc. It consists of a complex of overlapping summit lava domes surrounded by an apron of volcaniclastic debris that descends to the sea on all sides. Few lava flows are exposed; the flanks consist mainly of debris-avalanche and pyroclastic-flow deposits formed by repeated collapse and regrowth of the summit. The latest episode of edifice collapse occurred during Augustine's large 1883 eruption; subsequent dome growth has restored the edifice to a height comparable to that prior to 1883. The oldest dated volcanic rocks on Augustine are more than 40,000 years old. At least 11 large debris avalanches have reached the sea during the past 1,800-2,000 years, and five major pumiceous tephras have been erupted during this interval. Recorded eruptions have typically consisted of explosive activity with emplacement of pumiceous pyroclastic-flow deposits followed by lava dome extrusion with associated block-and-ash flows.

Iliamna
Iliamna is a prominent glacier-covered stratovolcano in Lake Clark National Park on the western side of Cook Inlet, about 225 km SW of Anchorage. Its flat-topped summit is flanked on the south, along a 5-km-long ridge, by the North and South Twin Peaks lava dome complexes. The Johnson Glacier dome complex lies on the NE flank. Steep headwalls on the S and E flanks expose an inaccessible cross-section of the volcano. Major glaciers radiate from the summit, and valleys below the summit contain debris avalanche and lahar deposits. Only a few major Holocene explosive eruptions have occurred from the deeply dissected volcano, which lacks a distinct crater. Most of the reported eruptions may represent plumes from vigorous fumaroles E and SE of the summit, which are often mistaken for eruption columns (Miller et al., 1998). Eruptions producing pyroclastic flows have been dated to 1778-1779 and 1876 CE. Elevated seismicity accompanying dike emplacement beneath the volcano was recorded in 1996.

Redoubt
Redoubt is a glacier-covered stratovolcano with a breached summit crater in Lake Clark National Park about 170 km SW of Anchorage. Next to Mount Spurr, Redoubt has been the most active Holocene volcano in the upper Cook Inlet. The volcano was constructed beginning about 890,000 years ago over Mesozoic granitic rocks of the Alaska-Aleutian Range batholith. Collapse of the summit 13,000-10,500 years ago produced a major debris avalanche that reached Cook Inlet. Holocene activity has included the emplacement of a large debris avalanche and clay-rich lahars that dammed Lake Crescent on the south side and reached Cook Inlet about 3,500 years ago. Eruptions during the past few centuries have affected only the Drift River drainage on the north. Historical eruptions have originated from a vent at the north end of the 1.8-km-wide breached summit crater. The 1989-90 eruption had severe economic impact on the Cook Inlet region and affected air traffic far beyond the volcano.

Spurr
Mount Spurr is the closest volcano to Anchorage, Alaska (130 km W) and just NE of Chakachamna Lake. The summit is a large lava dome at the center of a roughly 5-km-wide amphitheater open to the south formed by a late-Pleistocene or early Holocene debris avalanche and associated pyroclastic flows that destroyed an older edifice. The debris avalanche traveled more than 25 km SE, and the resulting deposit contains blocks as large as 100 m in diameter. Several ice-carved post-collapse cones or lava domes are present. The youngest vent, Crater Peak, formed at the southern end of the amphitheater and has been the source of about 40 identified Holocene tephra layers. Eruptions from Crater Peak in 1953 and 1992 deposited ash in Anchorage.

Hayes
Hayes volcano, located in a remote and rugged part of the Alaska Range NW of Anchorage and N of Mount Gerdine, was not discovered until 1975. It was named after nearby Hayes Glacier and consists of scattered remnants of a largely snow-and-ice covered volcano that has been destroyed by catastrophic eruptions. The most widespread Holocene eruptions in the Cook Inlet area originated from Hayes between about 3800 and 3400 years ago and produced six regional tephra layers with an average volume of 2.4 km3. The latest known eruption took place about 1000 years ago.

Buzzard Creek
Volcano type: Tuff ring(s)
Two Holocene tuff rings form craters 300 and 66 m wide near the headwaters of Buzzard Creek at the northern foot of the central Alaska Range NE of the town of Healy along the Parks Highway. Both contain small lakes, and the smaller ring is about 200 m SE of the larger one. The total volume of ejecta, most of which is accessory material, probably does not exceed 0.001 km3. The ejecta overlies young glacial terraces that correlate with a glacial stage that ended about 10,000 years ago, and radiocarbon dates give an age for the eruption that formed the tuff rings of about 3,000 years. This minor volcanic feature lies along trend with the Aleutian arc, but is located 320 km NE of its nearest Holocene neighbor (Hayes volcano), and directly over the northernmost corner of the subducting Pacific Plate.

Aleutian Ridge Volcanic Arc

Piip
Russia
Aleutian Ridge Volcanic Arc
Dredged rocks from the summits of volcanic cones rising from 2,500 m depth to within a few hundred meters of the surface yielded dacitic lavas and pumice apparently of Holocene age (Fedotov et al., 1989; Seliverstov et al., 1986). Tephrochronological studies on the Commander Islands suggest that the latest tephras from Piip volcano may be as young as a few centuries, and echograms indicate present-day gas emission from the volcano. The three steep-sided volcanic cones were constructed along a N-S trend and lie about 140-150 km from the axis of the Aleutian trench, a similar distance as other Aleutian arc volcanoes. The southern and northern cones exceed the central cone in size and have craters open to the SW about 500 and 300 m wide, respectively. A lava dome occupies the southern crater, and other domes or cones are found on the summit cones and flanks of the edifice. Vigorous gas emission from the northern cone rises about 300 m from "black smoker" vents on the crater floor.

Buldir
Aleutian Ridge Volcanic Arc
The westernmost volcanic center of the 2500-km-long Aleutian arc, the island includes the older Buldir volcano in the center and the younger East Cape volcano to the NE. The high point of the island is a tuff cone that tops the older center. A plug dome forms the summit of East Cape volcano, which has two principal peaks. The youngest volcanic feature on the isolated, 4.2 x 7.2 km island is a lava dome on the SE flank of East Cape volcano. The dome was considered by Coats (1951) to be of Pleistocene age based on morphologic considerations. Smith and Shaw (1975) suggested that the volcano may have been active within the last two thousand years, however, Holocene activity is uncertain, and the volcano may have ceased activity during the Pleistocene (Motyka et al. 1993, Nye et al. 1998). The flora is less varied than on neighboring islands, suggesting that Buldir is relatively young.

Kiska
Conical Kiska volcano is the westernmost historically active volcano of the 2500-km-long Aleutian arc. The volcano lies at the northern tip of the elongated Kiska Island, across a low isthmus containing East Kiska and West Kiska lakes. A 400-m-wide elliptical crater, breached to the north, caps the 1220-m-high stratovolcano. The volcano is surrounded on three sides by sea cliffs up to 450 m high and overlies an older volcanic center exposed to the south. A massive submarine debris-avalanche deposit extends 40 km to the NNW. The southern part of the NE-SW-trending island, the westernmost of the Rat Island group, has been glaciated, but all lava flows post-date the last major glaciation. Young, steep-sided blocky lava flows, primarily on the N and SW flanks, have originated from vents at locations ranging from the summit to near sea level. A flank cinder cone and associated lava flows were erupted in 1962 at Sirius Point on the northern coast. The island contains one of the best harbors in the Aleutian Islands, but is uninhabited.

Segula
The 6 x 7 km island of Segula east of Kiska volcano consists of a conical stratovolcano cut by a prominent NNW-SSE-trending fissure that extends to sea level at both ends of the island. The northern end of the fissure is flooded by the sea to produce a long, narrow cove. Segula was constructed above a 100-m-deep submarine platform that extends eastward to Khvostof and Davidof islands. A submarine debris-avalanche deposit extends up to 18 km offshore to the north. The summit contains a small, poorly defined caldera that is partly overtopped on the south by a cinder cone that forms the high point of the island and on the north by extensive lava flows that reach the NE coast along a broad front. Another lava field on the SE coast originated from a cinder cone at 300 m elevation on the SE flank. No historical eruptions are known, but Nelson (1959) considered fresh lava flows on the N flank to possibly be only a few hundred years old.

Davidof
A cluster of small islands between Segula and Little Sitkin in the western Aleutians, the largest of which is Davidof, are remnants of a stratovolcano that collapsed during the late Tertiary, forming a 2.7-km-wide caldera. The islands include Khvostof, Pyramid, Lopy, and Davidof; the latter three form the eastern rim of the mostly submarine caldera, sometimes referred to as the "Aleutian Krakatau." The islands were constructed above a roughly 100-m-deep submarine platform extending NW to Segula Island; the floor of the caldera lies 80 m below sea level. The islands are vegetated, but lava flows are recognizable, and Smith et al. (1978) suggested a possible Holocene age.

Little Sitkin
Diamond-shaped Little Sitkin Island is bounded by steep cliffs on the east, north, and NE sides. Little Sitkin volcano contains two nested calderas. The older, nearly circular Pleistocene caldera is 4.8 km wide, may have once contained a caldera lake, and was partially filled by a younger cone formed mostly of andesitic and dacitic lava flows. The elliptical younger caldera is 2.7 x 4 km wide; it lies within the eastern part of the older caldera and shares its eastern and southern rim. The younger caldera partially destroyed the lava cone within the first caldera and is of possible early Holocene age. Young-looking dacitic lava flows, erupted in 1828 (Kay, in Wood and Kienle 1990), issued from the central cone within the younger caldera and from a vent on the west flank outside the older caldera. Fumarolic areas are found near the western coast, along the NW margin of the older caldera, and from the summit crater down the southern flank for a 1 km distance.

Semisopochnoi
Semisopochnoi, the largest subaerial volcano of the western Aleutians, is 20 km wide at sea level and contains an 8-km-wide caldera. It formed as a result of collapse of a low-angle, dominantly basaltic volcano following the eruption of a large volume of dacitic pumice. The high point of the island is Anvil Peak, a double-peaked late-Pleistocene cone that forms much of the island's northern part. The three-peaked Mount Cerberus (renamed Mount Young in 2023) was constructed within the caldera during the Holocene. Each of the peaks contains a summit crater; lava flows on the N flank appear younger than those on the south side. Other post-caldera volcanoes include the symmetrical Sugarloaf Peak SSE of the caldera and Lakeshore Cone, a small cinder cone at the edge of Fenner Lake in the NE part of the caldera. Most documented eruptions have originated from Young, although Coats (1950) considered that both Sugarloaf and Lakeshore Cone could have been recently active.

Gareloi
The 8 x 10 km Gareloi Island, the northernmost volcano of the Delarof Group at the western end of the Andreanof Islands, consists of a stratovolcano with two summits and a prominent SE-trending fissure. The fissure was formed during an eruption in 1929 and extends from the southern summit to the sea. Steep sea cliffs that are cut into rocks of an older, eroded center are found on the SW coast, and submarine deposits of three debris avalanches produced by edifice collapse are found offshore. Young lava flows cover the older volcano from the summit to the coast along three broad axes trending NW, ENE, and S. The 1929 eruption originated from 13 craters along a 4-km-long fissure. Phreatic explosions were followed by the ejection of glassy pumice, lapilli, scoria, and older blocks, as well as by the emission of four short, steep lava flows, one of which reached the SE coast.

Tanaga
Tanaga volcano, the second largest volcanic center of the central Aleutians, is the central and highest of three youthful stratovolcanoes oriented along a roughly E-W line at the NW tip of Tanaga Island. Ridges to the east and south represent the rim of an arcuate caldera formed by collapse of an edifice during the Pleistocene. Most Holocene eruptions originated from Tanaga volcano itself, which consists of two large cones, the western of which is the highest, constructed within a caldera whose 400-m-high rim is prominent to the SE. At the westernmost end of the complex is conical Sajaka, a double cone that may be the youngest of the three volcanoes. Sajaka One volcano collapsed during the late Holocene, producing a debris avalanche that swept into the sea, after which the Sajaka Two cone was constructed within the collapse scarp.

Takawangha
Takawangha is a youthful volcano with an ice-filled caldera on northern Tanaga Island, near the western end of the Andreanof Islands. It lies across a saddle from historically active Tanaga volcano to the west; older, deeply eroded volcanoes lie adjacent to the east. The summit of the dominantly basaltic to basaltic andesite volcano is largely ice covered, with the exception of five Holocene craters that during the last few thousand years produced explosive eruptions and lava flows that reached the lower flanks. No historical eruptions are known, although radiocarbon dating indicates explosive eruptions have occurred within the past several hundred years.

Bobrof
The geology and timing of volcanism on this small uninhabited 3 x 4 km island, located in the Andreanof islands 50 km west of Adak and 15 km west of Kanaga volcano, are unknown (Coats, 1956). Apparent deposits of a massive submarine debris-avalanche deposit extend offshore to the NE. Smith et al. (1978) considered Bobrof to be of possible Holocene age. Andesitic pyroclastic-flow deposits are present on the 738-m-high volcano.

Kanaga
Symmetrical Kanaga stratovolcano is situated within the Kanaton caldera at the northern tip of Kanaga Island. The caldera rim forms a 760-m-high arcuate ridge south and east of Kanaga; a lake occupies part of the SE caldera floor. The volume of subaerial dacitic tuff is smaller than would typically be associated with caldera collapse, and deposits of a massive submarine debris avalanche associated with edifice collapse extend nearly 30 km to the NNW. Several fresh lava flows from historical or late prehistorical time descend the flanks of Kanaga, in some cases to the sea. Historical eruptions, most of which are poorly documented, have been recorded since 1763. Kanaga is also noted petrologically for ultramafic inclusions within an outcrop of alkaline basalt SW of the volcano. Fumarolic activity occurs in a circular, 200-m-wide, 60-m-deep summit crater and produces vapor plumes sometimes seen on clear days from Adak, 50 km to the east.

Moffett
Rising above Adak, the largest town of the Aleutians, Mount Moffett is a modest-sized, eroded stratovolcano with several flank lava domes. The summit cone has been largely destroyed by glacial erosion, and has been filled by an andesitic plug dome. Five other lava domes are scattered over the flanks of the volcano. The south flank lava dome is one of the youngest features of the northern Adak Island volcanoes. The Heart Lake lava flow west of Sweeper Cove on the SE side of the volcano is another young volcanic feature. Several Holocene ash layers on Adak Island have been attributed to Moffett volcano. Its proximity to Adak Naval Air Station makes this one of the most accessible of the Aleutian volcanoes. Kiguga Warm Springs are located at Cape Kiguga, west of Mount Moffet, and the northern part of Adak Island has been investigated for geothermal power production.

Great Sitkin
The Great Sitkin volcano forms much of the northern side of Great Sitkin Island. A younger volcano capped by a small, 0.8 x 1.2 km ice-filled summit caldera was constructed within a large late-Pleistocene or early Holocene scarp formed by massive edifice failure that truncated an older edifice and produced a submarine debris avalanche. Deposits from this and an even older debris avalanche from a source to the south cover a broad area of the ocean floor north of the volcano. The summit lies along the eastern rim of the younger collapse scarp. Deposits from an earlier caldera-forming eruption of unknown age cover the flanks of the island to a depth up to 6 m. The small younger caldera was partially filled by lava domes emplaced in 1945 and 1974, and five small older flank lava domes, two of which lie on the coastline, were constructed along northwest- and NNW-trending lines. Hot springs, mud pots, and fumaroles occur near the head of Big Fox Creek, south of the volcano. Eruptions have been recorded since the late-19th century.

Kasatochi
Located at the northern end of a shallow submarine ridge trending perpendicular to the Aleutian arc, Kasatochi is small 2.7 x 3.3 km island volcano with a 750-m-wide summit crater lake. The summit reaches only about 300 m elevation, and the lake surface lies less than about 60 m above the sea. A lava dome is located on the NW flank at about 150 m elevation. The asymmetrical island is steeper on the northern side than the southern, and the crater lies north of the center of the island. Reports of activity from the heavily eroded Koniuji volcano to the east probably refer to eruptions from Kasatochi. A lava flow may have been emplaced during the first recorded eruption in 1760. A major explosive eruption in 2008 produced pyroclastic flows and surges that swept into the sea, extending the island's shoreline.

Koniuji
The very small, 1 x 1.5 km Koniuji Island, between Atka and Kasatochi volcanoes, is the emergent top of a mostly submarine volcano. Located about 20 km N of the western side of Atka Island, the volcano is deeply dissected, with a steep, arcuate cliff on the west. Ar-Ar dating indicates that the island emerged above sea level about 15,000 years ago, and that several lava flows and domes were erupted during the Holocene. The summit lava dome is younger than about 3,000 years. Reports of observed eruptive activity may be erroneous, and are considered to refer to eruptions of the relatively undissected Kasatochi, 25 km W.

Atka Volcanic Complex
The Atka Volcanic Complex consists of a central shield and Pleistocene caldera and four notable volcanic cones. A major explosive dacitic eruption accompanied formation of the caldera about 500,000 to 300,000 years ago; approximately half of the caldera rime remains, open towards the NW. The Sarichef cone, ~5 km ESE of the caldera rim, retains a symmetrical profile, unlike most other heavily eroded features outside the caldera to the S and W. The Kliuchef stratovolcano grew within the caldera and exhibits five eruptive vents striking NE, including two at the summit, that have been active in the Holocene. A 700-m-diameter crater 1 km NE of the summit may have been the source vent for a large 1812 CE eruption. Hot springs and fumaroles are located on the flanks of Kliuchef and in a glacial valley to the SW. The most frequently active volcano of the complex is Korovin, at the NE tip of Atka Island about 5 km N of Kliuchef. An 800-m-diameter crater on the SE side of the summit contains a deep circular pit that sometimes contains a crater lake thought to be the source of phreatic ash explosions. The smaller Konia cone, slightly offset to the E, lies between Kliuchef and Korovin. Most of the lava flows in the complex are basaltic, though some dacitic flows are also present.

Seguam
The 11.5 x 24 km island of Seguam, between Amlia and Amukta Islands in the central Aleutians, contains two calderas with Holocene post-caldera cones. Growth of the basaltic-to-rhyolitic Wilcox volcano on the east side of the island during the late Pleistocene was followed by edifice collapse and an associated ignimbrite eruption about 9,000 years ago, leaving a caldera open to the west, inside which a rhyolitic cone was constructed. The 3 x 4 km westernmost caldera has a central scoria cone, Pyre Peak, which rises above the caldera rim and is the source of most of the reported eruptions. A very young basaltic field surrounds Pyre Peak, and lava flows partially fill the caldera and reach the southern coast. Older Holocene lava flows were erupted from vents within the eastern caldera, and a monogenetic Holocene cone forms Moundhill volcano on the eastern tip of the island.

Amukta
The symmetrical Amukta stratovolcano lies in the central Aleutians SW of Chagulak Island and is the westernmost of the Islands of the Four Mountains group. The stratovolcano was constructed at the northern side of an arcuate caldera-like feature that is open to the sea along the southern coast of the 8-km-wide Amukta Island. It overlies a broad shield volcano and is topped by a 400-m-wide crater, and a cinder cone is located near the NE coast. There have been several reported eruptions from both summit and flank vents.

Chagulak
The 3-km-diameter island of Chagulak is the exposed summit of a stratovolcano in the Islands of the Four Mountains group of the Aleutians. The sharp-topped summit is ~11 km NE of the summit of Amukta and 35 km W of Yunaska volcano. The visible edifice is steep and strongly eroded. No eruptions have been recorded and its age is not precisely known.

Yunaska
The elongated 9 x 23 km Yunaska in the Islands of the Four Mountains group of the Aleutian Islands is comprised of two distinct volcanic centers. The older western center consists of the eroded remnants of four overlapping stratovolcanoes that form a linear, NNE-trending ridge. Cinder cones and fissure-fed lava flows extend from the western end of the complex. The younger eastern complex consists of a shield volcano capped by two nested calderas. The 3.5-km-wide Coats caldera is located within an older 10 x 13 km caldera and contains cinder cones and a lava field. Two areas of youthful lava flows extend down the flank through a gap in the SW caldera rim and cover the upper N flank of the caldera. Vents are found on the flanks of the caldera within a kilometer of its rim. A post-caldera cone is capped by a small summit crater. The eastern center is presumably the source of eruptions recorded since the early 1800s.

Herbert
The 10-km-wide Herbert Island, the SW-most of the Islands of the Four Mountains group, lies across a strait SW of Mount Cleveland. This symmetrical stratovolcano has a summit truncated by a 2-km-wide caldera breached to NW. No historical eruptions have been recorded, and no geological studies have been published.

Carlisle
Carlisle Island is a steep-sided, conical stratovolcano across the Carlisle Pass strait from Mount Cleveland. Radar images suggest that this uninhabited, 7-km-wide island may contain two closely spaced volcanic cones (Myers, in Wood and Kienle 1990). Like nearby Herbert volcano, no geologic studies have been conducted on the volcano. Eruptions have been reported since the 18th century, but are very poorly documented. A variety of names was attached to Carlisle on early hydrographic maps, and Miller et al. (1998) noted that some 18th and 19th century eruptions reported at the closely spaced volcanoes of the "Islands of the Four Mountains" area could refer to Carlisle as well as Cleveland, Uliaga, or Kagamil volcanoes.

Cleveland
The symmetrical Mount Cleveland stratovolcano is situated at the western end of the uninhabited Chuginadak Island. It lies SE across Carlisle Pass strait from Carlisle volcano and NE across Chuginadak Pass strait from Herbert volcano. Joined to the rest of Chuginadak Island by a low isthmus, The native name, Chuginadak, refers to the Aleut goddess of fire, who was thought to reside on the volcano. Numerous large lava flows descend the steep-sided flanks. It is possible that some 18th-to-19th century eruptions attributed to Carlisle should be ascribed to Cleveland (Miller et al., 1998). In 1944 it produced the only known fatality from an Aleutian eruption.

Tana
The Tana volcanic complex forming the eastern half of the Chuginadak Island, opposite the conical Cleveland stratovolcano, is composed of two prominent E-W-trending volcanoes. The complex shows evidence of glacial erosion, but highly irregular coastlines forming peninsulas west of Applegate Cove on the NW side of the complex and Concord Point on the south side imply lava flows of mid- to late-Holocene age (Nye 2007, pers. comm.). Prominent lava flow levees are visible near Concord Point, where a low-silica rhyolite sample was obtained. The undissected cone and youthful crater forming the western summit also imply a post-glacial age, and youthful cinder cones also lie east of the isthmus between Cleveland and Tana volcanoes.

Uliaga
The small 3-km-wide island of Uliaga, located at the NE end of the Islands of the Four Mountains archipelago immediately NW of Kagamil Island, is an eroded stratovolcano. It is the smallest of the Islands of the Four Mountains volcanoes. There are no reports of historical eruptions, but is was considered to have been active during the Holocene by Nye et al. (1998).

Kagamil
Kagamil Island lies near the NE end of the Islands of the Four Mountains archipelago in the central Aleutians, between Chuginadak and Uliaga Islands. The southern half of the 5 x 10 km island contains two undissected cones of postglacial age with small summit craters. The larger cone is located at the SE end of the NNW-SSE-trending volcano. Arcuate ridges at the northern and southern ends of the island suggest a possible earlier caldera. Hot springs and fumaroles occur along a steaming beach at the SE coast. The early explorer Veniaminof (1840) indicated that Kagamil formerly "flamed and smoked," but the only eruptive report is of unspecified activity in 1929 (Coats 1950).

Vsevidof
The symmetrical Vsevidof stratovolcano, near the SW end of Umnak Island, contains a 1.2-km-wide, ice-filled summit crater that is breached by glaciers on the E and N sides. An E-W-trending zone of scoria cones that extends down much of the W flank has been the source of recorded eruptions. Most of the cone was constructed during the Holocene. Andesitic and dacitic lava flows originated from vents on the N and S flanks, and on the W-flank rift. The largest lava flow traveled down the W flank to the coast, forming Cape Kigushimkada.

Recheschnoi
The heavily glaciated Recheschnoi stratovolcano is located ENE of a roughly 900-m-high saddle across from Vsevidof volcano. It consists of an elongated, NE-SW-trending ridge dissected by deep glacier-filled valleys; erosion is more extensive at the NE end. Holocene andesitic pyroclastic cones and rhyolitic lava domes, the latter west of the head of Russian Bay, are situated on the E and W flanks. The Geyser Bight geothermal area on the NE flank consists of six zones of thermal springs and two fumarolic areas along upper Geyser Creek, and contains the only known geysers in the state. Other thermal areas occur at Hot Springs Cove and Partov Cove on the isthmus between Recheschnoi and Okmok.

Okmok
The basaltic Okmok shield volcano forms the NE end of Umnak Island in the Aleutian Islands. The summit of the low, 35-km-wide volcano is cut by two overlapping 10-km-wide calderas formed during eruptions about 12,000 and 2,050 years ago when dacitic pyroclastic flows reached the coast. More than 60 tephra layers from Okmok have been found overlying the 12,000-year-old caldera-forming tephra layer. Numerous cones and lava domes are present on the flanks down to the coast, including the SE-flank Mount Tulik, which is almost 200 m higher than the caldera rim. Some of the post-caldera cones show evidence of wave-cut lake terraces; more recent cones were formed after the caldera lake, once 150 m deep, disappeared. Eruptions have been reported since 1805 from cinder cones within the caldera, where there are also hot springs and fumaroles.

Bogoslof
Bogoslof is the emergent summit of a submarine volcano that lies 40 km N of the main Aleutian arc. It rises 1,500 m above the Bering Sea floor. Repeated construction and destruction of lava domes at different locations during historical time has greatly modified the appearance of this "Jack-in-the-Box" volcano and has introduced a confusing nomenclature applied during frequent visits by exploring expeditions. The present triangular-shaped, 0.75 x 2 km island consists of remnants of lava domes emplaced from 1796 to 1992. Castle Rock (Old Bogoslof) is a steep-sided pinnacle that is a remnant of a spine from the 1796 eruption. The small Fire Island (New Bogoslof), about 600 m NW of Bogoslof Island, is a remnant of a lava dome formed in 1883.

Makushin
The ice-covered Makushin volcano on northern Unalaska Island is capped by a 2.5 km caldera. Its broad, dome-like structure contrasts with the steep-sided profiles of most other Aleutian stratovolcanoes. Much of the edifice was formed during the Pleistocene, but the caldera (which formed about 8,000 years ago), Sugarloaf cone on the ENE flank, and a cluster of about a dozen explosion pits and cinder cones at Point Kadin on the WNW flank, are of Holocene age. A broad band of NE-SW-trending vents cuts across the volcano. The composite Pakushin cone, with multiple summit craters, lies 8 km SW. Table Top (Pleistocene, 68 +/- 14 ka) and Wide Bay (Holocene) cinder cones are about 20 km ENE on the peninsula across the bay from the City of Unalaska. Frequent explosive eruptions have occurred during the past 4,000 years, sometimes accompanied by pyroclastic flows and surges. Geothermal areas are found in the summit caldera and on the SE and E flanks. Small-to-moderate explosive eruptions have been recorded since 1786.

Akutan
Akutan contains a 2-km-wide caldera with a large cinder cone in the NE part of the caldera that has been the source of frequent explosive eruptions and occasional lava effusion that covers the caldera floor. An older, largely buried caldera was formed during the late Pleistocene or early Holocene. Two volcanic centers are located on the NW flank. Lava Peak is of Pleistocene age, and a cinder cone lower on the flank produced a lava flow in 1852 that extended the shoreline of the island and forms Lava Point. The 60-365 m deep younger caldera was formed during a major explosive eruption about 1,600 years ago and contains at least three lakes. A lava flow in 1978 traveled through a narrow breach in the north caldera rim almost to the coast. Fumaroles occur at the base of the caldera cinder cone, and hot springs are located NE of the caldera at the head of Hot Springs Bay valley and along the shores of Hot Springs Bay.

Westdahl
Volcano type: Stratovolcano?
Westdahl is a broad glacier-covered volcano occupying the SW end of Unimak Island. Two peaks protrude from the summit plateau, and a new crater formed in 1978 cuts the summit icecap. The volcano has a somewhat of a shield-like morphology and forms one of the largest volcanoes of the Aleutian Islands. The sharp-topped, conical Pogromni stratovolcano, 6 km N, rises several hundred meters higher than Westdahl, but is moderately glacially dissected and presumably older. Many satellitic cones of postglacial age are located along a NW-SE line cutting across the summit of Westdahl. Some of the historical eruptions attributed to the eroded Pogromni may have originated instead from Westdahl (Miller et al. 1998). The first historical eruption occurred in 1795. An 8-km-long fissure extending east from the summit produced explosive eruptions and lava flows in 1991.

Fisher
The Fisher caldera, on western Unimak Island NE of Westdahl volcano, is 11 x 18 km elongated in a NE direction It formed around 9,400 years ago, accompanied by emission of large-volume pyroclastic flows that reached the Bering Sea and the Pacific Ocean. Two cones are located below the N rim, NE of its high point at Eickelberg Peak, which rises more than 900 m above three lakes on the caldera floor, one of which drains through a notch in the southern caldera rim. A large composite cone, Mount Finch, is found at the center of the caldera, which also contains a small breached cinder cone. Eruptions have occurred in the 18th and 19th centuries. Low-temperature fumaroles are located on the W flank of Mount Finch, and Turquoise Lake, at the base of the cone, emits hydrogen sulfide gas.

Shishaldin
The symmetrical glacier-covered Shishaldin in the Aleutian Islands is the westernmost of three large stratovolcanoes in the eastern half of Unimak Island. The Aleuts named the volcano Sisquk, meaning "mountain which points the way when I am lost." Constructed atop an older glacially dissected edifice, it is largely basaltic in composition. Remnants of an older edifice are exposed on the W and NE sides at 1,500-1,800 m elevation. There are over two dozen pyroclastic cones on its NW flank, which is covered by massive aa lava flows. Frequent explosive activity, primarily consisting of Strombolian ash eruptions from the small summit crater, but sometimes producing lava flows, has been recorded since the 18th century. A steam plume often rises from the summit crater.

Roundtop
The flat-topped, glacier-covered Roundtop is the easternmost and lowest of an E-W-trending line of volcanoes on eastern Unimak Island, 13 km SW of the village of False Pass. The snow and ice-covered edifice fills much of a 3-km-wide caldera that formed during the early Holocene. The caldera-forming eruption produced pyroclastic flows and a rhyolitic tephra layer that is widespread throughout the southwestern end of the Alaska Peninsula. A group of lava domes was constructed south of the volcano. No historical eruptions are known, but in the 1930's warm springs were found on its slopes.

Amak
Amak, the easternmost of the Aleutian Islands, is a small island stratovolcano that lies north of the main Aleutian volcanic front, about 50 km NW of Frosty volcano on the western tip of the Alaska Peninsula. The summit of the small, roughly 1 km3 volcano is only 488 m above sea level. Blocky lava flows with prominent levees were emplaced during historical eruptions from 1700-1710 and in 1796 (Marsh, in Wood and Kienle 1990). The flows radiate from a well-defined central crater and cover much of the central part of the island. Earlier volcanism perhaps 4000-5000 years ago consisted of the emission of thin, platy andesitic lava flows. A flat alluvial plain on the S flank contains a flat-bottomed crater that may be a maar.

Frosty
Frosty Peak, the youngest of two large volcanic structures of the Cold Bay Volcanic Center, is the westernmost Holocene volcano on the Alaska Peninsula, SW of the village of Cold Bay. This symmetrical late-Pleistocene to Recent stratovolcano is constructed within one of two coalescing craters. The western wall of the ice-filled northern crater is breached by a large valley glacier. The symmetrical summit cone rises about 600 m above the floor of the southern crater. The oldest products of the roughly 100 km3 Cold Bay complex form the late-Pliocene to early Pleistocene Morzhovoi Volcanics at the southern end. Morzhovoi is an extensively eroded basaltic-to-andesitic stratovolcano with long U-shaped valleys extending from a central caldera. Only remnants of the volcano remain, with isolated peaks, such as North and South Walrus Peaks, that are fragments of the original caldera rim.

Dutton
The Mount Dutton volcanic center east of Cold Bay near the tip of the Alaska Peninsula consists of a glacier-covered central lava dome complex. Early andesitic lava flows and late-stage dacitic domes have been partially removed by one or more edifice collapses about 5100-6800 years ago. Debris avalanches traveled west and south, reaching Belkofski Bay. The important regional fishing center of King Cove lies less than 15 km from the volcano, and the village's airstrip is built on top of the southern avalanche deposit. A steep-sided complex of lava domes forms the summit, and young block-and-ash flow deposits extend to the east. Two small unglaciated lava domes on the NE flank 3.5 km from the summit are also of Holocene age. Major earthquake swarms near the volcano were recorded in 1984-85 and 1988.

Emmons Lake Volcanic Center
The Emmons Lake Volcanic Center, located north of Volcano Bay and SW of Pavlof volcano, includes the Emmons and Hague stratovolcanoes within the Emmons Lake caldera. The 9 x 15 km caldera contains a narrow elongated lake at its SW end that drains through a breach in the SE rim to the Pacific Ocean. The compound caldera was formed during six voluminous dacitic-to-rhyolitic eruptions between about 294,000 and 26,000 years ago that produced extensive ashflow tuffs. Mount Emmons, Mount Hague, and Double Crater are post-caldera cones of dominantly basaltic composition that were constructed along the SW-NE trend of the elongated caldera. Some Holocene flows have moved through a gap in the southern caldera rim to within 3 km of the ocean. A large fumarolic area is located on the south side of Mount Hague, and the only reported activity was the emission of steam plumes from Hague in 1990 and 1991.

Pavlof
The most active volcano of the Aleutian arc, Pavlof is a Holocene stratovolcano that was constructed along a line of vents extending NE from the Emmons Lake caldera. Pavlof and Pavlof Sister to the NE form a dramatic pair of symmetrical, glacier-covered stratovolcanoes that overlook Pavlof and Volcano bays. Little Pavlof is a smaller cone on the SW flank of Pavlof volcano, near the rim of Emmons Lake caldera. Unlike Pavlof Sister, eruptions have frequently been reported from Pavlof, typically Strombolian to Vulcanian explosive eruptions from the summit vents and occasional lava flows. The active vents lie near the summit on the north and east sides. The largest recorded eruption took place in 1911, at the end of a 5-year-long eruptive episode, when a fissure opened on the N flank, ejecting large blocks and issuing lava flows.

Pavlof Sister
Located near the western end of the Alaska Peninsula at the end of a chain of volcanoes trending NE from Emmons Lake caldera, the symmetrical Pavlof Sister stratovolcano is somewhat more eroded than Pavlof volcano to the SW. Pavlof Sister, along with Pavlof and Little Pavlof, formed outside of the Emmons Lake caldera; these and other volcanoes inside Emmons Lake caldera are not glaciated and thus would have formed since the area was last glaciated about 15-20,000 years ago. Pavlof Sister is almost 400 m lower than Pavlof and has a sharper-peaked summit. Some sources attributed a period of intermittent eruptive activity from 1762 to 1786 CE to Pavlof Sister, but other sources consider this event to have been from Pavlof.

Dana
Mount Dana is a small calc-alkaline volcano NE of Canoe Bay inlet at the head of Pavlof Bay consisting of an apron of volcaniclastic debris surrounding a central dome complex. The high point is located at the north rim of a 1.5 x 2 km crater, whose SW rim exposes Mesozoic sedimentary rocks. Andesitic lava domes occur on the west crater rim and as a small mound east of Knutson Lake inside the crater. Dana is the source of a mid-Holocene block-and-ash flow that reached the sea at Canoe Bay. No historical eruptions are known, but a 200-m-wide tufa mound and several cold springs are located on the SW flank.

Kupreanof
Kupreanof is the largest and NE-most of a group of five relatively closely spaced Quaternary volcanic centers opposite Stepovak Bay. A debris flow or block-and-ash flow with possible juvenile fragments descended a late-Pleistocene valley south of the volcano. This stratovolcano displays vigorous fumarolic activity, and although a "grayish-brown ash horizon" extending 15 km was reported by a pilot in 1987 after emissions from a SSW-flank solfatara field, the cause of this event is uncertain.

Veniaminof
Veniaminof, on the Alaska Peninsula, is truncated by a steep-walled, 8 x 11 km, glacier-filled caldera that formed around 3,700 years ago. The caldera rim is up to 520 m high on the north, is deeply notched on the west by Cone Glacier, and is covered by an ice sheet on the south. Post-caldera vents are located along a NW-SE zone bisecting the caldera that extends 55 km from near the Bering Sea coast, across the caldera, and down the Pacific flank. Historical eruptions probably all originated from the westernmost and most prominent of two intra-caldera cones, which rises about 300 m above the surrounding icefield. The other cone is larger, and has a summit crater or caldera that may reach 2.5 km in diameter, but is more subdued and barely rises above the glacier surface.

Stepovak Bay Group
The Stepovak Bay Group is a chain of four cones, extending over a distance of 18 km, just SW of Kupreanof volcano. Stepovak Bay 2 is a cinder cone with a Holocene andesitic lava flow extending initially to the NE, then SE. The Stepovak Bay 3 cinder cone has a thick Holocene lava flow that originated from an ice-filled 300-m-wide crater and entered the same valley as the lava flow from Stepovak Bay 2 (Wilson, 1989); however, Wilson (in Wood and Kienle, 1990) noted uncertainty about this being Holocene activity. Stepovak Bay 4 is a small stratovolcano with Holocene debris flows or block-and-ash flows, and a fumarole has been observed. Stepovak Bay 1, the southwesternmost of the chain is Pleistocene, with K-Ar dates of about 0.53 and 0.4 million years (Wilson, 1989).

Northwestern Pacific Volcanic Regions

Central Kamchatka Volcanic Arc

Khangar
Russia
Central Kamchatka Volcanic Arc
Khangar volcano, also spelled Hangar, is the southernmost volcano in the Sredinny Range of western Kamchatka. It is the dominant feature within a larger volcano-tectonic depression composed of two parts: a stratovolcano with a 2-km-wide Holocene caldera, and a large lava dome on its eastern flank. The steep-walled caldera, now filled by a lake, was formed during a major explosive eruption about 7,000 years ago. An arcuate zone of pre-caldera flank lava domes nearly surrounds the volcano, and post-caldera domes form islands in the caldera lake. Late-stage olivine basalts were erupted along a NE-trending line in the southern part of the depression. The latest dated eruption took place about 500 years ago.

Cherpuk Group
Russia
Central Kamchatka Volcanic Arc
Severny Cherpuk (South Cherpuk) and Yuzhny Cherpuk (North Cherpuk) are two cinder cones SW of Ichinsky volcano that comprise the largest monogenetic volcanoes of the Sredinny Range. Severny Cherpuk, 21 km SW of Ichinsky, is a double cone that fed 1.8 km3 lava flows down both sides of the range to the NW and SE. A narrow tongue of the SE flow diverted an additional 10 km S, for a total distance of 22 km. Yuzhny Cherpuk, 11 km SSW of Ichinsky, produced a 1.7 km3 lava flow that traveled 18 km S and then SE. The flow descended to 640 m elevation and dammed tributaries of the Ketachan River, producing three lakes. The two cones are sometimes considered to be satellitic cones to Ichinsky, but Pevzner et al. (2000) noted petrological distinctions that suggest an independent origin. Unpublished radiocarbon ages revise those in Pevzner et al. (2000) and indicate that both cones were formed about 6,500 years ago.

Ichinsky
Ichinsky, by far the highest peak in the Sredinny Range, is a massive, 450 km3 edifice. The andesitic Pleistocene-to-Holocene stratovolcano, also known as Icha, contains a 3 x 5 km-wide glacier-covered summit caldera filled by a large post-caldera edifice. Two glacier-capped lava domes form the highest peaks. A dozen late-Pleistocene to Holocene dacitic and rhyodacitic lava domes circle the peak below the caldera rim. Fresh-looking basaltic-to-dacitic lava flows, some with prominent flow ridges, were erupted from flank vents and traveled up to 10-15 km. The largest Holocene eruption took place about 6500 years ago, producing block-and-ash flows that traveled up to 15 km. Fumarolic activity occurs within the caldera and on the lower N flank. In 1956 steam jets rose 250 m above the caldera fumarole field.

Bolshoi-Kekuknaysky
Bolshoi (Bolshoy) and Kekuknaysky are two large, partially overlapping basaltic shield volcanoes located NW and NNW, respectively, of Uksichan volcano. The massive Pleistocene shield volcanoes were constructed west of the axis of the Sredinny Range. Hawaiian-type calderas are located at the summits, and their flanks have numerous youthful cinder cones. The summit caldera of Bolshoi is breached by four radial valleys, whereas the 6-km-wide caldera of Kekuknaysky (also known as Leningradets volcano) is breached to the north. Young cinder cones and lava flows are particularly abundant on the NE flank of Kekuknaysky. Kekuk crater on the lower N flank erupted about 7,200 years ago.

Alney-Chashakondzha
The glacier-capped Alney-Chashakondzha complex, one of the largest volcanoes of the Sredinny Range, consists of two large mostly Pleistocene andesitic stratovolcanoes constructed on a large Pliocene shield volcano. Both Alney on the north and Chashakondzha on the south are capped with andesitic lava domes. Three rhyodacitic-to-rhyolitic lava domes and associated lava flows were emplaced along ring faults enclosing a 15 x 20 km area. Two cinder cones on the east flanks of Alney and Chashakondzha erupted about 2600 years ago and produced lava flows, one of which traveled as far as 9 km. Alney is one of the few large stratovolcanoes in the Sredinny Range known to have been active throughout the Holocene, with more than 30 documented pyroclastic deposits. The last intense eruption took place about 350 years ago.

Shisheika
Volcano type: Lava dome
The andesitic Shisheika lava dome lies far to the west of the crest of the Sredinny Range, near the mouth of the Shishei River. The dome and associated lava flows were erupted about 4,200 years ago during one of several Holocene eruptions on the lower flanks of the Sredinny Range.

Terpuk
Terpuk is a small basaltic shield volcano west of the crest of the Sredinny Range, south of Leutongey volcano, and NW of Kebeney volcano. The shield is topped by small cinder cones aligned NE-SW. Sparsely vegetated lava flows that radiate from the summit vents blocked local drainages, forming several small lakes. Topography constrains the flows to be longer toward the west, away from the crest of the range. The flows are among the youngest in the Sedankinsky Dol region and were erupted about 2,500-3,000 years ago.

Sedanka Lava Field
The Sedanka lava field (Sedanka Dol) is located immediately west of the Sredinny Range axis and is formed by dominantly mafic lavas from small strato- and shield-like volcanoes, along with more than 100 cinder and lava cones of the late Pleistocene-Holocene age. For this compilation the volcanic field area is considered to be up to 10 km wide and stretching about 25 km from south of Gorny Institute volcano towards the NNW between Tuzovsky volcano to the SW and Titila to the NE. Other workers (eg. Nekrylov et al., 2015) define the field to include the eight large edifices from Terpuk on the SW to Shishel on the NE.

Gorny Institute
Gorny Institute volcano lies at the NE end of chain of small late-Quaternary volcanoes extending NE from Kebeney volcano in the central Sredinny Range. It was constructed near the steep-walled eastern margin of a major NE-SW-trending graben extending NE from Kebeney volcano. A line of cinder cones with the same orientation is located on the NE and SW flanks. More than 20 pyroclastic horizons have been documented, and the last major eruption took place about 700 years ago.

Kinenin
Kinenin maar lies at the eastern foot of the Sredinny Range, about 80 km NNW of Sheveluch volcano. The 2.5-km-wide, funnel-shaped maar was formed along the Kinenin River, a tributary of the Elovka. It is partially filled by a 1-km-wide lake whose surface is at 400 m elevation. The eastern rim at about 580 m is the high point of the crater. The eruption of Kinenin took place about 1,100 years ago, making it the youngest known maar in Kamchatka. Both silicic pyroclastic flows and mafic pyroclastic ejecta were produced, which were distributed primarily to the ENE. The location is north of the active Kamchatka subduction zone.

Bliznetsy
Volcano type: Lava cone
The Bliznetsy ("Twins") lava flows occupy a low-lying area east of the Sredinny Range and north of the Eastern Volcanic Zone volcanoes. The young flows lie south of the Ozernaya River about 80 km north of historically active Sheveluch volcano. Effusion of about 0.5 km3 of lava flows about 3000 years ago was preceded by weak phreatomagmatic eruptions.

Titila
Titila is a small basaltic shield volcano NW of Lake Glubokoye, west of the crest of the central Sredinny Range. Lava flows radiate from two summit craters, and cinder cones are prominent on its southern flank. Titila overlaps to the W with another small shield volcano, Rassoshina, along with other features in the Sedanka Lava Field to the south. The latest known eruption took place about 2,500 years ago.

Elovsky
This cluster of overlapping small basaltic shield volcanoes is located east of the crest of the Sredinny Range, NE of Shishel and SE of Alngey volcanoes. The largest edifice is the Elovsky shield, and the smaller Ozernovsky lies immediately to the SE. The massive early Holocene Ozernovsky lava flow, located immediately NE of Elovsky, traveled to the ESE down a glacially dissected valley. The flow is post-glacial in age, but older than roughly 7,000-year-old tephra layers from Khangar volcano. The massive flow dammed tributary valleys, creating several lakes near the headwaters of the Levaya and Pravaya Ozeraya rivers and forming a lava field covering an area of 100 km2.

Nylgimelkin
The basaltic Nylgimelkin (also known as Atlasov) shield volcano and the topographically higher but smaller shield of Novagrablenova are dwarfed by their neighbor, the glacier-clad Pleistocene Khuvkhoitun, the highest Quaternary volcano of the northern Sredinny Range. The two youthful shields were constructed on the W and NW flanks of Khuvkhoitun. Lava flows from them extend primarily to the west. Cinder cones and a lava flow were erupted along a fissure at Nylgimelkin about 5,500 years ago.

Spokoiny
The dacitic-to-rhyolitic Spokoiny stratovolcano lies immediately south of Ostry volcano and NE of Iktunup volcano in the northern Sredinny Range. The volcano, also known as Kutina, was active during the early and mid-Holocene. Deposits from five eruptions during this interval have been documented, the last of which took place about 5400 years ago. Cinder cones are located on the W flank, and lava flows from the symmetrical summit cone extend down drainages to both the east and west.

Ostry
Conical Ostry volcano (also known as Ostraya) is a late-Quaternary stratovolcano on the western side of the major NE-trending graben along the axis of the northern Sredinny Range. An unnamed cinder cone on the SW flank, informally referred to as "Cone X," erupted about 4,000 years ago, producing a basaltic lava flow.

Severny
Severny is a late Quaternary shield volcano located at the NW end of a major NE-trending graben along the crest of the northern Sredinny Range. It is capped by a small stratovolcano, a small shield volcano was constructed on its SW flank, and an even smaller shield grew on the NE flank. The basaltic Tobeltsen cinder cone on the WSW flank and associated lava flows were erupted about 3,500 years ago.

Eastern Kamchatka Volcanic Arc

Koryaksky
Eastern Kamchatka Volcanic Arc
The large symmetrical Koryaksky stratovolcano is the most prominent landmark of the NW-trending Avachinskaya volcano group, which towers above Kamchatka's largest city, Petropavlovsk. Erosion has produced a ribbed surface on the eastern flanks of the 3430-m-high volcano; the youngest lava flows are found on the upper W flank and below SE-flank cinder cones. Extensive Holocene lava fields on the western flank were primarily fed by summit vents; those on the SW flank originated from flank vents. Lahars associated with a period of lava effusion from south- and SW-flank fissure vents about 3900-3500 years ago reached Avacha Bay. Only a few moderate explosive eruptions have occurred during historical time, but no strong explosive eruptions have been documented during the Holocene. Koryaksky's first historical eruption, in 1895, also produced a lava flow.

Avachinsky
Eastern Kamchatka Volcanic Arc
Avachinsky, one of Kamchatka's most active volcanoes, rises above Petropavlovsk, Kamchatka's largest city. It began to form during the middle or late Pleistocene, and is flanked to the SE by Kozelsky volcano, which has a large crater breached to the NE. A large collapse scarp open to the SW was created when a major debris avalanche about 30,000-40,000 years ago buried an area of about 500 km2 to the south, underlying the city of Petropavlovsk. Reconstruction of the volcano took place in two stages, the first of which began about 18,000 years before present (BP), and the second 7,000 years BP. Most eruptions have been explosive, with pyroclastic flows and hot lahars being directed primarily to the SW by the collapse scarp, although there have also been relatively short lava flows. The frequent historical eruptions have been similar in style and magnitude to previous Holocene eruptions.

Dzenzursky
Volcano type: Compound
Dzenzursky is a strongly eroded stratovolcano of Pleistocene age that lies along a ridge extending NW from Zhupanovsky volcano. A series of Holocene cinder and lava cones along a ridge trending E and SE of the volcano produced extensive lava fields with flows that traveled primarily to the NE. Eruptions were reported in 1923 and 1957 CE (Vlodavetz and Piip 1959, Firstov et al. 1979); however, Fedotov and Masurenkov (1991) did not list any observed eruptions, and Ponomareva (1992, pers. comm.) stated that these reports were of hydrothermal or fumarolic activity.

Veer
Cinder cones along the Levaya Avacha River about 60 km N of Petropavlovsk-Kamchatskiy erupted lavas over young river terraces. The basaltic Veer cone, located on the W side of the river, produced a lava flow with prominent ridges that descended into the valley. Although Krijanovsky (1934) listed an 1856 eruption, stratigraphic studies have shown that the eruption occurred sometime between the 1,500 years before present (BP) eruption from Barany Amphitheater of Opala volcano and a 1,630 BP eruption from Avachinsky (Dirksen, 1999 pers. comm.). Nearby andesitic Pravy volcano is also of postglacial age.

Kostakan
A group of basaltic cinder cones lies south of Bakening volcano, west of the Srednaya Avacha (Middle Avacha) river valley. They are part of a broad zone of regional late Pleistocene to Holocene basaltic volcanism west of the Eastern volcanic zone of Kamchatka that extends from the Kostakan Lake area to the south. Several of the cinder cones are breached by lava flows, some of which extend into the Srednaya Avacha valley. The highest-elevation vent, Zmeya crater, was constructed within a landslide scarp. An unnamed maar is located about 2 km S of Kostakan Lake. Eruptions have occurred during two time periods, between about 11,000 to 7,000 years ago and between about 1,200 and 600 years ago.

Bakening
Bakening (also known as Bakenin) lies well west of the eastern volcanic range of Kamchatka, at the head of the Srednyaya Avacha River, about 100 km NNW of Petropavlovsk. Most of the volcano is of Pleistocene age, and subglacial rhyodacitic tuyas are located on the NW flanks. The andesitic stratovolcano has dacitic lava domes at its N and NE base, the latest of which (Novo Bakening) formed about 9,000-10,000 years ago. A large scarp open to the SE was the source of a large debris avalanche about 8,000-8,500 years ago that traveled 11 km E and S. The avalanche, which dammed drainages forming two lakes NE and E of the volcano, was followed by an explosive eruption and a block-and-ash flow. Several late-Pleistocene to Holocene cinder cones are located on the northern-to-southern flanks. The latest dated activity consisted of the construction of a cinder cone at the western foot of the volcano about 2,500 years ago.

Zavaritsky
Zavaritsky volcano consists of a complex of six cinder cones trending NW-SE, and an explosion crater located near the headwaters of the Levaya Avacha River west of the main Eastern Kamchatka volcanic arc. The six cones were formed during an eruption about 2,800 years ago, during which associated lava flows blocked the Levaya Avacha and Ozernaya rivers, forming Lake Vulkanischeskoe along the Ozernaya drainage. The highest cone, Mount Peschanaya, lies near the southern end of the cone group. Other monogenetic cinder cones are located NW and NE of the volcano. The Berezovy cinder cone to the NW erupted ~11,000-10,000 radiocarbon years ago. An unnamed cone near the crest of a range dividing the Srednaya Avacha and Kavicha river drainages, about 14 km WNW, erupted about 3,000-2,500 years ago; it is slightly closer to Bakening volcano, but the chemistry of its products are related to those of Zavaritsky.

Akademia Nauk
The lake-filled Akademia Nauk caldera is one of three volcanoes constructed within the mid-Pleistocene, 15-km-wide Polovinka caldera. The eroded Beliankin stratovolcano, in the SW part of Polovinka caldera, has been active in postglacial time (Sviatlovsky, 1959). Two nested calderas, 5 x 4 km Odnoboky and 3 x 5 km Akademia Nauk (also known as Karymsky Lake or Academii Nauk), were formed during the late Pleistocene, the latter about 30,000 years ago. Eruptive products varied from initial basaltic andesite lava flows to late-stage rhyodacitic lava domes. Two maars, Akademia Nauk and Karymsky, subsequently formed at the southern and northern margins of the caldera lake, respectively. The northern maar, Karymsky, erupted about 6,500 radiocarbon years ago and formed a small bay. The first recorded eruption from Akademia Nauk took place on 2 January 1996, when a day-long explosive eruption of unusual basaltic and rhyolitic composition occurred from vents beneath the NNW part of the caldera lake near Karymsky maar.

Zhupanovsky
The Zhupanovsky volcanic massif consists of four overlapping stratovolcanoes along a WNW-trending ridge. The elongated complex was constructed within a Pliocene-early Pleistocene caldera whose rim is exposed only on the eastern side. Three of the stratovolcanoes were built during the Pleistocene. An early Holocene stage of frequent moderate and weak eruptions from 7,000 to 5,000 years before present (BP) was followed by a period of infrequent larger eruptions that produced pyroclastic flows. The last major eruption took place about 800-900 BP. Recorded eruptions have consisted of relatively minor explosions from Priemysh, the third cone from the E about 2.5 km from the summit peak.

Karymsky
Karymsky is a symmetrical stratovolcano constructed within a 5-km-wide caldera that formed during the early Holocene. The caldera cuts the S side of the Pleistocene Dvor volcano and is located outside the N margin of the large mid-Pleistocene Polovinka caldera, which contains the smaller Akademia Nauk and Odnoboky calderas. Most seismicity preceding Karymsky eruptions originated beneath Akademia Nauk caldera, located immediately south. The enclosing caldera formed about 7,600-7,700 radiocarbon years ago; construction of the stratovolcano began about 2,000 years later. The latest eruptive period began about 500 years ago, following a 2,300 years of quiescence. Much of the cone is covered by lava flows less than 200 years old. Recorded eruptions have been Vulcanian or Vulcanian-Strombolian with moderate explosive activity and occasional lava flows from the summit crater.

Maly Semyachik
Maly Semyachik is a compound stratovolcano located in a 10-km-wide caldera within the 15 x 20 km mid-Pleistocene Stena-Soboliny caldera. Following construction during the late Pleistocene of the Paleo-Semiachik volcano beginning about 20,000 years before present (BP), activity migrated to the SW, forming Meso-Semiachik (about 11,000-9,000 BP) and Ceno-Semiachik (about 8,000 BP to the present). An initial stage lasting about 3,500 years was dominantly explosive, constructing the present cone. A second stage beginning about 4,400 years ago was marked by alternating constructive and destructive processes. A crater lake fills the historically active Troitsky Crater, which formed during a large explosive eruption about 400 years ago.

Bolshoi Semiachik
The Bolshoi Semiachik volcanic complex was constructed within a 10-km-wide caldera whose rim is exposed only on the west. The caldera occupies a large 20 x 30 km late-Pleistocene volcano-tectonic depression near the Pacific Coast of eastern Kamchatka. Post-caldera volcanism includes resurgent doming and the construction of numerous stratovolcanoes and lava domes, several of which have been active during the Holocene. Zubchatka (Bolshoi Semiachik), Zapadny Barany, Vostochny Barany, Zentralny Semiachik, Popkov, Plosky, and Burlyashchy volcanoes are the largest of the complex. The youngest volcanism and intense hydrothermal activity is located outside the caldera to the SE.

Taunshits
Taunshits volcano, located west of the massive Uzon caldera, is an andesitic stratovolcano that was constructed beginning about 39,000 years before present (BP) on top of a large Pleistocene tuya pedestal. The summit is truncated by an open crater breached to the west that formed about 8,000 BP during an eruption producing a directed blast and a 3 km3 debris avalanche that traveled 19 km W. Another strong explosive eruption took place about 2,500 BP. Two satellitic cones occupy the S flank, and a cluster of Holocene cinder cones farther to the south may also be related to Taunshits.

Uzon
Volcano type: Caldera(s)
The Uzon and Geysernaya calderas, containing Kamchatka's largest geothermal area, form a 7 x 18 km depression that originated during multiple mid-Pleistocene eruptions. Widespread ignimbrite deposits associated with caldera formation have a volume of 20-25 km3 (exclusive of airfall deposits) and cover an area of 1,700 km2. Post-caldera activity was largely Pleistocene in age and consisted of the extrusion of small silicic lava domes and flows and maar formation in the Geysernaya caldera. The Lake Dal'ny maar in the NE part of the 9 x 12 km western Uzon caldera is early Holocene in age, and several Holocene phreatic eruptions have been documented in the Geysernaya caldera. The extensive high-temperature hydrothermal system includes the many hot springs, mudpots, and geysers of the Valley of Geysers, a 4-km-long canyon on the SE margin of the depression. Hydrothermal explosions took place in the caldera in 1986 and 1989.

Kikhpinych
Kikhpinych, the youngest stratovolcano of the Eastern Volcanic Zone of Kamchatka, contains three summits constructed along a roughly E-W line above the eroded Pleistocene Pik volcano, NE of the Uzon caldera. Growth of the modern volcano began during the mid-Holocene about 4,800 years ago with construction of the Zapadny cone. After a long quiescence, the younger Savich cone was built about 1,400 years ago, which included strong explosive activity that destroyed part of the Zapadny and Pik cones. Numerous young lava flows mantle the flanks of Savich; it was last active about 400 years ago, when the Krab lava dome grew on its E flank. Numerous thermal fields are found throughout the complex, including two geysers (now the site of vigorous fumaroles) that were active in the summit crater of Stary Kikhpinych prior to burial by a rockfall avalanche that occurred sometime between September 1981 and July 1982.

Krasheninnikov
The late Pleistocene to Holocene Krasheninnikov volcano is comprised of two overlapping stratovolcanoes within a 9 x 10 km Pleistocene caldera. Young lava flows from summit and flank vents descend both into the caldera and down its outer flanks, and older flows that covered much of the SE caldera rim extended downslope at least 7 km. Tephra deposits from the caldera-forming eruption directly overlie a 39,000 years before present (BP) tephra thought to be associated with the formation of Uzon caldera (Florenskii, 1988). The intra-caldera stratovolcanoes are situated along a NE-SW-trending fissure that has also produced zones of Holocene cinder cones extending 15-20 km beyond the caldera. Construction of the southern edifice began about 11,000 years BP and lasted for about 4,500 years; it has a summit crater about 800-900 m wide. The northern edifice was constructed during a cycle of similar length that began about 6,500 years ago; it has a summit crater about 1.5 km wide, within which is low cone with an 800-m-wide crater containing another small cone. An eruptive cycle during about 600-400 years BP (1350-1550 CE) produced the Pauk lava cone in the crater of the northern cone and the Yuzhny lava flow on SW flank outside the caldera, followed by the Molodoy flow from the upper SW flank (Ponomareva, 1987; Ponomareva and Tsyurupa, 1985; Ponomareva and Braitseva, 1990).

Kronotsky
The symmetrical Kronotsky stratovolcano on the Kamchatka Peninsula lies between the Pacific Ocean and Lake Kronotsky. Extensive lava flows on the south side of the volcano dammed the Listvenichnaya River to form the lake. A steep summit ridge forms the peak above flanks that are dissected by radial valleys up to 200 m deep. Small cinder cones are present on the lower N and S flanks, 5-10 km from the summit. Lavas have been dominantly basaltic, with the exception of the small basaltic andesite summit lava extrusion and a flank lava flow. Fumarolic activity has been reported from near the summit. Gorbach et al. (2024) found scoria horizons associated with explosive eruptions dated to ~5,200-5,400 and ~6,000 years BP.

Gamchen
Gamchen is a complex volcano composed of four stratovolcanoes, one of which is of Holocene age. Yuzhny Gamchen and Severny Gamchen are steep-sided eroded stratovolcanoes of Pleistocene age. Edifice-collapse events during the early Holocene produced several large debris-avalanche deposits below the eastern flanks. Molodoi, a small stratovolcano with a shallow crater, is located on the E flank of Severvy Gamchen. Barany, a young stratovolcano with a crater 500 m wide and 200 m deep, is located on the SE flank of Yuzhny Gamchen. Barany is the source of a lava field extending to the E and NE that was active between about 3,600 and 3,000 years ago. Lava domes are found on the flanks of the volcanoes; the youngest of these is Lukovitsa dome, which formed during the final stages of activity at Barany. No reported eruptions are known.

Vysoky
Visoky, at the northern end of a chain of small volcanoes trending NNW from Gamchen volcano, is a small Holocene stratovolcano with a youthful-looking summit crater constructed over the east flank of the Pleistocene Bogdanovich shield volcano. Vysoky (also spelled Vysokii) lies only 4 km NE of Komarov volcano. Another small Holocene volcano lies between Komarov and Vysoky. These mark the northernmost Holocene volcanoes of the Gamchen volcanic ridge and the northernmost of the near-trench portion of the Eastern volcanic belt of Kamchatka related to subduction of the Pacific Plate. Visoky was active throughout much of the Holocene until as recently as at least about 2000 years ago, when voluminous lava flows were traveled down the volcano's flanks.

Komarov
Komarov volcano is a complex structure along the Gamchen ridge. The summit area includes two irregular craters ~300m in diameter. Lengthy Holocene lava flows extend to the east and west. Growth began about 1,500 years ago following cessation of activity at Vysoky volcano. No reported eruptions are known, but the summit region has undergone extensive hydrothermal alteration, and fumarolic areas occur there and on the northern and southern flanks.

Kizimen
Kizimen is an isolated, conical stratovolcano that is morphologically similar to St. Helens prior to its 1980 eruption. The summit consists of overlapping lava domes, and blocky lava flows descend the flanks of the volcano, which is the westernmost of a volcanic chain north of Kronotsky volcano. The 2334-m-high edifice was formed during four eruptive cycles beginning about 12,000 years ago and lasting 2000-3500 years. The largest eruptions took place about 10,000 and 8300-8400 years ago, and three periods of long-term lava dome growth have occurred. The latest eruptive cycle began about 3000 years ago with a large explosion and was followed by intermittent lava dome growth lasting about 1000 years. An explosive eruption about 1100 years ago produced a lateral blast and created a 1.0 x 0.7 km wide crater breached to the NE, inside which a small lava dome (the fourth at Kizimen) has grown. Prior to 2010, only a single explosive eruption, during 1927-28, had been recorded in historical time.

Udina
The Udina volcanic massif consists of two conical stratovolcanoes constructed along a WNW-ESE line at the south end of the Kliuchevskaya volcanic group, SE of Tolbachik volcano. The andesitic western volcano, Bolshaya Udina, has a prominent lava dome on its SW flank. The basaltic Malaya Udina rises above a low saddle at the eastern end of the complex; small lava domes also occur on its flanks.

Zimina
The eroded stratovolcanoes of Ostraya and Ovalnaya Zimina form a ridge north of the Udina complex at the SE end of the Kliuchevskaya volcano group. The larger Ovalnaya Zimina, on the W side of the complex, has a large icecap and contains two summits. The extensively eroded Ostraya Zimina to the E has a sharp-peaked summit spire. A large debris avalanche from Ovalnaya Zimina traveled more than 10 km. No eruptions are known to have occurred from these volcanoes.

Tolbachik
The massive Tolbachik volcano is located at the southern end of the Kliuchevskaya volcano group. The massif is composed of two overlapping, but morphologically distinct, volcanoes. The flat-topped Plosky Tolbachik shield volcano with its nested Holocene calderas up to 3 km in diameter is located east of the older and higher sharp-topped Ostry Tolbachik stratovolcano. The summit caldera at Plosky Tolbachik was formed in association with major lava effusion about 6,500 years ago and simultaneously with a major southward-directed sector collapse of Ostry Tolbachik. Long rift zones extending NE and SSW of the volcano have erupted voluminous basaltic lava flows during the Holocene, with activity during the past two thousand years being confined to the narrow axial zone of the rifts. The 1975-76 eruption originating from the SSW-flank fissure system and the summit was the largest historical basaltic eruption in Kamchatka.

Kamen
The steep-sided Kamen stratovolcano lies at the center of a N-S chain of volcanoes, flanked by Bezymianny and Kliuchevskoi. It formed during the late Pleistocene, but activity continued into the Holocene (Melekestsev et al., 1990). A major slope failure about 1,200-1,300 years ago removed much of the eastern side of the volcano, producing a 4-6 km3 debris avalanche that traveled more than 30 km SE.

Bezymianny
The modern Bezymianny, much smaller than its massive neighbors Kamen and Kliuchevskoi on the Kamchatka Peninsula, was formed about 4,700 years ago over a late-Pleistocene lava-dome complex and an edifice built about 11,000-7,000 years ago. Three periods of intensified activity have occurred during the past 3,000 years. The latest period, which was preceded by a 1,000-year quiescence, began with the dramatic 1955-56 eruption. This eruption, similar to that of St. Helens in 1980, produced a large open crater that was formed by collapse of the summit and an associated lateral blast. Subsequent episodic but ongoing lava-dome growth, accompanied by intermittent explosive activity and pyroclastic flows, has largely filled the 1956 crater.

Ushkovsky
The Ushkovsky (formerly known as Plosky) complex is a large compound volcanic massif located at the NW end of the Kliuchevskaya volcano group. The summit of Krestovsky (Blizhny Plosky) volcano, about 10 km NW of Kliuchevskoy, is the high point of the complex. Linear zones of cinder cones are found on the SW and NE flanks and on lowlands to the west. The Ushkovsky (Daljny Plosky) edifice SE of Krestkovsky is capped by an ice-filled 4.5 x 5.5 km caldera containing two glacier-clad cinder cones with large summit craters. A younger caldera at the summit of Daljny was formed in association with the eruption of large lava flows and pyroclastic material from the Lavovy Shish cinder cones at the foot of the volcano about 8,600 years ago. An explosive eruption took place from the summit cone in 1890.

Klyuchevskoy
Klyuchevskoy is the highest and most active volcano on the Kamchatka Peninsula. Since its origin about 6,000 years ago, this symmetrical, basaltic stratovolcano has produced frequent moderate-volume explosive and effusive eruptions without major periods of inactivity. It rises above a saddle NE of Kamen volcano and lies SE of the broad Ushkovsky massif. More than 100 flank eruptions have occurred during approximately the past 3,000 years, with most lateral craters and cones occurring along radial fissures between the unconfined NE-to-SE flanks of the conical volcano between 500 and 3,600 m elevation. Eruptions recorded since the late 17th century have resulted in frequent changes to the morphology of the 700-m-wide summit crater. These eruptions over the past 400 years have originated primarily from the summit crater, but have also included numerous major explosive and effusive eruptions from flank craters.

Sheveluch
The high, isolated massif of Sheveluch volcano (also spelled Shiveluch) rises above the lowlands NNE of the Kliuchevskaya volcano group. The 1,300 km3 andesitic volcano is one of Kamchatka's largest and most active volcanic structures, with at least 60 large eruptions during the Holocene. The summit of roughly 65,000-year-old Stary Shiveluch is truncated by a broad 9-km-wide late-Pleistocene caldera breached to the south. Many lava domes occur on its outer flanks. The Molodoy Shiveluch lava dome complex was constructed during the Holocene within the large open caldera; Holocene lava dome extrusion also took place on the flanks of Stary Shiveluch. Widespread tephra layers from these eruptions have provided valuable time markers for dating volcanic events in Kamchatka. Frequent collapses of dome complexes, most recently in 1964, have produced debris avalanches whose deposits cover much of the floor of the breached caldera.

Kuril Volcanic Arc

Rishirizan
Japan
Kuril Volcanic Arc
Rishirizan is a highly dissected andesitic stratovolcano that forms a 20-km-wide island west of the northern tip of Hokkaido. Extensive erosion has produced an extremely rugged topography, with a dramatic sharp-topped, summit flanked by steep-sided radial ridges. A stratovolcano and flank lava domes were constructed beginning less than 200,000 years ago. After about 37,000 years ago only flank vents were active. Late-stage eruptions took place from scoria cones and maars along a 15-km-long NW-SE trend that extends to the SE coast. Flank eruptions were dominantly basaltic, but also included andesitic and rhyolitic activity. Extensive lava flows during the late Pleistocene form much of the northern and western coasts and extend offshore. The latest eruptions took place a few thousand years ago.

Tokachidake
Japan
Kuril Volcanic Arc
Tokachidake volcano consists of a group of dominantly andesitic stratovolcanoes and lava domes arranged on a NE-SW line above a plateau of welded Pleistocene tuffs in central Hokkaido. Numerous explosion craters and cinder cones are located on the upper flanks of the small stratovolcanoes, with the youngest Holocene centers located at the NW end of the chain. Frequent historical eruptions, consisting mostly of mild-to-moderate phreatic explosions, have been recorded since the mid-19th century. Two larger eruptions occurred in 1926 and 1962. Partial cone collapse of the western flank during the 1926 eruption produced a disastrous debris avalanche and mudflow.

Maruyama
Japan
The Nipesotsu-Maruyama volcano group, located west of Nukabira Lake about 20 km E of Tokachidake volcano, is composed of a number of overlapping andesitic-to-rhyolitic stratovolcanoes and lava domes constructed along a NW-SE trend. These volcanoes overlap the SW rim and SW caldera floor of the Pleistocene Tokachimitsumata caldera. The highest peak in the complex is Nipesotsuyama stratovolcano, which was active during the mid-Pleistocene, about 400,000-200,000 years ago. The Maruyama stratovolcano and lava dome at the southern end of the complex was discovered to be a Quaternary volcano in 1989. It is also referred to as Higashi-Tokachi-Maruyama to distinguish it from several other volcanoes named Maruyama, which means "Round Mountain." A minor phreatic eruption took place at the lava dome in 1898, and fumaroles are present on one of its summit craters.

Taisetsuzan
The Taisetsuzan volcano group lies at the northern end of the Taisetsu-Tokachi graben in central Hokkaido. It consists of a complex of stratovolcanoes and lava domes associated with a 2-km-wide caldera. The eight satellitic volcanoes are aligned along a ring fracture that is centered over the eastern rim of the caldera. Asahidake, the highest peak of the complex, was constructed 3 km SW of the center of the caldera. Other stratovolcanoes are located along a NE-SW line cutting through the caldera that trends toward the Tokachi volcano complex to the SW. In contrast to the Tokachi group, no historical eruptions are known, although the latest phreatic eruption took place sometime after 1739 CE. Fumarolic areas are located on Asahidake, where at one time sulfur was mined, and in the caldera.

Akan
Akan is a 13 x 24 km caldera located immediately SW of Kussharo caldera in eastern Hokkaido. The elongated, irregular outline of the caldera rim reflects its incremental formation during major explosive eruptions from the early to mid-Pleistocene. There are four post-caldera stratovolcanoes, three at the SW end of the caldera and the other on the NE side. Conical Oakandake was frequently active during the Holocene. The 1-km-wide Nakamachineshiri crater of Meakandake was formed during a major pumice-and-scoria eruption about 13,500 years ago. The Meakandake group, composed of nine overlapping cones E of Lake Akan, has produced mild phreatic eruptions since the beginning of the 19th century. The main cone of Meakandake proper has a triple crater at its summit. Although recorded eruptions at Meakandake have consisted of minor phreatic explosions, four major magmatic eruptions with pyroclastic flows have also occurred during the Holocene.

Mashu
Mashu is a 6-km-wide Holocene caldera that truncates a stratovolcano constructed on the ESE rim of the large Kussharo caldera. The steep-walled caldera, filled by Lake Mashu, is one of the scenic highlights of Hokkaido. Following caldera collapse about 7,000 years ago, a small andesitic stratovolcano, Kamuinupuri, was formed beginning about 4,000 years ago, creating a reentrant into the SE side of the deep caldera lake. A large explosive eruption about 1,000 years ago, the latest dated eruption, created a 1.2 x 1.5 km crater at the summit of Kamuinupuri. The small island of Kamuishu in the center of Lake Mashu represents the tip of a mostly submerged dacitic lava dome.

Rausudake
Rausudake is an andesitic-to-dacitic stratovolcano with summit lava domes on the Shiretoko Peninsula in NE Hokkaido. The 1660-m-high volcano is located along a ridge 5 km SW of Shiretoko-Iozan volcano, the NE-most Holocene volcano in Hokkaido. Young lava flows descend the NW flank and broad areas along the SE flank, and an older lava flow traveled about 9 km W, reaching the coast of the Sea of Okhotsk along a broad front. Eruptions produced pumiceous tephras with associated pyroclastic flows about 2200, 1400, and 800 years ago. Recent work has documented a pyroclastic-flow deposit that overlies the 1739 tephra from Tarumai volcano in SW Hokkaido. Stratigraphic relationships place this eruption, the most recent known from Rausudake, between about 1750 and 1850 CE.

Kussharo
The 20 x 26 km Kussharo caldera (also spelled Kutcharo or Kuccharo), is the largest of a cluster of calderas in NE Hokkaido. The caldera was formed in a series of major eruptions between about 340,000 and 30,000 years ago. Nakajima, a Holocene post-caldera dacitic-to-rhyolitic lava-dome complex, forms an island in the large lake that fills much of the western half of the caldera. The Holocene Atosanupuri stratovolcano and lava-dome complex is located near the center of the caldera, east of the crescent-shaped Lake Kutcharo. Many lava domes were formed between about 1000-10,000 years ago. No historical eruptions are known, although intense fumarolic activity occurs on and around Atosanupuri volcano and along the shores of Lake Kutcharo.

Shiretoko-Iozan
Shiretoko-Iozan, one of many Japanese "sulfur mountains," is noted for the extrusion of molten sulfur during eruptions in 1889 and 1936. Located at the NE tip of Hokkaido on the Shiretoko Peninsula, the andesitic volcano contains two large craters at the summit that are breached to the NW. The southern crater contains a small flat-topped lava dome. The main cone, Nakadake, was constructed NW of the headwalls of the two breached craters. Historical eruptions have originated from the southernmost of three explosion craters along a NNE-SSW line on the NW flank of the main cone.

Tomariyama [Golovnin]
Japan - administered by Russia
Tomariyama, also known as Golovnin, forms the southern end of Kunashir Island, across the Nemuro Strait from Hokkaido. Explosive activity has dominated in the formation of this andesitic-dacitic volcano; no lava flows are exposed. The gently sloping stratovolcano is truncated by a 4-5 km caldera that formed during a series of late-Pleistocene eruptions beginning about 43,000 years ago. Several lava domes were subsequently emplaced on the caldera floor. Topographic highs outside the caldera rim are lava domes extruded along a ring structure or an outer caldera. A 1 x 2.5 km caldera lake on the northern side of the inner caldera drains through a narrow breach in the western caldera wall. Solfataric activity occurs at the northern lake shore and at explosion craters (one of which contains a hot crater lake with reported temperatures from 36-100�C) that cut the caldera-floor lava domes. The only known recorded eruption was a minor explosion in 1848.

Ruruidake [Smirnov]
Japan - administered by Russia
Ruruidake is a late Pleistocene andesitic-to-dacitic volcanic complex on the NW tip of Kunashir Island in the southern Kuriles, NW of Chachadake [Tiatia} volcano. About 2.5 km SSW of the Ruruidake peak, the gently sloping Smirnov edifice partially retains a constructional form, but the southern side has been heavily eroded by glaciers, exposing its Tertiary basement. A wide glacial trough on the SE flank of Smirnov contains a pyroclastic cone at its head that fed a 4 km lava flow. Another pyroclastic cone is located at the base of the trough near the terminus of the lava flow. Two fresh-looking lava domes of Holocene age also lie within the glacial valley to the north.

Raususan [Mendeleev]
Japan - administered by Russia
Raususan, also known as Mendeleev, is a low compound stratovolcano located in the southern part of Kunashir Island. The dominantly andesitic-dacitic volcano is cut by two nested calderas, the larger 6-7 km in diameter and the smaller 3-3.5 km. A central cone that formed inside the younger caldera was breached to the west by a large debris avalanche about 4200 years ago. A lava dome that grew inside the avalanche scarp forms the 888 m high point of the volcano. Additional lava domes in the northern part of the older caldera are considered to represent flank activity of the younger caldera. The only unambiguous historical eruption was a small phreatic explosion in 1880. Four solfatara fields lie at the eastern and northern flanks of the central cone, and a geothermal field is located outside the caldera along the eastern coast.

Chachadake [Tiatia]
The symmetrical Chachadake, also known as Tiatia, is on the SE side of northern Kunashir Island in the southern Kuriles. The active cone rises above the rim of a filled 2.1 x 2.4 km summit caldera with erosionally furrowed flanks. The central cone, mostly formed by basaltic to basaltic andesite Strombolian eruptions, rises 400 m above the floor of the caldera and contains a 400 x 250 m crater. Dark lava flows cover much of the SW caldera floor and have overflowed the rim, extending to the foot of the older edifice, which formed during the late Pleistocene or early Holocene. A 500-m-wide crater about 2 km down the SE flank from the caldera rim is surrounded by an unvegetated area of volcanic deposits. The first recorded eruption was in 1812, and a major explosive eruption with lava flows in 1973 originated from vents on the central cone.

Berutarubesan [Berutarube]
The Berutarubesan andesitic-to-dacitic stratovolcano forms the SW tip of Iturup Island in the southern Kuriles. The flanks are deeply dissected by wide glacial valleys; a low saddle on the NE side separates it from the slopes of the Moekeshiwan [Lvinaya Past] caldera. The only known Holocene activity produced a small pyroclastic cone that was superposed on the intersecting headwalls of U-shaped valleys and cirques on the broad eroded summit. The hydrothermally altered summit cone was the source of two small lava flows. Gorshkov (1970) estimated that eruptions ceased only a few hundred to at most 1,000 years ago. No confirmed eruptions are known, although there are fumarolic areas near the summit with sulfur deposits.

Etorofu-Atosanupuri [Atosanupuri]
The conical Etorofu-Atosanupuri stratovolcano forms a peninsula joined to the SW side of Iturup (Etorofu) Island by an isthmus 30 m high. A somma volcano whose caldera rim is exposed only at about 900 m elevation on the SE side was constructed during the late Pleistocene or early Holocene, forming an island up to about 1.5 km high that was later connected to the main island by erosional material. A fault with large displacement offsets the NW side of the somma. The 2-km-wide caldera was subsequently largely overtopped by a central cone that forms the present summit. Strombolian eruptions have dominated the history of this basaltic volcano; few lava flows are exposed. Eruptions were reported in 1812 and 1932.

Hitokappu Volcano Group [Bogatyr Ridge]
The Hitokappu Volcano Group [Bogatyr Ridge] on Iturup Island in the southern Kuriles consists of a cluster of late-Pleistocene to Holocene cones and craters extending ~14 km NE-SW. The basaltic andesite to andesitic Nishihitokappuyama (also known as Stokap) stratovolcano at the SW end of the ridge appears to be the location of the most recent eruptions, with a summit area that includes 8-10 cones and explosion craters, the largest of which contains a lake. The volcanic chain was constructed over a high Pleistocene base, whose glaciated surface is covered by lava flows from Nishihitokappuyama that reach to both the Pacific Ocean and the Sea of Okhotsk. JMA (2013) does not include this as a Holocene volcano.

Etorofu-Yakeyama [Grozny Group]
The Etorofu-Yakeyama (Ivan Grozny) complex is located in the center of Iturup Island. It has a 3-3.5 km diameter caldera open to the south, where a large extrusive andesitic dome was emplaced. Several other lava domes of Holocene age were constructed to the NE; extrusion of these domes has constricted a former lake in the northern side of the caldera to an extremely sinuous shoreline. Recorded eruptions, the first of which took place in 1968, have been from the central Yakeyama (Grozny) dome.

Sashiusudake [Baransky]
The Sashiusudake (also known as Baransky) volcanic complex along the Pacific coast in the central part of Iturup Island consists of a Holocene stratovolcano built over an eroded Pleistocene edifice. A young summit lava dome is cut by a NW-trending chain of small explosion craters. A group of flank cones farther to the NW with a similar NW-SE orientation is partially surrounded by lava flows from the central crater of the andesitic-dacitic volcano. Lava flows descended 4-5 km SE to reach the Pacific Ocean along a broad front. The only observed eruption occurred in 1951, when local inhabitants reported weak explosive activity at the summit. Strong solfataric activity continues from the summit and several flank craters, and the SW flank geothermal field contains hot springs and geysers. A small hydrothermal explosion took place in 1992 at an exploratory well in the SW-flank geothermal field.

Moyorodake [Medvezhia]
The Moyorodake volcanic complex (also known as Medvezhia) occupies the NE end of Iturup (Etorofu) Island. Two overlapping calderas, 14 x 18 and 10 x 12 km in diameter, were formed during the Pleistocene. The caldera floor contains several lava domes, cinder cones and associated lava fields, and a small lake. Four small closely spaced stratovolcanoes were constructed along an E-W line on the eastern side of the complex. The easternmost and highest, Medvezhii, lies outside the western caldera, along the Pacific coast. Srednii, Tukap, and Kudriavy (Moyorodake) volcanoes lie immediately to the west. Historically active Moyorodake is younger than 2000 years; it and Tukap remain fumarolically active. The westernmost of the post-caldera cones, Menshoi Brat, is a large lava dome with flank scoria cones, one of which has produced a series of young lava flows up to 4.5 km long that reached Slavnoe Lake. Eruptions have been documented since the 18th century, although lava flows from cinder cones on the flanks of Menshoi Brat were also probably erupted within the past few centuries.

Ivao Group
The Ivao group of cones along the Krishtofovich Ridge of SW Urup Island contains several well-preserved cones of Holocene age. The first of a group of three young cones, at the NW end of the chain, is the Ivao cone. The SE-most cone bisects a glacial valley, forming Lake Ivao. The elongated central cone, Krutaya Mountain, is the youngest, and produced a viscous lava flow that traveled to the east.

Kolokol Group
A group of Holocene volcanoes in central Urup Island is named after its most prominent volcano, Kolokol. Berg and Trezubetz volcanoes, flanking Kolokol on the NW, have breached summit calderas partially filled by lava domes. Trezubetz, whose name means "Trident," has an eroded crater rim with three large peaks when seen at sea from the north. Kolokol is sometimes known as Urup-Fuji because of its symmetrical profile. The crater of Kolokol is not well preserved, but there is no evidence of glacial erosion. Several lava flows originate from Kolokol; one of these extends almost to the Sea of Okhotsk coast; a viscous lava flow armoring the SE flank is probably the most recent. Borzov volcano, the oldest of the group, lies to the SW of Kolokol. Eruptions have been observed since the late-18th century. Berg volcano has been most active, but Trezubetz erupted in 1924.

Kuril Arc at 46.3�N
Volcano type:
A shallow flat-topped edifice ~8 km in diameter, with depths from 0-50 m, is located in the Urup Strait ~15 km S of the Chernyye Brat'ya (Black Brothers) islands and ~20 km ENE of Urup Island in the Kuril Islands. Although visible using satellite bathymetry and appearing simply as a shallow platform on a map in Blokh et al. (2019) rather than a previously identified volcanic seamount, there is no available research about this edifice. Two reports of uncertain volcanic activity are assigned to this feature. This volcano number was previously created and placed at a location 7.5 km SE of the coast of Urup (~35 km SW), due to reported bubbling water seen from a fishing boat in March 1978 (SEAN 03:05), but was removed from the catalog due to insufficient evidence of any volcanic features. Hydrophones signals detected in April 1972 were interpreted to be from a submarine eruption in the Kuriles, probably between Simushir and Urup Island (Smithsonian CSLP 33-72). This activity was previously arbitrarily linked to Arkhangelsky, the submarine feature most centrally located between Urup and Simushir Islands, but has been reassigned following research showing a Pleistocene age for that massif.

Chirpoi
Chirpoi, a small island lying between the larger islands of Simushir and Urup, contains a half dozen volcanic edifices constructed within an 8-9 km wide, partially submerged caldera. The southern rim of the caldera is exposed on nearby Brat Chirpoev Island. The symmetrical Cherny volcano, which forms the central cone of the island, erupted twice during the 18th and 19th centuries. The youngest volcano, Snow, originated between 1770 and 1810. It is composed almost entirely of lava flows, many of which have reached the sea on the southern coast. No recorded eruptions are known from Brat Chirpoev, but its youthful morphology suggests recent Strombolian activity.

Milna
Milna (or Mil'na) is the southernmost volcano on Simushir Island in the central Kuriles, and includes the Goriaschaia Sopka lava dome on the NW flank. The outer flanks of the steep-sided 1500-m-high volcano are dissected by deep gullies. A 3-km-wide caldera breached widely to the SE was formed during the Pleistocene and became a center of glaciation. A small central cone capped by an andesitic lava dome was constructed within the caldera during postglacial time and forms the highest point on Simushir Island. Lava flows from the cone descend 4-5 km to the sea. Goriaschaia Sopka, previously identified as a distinct volcano, is a historically active andesitic lava dome that grew just beyond what appears to be a NE-SW erosional scarp along the NW flank. Numerous fresh lava flows with prominent marginal levees extend from the dome, with some reaching the sea. It may have formed as recently as the late-19th century; dominantly mild-to-moderate explosive eruptions have occurred since 1842.

Zavaritzki Caldera
The Zavaritzki volcano on Simushir Island in the central Kuril Islands contains three nested calderas 10, 8, and 3 km in diameter. The steep-walled youngest caldera was formed during the Holocene and includes several young cones and lava domes near the margins of Biryuzovoe Lake. The current lake surface is at ~40 m elevation with the bottom ~30 m below sea level, but lacustrine sediments overlying pumice deposits indicate that the surface of an earlier caldera lake lay at 200 m above sea level. A small 500-m-diameter scoria cone, sketched by Gorshkov (1958, CAVW) that reportedly grew between 1916 and 1931, formed a peninsula extending into the lake from the NE caldera wall. Explosive eruptions in 1957 removed the cone and filled much of the NW part of the lake, including emplacement of a 350-m-wide, 40-m-high dome. Hutchison et al. (2024) provided convincing evidence that Zavaritski Caldera was the source for a significant sulfur-rich eruption in 1831 CE, which was previously known only from ice core data and thought to have possibly originated from Babuyan Claro volcano.

Uratman
The northernmost volcano on Simushir Island, Uratman consists of a 7.5-km-wide Pleistocene caldera with walls that rise 450 m above a 250-m-deep caldera bay. A narrow gap in the northern rim provides ocean access into Brouton Bay, which fills the NW half of the caldera. The andesitic central cone grew during the Holocene in the SE part of the caldera. Two cinder cones are located along the N flank of Uratman, and a lava dome was formed on its NW flank along Brouton Bay. No recorded eruptions are known.

Prevo Peak
Symmetrical Prevo Peak, also known as Simushiru-Fuji for its resemblance to Japan's noted volcano, is capped by a 500 x 600 m summit crater. A nested inner cone contains a deep 350-m-wide crater with a small lake. Lava flows reach both coasts of central Simushir Island. Two small pyroclastic cones on the western flank produced lava flows that reached to or near the Sea of Okhotsk. A large eruption during the 1760s produced pyroclastic flows that destroyed all vegetation at the foot of the volcano. Weak explosive activity occurred during the most recent eruption, which took place during the first half of the 19th century.

Ketoi
The circular 10-km-wide Ketoi island, which rises across the 19-km-wide Diana Strait from Simushir Island, hosts of one of the most complex volcanic structures of the Kuril Islands. The rim of a 5-km-wide Pleistocene caldera is exposed only on the NE side. A younger stratovolcano forming the NW part of the island is cut by a horst-and-graben structure containing two solfatara fields. A 1.5-km-wide freshwater lake fills an explosion crater in the center of the island. Pallas Peak, a large andesitic cone in the NE part of the caldera, is truncated by a 550-m-wide crater containing a brilliantly colored turquoise crater lake. Lava flows from Pallas Peak overtop the caldera rim and descend nearly 5 km to the SE coast. The first historical eruption of Pallas Peak, during 1843-46, was its largest.

Srednii
Remnants of the Srednii submarine volcano form a hazardous obstruction in the strait between Rasshua and Ushishur Islands. Flat-topped Khitraya Rock may be a young (Holocene) extrusion dome, and adjoining rocks may be the rim of an old caldera (Gorshkov, 1970). Sapper (1917), Neumann Van Padang (1938), and Gushchenko (1979) reported a submarine eruption between Rasshua and Ushishur Islands on 12 July, possibly in 1880 (the year is uncertain).

Ushishur
The subaerial portion of Ushishur volcano in the central Kuriles is exposed in two small islands, the southern containing the summit caldera and the northern a portion of the volcano's flanks. A small 1.6-km-wide caldera that formed about 9,400 years ago is narrowly breached on the south, allowing seawater to fill the caldera. Two andesitic lava domes occupy part of the caldera bay; two other older domes are joined by a sand bar to the SE caldera wall. The two younger domes, erupted sometime after the 1769 visit of Captain Snow, form islands in the bay. A cluster of strong fumaroles and hot springs are present along the SE caldera shoreline, and vigorous submarine hydrothermal activity has modified the geochemistry of water within the caldera bay. Aside from growth of the two younger lava domes, only minor phreatic eruptions have been recorded.

Rasshua
The elongated 6 x 13 km island of Rasshua in the central Kuriles contains three overlapping central cones within a 6 km caldera whose eastern margin is beyond the shoreline. An eroded central cone was constructed during the late Pleistocene, along with an isolated cone near the NW coast. Two Holocene cones were built within the crater of the central cone. The westernmost forms the 956 m high point of the island and is the source of lava flows that flooded the crater floor and descended to the coast. The easternmost cone, active during historical time, is truncated by a 500-m-wide crater that is breached to the SE. This crater may have formed during a violent eruption in 1846. The only other known historical eruption produced weak explosions in 1957. Fumarolic activity continues in the eastern crater and in the saddle between the two summit cones.

Sarychev Peak
Sarychev Peak, one of the most active volcanoes of the Kuril Islands, occupies the NW end of Matua Island in the central Kuriles. The andesitic central cone was constructed within a 3-3.5-km-wide caldera, whose rim is exposed only on the SW side. A dramatic 250-m-wide, very steep-walled crater with a jagged rim caps the volcano. The substantially higher SE rim forms the 1496 m high point of the island. Fresh-looking lava flows, prior to activity in 2009, had descended in all directions, often forming capes along the coast. Much of the lower-angle outer flanks of the volcano are overlain by pyroclastic-flow deposits. Eruptions have been recorded since the 1760s and include both quiet lava effusion and violent explosions. Large eruptions in 1946 and 2009 produced pyroclastic flows that reached the sea.

Raikoke
A low truncated volcano forms the small barren Raikoke Island, which lies 16 km across the Golovnin Strait from Matua Island in the central Kuriles. The oval-shaped basaltic island is only 2 x 2.5 km wide and rises above a submarine terrace. An eruption in 1778, during which the upper third of the island was said to have been destroyed, prompted the first volcanological investigation in the Kuril Islands two years later. Incorrect reports of eruptions in 1777 and 1780 were due to misprints and errors in descriptions of the 1778 event (Gorshkov, 1970). Another powerful eruption in 1924 greatly deepened the crater and changed the outline of the island. Prior to a 2019 eruption, the steep-walled crater, highest on the SE side, was 700 m wide and 200 m deep. Lava flows mantle the eastern side of the island.

Chirinkotan
The small, mostly unvegetated 3-km-wide island of Chirinkotan occupies the far end of an E-W volcanic chain that extends nearly 50 km W of the central part of the main Kuril Islands arc. It is the emergent summit of a volcano that rises 3000 m from the floor of the Kuril Basin. A small 1-km-wide caldera about 300-400 m deep is open to the SW. Lava flows from a cone within the breached crater reached the shore of the island. Historical eruptions have been recorded since the 18th century. Lava flows were observed by the English fur trader Captain Snow in the 1880s.

Ekarma
The small 5 x 7.5 km island of Ekarma lies 8.5 km N of Shiashkotan Island along an E-W-trending volcanic chain extending westward from the central part of the main Kuril Island arc. It is composed of two overlapping basaltic andesite to andesitic volcanoes, the western of which has been historically active. Lava flows radiate 3 km in all directions from the summit of the younger cone to the sea, forming a lobate shoreline. A lava dome that was emplaced during the first historical eruption, in 1776-79, forms the peaked summit of the island.

Sinarka
Sinarka volcano, occupying the northern end of Shiashkotan Island in the central Kuriles, has a complex structure. A small, 2-km-wide depression open to the NW has been largely filled and overtopped by an andesitic postglacial central cone that itself contains a lava dome that forms the high point of the island. Another lava dome, Zheltokamennaya Mountain, lies 1.5 km to the SW along the buried SW rim of the caldera, and a smaller dome lies along the northern caldera rim. Historical eruptions have occurred during the 17th and 18th centuries. The last and largest of these, during 1872-78, was once thought to originate from Kuntomintar volcano at the southern end of the island, but is now attributed to Sinarka (Gorshkov, 1970).

Kharimkotan
The 8 x 12 km island of Kharimkotan (also spelled Harimkotan) in the northern Kuriles consists of a stratovolcano cut by two breached depressions on the east and NW sides. These horseshoe-shaped craters were formed by slope failure, which produced debris-avalanche deposits that form large broad peninsulas on the east and NW coasts. Evidence of additional slope failures followed by plinian eruptions are found in sea cliffs of the island. Historical explosive eruptions have occurred since the early 18th century. A central cone, Severgin, was largely destroyed during the 1933 eruption, one of the largest in the Kuril Islands during historical time. Impact of a debris avalanche into the sea from the collapse of Severgin produced a tsunami that swept the island's coast and reached Onekotan and Paramushir Islands, killing two people. A large lava dome emplaced during the 1933 eruption now fills the head of the eastern crater.

Tao-Rusyr Caldera
The southern half of Onekotan Island in the northern Kuril Islands contains the 7.5-km-wide Tao-Rusyr caldera, which is mostly filled by Kal'tsevoe lake. The basaltic-to-andesitic caldera formed about 7,500 years ago, in which the large post-caldera Krenitsyn Peak grew, building a 4-km-wide island in the NW part of the lake that rises above the caldera rim. A 350-m-wide, 100-m-deep crater truncates the peak, and a large crater is located on the upper NE side. An eruption in 1952 formed a small lava dome in an explosion crater along the eastern shore of the island.

Nemo Peak
Nemo Peak volcano at the northern end of Onekotan Island in the northern Kuriles is truncated by two preglacial nested calderas, the largest of which is 10 km in diameter and extends to the northern coast. A third 5-km-wide caldera formed about 25,000 years ago by collapse of an interglacial cone that was constructed over the glaciated surfaces of the earlier calderas. The central cone of Nemo Peak is composed of two coalescing andesitic cones that were constructed at the SW side of the youngest caldera and formed in four stages beginning in the early Holocene about 9,500 years ago. Construction of the central cone has left the crescent-shaped Chernoe Lake in the NE part of the youngest caldera; lava flows from Nemo Peak form the broad SW shoreline of the lake. The final activity built a lava dome that completely overtops a 350-m-wide crater and has a 150-m-wide crater at its summit. Eruptions from Nemo Peak have been reported since the early 18th century.

Shirinki
The 3-km-diameter island of Shirinki is located west of the main Kuril Island arc and ~20 km WSW of Fuss Peak on Paramushir Island. The truncated andesitic cone has a 750-m-wide breached summit crater with multiple peaks around the rim and two lava domes near the headwall of the breached crater. No eruptions have been documented, but the summit domes were considered to be very young by Gorshkov (1970). The remnants of an older edifice on the eastern side of the island are mostly covered by pumiceous pyroclastic-fall deposits.

Fuss Peak
Fuss Peak forms a peninsula that lies across a low isthmus on the SW coast of Paramushir Island in the northern Kuriles. This isolated symmetrical andesitic stratovolcano has a 700-m-wide, steep-walled crater that is 300 m deep. A deep notch cuts the NW rim of the crater to the level of the crater floor, at the head of a canyon that reaches the coast. Well-preserved lava flows occupy the middle and lower flanks, particularly on the E and SE sides. Only one unambiguous recorded eruption, in 1854 CE, is known; reports of eruptions in 1737, 1793, 1857, and 1859 are false (Gorshkov, 1970). Murayama (1987) also listed an eruption in 1742 (only earthquakes and a tsunami are cited by Sapper, 1917) and "smoke" emission in 1933.

Karpinsky Group
The Karpinsky Group on southern Paramushir Island in the Kuril Islands consists of three Holocene andesitic volcanic centers at the southern end of the Karpinsky Ridge. A postulated caldera is thought to have been primarily excavated by glaciers (Gorshkov, 1970). The NE cone has a crater breached to the NW that contains a small arcuate cone and a vigorous fumarole along the NE crater wall. A lava flow originating from the cone traveled 7 km to the SE. The southern cone forms the high point of the massif and fed lava flows to the SE and W. The NW cone displays hot springs and cones that occasionally eject liquid sulfur. Dark-colored gases were observed rising from the fumarolic area following a tectonic earthquake in November 1952 (Gorshkov, 1970). No confirmed eruptions have been observed, and no lava flows have been dated.

Chikurachki
Chikurachki, the highest volcano on Paramushir Island in the northern Kuriles, is a relatively small cone constructed on a high Pleistocene edifice. Oxidized basaltic-to-andesitic scoria deposits covering the upper part of the cone give it a distinctive red color. Frequent basaltic Plinian eruptions have occurred during the Holocene. Lava flows have reached the sea and formed capes on the NW coast; several young lava flows are also present on the E flank beneath a scoria deposit. The Tatarinov group of six volcanic centers is located immediately to the south, and the Lomonosov cinder cone group, the source of an early Holocene lava flow that reached the saddle between it and Fuss Peak to the west, lies at the southern end of the N-S-trending Chikurachki-Tatarinov complex. The Tatarinov centers are extensively modified by erosion and have a more complex structure. Tephrochronology gives evidence of an eruption around 1690 CE from Tatarinov, although its southern cone contains a sulfur-encrusted crater with fumaroles that were active along the margin of a crater lake until 1959.

Vernadsky Ridge
The Vernadsky Ridge on northern Paramushir island in the northern Kuriles is a large massif with over 40 volcanic centers in three volcano groups each ~7-8 km apart. The active Ebeko complex is at the N end, with the Bogdanovich group in the center and the Vernadsky group towards the S end. The latter two groups were considered to have been active in the Holocene by Gorshkov (1970). A geological map in Belovezhets et al. (2023), modified from Melekestsev et al. (1993) and State Geological Map (2001), identified Holocene lava flows from the Bogdanovich, Krasnuhk, Kozyrevsky, and Krasheninnikov cones in the central group, and from the Bilibin and Vernadsky cones in the southern group; these were also previously mapped by Gorshkov (1970). No eruption dates are known. A shear-wave seismic velocity model by Belovezhets et al. (2023) identified one "low-velocity anomaly at the depth of 4?6 km associated with magma reservoirs, which is overlaid by a prominent high-velocity anomaly representing the rigid cover" below the southern and central ridge, separate from that below Ebeko.

Ebeko
The flat-topped summit of the central cone of Ebeko volcano, one of the most active in the Kuril Islands, occupies the northern end of Paramushir Island. Three summit craters located along a SSW-NNE line form Ebeko volcano proper, at the northern end of a complex of five volcanic cones. Blocky lava flows extend west from Ebeko and SE from the neighboring Nezametnyi cone. The eastern part of the southern crater contains strong solfataras and a large boiling spring. The central crater is filled by a lake about 20 m deep whose shores are lined with steaming solfataras; the northern crater lies across a narrow, low barrier from the central crater and contains a small, cold crescentic lake. Historical activity, recorded since the late-18th century, has been restricted to small-to-moderate explosive eruptions from the summit craters. Intense fumarolic activity occurs in the summit craters, on the outer flanks of the cone, and in lateral explosion craters.

Alaid
The highest and northernmost volcano of the Kuril Islands, Alaid is a symmetrical stratovolcano when viewed from the north, but has a 1.5-km-wide summit crater that is breached open to the south. This basaltic to basaltic andesite volcano is the northernmost of a chain constructed west of the main Kuril archipelago. Numerous pyroclastic cones are present the lower flanks, particularly on the NW and SE sides, including an offshore cone formed during the 1933-34 eruption. Strong explosive eruptions have occurred from the summit crater beginning in the 18th century. Reports of eruptions in 1770, 1789, 1821, 1829, 1843, 1848, and 1858 were considered incorrect by Gorshkov (1970). Explosive eruptions in 1790 and 1981 were among the largest reported in the Kuril Islands.

Kambalny
The southernmost major stratovolcano on the Kamchatka peninsula, Kambalny has a summit crater that is breached to the SE. Five Holocene cinder cones on the W and SE flanks have produced fresh-looking lava flows. Beginning about 6,300 radiocarbon years ago, a series of major collapses of the edifice produced at least three debris-avalanche deposits. The last major eruption took place about 600 years ago, although younger tephra layers have been found, and an eruption was reported in 1767. Active fumarolic areas are found on the flanks of the volcano, which is located south of the massive Pauzhetka volcano-tectonic depression.

Yavinsky
Yavinsky is an early to mid-Pleistocene basaltic volcano that forms an arcuate ridge (Yavinsky Khrebet) along the SW coast of Kamchatka, overlooking the town of Ozernovsky and the mouth of the Ozernaya River. A Holocene basaltic cinder cone named Ukho (which means "Ear" in Russian), related to regional basaltic monogenetic volcanism, was constructed on the NW flank about 6,000 years ago, based on stratigraphic evidence. However, Yavinsky itself was not included by Ponomareva et al. (2007) in their review of Holocene volcanoes in Kamchatka.

Diky Greben
Diky Greben is a lava-dome complex that formed in the center of the 20 x 25 km Pauzhetka caldera, which also contains the Kurile Lake caldera to the east. This large caldera was associated with eruption of the voluminous rhyolitic Golygin ignimbrite during the late Pleistocene, about 443,000 years ago. The initial Diky Greben eruptions took place about 7,600-7,700 years ago, immediately following the Kurile Lake eruption. Most of the volcano, particularly the thick lava flows north and south of Nepriyatnaya Mountain, was formed during an eruption about 1,600 years ago. A total of 9-10 km3 of dacitic and 2-3 km3 of andesitic lavas and tephras were erupted at this time. Two large craters and a few smaller vents were formed after this eruption.

Kurile Lake
Kurile Lake caldera lies within the eastern part of the massive Pauzhetka caldera, but is considered as a separate volcanic system here. The low-rimmed caldera was formed in two stages during the late Pleistocene and early Holocene. The first caldera-forming eruption took place about 41,500 radiocarbon years ago. The second episode of caldera formation occurred about 7,600 radiocarbon years ago during one of the largest known Holocene eruptions. A total of 140-170 km3 of material was ejected, and extensive thick pyroclastic-flow deposits from the caldera-forming eruptions cover the area. Ash fell more than 1,000 km away on mainland Asia. The eruption resulted in the formation of an 8 x 14 km caldera, now largely filled by Kurile Lake. The steep-sided Serdtze Alaida (Heart of Alaid), which forms a small island rising 300 m from the caldera floor in the center of the lake, is a rhyodacitic lava dome that formed at the end of the caldera-forming eruption.

Koshelev
Koshelev is at the southern end of the Kamchatka Peninsula, SW of the Pauzhetka volcano-tectonic depression and NW of Kambalny volcano. It is a complex group of four stratovolcanoes constructed along an E-W line over a Pleistocene shield volcano. Central Koshelev stratovolcano, the highest peak of the volcanic massif, is Holocene in age; N- and SE-flank craters have also been active during the Holocene. Gorely, a Holocene cinder cone related to regional basaltic monogenetic volcanism, is located about 12 km NW. The largest Holocene eruption took place from the eastern cone about 6,500 years ago. An explosive eruption was reported at the end of the 17th century. Major thermal fields are located in the summit crater of Valentin volcano and on the western flanks of west Koshelev volcano.

Iliinsky
The conical Iliinsky volcano (also spelled Ilyinsky), rising dramatically to 1555 m above the NE shore of Kurile Lake, was constructed beginning about 7600 radiocarbon years ago at the NE margin of Kurile Lake caldera. The modern edifice grew within a 4-km-wide caldera produced by collapse of an earlier volcano creating large debris avalanches at about the time of formation of the adjacent Kurile Lake caldera. A period of strong silicic explosive volcanism during the mid-Holocene lasted about 800 years. A series of youthful lava flows cover much of the northern flanks. Growth of the modern cone was completed about 1900 years ago, after which a long quiescent period began. The only recorded historical eruption, in 1901, produced a large 1-km-wide crater on the NE flank.

Zheltovsky
Zheltovsky volcano was constructed during the last 8000 years within a 4 x 5 km caldera truncating an earlier Pleistocene edifice. A late-Holocene explosive eruption formed a 1.6-km-wide summit crater that was subsequently largely filled by four lava domes, the latest of which forms the present summit. Several of the lava domes were emplaced along the buried SE rim of the summit crater. More than ten cinder cones and lava domes were constructed on the flanks, particularly on the NW side. Only a few eruptions are known in historical time. The largest, in 1923, produced explosive activity and a lava flow down the SE flank that also partly flowed into the summit crater.

Olkoviy-Ozernoy Volcanic Field
A large group of Quaternary basaltic pyroclastic cones and associated lava flows (Masurenkov, 1980) fills a topographic low W and NW of Ksudach and Khodutka volcanoes. The Pleistocene Plosky and Holocene Olkoviy small shields lie 13-16 km W of Khodutka. Masurenkov (1980) considered this volcanic field to be bounded by rivers on the E (Pravaya Khodutka) and S (Pravaya Khodutka), with Ozernoy listed as a separate small basaltic shield considered to be Holocene further SW. In their review of Holocene volcanoes in Kamchatka, Ponomareva et al. (2007) did not identify Ozernoy as a distinct major volcano, but did include an unnamed volcanic field in this area. This catalog, under the unofficial designation of Olkoviy-Ozernoy Volcanic Field, includes these small shields along with a large number of small cones and some maars, extending from the Krugloe maar (13 km W of Ksudach) to volcanic features ~50 km NE between older Pleistocene edifices (24 km NW of Khodutka).

Khodutka
Khodutka stratovolcano was formed during the late-Pleistocene to early Holocene, partially covering the older Priemysh stratovolcano on the NW flank. At least 10 explosion craters, small lava cones, and lava domes are located along the flanks, and cinder cones produced by regional basaltic volcanism occur to the west. The Khodutkinsky maar on the WNW flank was created about 2,800 years ago during an eruption that deposited tephra across much of southern Kamchatka. Formation of the maar was accompanied by small pyroclastic flows, followed by emplacement of lava flows and domes. The last dated eruption took place from the summit vent about 2,000-2,500 years ago. The Khodutka Springs geothermal field occupies an explosion crater on the NW flank of Priemysh.

Asacha
The Asacha group is a complex massif of Pleistocene-to-Holocene volcanoes located within a distinctly fault-bounded crustal block WSW of Mutnovsky volcano. An older Asacha shield volcano, Zheltyi stratovolcano to the east, a younger Asacha stratovolcano, and the small Tumanov lava cone (the best-preserved major cone of the group) were constructed during the late Pleistocene. Most of the ten lava domes on the flanks of the Asacha volcanoes were formed during the Pleistocene, but some may be early Holocene. Holocene basaltic cinder cones and lava flows related to regional volcanism were erupted along the western and southern flanks of the complex. A major volcano-tectonic earthquake swarm occurred near Zheltyi volcano in 1983, suggesting that the complex remains volcanically active.

Visokiy
The basaltic Visokiy cone is the largest and central feature of a 10-km-long line of basaltic cinder cones between Asacha to the SW and Gorely to the NE. The small Golyi shield volcano lies immediately to the WSW (Masurenkov, 1980; Kozhemyaka et al., 1984).

Ksudach
Ksudach is unique among Kamchatka volcanoes in its morphology and geologic history. It is a large, low-angle stratovolcano, constructed of alternating basaltic-andesitic lavas and dacitic pyroclastics, and is truncated by an intricate complex of five calderas. An array of post-caldera structures is truncated by later calderas, the last three of which formed during the Holocene, about 7,900 and 5,000 BCE and about 240 CE. The latter eruption was the second largest in Kamchatka during the Holocene, and produced about 20 km3 of rhyodacitic airfall tephra and 3-4 km3 of pyroclastic flows. The eastern part of the caldera complex contains two lakes, the northern of which forms an embayment in Shtyubel' (Stubel) Crater, a low-angle cone that began forming about 1,600 years ago in the youngest caldera. The only historical eruption, in 1907, originated from Shtyubel'.

Mutnovsky
Massive Mutnovsky, one of the most active volcanoes of southern Kamchatka, is formed of four coalescing stratovolcanoes of predominantly basaltic composition. Multiple summit craters cap the volcanic complex. Growth of Mutnovsky IV, the youngest cone, began during the early Holocene. An intracrater cone was constructed along the northern wall of the 1.3-km-wide summit crater. Abundant flank cinder cones were concentrated on the SW side. Holocene activity was characterized by mild-to-moderate phreatic and phreatomagmatic eruptions from the summit crater. Explosive eruptions have been common since the 17th century, with lava flows produced during the 1904 eruption.

Gorely
Gorely volcano consists of five small overlapping stratovolcanoes constructed along a WNW-ESE line within a large 9 x 13 km caldera. The caldera formed about 38,000-40,000 years ago accompanied by the eruption of about 100 km3 of tephra. The massive complex includes about 40 cinder cones, some of which contain acid or freshwater crater lakes; three major rift zones cut the complex. Another Holocene stratovolcano is located on the SW flank. Activity during the Holocene was characterized by frequent mild-to-moderate explosive eruptions along with a half dozen episodes of major lava extrusion. Early Holocene explosive activity, along with lava flows filled in much of the caldera. Quiescent periods became longer between 6,000 and 2,000 years ago, after which the activity was mainly explosive. About 600-650 years ago intermittent strong explosions and lava flow effusion accompanied frequent eruptions. Historical eruptions have consisted of moderate Vulcanian and phreatic explosions.

Tolmachev Dol
Tolmachev Dol (Tomachev Plateau) is broad volcanic highland NE of Opala volcano that includes numerous late-Pleistocene and Holocene cinder cones and associated lava flows. The cones and lava fields cover a broad area on both sides of Lake Tolmachev, which lies in large depression halfway between Opala and Gorely volcanoes. The Pleistocene Tolmachev stratovolcano lies on the SE side of the lake. A major explosive eruption took place about 4,600 years ago from Chasha crater in the northern part of the plateau, during which about 1 km3 of rhyolitic tephra was ejected. The latest dated eruption occurred from a cinder cone in the NW part of the plateau about 1,600-1,700 years ago.

Vilyuchinsky
Vilyuchinsky, or Vilyuchik, is a steep-sided Pleistocene-to-Holocene stratovolcano south of Avachinsky Bay. Deep erosional gullies dissect the flanks, with Lava domes and young basaltic cinder cones at its base. Most of the growth of the volcano took place during the late Pleistocene. The last significant eruption took place from the summit crater about 10,000 years ago, producing a moderate airfall deposit and a lava flow. Landslides and rock avalanches have affected habited areas.

Barkhatnaya Sopka
The Barkhatnaya Sopka group of Pleistocene andesitic-to-rhyolitic lava domes and Holocene basaltic pyroclastic cones is located along the Paratunka River about 30 km NNW of Gorely volcano. The cinder cones are sitting on an uplifted block of eroded Miocene-Pliocene rocks. Most of the younger cones lie on the S and SE sides of the volcanic field. The Barkhatnaya cinder cone formed about 3,000-4,000 years ago (Ponomareva, 1992 p.c.).

Opala
The steep-sided conical Opala stratovolcano was constructed during the late-Pleistocene to Holocene at the northern end of the 12 x 14 km, 40,000-year-old Opala caldera. The volcano has produced andesitic-dacitic lavas and tephras through most of the Holocene. The latest major explosive eruption formed the prominent Barany Amphitheater on the SE flank about 1,500 years ago, producing a voluminous 9-10 km3 regional rhyolitic tephra layer. The 2 x 2.5 km crater is filled by a lava dome 1 km wide. Mild explosive eruptions have been reported from summit and flank vents, although no associated tephra deposits have been found. Tephrochronology work has revealed evidence for a large explosive eruption from the summit crater about 300 years ago.

Odamoisan [Tebenkov]
Odamoisan (also known as Tebenkov), lies in the center of Iturup Island along the E coast. This forested andesitic volcano is ~4 km NE of the Etorofu-Yakeyama (Ivan Grozny) dome complex. A large eroded valley on the S side, named the Machekh crater, displays strong fumarolic activity and heavily altered surface deposts. There have been no observed eruptions.

Tenchozan
Volcano type: Crater rows
Phreatic eruptions at Tenchozan occurred approximately 1,900 years ago. Towards the end of those eruptions there was a phreatomagmatic or small magmatic eruption. The chain of explosion craters, stretching from the NE to the SW, are considered to be a result of this series of eruptions (Goto et al., 2005; Goto, 2011).

Northeast Japan Volcanic Arc

Yokodake
Northeast Japan Volcanic Arc
The Yokodake lava dome, with eight small craters, is at the northern edge of the Kita-Yatsugatake (North Yatsugatake) group of stratovolcanoes and lava domes at the NW end of the NNW-SSE-trending Yatsugatake volcanic massif. The most recent eruption took place about 800 years ago, when ash emission accompanied emplacement of a small lava flow. The basaltic-to-dacitic Kita Yatsugatake group also contains the Tateshinayama, Shimagareyama, Chausuyama and Futagomine volcanoes. Tateshinayama is sometimes known as Suwa Fuji because of its conical profile. A large lava flow forms the Tateshina-kogen plateau south of Tateshinayama and Yokodake. A debris avalanche from edifice collapse in 888 CE created Matsubara Lake on the east side of the massif.

Niigata-Yakeyama
Northeast Japan Volcanic Arc
Niigata-Yakeyama, one of several Japanese volcanoes named Yakeyama ("Burning Mountain"), is an andesitic-to-dacitic lava dome in Niigata prefecture in west-central Honshu, about 20 km from the coast. The volcano was constructed on a base of Tertiary mountains beginning about 3,100 years ago. Three major eruptions in the past 1,000 years have produced pyroclastic flows and lava flows that traveled mainly down the Hayakawa river valley to the N and NW. The first of these eruptions, in 887 CE (and possibly 989 CE), produced the Hayakawa pyroclastic flow, which reached the coast, and the massive Mae-yama lava flow, which traveled about 6.5 km down the Hayakawa river valley. The summit lava dome was emplaced during the 1361 CE eruption, and the last magmatic eruption took place in 1773 CE. Eruptive activity since 1773 has consisted of relatively minor phreatic explosions from several radial fissures and explosion craters that cut the summit and flanks of the dome.

Myokosan
Myokosan is a steep-sided basaltic-to-dacitic stratovolcano north of Nagano City that overlooks Lake Nojiri below its SE flank. A 3-km-wide caldera breached widely to the east is filled by a flat-topped lava dome that forms the summit. It was constructed during four stages beginning about 300,000 years ago, each evolving from basaltic to andesitic and dacitic eruptions. The latest eruptive stage began about 43,000 years ago. Several episodes of edifice collapse during the late Pleistocene to early Holocene have produced major debris avalanches that traveled to the E and NE. Pyroclastic flows traveled down the eastern flanks during the mid-Holocene about 5,800 and 4,200 years ago, and the latest dated eruption produced pyroclastic surges about 2,800-2,500 years ago. Constant solfataric activity occurs between the dome and the south caldera wall at a place where sulfur was once mined.

Asamayama
Asamayama, Honshu's most active volcano, overlooks the resort town of Karuizawa, 140 km NW of Tokyo. The volcano is located at the junction of the Izu-Marianas and NE Japan volcanic arcs. The modern Maekake cone forms the summit and is situated east of the remnant of an older andesitic volcano, Kurofuyama, which was destroyed by a late-Pleistocene landslide about 20,000 years before present (BP). Growth of a dacitic shield volcano was accompanied by pumiceous pyroclastic flows, the largest of which occurred about 14,000-11,000 BP, and by growth of the Ko-Asamayama lava dome on the east flank. Maekake, capped by the Kamayama pyroclastic cone that forms the present summit, is probably only a few thousand years old and has observed activity dating back at least to the 11th century CE. Maekake has had several major Plinian eruptions, the last two of which occurred in 1108 (Asamayama's largest Holocene eruption) and 1783 CE.

Shiga
The Shiga volcanic complex immediately north of Kusatsu-Shirane volcano consists of a group of small andesitic shield volcanoes and pyroclastic cones. A large lava plateau was erupted between about 200-300 ka. The latest activity occurred between about 250,000 and 10,000 years ago (Nakano et al., 2001-). The Shiga-Kogen (Shiga Plateau) area is a popular winter sports destination.

Harunasan
Harunasan is truncated by a small summit caldera containing the symmetrical post-caldera pyroclastic cone of Haruna-Fuji. Harunasan formed prior to 300,000 years ago and had caldera-producing eruptions at about 200,000 and 40,000 years ago. Viscous lava flows and lava domes were subsequently extruded within and around the caldera, the western side of which is currently partially filled by Lake Haruna. The Futatsudake lava dome east of the caldera was the source of two large explosive eruptions during the 6th century CE.

Kusatsu-Shiranesan
The Kusatsu-Shiranesan complex, located immediately north of Asama volcano, consists of a series of overlapping pyroclastic cones and three crater lakes. The andesitic-to-dacitic volcano was formed in three eruptive stages beginning in the early to mid-Pleistocene. The Pleistocene Oshi pyroclastic flow produced extensive welded tuffs and non-welded pumice that covers much of the E, S, and SW flanks. The latest eruptive stage began about 14,000 years ago. Historical eruptions have consisted of phreatic explosions from the acidic crater lakes or their margins. Fumaroles and hot springs that dot the flanks have strongly acidified many rivers draining from the volcano. The crater was the site of active sulfur mining for many years during the 19th and 20th centuries.

Hiuchigatake
Hiuchigatake volcano lies in Nikko National Park and erupted the 8 km3 Hiuchigatake-Nanairi tephra and pyroclastic flow deposit about 170,000-160,000 years ago. Two lava domes at the southern end of the summit overlook Ozenuma lake, a popular hiking destination in the national park. The southern of the two domes, Akanagure, produced a series of viscous lava flows about 3500 years ago that extend to the S and W flanks. The northern dome, Miike, was the source of a tephra layer correlated with a report of historical activity in 1544 (Hayakawa, 1994b).

Akagisan
The broad, low dominantly andesitic Akagisan volcano rises above the northern end of the Kanto Plain. It contains an elliptical, 3 x 4 km summit caldera with post-caldera lava domes arranged along a NW-SE line. Lake Ono is located at the NE end of the caldera. An older stratovolcano was partially destroyed by edifice collapse, producing a debris-avalanche deposit along the south flank. A series of large plinian eruptions accompanied growth of a second stratovolcano during the Pleistocene. Construction of the central cone in the late-Pleistocene summit caldera began following the last of the plinian eruptions about 31,000 years ago. During historical time unusual activity was recorded on several occasions during the 9th century, but reported eruptions in 1251 and 1938 are considered uncertain.

Nantaisan
Nantaisan stratovolcano rises above the north shore of Lake Chuzenji in Nikko National Park. Lava flows from the early stage of edifice construction dammed the Daiyo River, forming Lake Chuzenji; the Kegon waterfall plunges over this barrier. A late-stage collapse occurred on the north side. Two major late-stage eruptions ejected large amounts of scoria, followed by the emission of pyroclastic flows. The latest effusive activity produced the Osawa lava flow, a thick, viscous dacitic flow that traveled from the breached crater down the N flank. The Bentengawara pyroclastic-flow deposit, representing the latest known eruptive activity, was radiocarbon dated at about 10,000 years Before Present and was emplaced following a quiescent period of about 3,000 years.

Omanago Group
The Omanago volcano group consists of a series of five closely spaced lava domes that were constructed north and NW of Nantai volcano in Nikko National Park. The highest of the dacitic domes is Omanago, which later erupted andesitic lavas. The Mitsudake dome, which overlooks the hot spring resort of Lake Yunoko, was radiocarbon dated at about 5,000 years ago. Mitsudake was constructed on a southerly dipping slope, so that the southern of its two flat-topped domes is lower, and is overlapped by sediments of the Senjogahara plain.

Takaharayama
Takaharayama is a small stratovolcano with lava domes located SW of Nasudake volcano and NNW of Utsunomiya city in central Honshu. The basaltic-to-dacitic volcano lies within the Shiobara caldera, which was formed during the late Pleistocene at the time of the eruption of the Otawara pumice-flow deposit. The latest dated eruption of Takahara took place about 6500 years ago along the NW-SE-trending Yumoto-Shiobara fissure system within the caldera. Eruptions along this fissure initially produced the phreatic Takahara-Uenohara tephra deposit, which was distributed primarily to the east. The symmetrical Fujiyama lava dome, one of many conical volcanoes named after Japan's renowned Mount Fuji, was extruded at the end of the eruption.

Nikko-Shiranesan
Nikko-Shiranesan is a relatively small, 2578-m-high andesitic volcano consisting of a group of four lava domes resting on a shield volcano that rises to the NW of scenic Lake Chuzenji in Nikko National Park. All historical eruptions, recorded during the 17th-20th centuries, have consisted of phreatic explosions from Shiranesan, the youngest lava dome. Viscous lava flows with prominent levees from the underlying shield volcano Keizukayama were responsible for the formation of several scenic lakes north of the volcano.

Numazawa
Numazawa is a small, 2-km-wide dominantly dacitic-to-rhyolitic caldera constructed within an older Pliocene caldera. Eruptions of the 110,00 years before present (BP) rhyolitic Shibahara pyroclastic-fall deposit and the 71,000 BP rhyolitic Mukuresawa lava dome were followed by the dacitic Plinian Mizunuma eruption about 45,000 BP, emplacement of the Sozan lava dome at about 40-43 ka and the Maeyama lava dome at about 24,000 cal BP. The Numazawako pumice flow and Plinian eruption about 4,600 years BP resulted in formation of the 1.5 x 2 km Numazawako caldera, now largely filled by a caldera lake.

Nasudake
The Nasudake volcanic group consists of a N-S-trending cluster of stratovolcanoes and lava domes at the north end of the Kanto Plain. Volcanic activity dates back about 500,000 years. Growth of three large basaltic-to-dacitic stratovolcanoes, each lasting about 200,000 years, was followed by construction of three smaller andesitic stratovolcanoes (Asahidake, Futamatayama, and Chausudake). Activity during the last 55,000 years included the collapse of Asahidake ~30-40,000 years ago, producing the massive Ofujisan debris-avalanche deposit, which covers a broad area SE of the volcano. Chausudake, began forming about 16,000 years ago, and has had six known magmatic eruptions, with the latest in 1408-1410 CE that built the summit lava dome formed. These eruptions produced block-and-ash flows and concluded with the extrusion of lava flows. Smaller phreatic eruptions have occurred every few hundred years during the past 5,000 years.

Bandaisan
One of Japan's most noted volcanoes, Bandaisan rises above the north shore of Lake Inawashiro. This complex is formed of several overlapping andesitic stratovolcanoes, the largest of which is Obandai. Kobandaisan peak, which collapsed in 1888, was formed about 50,000 years ago. Obandai was constructed about 40,000 years ago after a Plinian eruption resulted in the collapse of an older edifice and the Okinajima debris avalanche to the SW. The last magmatic eruption took place more than 25,000 years ago, but four major phreatic eruptions have occurred during the past 5,000 years, most recently in 806 and 1888 CE. Seen from the south, Bandaisan presents a conical profile, but much of the north side of the volcano is missing as a result of the collapse of Kobandaisan during the 1888 eruption, causing a debris avalanche that buried several villages and formed several large lakes.

Adatarayama
The broad forested massif of Adatarayama volcano is located E of Bandai volcano, about 15 km SW of Fukushima city. It consists of a group of dominantly andesitic stratovolcanoes and lava domes that rise above Tertiary rocks on the south and abut Azumayama volcano on the north. Construction took place in three main stages that began about 550,000, 350,000, and 200,000 years ago. The high point of the complex is 1728-m-high Minowasan, a dome-shaped stratovolcano north of Tetsuzan, the currently active stratovolcano. Numanotaira, the active summit crater, is surrounded by hot springs and fumaroles and is breached by the Iogawa river ("Sulfur River") on the west. Seventy-two workers of a sulfur mine in the summit crater were killed during an eruption in 1900. Historical eruptions have been restricted to the 1.2-km-wide, 350-m-deep Numonotaira crater.

Azumayama
The Azumayama volcanic group consists of a cluster of stratovolcanoes, shield volcanoes, lava domes, and pyroclastic cones. The andesitic and basaltic complex was constructed in two E-W rows above a relatively high basement of Tertiary sedimentary rocks and granodiorites west of Fukushima city. Volcanic activity has migrated to the east, with the Higashi-Azuma volcano group being the youngest. The symmetrical Azuma-Kofuji crater and a nearby fumarolic area on the flank of Issaikyo volcano are popular tourist destinations. The Azumayama complex contains several crater lakes, including Goshikinuma and Okenuma. Historical eruptions, mostly small phreatic explosions, have been restricted to Issaikyo volcano at the northern end of the Higashiyama group.

Hijiori
Hijiori caldera is a small, inconspicuous caldera located NE of the Pleistocene Gassan stratovolcano. The low 2.5-km-wide caldera formed during a large eruption about 10,300 radiocarbon years ago. This eruption was accompanied by dacitic pyroclastic flows and tephra fall that extended to the east and reached the Pacific coast and growth of a lava dome. Small local tephra deposits overlie lacustrine deposits. Hot springs occur at Hijiori, and caldera lake deposits have undergone extensive hydrothermal alteration.

Zaozan [Zaosan]
The Zaozan (or Zaosan) volcano group consists of a complex cluster of stratovolcanoes in north-central Honshu about 40 km W of Sendai Bay. The Pleistocene Ryuzan volcano forms the western group (Nishi-Zao), and Byobu and Fubo volcanoes form the southern group (Minami-Zao). The Zaozan edifice forms the central group (Chuo-Zao), a complex topped by several lava domes and the Goshikidake tuff cone, aligned NW-SE. Several episodes of edifice collapse produced debris avalanches during the Pleistocene. Goshikidake contains the active Okama crater, filled with a strongly acidic crater lake; it has been the source of most of the frequent eruptions recorded since the 8th century CE.

Naruko
Naruko is a poorly defined, 5.5 x 7 km caldera NW of the city of Sendai. Formed during eruptions about 73,000 and 45,000 years ago, it contains a cluster of four dacitic lava domes of Holocene age surrounding the 400-m-wide lake-filled Katanuma crater. The highest of the low, but steep-sided lava domes, Ogadake, lies SE of the lake and reaches only 470 m above sea level. Ogadake and Kurumigadake domes are capped by conglomerates and mudstones uplifted during dome growth. The only recorded eruption in occurred in 837 CE. Water vapor and sulfur-dioxide gas emission occurs from Shurado crater on Toyagamori lava dome west of the lake and from the bottom of the crater lake, which is one of the most acidic in Japan, with a pH of 1.6. Solfataras are found on the western shore of Katanuma, and sulfur is mined from sediments on the lake floor.

Kurikomayama
Elevation: m
The summit of Kurikomayama is cut by a 4-km-wide caldera breached to the north that is partially filled by the Tsurugidake central cone, once mined for sulfur. The complex andesitic-to-dacitic stratovolcano was constructed over a relatively high basement of Tertiary dacitic tuffs and sedimentary rocks. Early stage eruptions beginning about 500,000 years ago produced lava flows to the north and south, followed by growth of the Higashi-Kurikoma (East Kurikoma) stratovolcano. Magusadake volcano on the western side of the complex was active until about 100,000 years ago. Construction of the main cone concluded with lava flows to the E, SE, and W. Daichigamori lava dome and Aguroshi-yama pyroclastic cone are located on the southern flank. A few minor phreatic eruptions from the central cone have been recorded over the past 600 years.

Chokaisan
Chokaisan is composed of two overlapping stratovolcanoes with a conical profile that inspired the local names of Akita-Fuji or Dewa-Fuji. The summit of the gently sloping western edifice (Nishi-Chokaisan) is cut by a large scarp open to the south that contains lava domes. The younger eastern volcano (Higashi-Chokaisan) began forming about 20,000 years ago, and also has a large scarp, breached to the north. An eruption about 2,600 years ago was the source of the voluminous Kisakata debris avalanche, which reached the Pacific coast. Two post-caldera lava domes have been constructed at the upper SE end of the caldera. Intermittent reports of eruptions date back to the 6th century CE.

Akita-Komagatake
Two calderas partially filled by basaltic cones cut the summit of Akita-Komagatake volcano. The larger southern caldera is 1.5 x 3 km wide and has a shallow sloping floor that is drained through a narrow gap cutting the SW caldera rim. On its northern side is a smaller more circular 1.2-km-wide caldera whose rim is breached widely to the NE. The two calderas were formed following explosive eruptions at the end of the Pleistocene, between about 13,500 and 11,600 years ago. Two cones, Medake and Kodake, occupy the NE corner of the southern caldera, whose long axis trends NE-SW. The Onamedake cone within the northern caldera has produced lava flows to the north and east; it has a 100-m-wide summit crater. Small-scale historical eruptions have occurred from cones and fissure vents inside the southern caldera. The temperatures of geothermal areas increased beginning in 2005, and some fumarolic plumes were observed in 2011-12.

Iwatesan
Viewed from the east, Iwatesan volcano has a symmetrical profile that invites comparison with Fuji, but on the west an older cone is visible containing an oval-shaped, 1.8 x 3 km caldera. After the growth of Nishi-Iwate volcano beginning about 700,000 years ago, activity migrated eastward to form Higashi-Iwate volcano. Iwate has collapsed seven times during the past 230,000 years, most recently between 739 and 1615 CE. The dominantly basaltic summit cone of Higashi-Iwate volcano, Yakushidake, is truncated by a 500-m-wide crater. It rises well above and buries the eastern rim of the caldera, which is breached by a narrow gorge on the NW. A central cone containing a 500-m-wide crater partially filled by a lake is located in the center of the oval-shaped caldera. A young lava flow from Yakushidake descended into the caldera, and a fresh-looking lava flow from the 1732 eruption traveled down the NE flank.

Hachimantai
Hachimantai was constructed from widely scattered vents during the Pleistocene and is capped with andesitic lavas from vents in the center of the complex. The summit forms an undulating plateau surrounded by steep slopes. Circular craters are located near Komonomore and Mokkodake in the center of the plateau. The craters are youthful looking, but have not been dated. Hayakawa (1996, pers. comm.) considered Hachimantai to be of possible Holocene age. No historical eruptions have been recorded, but active solfataras are found on the western and southern flanks.

Megata
Megata, a group of three small maars along the tip of the Oga Peninsula in NW Honshu, has been active during the Holocene (Ishikawa et al., 1957). Lakes 300-600 m wide fill the basaltic-to-dacitic maars, which are a noted locality for mantle-derived xenoliths. Ichinomegata, the easternmost, largest, and oldest of the three maars, is 600 m in diameter. Ninomegata and Sannomegata are located immediately E and S of Toga Bay, which itself is a maar. The rim of the rhyolitic Toga (Togowan) maar, larger than the Megata maars, is breached by the sea on the western side and was formed about 450,000 years ago. The Megata maars are mostly late Pleistocene in age, but Murayama (1987) noted that pottery from roughly 4,000 years before present (Jomon Period) has been found within tephra layers from the maars.

Akita-Yakeyama
One of several Japanese volcanoes named Yakeyama ("Burning Mountain"), Akita-Yakeyama is the most recently active of a group of coalescing edifices in NW Honshu immediately west of Hachimantai volcano. The main volcano, Yakeyama, contains a small lava dome in its 600-m-wide summit crater. Tsugamori to the east is a stratovolcano of roughly the same height and has a 2-km-wide crater breached to the NE. The flat-topped lava dome of Kuroshimori lies 4 km S of Yakedake. One of several thermal areas, the Tamagawa Spa at the western foot has strongly acidic and slightly radioactive water. The last magmatic eruption formed the Onigajo lava dome in the summit crater about 5000 years ago. There have been somewhat uncertain reported 19th-century eruptions and mild phreatic eruptions in the 20th century.

Towada
The lake-filled, 11-km-wide, Towada caldera in northern Honshu formed during as many as six major explosive eruptions over a 40,000-year period ending about 13,000 years ago. Pre-caldera eruptive activity dates back about 2 million years and produced basaltic-to-dacitic lava cones. Following late-Pleistocene andesitic-to-rhyolitic caldera-forming eruptions, the basaltic Ninokura stratovolcano grew in the SSE section of the caldera. Successive dacitic-to-rhyolitic explosive eruptions from the Goshikiiwa cone led to the formation of the roughly 2-km-wide Nakanoumi caldera, whose SW and NE rims form peninsulas extending into Lake Towada. The andesitic-to-dacitic Ogurayama lava dome was built over the NE rim of Nakanoumi. The latest eruption took place in 915 CE, when eruptions from Ogurayama produced widespread ashfall and pyroclastic flows.

Iwakisan
Iwakisan volcano, symmetrical on all but its western flanks, has a 2-km-wide summit crater filled by a lava dome flanked by six explosion craters. Three more lava domes are found on the western and southern flanks of the andesitic volcano. Eruptions have been reported since 1600 CE, consisting primarily of small-to-moderate phreatic explosions.

Hakkodasan
The Hakkodasan complex includes at least 17 stratovolcanoes and lava domes south of Mutsu Bay at the northern end of Honshu. The NE rim of an 8-km-wide Pleistocene caldera forms an arcuate ridge across a flat caldera-floor moat NE of the Hakkoda group volcanoes, which bury the SE caldera wall. A northern group of volcanoes, constructed within the caldera, appears to be younger. The craters at Hakkoda-Odake, Ido-dake, and Tsurugi-dake appear morphologically young. Akakuradake has a 1-km-wide explosion crater breached to the north. An active solfatara occurs at Idodake, and hot springs are found at several locations within the caldera. Three minor phreatic events from Jigokunuma on the SW flank of Odake volcano produced tephra radiocarbon dated to the 13th-17th centuries. Three soldiers on a training mission in July 1997 were killed on the lower N flank of Hakkoda when they slipped into a depression containing a high percentage of CO2 gas wiht a magmatic origin.

Osorezan
Osorezan, on the Shimokita Peninsula in northernmost Honshu, contains a 5-km-wide caldera partly occupied by a shallow lake that drains through the N caldera wall. Dissected lava domes ring the caldera floor. The andesitic-to-dacitic volcano is largely Pleistocene in age, with activity dating back about 800,000 years. The last identified distal tephra deposit was erupted during the late Pleistocene. The only report of historical activity was in a Tohoku district travel document published in 1787, which stated that Yakeyama in Mutsu country (Osoreyama) had erupted. Older residents reported that large fires and clouds were sometimes seen from the summit, accounting for the volcano's local name, Yakeyama, or "Burning Mountain" (Murayama, 1987). Earthquake swarms have been documented during the second half of the 20th century, and magma bodies have been detected beneath the volcano.

Esan
Esan is a small volcanic complex of seven overlapping andesitic-to-dacitic lava domes on the eastern tip of the Oshima Peninsula across the Tsugaru Strait from Honshu. The complex consists of five late Pleistocene and two early Holocene lava domes, Esan and Misaki. A minor phreatic eruption in 1846 produced a mudflow that caused many fatalities. The latest activity was a small eruption in 1874. Active fumaroles occur at a thermal area on the upper NW flank.

Oshima-Oshima
Oshima-Oshima, a 10 km2 island about 105 km W offshore from the SW tip of Hokkaido, is the emergent summit of two coalescing basaltic-to-andesitic stratovolcanoes. Higashiyama, at the east end of the island, is cut by a 2-km-wide caldera covered on its west side by Nishiyama volcano. The western cone failed during an eruption in 1741 CE, producing a mostly submarine debris avalanche that traveled 16 km and leaving a scarp open to the north. A tsunami associated with the collapse swept the coasts of Hokkaido, western Honshu, and Korea, and caused nearly 1,500 fatalities. The 1741 eruption concluded with the construction of a basaltic pyroclastic cone at the head of the amphitheater. No eruptions have occurred since the late-18th century.

Hokkaido-Komagatake
Much of the truncated Hokkaido-Komagatake andesitic volcano on the Oshima Peninsula of southern Hokkaido is Pleistocene in age. The sharp-topped summit lies at the western side of a large breached crater that formed as a result of edifice collapse in 1640 CE. Hummocky debris avalanche material occurs at the base of the volcano on three sides. Two late-Pleistocene and two Holocene Plinian eruptions occurred prior to the first historical eruption in 1640, which began a period of more frequent explosive activity. The 1640 eruption, one of the largest in Japan during historical time, deposited ash as far away as central Honshu and produced a debris avalanche that reached the sea. The resulting tsunami caused 700 fatalities. Three Plinian eruptions have occurred since 1640; in 1694, 1856, and 1929.

Niseko
The Niseko volcano group in SW Hokkaido contains a cluster of andesitic stratovolcanoes and lava domes that extends 25 km E-W and 15 km N-S. The volcanic complex is located NW of Niseko City. The latest dated activity was a phreatic to magmatic eruption about 7000 years ago. Fumarolic areas and hot springs are found at various locations.

Yoteizan
Yoteizan is a symmetrical andesitic-to-dacitic stratovolcano NW of Toya caldera. Its summit is truncated by a 700-m-wide crater that is cut on its NW rim by overlapping smaller craters. Deep radial gullies cut the flanks. The latest eruption from the main edifice took place about 5,000-6,000 years ago. Hangetsu-ko (Half Moon Lake), a tuff cone on the lower NW flank, was estimated from stratigraphic evidence to have erupted about 3,000 years ago.

Kuttara
The Kuttara volcanic group consists of a series of small stratovolcanoes, lava domes, pyroclastic cones, and a caldera near the Pacific coast SE of Toya caldera and SW of Shikotsu caldera. The Kuttara group was constructed during five major eruptive stages, the first of which occurred more than 60,000 years ago. A major dacitic pumice eruption at the end of the 4th stage about 40,000 years ago resulted in the formation of the 3-km-diameter Kuttara caldera. The caldera cut a basaltic-to-andesitic stratovolcano complex, which late in its activity produced two major andesitic lava flows on its north side at Kita-yama. Explosions, probably in early Holocene time, formed two large craters on the west flank of the caldera, and a dacitic lava dome was emplaced about 10,000 years ago. Late-stage phreatic explosion products from Jigoku-dani, a 300-400 m wide crater south of the lava dome, overlie the 1663 tephra from Usu volcano. Jigoku-dani and Noboribetsu Spa are the sites of intense thermal activity, including fumaroles, hot springs, and geysers.

Toya
Usuzan, one of Hokkaido's most well-known volcanoes, is a small stratovolcano located astride the southern topographic rim of the 110,000-year-old Toya caldera. The center of the 10-km-wide, lake-filled caldera contains Nakajima, a group of forested Pleistocene andesitic lava domes. The summit of the basaltic-to-andesitic edifice of Usu is cut by a somma formed about 20-30,000 years ago when collapse of the volcano produced a debris avalanche that reached the sea. Dacitic domes erupted along two NW-SE-trending lines fill and flank the summit caldera. Three of these domes, O-Usu, Ko-Usu and Showashinzan, along with seven crypto-domes, were erupted during historical time. The 1663 eruption of Usu was one of the largest in Hokkaido during historical time. The war-time growth of Showashinzan from 1943-45 was painstakingly documented by the local postmaster, who created the first detailed record of growth of a lava dome.

Shikotsu
The 13 x 15 km Shikotsu caldera, largely filled by the waters of Lake Shikotsu, was formed during one of Hokkaido's largest Quaternary eruptions about 31-34,000 years ago. The small andesitic Tarumaesan stratovolcano was then constructed on its SE rim and has been frequently active over the past 300 years. Pyroclastic-flow deposits from Tarumaesan extend nearly to the Pacific coast. Two other Holocene post-caldera volcanoes, Fuppushidake (adjacent to Tarumaesan) and Eniwadake (on the opposite side of the caldera), occur on a line trending NW from Tarumaesan, and were constructed just inside the caldera rim. Minor eruptions took place from the summit of Eniwadake as late as the 17th century. The summit of Tarumaesan contains a small 1.5-km-wide crater formed during eruptions in 1667 and 1739. Tarumaesan is now capped by a flat-topped summit lava dome that formed in 1909.

Izu Volcanic Arc

Izu-Tobu
Izu Volcanic Arc
The Izu-Tobu (or Higashi-Izu) volcano group is scattered over a broad, plateau-like area of more than 400 km2 on the E side of the Izu Peninsula. Construction of several stratovolcanoes continued throughout much of the Pleistocene and overlapped with growth of smaller monogenetic volcanoes beginning about 300,000 years ago. About 70 subaerial monogenetic volcanoes formed during the last 140,000 years, and chemically similar submarine cones are located offshore. These features were built over late-Tertiary volcanic rocks and related sediments, and on the flanks of three Quaternary stratovolcanoes: Amagi, Tenshi, and Usami. Some eruptive vents are controlled by fissure systems trending NW-SE or NE-SW. Thirteen eruptive periods have been documented during the past 32,000 years. Kawagodaira maar produced pyroclastic flows during the largest Holocene eruption about 3,000 years ago. The latest eruption occurred in 1989, when a small submarine crater was formed NE of Ito City.

Hakoneyama
Izu Volcanic Arc
Hakoneyama volcano is truncated by two overlapping calderas, the largest of which is 10 x 11 km wide. The calderas were formed as a result of two major explosive eruptions about 180,000 and 49,000-60,000 years ago. Scenic Lake Ashi lies between the SW caldera wall and a half dozen post-caldera lava domes that were constructed along a NW-SE trend cutting through the center of the calderas. Dome growth occurred progressively to the NW, and the largest and youngest of these, Kamiyama, forms the high point. The calderas are breached to the east by the Hayakawa canyon. A phreatic explosion about 3000 years ago was followed by collapse of the NW side of Kamiyama, damming the Hayakawa valley and creating Lake Ashi. The latest magmatic eruptive activity about 2900 years ago produced a pyroclastic flow and a lava dome in the explosion crater, although phreatic eruptions took place as recently as the 12-13th centuries CE. Seismic swarms have occurred during the 20th century. Lake Ashi, along with the thermal areas in the caldera, is a popular resort destination SW of Tokyo.

Fujisan
The conical form of Fujisan, Japan's highest and most noted volcano, belies its complex origin. The modern postglacial stratovolcano is constructed above a group of overlapping volcanoes, remnants of which form irregularities on Fuji's profile. Growth of the Younger Fuji volcano began with a period of voluminous lava flows from 11,000 to 8000 years before present (BP), accounting for four-fifths of the volume of the Younger Fuji volcano. Minor explosive eruptions dominated activity from 8000 to 4500 BP, with another period of major lava flows occurring from 4500 to 3000 BP. Subsequently, intermittent major explosive eruptions occurred, with subordinate lava flows and small pyroclastic flows. Summit eruptions dominated from 3000 to 2000 BP, after which flank vents were active. The extensive basaltic lava flows from the summit and some of the more than 100 flank cones and vents blocked drainages against the Tertiary Misaka Mountains on the north side of the volcano, forming the Fuji Five Lakes, popular resort destinations. The last confirmed eruption of this dominantly basaltic volcano in 1707 was Fuji's largest during historical time. It deposited ash on Edo (Tokyo) and formed a large new crater on the east flank.

Toshima
The small 2 x 2.4 km island of Toshima is located in the northern Izu Islands south of Izu-Oshima Island about 20 km W of the main volcanic front. Steep cliffs up to 300 m high ring the basaltic to basaltic andesite island on three sides. The summit is asymmetrically located opposite the more gentle slopes of the northern side of the island, where the village of Toshima is located. The latest known eruption of this stratovolcano occurred sometime between about 9,000 and 4,000 years ago, producing a lava flow from Kajiana crater.

Izu-Oshima
Izu-Oshima volcano in Sagami Bay, east of the Izu Peninsula, is the northernmost of the Izu Islands. The broad, low stratovolcano forms an 11 x 13 km island constructed over the remnants of three older dissected stratovolcanoes. It is capped by a 4-km-wide caldera with a central cone, Miharayama, that has been the site of numerous recorded eruptions since the 7th century CE. More than 40 cones are located within the caldera and along two parallel rift zones trending NNW-SSE. Although it is a dominantly basaltic volcano, strong explosive activity has occurred at intervals of 100-150 years throughout the past few thousand years. A major eruption in 1986 produced lava fountains up to 1,600 m high and a 16-km-high eruption column; more than 12,000 people were evacuated from the island.

Niijima
The elongated island of Niijima, SSW of Oshima, is 11 km long and only 2.5 km wide. Eight low rhyolitic lava domes are clustered in two groups at the northern and southern ends of the island, separated by an area of flat-topped domes and a low isthmus of pyroclastic deposits. The Mukaiyama complex on the south and the Atchiyama lava dome on the north were formed during eruptions in the 9th century CE, the last known activity. Shikineyama and Zinaito domes form small islands immediately to the SW and W, respectively, during earlier stages of volcanism. Earthquake swarms occurred during the 20th century.

Kozushima
A cluster of rhyolitic lava domes and associated pyroclastic deposits form the 4 x 6 km island of Kozushima in the northern Izu Islands. The island is the exposed summit of a larger submarine edifice more than 20 km long that lies along the Zenisu Ridge, one of several en-echelon ridges oriented NE-SW, transverse to the trend of the northern Izu arc. The youngest and largest of the 18 lava domes, Tenjosan, occupies the central portion of the island. Most of the older domes, some of which are Holocene in age, flank Tenjosan to the north, although late-Pleistocene domes are also found at the southern end of the island. A lava flow may have reached the sea during an eruption in 832 CE. The Tenjosan dome was formed during a major eruption in 838 CE that also produced pyroclastic flows and surges. Earthquake swarms took place during the 20th century.

Mikurajima
Mikurajima is a small steep-sided island located between the more well-known Miyakejima and Hachijojima volcanoes. Oyama forms the summit of the basaltic-to-andesitic island, which is surrounded by cliffs and dissected on the southern-to-eastern sides. The sparsely populated island consists of a large stratovolcano with lava domes on the SE side. Several small sea stacks are located immediately offshore. Growth of the stratovolcano took place until about 7,000 years ago, and the latest activity occurred about 6,000 years ago, when explosive eruptions and pyroclastic surges accompanied lava dome growth.

Kurose Hole
Kurose Hole, between Mikura and Hachijo-jima islands, is a nearly circular submarine caldera 5-7 km in diameter with a 600-760 m deep floor. The high point of the caldera rim rises to about 100 m of the ocean surface. Large amounts of dacitic pumice have been recovered from dredges along the inner caldera wall. The age of its most recent eruption is not known.

Miyakejima
The circular, 8-km-wide island of Miyakejima forms a low-angle stratovolcano that rises about 1,100 m from the sea floor in the northern Izu Islands about 200 km SSW of Tokyo. The basaltic volcano is truncated by small summit calderas, one of which, 3.5 km wide, was formed during a major eruption about 2,500 years ago. Numerous craters and vents, including maars near the coast and radially oriented fissure vents, are present on the flanks. Frequent eruptions have been recorded since 1085 CE at vents ranging from the summit to below sea level, causing much damage on this small populated island. After a three-century-long hiatus ending in 1469 CE, activity has been dominated by flank fissure eruptions sometimes accompanied by minor summit eruptions. A 1.6-km-wide summit crater was slowly formed by subsidence during an eruption in 2000.

Hachijojima
Hachijojima, in the central Izu Islands about 300 km S of Tokyo, consists of two small Quaternary dominantly basaltic stratovolcanoes forming an elongated NW-SE-trending island. The eroded Pleistocene-to-Holocene Higashiyama volcano occupies the SE end of the 14-km-long island. The symmetrical Holocene Nishiyama volcano the NW end has cones on the SE flank. The small volcanic island of Kojima lies several kilometers W of Hachijojima. Growth of Higashiyama began several tens of thousands of years ago, and included the formation of two small calderas. The initial submarine and early subaerial eruptions of Nishiyama took place from 10,000 to 8,000 years before present (BP). Its latest major activity, from the early Holocene until about 4,000 BP, was restricted to flank eruptions. Eruptions recorded since the 15th century have been restricted to the summit of Nishiyama and a submarine vent of unknown location.

Kita-Bayonnaise
The large submarine Kita-Bayonnaise (North Bayonnaise) submarine caldera, also known as Myojin Knoll, lies between the Aogashima and Myojinsho (also called Beyonesu Rocks) calderas about 300 km SSE of the Izu Peninsula. The 6-7 km wide caldera has walls 500-900 m high that reveal rhyolitic lava flows, shallow intrusions, and volcaniclastic deposits. The high point on the western rim is a pumice-mantled remnant of the pre-collapse volcanic complex that reaches a depth of 360 m. A voluminous deposit of coarse rhyolitic pumice from the caldera-forming eruption covers the rim and outer flanks. Post-caldera eruptions formed a lava dome that rises 250 m above the caldera floor. The age of the caldera is not known, but was considered by Fiske et al. (2001) to perhaps be as young as a few thousand years. An active hydrothermal vent field lies on the eastern caldera floor and has produced a polymetallic sulfide deposit from vent chimneys up to 30 m high that emit fluids as hot as 278�C.

Aogashima
The small 2.5 x 3.5 km dominantly basaltic island of Aogashima is surrounded by steep cliffs and contains a small 1.7 x 1.5-km-wide caldera. Two pyroclastic cones were formed inside the caldera during the latest eruption from 1780 to 1785. Growth of the volcano began with construction of the Kurosaki stratovolcano in the NW part of the island, after which the main stratovolcano began growing in the SE. Both summit and flank vents produced pyroclastic surges and lava flows. Late in the construction of the main cone a 1-1.5 km crater was formed on the SE flank. About 3000 years ago pyroclastic surges swept over the entire island. During about the next 600 years, lava flows and scoria deposits filled the SE crater, which also collapsed repeatedly. The current Ikenosawa crater was considered by Takada et al. (1992) to have formed by ring collapse at the time of a debris avalanche, after which the volcano was quiescent until the eruptions of historical time.

Myojinsho
Beyonesu Rocks are part of the barely exposed rim of the largely submarine Myojinsho caldera. Formation of the 8-9 km wide caldera was followed by construction of a large (2.6 km3) lava dome and/or lava flow complex on the caldera floor, originally located at a depth of 1,000-1,100 m. Most eruptions recorded since the late-19th century have occurred from the dacitic post-caldera Myojinsho lava dome on the NE caldera rim. Deposits from submarine pyroclastic flows associated with growth of the dome cover it and extend both into the NE part of the caldera and down its outer slopes. An explosive submarine eruption from Myojinsho in 1952 destroyed a Japanese research vessel, killing all 31 on board. Submarine eruptions have also been observed from other points on the caldera rim and outside of the caldera. The Beyonesu Rocks were named after the French warship the Bayonnaise, which was surveying volcanic islands south of Tokyo Bay in 1850.

Sumisujima
Sumisujima (also known as Smith Rocks) is a steep-sided basaltic pinnacle that forms part of the outer southern flank of a 8-9 km submarine caldera that truncates a 20-km-wide seamount. The caldera was formed between about 60,000 and 30,000 years ago. The Shirane dacitic central cone, 3 km wide and 800 m high, rises to within 8 m of the ocean surface in the eastern side of the caldera, whose 600-700 m walls and outer flanks expose basaltic, andesitic, and rhyolitic rocks. Two large submarine cones, Sumisu Knolls No. 1 and 2, lie west of the caldera. Submarine eruptions have been reported from a number of locations near Sumisujima, the last of which occurred in 1916. Water discoloration has frequently been observed since the 1970's. In October 1992 a 6-km-long zone of discolored water was seen extending from the shallow Shirane rock mass near the eastern rim of the caldera, which rises to within 7 m of the ocean surface and is the youngest feature of the volcanic complex.

Sofugan
Sofugan is a steep-sided pinnacle that rises 99 m above the sea surface south of Torishima volcano. Its dramatic and isolated setting prompted it to also be known as "Lot's Wife Rocks." The basaltic-to-andesitic pinnacle is the remnant of a large stratovolcano that is 28 km wide at its base and rises 2200 m above the sea floor. A submarine depression lies between the pinnacle and an arcuate submarine ridge to the SW that rises to less than 150 m of the sea surface. In 1975 discolored sea water was observed about 500 m north of Sofugan, and the volcano was reclassified as active by the Japan Meteorological Agency in 2003.

Izu-Torishima
The circular, 2.7-km-wide island of Izu-Torishima in the southern Izu Islands is capped by an unvegetated summit cone formed during an eruption in 1939. Fresh lava flows from this eruption form part of the northern coastline of the basaltic-to-dacitic edifice. The volcano is referred to as Izu-Torishima to distinguish it from the several other Japanese island volcanoes called Torishima ("Bird Island"). The main cone is truncated by a 1.5-km-wide caldera that contains two central cones, of which Ioyama is the highest. Historical eruptions have also occurred from flank vents near the north coast and offshore submarine vents. A submarine caldera 6-8 km wide lies immediately to the north.

Ogasawara Volcanic Arc

Suiyo Seamount
Ogasawara Volcanic Arc
Suiyo, one of the Shichiyo Seamounts, named for the seven days of the week, lies south of Sofugan volcano. Suiyo ("Wednesday") is a basaltic-to-dacitic submarine volcano and lava dome that rises about 1,400 m from the sea floor to within about 1,000 m of the surface. The summit crater is 1.5 km wide and about 500 m deep. Major hydrothermal activity was observed in July 1991, with temperatures reaching more the 290�C, and the volcano was reclassified as active by the Japan Meteorological Agency.

Mokuyo Seamount
Ogasawara Volcanic Arc
Mokuyo is one of the Shichiyo Seamounts, named for the seven days of the week. Mokuyo ("Thursday") is a basaltic andesite submarine volcano that rises 1,780 m from the sea floor to within less than 1,000 m of the surface. The summit crater is 3 x 2.3 km and about 450 m deep with a 180-m-high lava dome in its center. Major hydrothermal activity was observed in July 1990, and the volcano was reclassified as active by the Japan Meteorological Agency.

Doyo Seamount
Doyo is the southernmost of the Shichiyo Seamounts, named for the seven days of the week. Doyo ("Saturday") is a basaltic andesite submarine volcano that rises 2,340 m from the sea floor to within less than 600 m of the surface. An open collapse scarp is 3 x 10 km. Major hydrothermal activity was observed in July 1990, and the volcano was reclassified as active by the Japan Meteorological Agency.

Nishinoshima
The small island of Nishinoshima was enlarged when several new islands coalesced during an eruption in 1973-74. Multiple eruptions between 2013 and 2023 completely covered the previous exposed surface and continued to enlarge the island. The island is the summit of a massive submarine volcano that has prominent peaks to the S, W, and NE. The summit of the southern cone rises to within 214 m of the ocean surface 9 km SSE.

Kaikata Seamount
Kaikata Seamount is a basaltic-to-dacitic submarine volcano located north of Kaitoku Seamount. The volcano rises 2,350 m from the sea floor to within 165 m of the surface. Two major summit peaks are oriented NE-SW, with the SW peak being the highest. Hydrothermal activity was observed in 1988 at a depth of 460 m, and the volcano was reclassified as active by the Japan Meteorological Agency.

Kaitoku Seamount
Submarine eruption have been observed during March 1984 and August 2022-January 2023 from Kaitoku Seamount (Kaitoku Kaizan), a three-peaked submarine volcano 80 km NNW of Kita-Ioto. The type of activity related to other observations of discolored water or bubbling, including an observation from 1543 CE, is uncertain.

Funka Asane
Eruptions have been recorded since the 18th century from Funka Asane, a submarine edifice ~4 km NW of Kita-Ioto, the northernmost of the Kazan Retto (Volcano Islands), in the southern Ogasawara Volcanic Arc. Frequent observations of discolored water above this vent area have been reported, including 16 times during 1982-2007. Eruptive activity in 2022 produced a plume to 5.5 km altitude. No eruptions are known from the heavily eroded, steep-sided, Kita-Ioto basaltic cone. Multiple submarine volcanic features extend ~30 km from the island to the NW and S, comparable to other large volcanic complexes along the arc.

Kita-Fukutokutai
Kita-Fukutokutai is a submarine volcano halfway between the Ioto and Minami-Ioto islands. The volcano rises to within 73 m of the ocean surface. Water discoloration was reported several times beginning in 1937, and floating pumice was seen during 1953-54. In 1988 a fishing boat reported an eruption column about 100 m high, although the report was not confirmed at the time. The Japan Meteorological Agency has classified Kita-Fukutokutai as an active volcano.

Ioto
Ioto, also known as Ogasawara-Iojima to distinguish it from several other "Sulfur Island" volcanoes, lies within a 9-km-wide submarine caldera.The triangular, low-elevation, 8-km-long island narrows toward its SW tip and has produced trachyandesitic and trachytic rocks that are more alkalic than those of other volcanoes in the Ogasawara Volcanic Arc. The island has undergone uplift for at least the past 700 years, accompanying resurgent doming of the caldera; a shoreline landed upon by Captain Cook's surveying crew in 1779 is now 40 m above sea level. The Motoyama plateau on the NE half of the island consists of submarine tuffs overlain by coral deposits and forms the island's high point. Many fumaroles are oriented along a NE-SW zone cutting through Motoyama. Numerous recorded phreatic eruptions, many from vents on the W and NW sides of the island, have accompanied the uplift.

Fukutoku-Oka-no-Ba
Fukutoku-Oka-no-ba is a submarine volcano located 5 km NE of the island of Minami-Ioto. Water discoloration is frequently observed, and several ephemeral islands have formed in the 20th century. The first of these formed Shin-Ioto ("New Sulfur Island") in 1904, and the most recent island was formed in 1986. The volcano is part of an elongated edifice with two major topographic highs trending NNW-SSE, and is a trachyandesitic volcano geochemically similar to Ioto.

Mariana Volcanic Arc

Minami-Hiyoshi
Mariana Volcanic Arc
Periodic water discoloration and water-spouting have been reported over the Minami-Hiyoshi submarine volcano since 1975, when detonation sounds and an explosion were also reported. It lies near the SE end of a coalescing chain of youthful seamounts, and is the only vent with recorded activity. The reported depth of the summit of the trachyandesitic volcano has varied between 274 and 30 m. The morphologically youthful seamounts Kita-Hiyoshi and Naka-Hiyoshi lie to the NW, and Ko-Hiyoshi to the SE.

Nikko
Mariana Volcanic Arc
Nikko submarine volcano is a massive seamount that rises from nearly 3 km depth to within 392 m of the ocean surface near the N end of the Mariana Volcanic Arc. Two large cones at the basaltic-to-andesitic volcano have been constructed on the NW and NE rims of a roughly 3-km-wide, flat-floored submarine caldera, whose rim is prominently displayed on the southern side, but largely buried on the north. A smaller cone is present on the SE caldera floor. The larger NW cone lies within a partially buried crater and displays hydrothermal activity. Discolored water was observed in July 1979, but none has been observed during semi-regular seasonal reconnaissance flights since then. Hydrothermal venting was documented during a NOAA expedition.

Fukujin
Fukujin seamount in the Mariana Volcanic Arc has risen on occasion to just beneath the ocean surface. Intermittent periods of water discoloration have been observed since the mid-20th century, and eruptions producing floating pumice were noted on several occasions.

Kasuga 1
Kasuga 1, the northernmost of three seamounts in the Kasuga seamount chain SE of Fukujin, rises from a depth of 3,000 m to within about 600 m of the ocean surface. A series of flank vents are located low on the southern side of the edifice. The summit does not have a caldera or display hydrothermal activity, and is largely covered by volcaniclastics. Altered basaltic and andesitic rocks dredged from the summit suggest that it is the oldest of the three seamounts, although delicately preserved lava flow lobes and toes from a flank eruption suggest a very youthful age. It is listed as an active volcano by the Japan Meteorological Agency, and floating pumice attributed to a submarine eruption was seen south of it in the summer of 1959. Water discoloration from a possible submarine eruption was reported near the seamount in November 1975.

Kasuga 2
Kasuga 2, also referred to as Minami Kasuga (South Kasuga), is the central of three volcanoes forming the Kasuga seamount chain, which trends SSW from the volcanic front of the Izu-Marianas arc. It rises from about 3,000 m depth to within 170 m of the ocean surface. Two subsidiary cones are located low on the E flank. The morphology is more complex than Kasuga 1 to the north, and prominent ridges separate slopes of interspersed volcaniclastic and lava flow fields. Radiometric dating indicates an age of less than 8,000 years and probably less than 1,000 years; radium/thorium disequilibrium ratios suggest the flows may be only a few centuries old (Fryer et al., 1997). Active hydrothermal vents are located at the summit, at the base of summit ridges, and on the lower flanks.

NW Eifuku
NW Eifuku is a small submarine volcano that exhibits vigorous thermal activity. The summit of the basaltic-to-andesitic volcano lies 1,535 m below the ocean surface; the seamount lies at the NW end of a 25-km-long chain of submarine volcanoes that includes Eifuku and Daikoko. Hydrothermal fluid emission includes liquid carbon dioxide bubbles venting from "white smokers," one of only two places where natural liquid carbon dioxide emission has been observed. The hydrothermal field, named Champagne, was discovered during a 2003 NOAA expedition and lies in the steep headwall of a slope-failure scarp that cuts the summit and SW side of the volcano.

Daikoku
The conical summit of Daikoku seamount lies along an E-W ridge SE of Eifuku and rises to within 323 m of the sea surface. A steep-walled, 50-m-wide crater on the N flank, about 75 m below the summit, is at least 135 m deep and was observed to emit cloudy hydrothermal fluid. During a NOAA expedition in 2006, scientists observed a convecting black pool of liquid sulfur with a partly solidified, undulating sulfur crust at a depth of 420 m below the summit. Gases, particulates with the appearance of smoke, and liquid sulfur were bubbling up from an edge of the sulfur pool.

Ahyi
Ahyi seamount is a large conical submarine volcano ~18 km SE of the island of Farallon de Pajaros in the northern Marianas. Water discoloration has been observed there, and in 1979 the crew of a fishing boat felt shocks over the summit area, followed by upwelling of sulfur-bearing water. On 24-25 April 2001 an explosive eruption was detected seismically by a station on Rangiroa Atoll, Tuamotu Archipelago. The event was well constrained (+/- 15 km) at a location near the southern base of Ahyi. An eruption in April-May 2014 was detected by NOAA divers, hydroacoustic sensors, and seismic stations.

Supply Reef
Supply Reef is a conical submarine volcano in the northern Mariana Islands that rises to within 8 m of the surface. The andesitic seamount lies about 17 km NW of the Maug Islands, the emergent summit of a submarine volcano that is joined to Supply Reef by a low saddle at a depth of about 1,800 m. Supply Reef was mapped as Quaternary; living corals on the crater rim suggest no recent activity (Corwin, 1971). Submarine eruptions previously attributed to this volcano based primarily on acoustic data have been reassigned to Ahyi Seamount, which was unknown at the time of those reports.

Maug Islands
The three small elongated Maug Islands, the largest ~2.3 km long, represent the rim of a 2.5-km-wide caldera on a submarine edifice more than 20 km in diameter. The caldera has an average submarine depth of about 200 m and contains a central lava dome that rises to within about 20 m of the ocean surface. The truncated inner walls of the caldera on all three islands expose lava flows and pyroclastic deposits that are cut by radial dikes; bedded ash deposits overlie the outer flanks of the islands. No eruptions are known since the islands were documented by Espinosa in 1522 CE. The presence of poorly developed coral reefs and coral on the central lava dome suggests a long period of general quiescence, although it does not exclude mild eruptions (Corwin, 1971). A 2003 NOAA expedition detected possible evidence of submarine geothermal activity.

Farallon de Pajaros
The small 2-km-wide island of Farallon de Pajaros (also known as Uracas) is the northernmost and most active volcano of the Mariana Islands. Its relatively frequent eruptions dating back to the mid-19th century have caused the andesitic volcano to be referred to as the "Lighthouse of the western Pacific." The symmetrical, sparsely vegetated summit is the central cone within a small caldera cutting an older edifice, remnants of which are seen on the SE and southern sides near the coast. Flank fissures have fed lava flows that form platforms along the coast. Eruptions have been recorded from both summit and flank vents.

Asuncion
A single large asymmetrical stratovolcano forms 3-km-wide Asuncion Island. The steeper NE flank terminates in high sea cliffs, while the gentler SW flanks have low-angle slopes bounded by sea cliffs only a few meters high. The southern flank is cut by a large landslide scar. The S and W flanks are covered by ash deposits. An explosive eruption in 1906 produced lava flows that descended about halfway down the W and SE flanks, but several other eruption reports are of uncertain validity.

Agrigan
The highest of the Marianas arc volcanoes, Agrigan contains a 500-m-deep, flat-floored caldera. The elliptical island is 8 km long; its summit is the top of a massive 4000-m-high submarine volcano. Deep radial valleys dissect the flanks of the thickly vegetated stratovolcano. The elongated caldera is 1 x 2 km wide and is breached to the NW, from where a prominent lava flow extends to the coast and forms a lava delta. The caldera floor is surfaced by fresh-looking lava flows and also contains two cones that may have formed during the only historical eruption in 1917. This eruption deposited large blocks and 3 m of ash and lapilli on a village on the SE coast, prompting its evacuation.

Pagan
Pagan Island, the largest and one of the most active of the Mariana Islands volcanoes, consists of two stratovolcanoes connected by a narrow isthmus. Both North and South Pagan stratovolcanoes were constructed within calderas, 7 and 4 km in diameter, respectively. North Pagan at the NE end of the island rises above the flat floor of the northern caldera, which may have formed less than 1,000 years ago. South Pagan is a stratovolcano with an elongated summit containing four distinct craters. Almost all of the recorded eruptions, which date back to the 17th century, have originated from North Pagan. The largest eruption during historical time took place in 1981 and prompted the evacuation of the sparsely populated island.

Alamagan
Alamagan is the emergent summit of a large stratovolcano in the central Mariana Islands with a roughly 350-m-deep summit crater east of the center of the island. The exposed cone is largely Holocene in age. A 1.6 x 1 km graben cuts the SW flank. An extensive basaltic andesite lava flow has extended the northern coast of the island, and a lava platform also occurs on the S flank. Pyroclastic-flow deposits erupted about 1000 years ago have been dated, but reports of historical eruptions were considered invalid (Moore and Trusdell, 1993).

Zealandia Bank
Zealandia Bank consists of two pinnacles about 1 km apart rising from a submerged bank to near the ocean surface between Guguan and Sarigan Islands. One pinnacle reaches more than 1 m above water at low tide. Andesitic rocks were dredged at the southern peak, which showed some evidence of coral growth. Freshly broken pahoehoe basaltic rocks were recovered from 1.7 km depth on the western flank. The age of the most recent eruptive activity is not known, but a NOAA bathymetric survey in 2004 detected fumarolic activity.

Sarigan
Sarigan volcano forms an irregular 3-km-long island consisting of a low truncated cone with a 750-m-wide summit crater that contains a small ash cone. The most recent eruptions produced two lava domes from vents above and near the south crater rim. Lava flows from each dome reached the coast and extended out to sea. The northern flow overtopped the crater rim on the N and NW sides. The sparse vegetation on the flows indicated to Meijer and Reagan (1981) that they are of Holocene age.

Guguan
The island of Guguan, ~2.8 km in diameter, is composed of an eroded volcano on the south, a caldera with a post-caldera cone, and a northern volcano. The latter has three coalescing cones and a breached summit crater that fed lava flows to the W and NW. The only known reported eruption, between 1882 and 1884, produced the northern volcano and lava flows that reached the coast. Freycinet (Uranie 1817 Expedition) confused Guguan and Alamagan; reported eruptions in 1819 and 1901 (Kuno, 1962 CAVW) actually refer to solfataric activity on Alamagan (Corwin, 1971).

East Diamante
The dacitic East Diamante submarine volcano contains an elongated NE-SW-trending caldera with a pronounced rim on the NE side. A large post-caldera cone lies on the SW caldera rim, and a complex of lava domes was constructed in the center of the caldera. Several areas of hydrothermal activity including "black smoker" sulfide chimneys at the Black Forest site were detected on the central dome complex at depths of only a few hundred meters. The summit extends to within 127 m of the ocean surface. West Diamante seamount lies 28 km W, with the much smaller Middle Diamante about 15 km W.

Ruby
Ruby is a basaltic submarine volcano that rises to within about 200 m of the ocean surface near the southern end of the Mariana arc NW of Saipan. An eruption was detected in 1966 by sonar signals (Norris and Johnson, 1969). Submarine explosions were heard in 1995, accompanied by a fish kill, sulfurous odors, bubbling water, and the detection of volcanic tremor.

Anatahan
The elongate, 9-km-long island of Anatahan in the central Mariana Islands consists of a large stratovolcano with a 2.3 x 5 km compound summit caldera. The larger western portion of the caldera is 2.3 x 3 km wide, and its western rim forms the island's high point. Ponded lava flows overlain by pyroclastic deposits fill the floor of the western caldera, whose SW side is cut by a fresh-looking smaller crater. The 2-km-wide eastern portion of the caldera contained a steep-walled inner crater whose floor prior to the 2003 eruption was only 68 m above sea level. A submarine cone, named NE Anatahan, rises to within 460 m of the sea surface on the NE flank, and numerous other submarine vents are found on the NE-to-SE flanks. Sparseness of vegetation on the most recent lava flows had indicated that they were of Holocene age, but the first historical eruption did not occur until May 2003, when a large explosive eruption took place forming a new crater inside the eastern caldera.

NW Rota-1
A submarine volcano detected during a 2003 NOAA bathymetric survey of the Mariana Island arc was found to be hydrothermally active and named NW Rota-1. The basaltic to basaltic andesite seamount rises to within 517 m of the ocean surface SW of Esmeralda Bank, 64 km NW of Rota Island and ~100 km N of Guam. When Northwest Rota-1 was revisited in 2004, a minor submarine eruption from a vent named Brimstone Pit on the upper south flank about 40 m below the summit intermittently ejected a plume several hundred meters high containing ash, rock particles, and molten sulfur droplets that adhered to the surface of the remotely operated submersible vehicle. The active vent was funnel-shaped, about 20 m wide and 12 m deep. Prominent structural lineaments about a kilometer apart cut across the summit of the edifice and down the NE and SW flanks.

Esmeralda Bank
Esmeralda Bank is a massive submarine volcano with three cones oriented N-S over about 15 km. The high points on the crater rim of the large middle edifice, with a collapse scarp open to the W, are about 75 m below the ocean surface. Frequent sulfur-rich surface bubbling and water discoloration have been observed, which have variously been attributed to eruptive events or fumarolic activity.

Forecast Seamount
Forecast Seamount lies about 70 km W of the southern tip of Guam and about 19 km NW of Seamount X. Hydrothermal fluid temperatures up to 200�C, one of the highest temperature vent systems known in the Mariana arc, were measured during a 2006 NOAA expedition.

Seamount X
Hydrothermal activity was detected during a 2003 NOAA expedition at a submarine volcano about 70 km WSW of Guam. The summit of the volcano, referred to as Seamount X, lies 1,230 m below the ocean surface. Diffuse sites of thermal venting colonized by shrimps, crabs, and scaleworms were detected near the summit during a 2006 NOAA expedition, and thick deposits of sulfur flows originating from the hydrothermal vent were observed that were covered with thousands of squat lobsters. Basaltic rocks were recovered along with sulfur samples. The summit of the volcano is cut by an elongated caldera.

South Sarigan Seamount
South Sarigan seamount, rising to within about 184 m of the ocean surface 12 km S of Sarigan Island, was the site of a short explosive submarine eruption in May 2010 that produced a plume of ash and steam to 12 km altitude. Sidescan sonar imagery taken in 2003 shows an irregular summit with multiple peaks, including a possibly young cone at about 350 m depth, and flank morphology suggests it is a frequently active volcano.

Mariana Back-Arc Segment at 15.5�N
Volcano type: Fissure vent
The Mariana back-arc spreading segment centered at 15.5�N is part of a line of recently surveyed segments with anomalous hydrothermal plumes. The line parallels the Mariana Islands (about 100 km E) and the Mariana Trench (~300 km E). A series of very recently erupted lava flows were discovered in late 2015 along this back-arc zone about 130 km WNW of Saipan. Flows near 15.4�N were not present at the time of a February 2013 bathymetric survey. Large hydrothermal plumes and intense chemical anomalies in the ocean overlie the area. The sediment-free pillow lavas have a dark glassy crust at water depths of between 4,100 and 4,450 m, believed to be the deepest reported eruption known, and the first to be found along a slow-spreading ridge.

Western Pacific Volcanic Regions

Nankai Volcanic Arc

Fukue
Nankai Volcanic Arc
A group of small olivine basaltic shield volcanoes and cinder cones lies at the eastern end of Fukuejima in the Goto Islands off the western coast of Kyushu. Activity at the Fukue volcano group began about 900,000 years ago, and the latest activity took place about 2,000-3,000 years ago (Nakano et al., 2001-). The volcanic field, whose high point is the Onidake cinder cone (about 300 m elevation), forms peninsulas at the E and SE tips of Fukue Island as well as several smaller islands to the SE.

Unzendake
Nankai Volcanic Arc
The massive Unzendake volcanic complex comprises much of the Shimabara Peninsula east of the city of Nagasaki. An E-W graben, 30-40 km long, extends across the peninsula. Three large stratovolcanoes with complex structures, Kinugasa on the north, Fugen-dake at the east-center, and Kusenbu on the south, form topographic highs on the broad peninsula. Fugendake and Mayuyama volcanoes in the east-central portion of the andesitic-to-dacitic volcanic complex have been active during the Holocene. The Mayuyama lava dome complex, located along the eastern coast west of Shimabara City, formed about 4000 years ago and was the source of a devastating 1792 CE debris avalanche and tsunami. Historical eruptive activity has been restricted to the summit and flanks of Fugendake. The latest activity during 1990-95 formed a lava dome at the summit, accompanied by pyroclastic flows that caused fatalities and damaged populated areas near Shimabara City.

Asosan
The 24-km-wide Asosan caldera was formed during four major explosive eruptions from 300,000 to 90,000 years ago. These produced voluminous pyroclastic flows that covered much of Kyushu. The last of these, the Aso-4 eruption, produced more than 600 km3 of airfall tephra and pyroclastic-flow deposits. A group of 17 central cones was constructed in the middle of the caldera, one of which, Nakadake, is one of Japan's most active volcanoes. It was the location of Japan's first documented historical eruption in 553 CE. The Nakadake complex has remained active throughout the Holocene. Several other cones have been active during the Holocene, including the Kometsuka scoria cone as recently as about 210 CE. Historical eruptions have largely consisted of basaltic to basaltic andesite ash emission with periodic strombolian and phreatomagmatic activity. The summit crater of Nakadake is accessible by toll road and cable car, and is one of Kyushu's most popular tourist destinations.

Kujusan
Kujusan is a complex of stratovolcanoes and lava domes lying NE of Aso caldera in north-central Kyushu. The group consists of 16 andesitic lava domes, five andesitic stratovolcanoes, and one basaltic cone. Activity dates back about 150,000 years. Six major andesitic-to-dacitic tephra deposits, many associated with the growth of lava domes, have been recorded during the Holocene. Eruptive activity has migrated systematically eastward during the past 5000 years. The latest magmatic activity occurred about 1600 years ago, when Kurodake lava dome at the E end of the complex was formed. The first reports of historical eruptions were in the 17th and 18th centuries, when phreatic or hydrothermal activity occurred. There are also many hot springs and hydrothermal fields. A fumarole on Hosho lava dome was the site of a sulfur mine for at least 500 years. Two geothermal power plants are in operation at Kuju.

Yufu-Tsurumi
Elevation: m
A group of lava domes rises above the hot spring resort city of Beppu on Japan's Inland Sea, possibly within an ancient breached caldera. Two large lava domes, Tsurumidake and Yufudake (the highest at 1,584 m), are located at the east and west sides of the complex, respectively. Three smaller lava domes are on the N flank of Tsurumidake, including Garandake. The latest activity at both the andesitic-to-dacitic Tsurumi and Yufu groups postdates the 6,300-year-old Akahoya ash from Kikai volcano. Pyroclastic flows dominated during older eruptions, whereas lava domes and lava flows are most common in more recent eruptions. An eruption about 2,200 years ago from Yufudake began with collapse of the N flank that produced a debris avalanche and was followed by lava dome growth and associated pyroclastic flows. The most recent known eruption was from Tsurumi in 867 CE, when there was explosive activity from the summit area. The colorful hot spring pools and mudpots of Beppu along the coast are a noted thermal area.

Abu
The dominantly Pleistocene Abu volcano group, located along northern coast near the SW end of Honshu, consists of basaltic-to-dacitic lava flows, small shield volcanoes (some with associated cinder cones), and lava domes. More than 40 monogenetic volcanoes are located in an area of 400 km2. Iraoyama forms the high point of this group of edifices, some of which form offshore islands or submarine vents. Volcanism here is considered to be related to subduction of the Philippine Sea Plate. An earlier phase of activity during the late-Pliocene to early Pleistocene was followed by renewed activity about 800,000 years ago that continued into the Holocene. The latest known activity was determined by thermoluminescence to be about 8,800 years ago, when the Kasayama scoria cone was formed.

Sanbesan
Sanbesan stratovolcano, near the northern coast of SW Honshu, has a summit cut by a small caldera about 1 km in diameter. The highest point on the dacitic-to-andesitic volcano is O-Sanbe, at the northern end of the complex. There have been several large explosive eruptions during the Pleistocene and one strong Holocene eruption from the Taiheizan lava dome about 3,700 years ago. This eruption was accompanied by pyroclastic flows that swept down the NE-to-SE flanks and traveled 9 km down the Hayamizu River to the SW. Younger, undated eruptions have also occurred (Machida and Arai, 1992).

Ontakesan
The massive Ontakesan stratovolcano, the second highest volcano in Japan, lies at the southern end of the Northern Japan Alps. It is constructed within a largely buried 4 x 5 km caldera and occupies the southern end of the Norikura volcanic zone, which extends northward to Yakedake volcano. The older volcanic complex consisted of at least four major stratovolcanoes constructed from about 680,000 to about 420,000 years ago, after which Ontakesan was inactive for more than 300,000 years. The broad, elongated summit of the younger edifice is cut by a series of small explosion craters along a NNE-trending line. Several phreatic eruptions post-date the roughly 7,300-year-old Akahoya tephra from Kikai caldera. The first recorded eruption took place in 1979 from fissures near the summit. A non-eruptive landslide in 1984 produced a debris avalanche and lahar that swept down valleys to the south and east. Very minor phreatic activity caused a dusting of ash near the summit in 1991 and 2007. A significant phreatic explosion in September 2014, when a large number of hikers were at or near the summit, resulted in many fatalities.

Hakusan
Hakusan is a complex andesitic-dacitic stratovolcano near the western coast of central Honshu. It was constructed over a high basement of sedimentary rocks in a region of very heavy snowfall that has contributed to erosional dissection. Holocene eruptions have consisted of phreatic or phreatomagmatic explosions from several summit craters. Partial collapse of the summit produced a debris avalanche down the E flank during the mid-Holocene. Eruptions were recorded over almost a thousand-year period until the 17th century.

Norikuradake
Norikuradake volcano consists of an elongated group of small andesitic stratovolcanoes and craters arranged along a N-S line above a ridge crest in the southern part of the Northern Japan Alps. The 3026-m-high andesitic-to-dacitic volcano is the third highest in Japan and lies at the center of the Norikura volcanic zone extending from Yakedake on the north to Ontake on the south. Early eruptions occurred at both the northern and southern ends of the present-day volcano, forming stratovolcanoes that have been largely buried by later southward-migrating eruptions. It was active during the early Holocene, and the last eruption took place about 2000 years ago.

Yakedake
Yakedake rises above the popular resort of Kamikochi in the Northern Japan Alps. The small dominantly andesitic stratovolcano, one of several Japanese volcanoes named Yakedake or Yakeyama ("Burning Peak" or "Burning Mountain"), was constructed astride a N-S-trending ridge between the older volcanoes of Warudaniyama and Shirataniyama. Akandanayama, about 4 km SSW, is a stratovolcano with lava domes that was active into the Holocene. A 300-m-wide crater is located at the summit, and explosion craters are found on the SE and N flanks. Frequent small-to-moderate phreatic eruptions have occurred during the 20th century. On 11 February 1995 a hydrothermal explosion in a geothermal area killed two people at a highway construction site.

Midagahara
Midagahara volcano is a dissected andesitic-to-dacitic stratovolcano on a plateau surrounded by high peaks of the North Japan Alps. The granite-and-gneiss peak of Tateyama lies immediately to the east. Formation of a 4-km-wide erosional caldera was followed by repeated eruptions of lava and pyroclastics forming the Midagahara plateau that was later dissected by the Yukawa river. Holocene eruptions have been restricted to small phreatic explosions that formed craters. A minor historical eruption occurred in the 19th century. An earthquake swarm took place in 1990. Hot springs occur in seven locations on the floor of the poorly defined erosional caldera.

Akandanayama
Akandanayama is located NW of Abo Pass in south-central Honshu. It is a stratovolcano composed of a lava dome, lava flow, and pyroclastic deposits. Shirataniyama volcano and the active Yakedake volcano are to the N. Volcanic activity began with the formation of a lava dome that covered Shirataniyama, ending about 10,000 years ago. Collapse of the dome produced pyroclastic deposits, and afterwards a landslide went SW from the summit (JMA, 2013).

Ryukyu Volcanic Arc

Kueishantao
Taiwan
Ryukyu Volcanic Arc
Kueishantao Island, the southernmost of five small volcanic islands off the NE coast of Taiwan, is also known as Guieshan Island and "Turtle Mountain Island" due to its profile as seen from some points on Taiwan. It is the southwesternmost volcano along the axis of the Okinawa Trough back-arc basin that extends to the NE from Taiwan to Unzen volcano in Kyushu. The SW tip of the Okinawa Trough extends past Kueishantao onto the Ilao Plain on Taiwan. The island consists of andesitic lava flows and volcaniclastic material. Accounts during the time of King Qianlong of the Qing Dynasty (1775-1795 CE) noted a lava flow on the mountain. Observations from ships in 1853 were likely from this location. Vigorous submarine fumaroles and solfataras discolor seawater in the area.

Tatun Volcanic Group
Taiwan
Ryukyu Volcanic Arc
The Tatun (Datun) group consists predominately of a series of andesitic lava domes in the northernmost part of Taiwan. About 20 volcanoes, the southernmost of which is only 15 km N of the capital city of Taipei, are included in the Tatun group, which was constructed along E-W and NE-SW trending ridges. The highest and youngest volcano is the Cising (Chisingshan) lava dome. Several magmatic eruptions took place in the group about 23,000 to 13,000 years ago, and a phreatic eruption associated with collapse of the lava dome, possibly closely following lava effusion, took place about 6,000 years ago. Hot springs, fumaroles, and solfataras are found over wide areas along a zone parallel to the SW-NE-trending Chinshan fault and extending to the NE coast of Taiwan, and extensive geothermal exploration has occurred at the Daiton geothermal area.

Submarine Volcano NNE of Iriomotejima
The southernmost Ryukyu Islands volcano is a shallow submarine volcano 20 km NNE of Iriomotejima island and 35 km WSW of the northern tip of the island of Ishigakishima in an area with an estimated depth of 200-300 m. A major submarine eruption on 31 October 1924 produced rhyolitic pumice rafts with an estimated volume of about 1 km3 that were carried by currents along both coasts of Japan as far north as Hokkaido. The largest pumice blocks exceeded 1 x 2 m in size, and the volume of ejecta places this poorly known eruption among the largest recorded in Japan.

Yokoatejima
Yokoatejima is a 3.5-km-long island NW of Amami Oshima Island at the SW end of the Tokara island chain. Two peaks, the higher Higashimine on the east and Nishimine on the west, form the andesitic island. Higashimine has a steep-walled, well-preserved summit crater. An arcuate ridge east of Yokoatejima appears to be part of 7 x 10 km submarine caldera, with Yokoatejima and Kaminonejima to the NNE being post-caldera cones (Nakano et al., 2001-). Yokoatesho (Yokoate Reef) and Kaminone Kaikyu (Kaminone Knoll) lie to NNW and NE of Yokoatejima, respectively. Documents from the end of the Edo Period mention ash plumes from Yokoatejima.

Akusekijima
Akusekijima is a small stratovolcano in the southern Ryukyu Islands. Most of the island is surrounded by steep cliffs, and beaches are found only on the SW and SE sides. The andesitic-dacitic volcano consists of two older somma volcanoes, Biroyama and Nakadake. Mitake lava dome forms the high point of the small 2.5 x 3.2 km wide island. The dacitic Omune lava flow on the NE flank was K-Ar dated at less than 80,000 BP; its youthful morphology and lack of overlying tephra layers suggests it could be as young as the Holocene (Furuyama et al., 2002). The lava flow, the youngest product of the volcano, forms a low-angle plateau overlying cliffs forming the northern coast.

Io-Torishima
The 1 x 2.7 km island of Io-Torishima, located north of the largest island of the Ryukyus, Okinawa, is composed of two andesitic volcanoes. Torishima (Bird Island) is a common name for offshore islands in Japan. Kusuku lava dome occupies the center of the inner of two sommas on the SE-most volcano. The summit crater of the NW-most volcano, Iodake, contains a small lake, solfataras, and sulfur deposits that were mined in the past. Historical eruptions dating back to 1664 have consisted of mild-to-moderate explosive activity.

Suwanosejima
The 8-km-long island of Suwanosejima in the northern Ryukyu Islands consists of an andesitic stratovolcano with two active summit craters. The summit is truncated by a large breached crater extending to the sea on the E flank that was formed by edifice collapse. One of Japan's most frequently active volcanoes, it was in a state of intermittent Strombolian activity from Otake, the NE summit crater, between 1949 and 1996, after which periods of inactivity lengthened. The largest recorded eruption took place in 1813-14, when thick scoria deposits covered residential areas, and the SW crater produced two lava flows that reached the western coast. At the end of the eruption the summit of Otake collapsed, forming a large debris avalanche and creating an open collapse scarp extending to the eastern coast. The island remained uninhabited for about 70 years after the 1813-1814 eruption. Lava flows reached the eastern coast of the island in 1884. Only about 50 people live on the island.

Kuchinoshima
Kuchinoshima, lying in the northern Ryukyu Islands between the volcanic islands of Nakanoshima and Kuchinoerabujima, consists of two andesitic stratovolcanoes and a NW-SE-trending chain of lava domes. Two small villages, Nishinohama and Kuchinoshima, lie at the northern end of the mostly uninhabited island. The compound 628-m-high Maedake lava dome, forming the highest point on the 3 x 7 km wide island, was constructed east of the summit of 501-m-high Yokodake stratovolcano. The last magmatic eruption took place about 1200-1300 years ago.

Nakanoshima
The 9 x 5 km island of Nakanoshima is surrounded by coral reefs. A flat plateau separates the older dissected Sakiwaridake volcano on the south from the active andesitic cone of Ontake, which forms the northern half of the island. Ontake contains a summit crater that is filled with water during the rainy season. Sulfur deposits were mined at a SE-flank solfatara until 1944. Only very minor activity has been reported in historical time. A small mud eruption took place in 1914 at the summit crater, and "smoking" increased in 1949.

Kuchinoerabujima
A group of young stratovolcanoes forms the eastern end of the irregularly shaped island of Kuchinoerabujima in the northern Ryukyu Islands, 15 km W of Yakushima. The Furudake, Shindake, and Noikeyama cones were erupted from south to north, respectively, forming a composite cone with multiple craters. All historical eruptions have occurred from Shindake, although a lava flow from the S flank of Furudake that reached the coast has a very fresh morphology. Frequent explosive eruptions have taken place from Shindake since 1840; the largest of these was in December 1933. Several villages on the 4 x 12 km island are located within a few kilometers of the active crater and have suffered damage from eruptions.

Kikai
Multiple eruption centers have exhibited recent activity at Kikai, a mostly submerged, 19-km-wide caldera near the northern end of the Ryukyu Islands south of Kyushu. It was the source of one of the world's largest Holocene eruptions about 6,300 years ago when rhyolitic pyroclastic flows traveled across the sea for a total distance of 100 km to southern Kyushu, and ashfall reached the northern Japanese island of Hokkaido. The eruption devastated southern and central Kyushu, which remained uninhabited for several centuries. Post-caldera eruptions formed Iodake (or Iwo-dake) lava dome and Inamuradake scoria cone, as well as submarine lava domes. Recorded eruptions have occurred at or near Satsuma-Iojima (also known as Tokara-Iojima), a small 3 x 6 km island forming part of the NW caldera rim. Showa-Iojima lava dome (also known as Iojima-Shinto), a small island 2 km E of Satsuma-Iojima, was formed during submarine eruptions in 1934 and 1935. Mild-to-moderate explosive eruptions have occurred during the past few decades from Iodake, a rhyolitic lava dome at the eastern end of Satsuma-Iojima.

Ata
Volcano type: Caldera(s)
The submerged 15 x 25 km Ata caldera under Kagoshima Bay is one of several large calderas in southern Kyushu and the source of major pyroclastic flows associated with its formation more than 40,000 years ago. The National Catalogue of the Active Volcanoes of Japan (JMA, 2013) included features of the Ibusuki volcanic field as part of the Ata post-caldera system. That area consists of numerous central cones and maars, the 4-km-diamter lake-filled Ikeda caldera, and Kaimondake stratovolcano. The symmetrical andesitic Kaimondake is the most prominent feature, and is capped by a lava dome. Ibusuki has been very active during the Holocene, forming the Ikeda caldera about 4,600 years ago along with numerous maars and lava domes. Kaimondake formed during the last 4,000 years, from which all eruptive activity has occurred after about 2,650 years ago; its last eruption took place in the 9th century. JMA (2013) listed as distinct volcanoes both Kaimondake and the combination of Ikeda and Yamagawa, while also including them all as features of the Ata Caldera, as in this catalog.

Yonemaru-Sumiyoshiike
Yonemaru and Sumiyoshiike are basaltic maars formed in coastal lowland deposits north of the Aira caldera, on the SW and SE flanks of the small Pleistocene Aojiki cone. The three features are also known as the Kamo Volcanic Field. The maar eruptions occurred during a period of rising sea level at the beginning of the Holocene. The 500-m-wide Sumiyoshiike was created about 7,000 years ago. The larger, 1.2-km-wide Yonemaru erupted about 2 km W of Sumiyoshiike about 6,500 years ago and produced pyroclastic surges that traveled 4 km from the vent.

Aira
The Aira caldera in the northern half of Kagoshima Bay contains the post-caldera Sakurajima volcano, one of Japan's most active. Eruption of the voluminous Ito pyroclastic flow accompanied formation of the 17 x 23 km caldera about 22,000 years ago. The smaller Wakamiko caldera was formed during the early Holocene in the NE corner of the caldera, along with several post-caldera cones. The construction of Sakurajima began about 13,000 years ago on the southern rim and built an island that was joined to the Osumi Peninsula during the major explosive and effusive eruption of 1914. Activity at the Kitadake summit cone ended about 4,850 years ago, after which eruptions took place at Minamidake. Frequent eruptions since the 8th century have deposited ash on the city of Kagoshima, located across Kagoshima Bay only 8 km from the summit. The largest recorded eruption took place during 1471-76.

Kirishimayama
Kirishimayama is a large group of more than 20 Quaternary volcanoes located north of Kagoshima Bay. The late-Pleistocene to Holocene dominantly andesitic group consists of stratovolcanoes, pyroclastic cones, maars, and underlying shield volcanoes located over an area of 20 x 30 km. The larger stratovolcanoes are scattered throughout the field, with the centrally located Karakunidake being the highest. Onamiike and Miike, the two largest maars, are located SW of Karakunidake and at its far eastern end, respectively. Holocene eruptions have been concentrated along an E-W line of vents from Miike to Ohachi, and at Shinmoedake to the NE. Frequent small-to-moderate explosive eruptions have been recorded since the 8th century.

Luzon Volcanic Arc

Banahaw
Philippines
Luzon Volcanic Arc
Banahaw (also known as Banahao), the highest of a group of volcanoes south and east of Manila, is flanked by San Cristobal (7 km W) and Banahaw de Lucban on the NE. Andesitic-to-dacitic lava domes occur on the flanks of both Banahaw and San Cristobal. Deposits from two major Holocene debris avalanches from Banahaw extend 13 km NE and 26 km SE, where it forms 10 km of the coastline of Tayabas Bay. The youthful morphology of the San Cristobal stratovolcano suggests that it postdates Banahaw. Banahaw de Lucban stratovolcano was constructed within the 8-km-wide amphitheater related to the two debris avalanches, and is the youngest volcano of the complex. The 2-km-wide, 600-m-deep summit crater of Banahaw is open to the SSW and contained a crater lake until 1730, when it drained, forming mudflows. Mudflows were also recorded in 1743?, 1843, and 1909 CE, possibly also associated with explosive activity.

San Pablo Volcanic Field
Philippines
Luzon Volcanic Arc
The San Pablo Volcanic Field, (also known as the Laguna Volcanic Field) lies at the southern end of Laguna de Bay, the largest lake on Luzon Island. The field contains dozens of scoria cones and maars. Three generations of maars are present, with the oldest being sediment-filled and the youngest containing deep lakes. Many of the maars are aligned along a NE-SW trend. Local legends suggest that the youngest maar, 1.2-km-wide Sampaloc Lake, was formed about 500-700 years ago. The high point of the field is the eroded Maquiling (Makiling) andesitic-to-rhyolitic stratovolcano, which has a deep crater whose floor is 480 m below its north rim. Maquiling has several cones, maars, and numerous thermal areas at its northern base; a geothermal project is located on the S flank.

Taal
Philippines
Taal is one of the most active volcanoes in the Philippines and has produced some powerful eruptions. The 15 x 20 km Talisay (Taal) caldera is largely filled by Lake Taal, whose 267 km2 surface lies only 3 m above sea level. The maximum depth of the lake is 160 m, with several submerged eruptive centers. The 5-km-wide Volcano Island in north-central Lake Taal is the location of all observed eruptions. The island is composed of coalescing small stratovolcanoes, tuff rings, and scoria cones. Powerful pyroclastic flows and surges have caused many fatalities.

Pinatubo
Prior to 1991 Pinatubo volcano was a relatively unknown, heavily forested lava dome complex located 100 km NW of Manila with no records of historical eruptions. The 1991 eruption, one of the world's largest of the 20th century, ejected massive amounts of tephra and produced voluminous pyroclastic flows, forming a small, 2.5-km-wide summit caldera whose floor is now covered by a lake. Caldera formation lowered the height of the summit by more than 300 m. Although the eruption caused hundreds of fatalities and major damage with severe social and economic impact, successful monitoring efforts greatly reduced the number of fatalities. Widespread lahars that redistributed products of the 1991 eruption have continued to cause severe disruption. Previous major eruptive periods, interrupted by lengthy quiescent periods, have produced pyroclastic flows and lahars that were even more extensive than in 1991.

Cagua
The Mount Cagua stratovolcano lies at the NE tip of Luzon. The circular summit crater is 1.5 km in diameter, with steep, 60-m-high walls. basaltic andesite and basaltic lava effusion characterized the initial stage of volcanism during the early Pleistocene. From about 600,000 to 300,000 years ago thick pyroclastic flows covered the entire volcano. Recent periods of phreatomagmatic activity have produced ash flows. The forested volcano is locally known as the "Mountain of Fire." A phreatic explosion in 1860 CE may have been accompanied by a pyroclastic flow. Strong solfataric activity occurred in 1907, and thermal areas are located near the summit crater and on the NW to NNE flanks.

Camiguin de Babuyanes
Forested Mount Camiguin occupies the SW tip of 22-km-long Camiguin Island in the Babuyan archipelago, north of Luzon Island. Following construction of an andesitic volcano during the Pliocene, the subsidiary cones of Minabul to the north and Caanoan to the east were constructed on the northern part of the island. The southern part of the island consists of three volcanic centers located along a SSE-NNW line, the andesitic Mount Camiguin stratovolcano and the young andesitic lava domes of Mt. Malabsing and Pamoctan. A phreatic eruption, possibly in part submarine, was reported from Camiguin de Babuyanes around 1857. Fumaroles are found on the SW, W, and E flanks of the volcano, and a boiling spring is located near sea level on the W flank.

Didicas
Didicas, 22 km NE of Camiguin Island in the Babuyanes Islands north of Luzon, was a submarine volcano prior to 1952, when a permanent island was formed. It now consists of an andesitic lava dome about 200 m above sea level and 1.4 km in longest exposed dimension. A 400-m-wide crater was formed during the 1952 eruption. The first certain submarine eruption began in 1856, building a subaerial cone that reached a height of over 200 m in 1860, but soon was eroded beneath the sea. Three rock masses up to 82 m high were left after an eruption in 1900. Two eruptions have occurred since 1952 at an explosion crater on the northern side of the island.

Babuyan Claro
Multiple Quaternary volcanic centers occupy Babuyan de Claro Island north of Luzon. The largest edifice is Babuyan Claro (Mount Pangasun) at the center of the island, a stratovolcano with a 500-m-diameter summit crater and a smaller crater on the upper E flank. An older edifice lies just 1.5 km WSW, but the basaltic andesite Smith volcano (Mount Babuyan), about 4 km ENE of the summit, is the youngest volcanic feature on the island. Eruptions from Smith were recorded most recently during 1907-1924. Askedna Hot Spring is located at the southern base of Babuyan Claro.

Iraya
The morphologically youthful Iraya stratovolcano is the northernmost active volcano in the Philippines. It is the most prominent feature of the 20-km-long Batan Island, located in the Luzon Strait between Luzon and Taiwan. The 1.5-km-wide summit crater is largely filled by a younger cone that forms the summit. Observed late-Pleistocene and Holocene products are exclusively explosive. The youngest dated unit is a pyroclastic-flow deposit 14C dated at about 1,500 years ago (Richard et al., 1986). The Philippines Institute of Volcanology and Seismology (2004-) listed an eruption in 1454 CE of unspecified character.

Eastern Philippine Volcanic Arc

Leonard Range
Eastern Philippine Volcanic Arc
An andesitic-to-dacitic stratovolcano complex in the Leonard Range is truncated by a 4 x 5 km caldera partially filled by Lake Leonard. The Leonard Kniazeff stratovolcano is located east of the head of Davao Gulf in SE Mindanao, east of the major N-S-trending Philippine Fault. Activity in the Leonard Range dates back to 1.1 million years. A dome building stage began about 290,000 years ago, producing a series of lava domes in the region surrounding Lake Leonard. A younger stage involved the eruption of the Paloc pyroclastic deposits from the late-Pleistocene to Holocene and the formation of the caldera. Radiocarbon dates ranging from about 6,000 to 1,800 years ago were obtained from the Paloc pyroclastic deposits. The Manat thermal area is located north of Lake Leonard, solfataras occur its SW rim, and active solfataras, fumaroles, and hot springs are found in the Amacan-Gopod thermal area south of the lake.

Cabal�an
Eastern Philippine Volcanic Arc
Mount Cabal�an, at the SE tip of Leyte Island, is dissected by steep radial ridges that are moderately to thickly vegetated. A lake fills the summit crater of the andesitic volcano, which has an irregular rim with two high peaks on the southern side. A thermoluminescence date of about 510,000 years BP was obtained from Cantoloc stratovolcano immediately to the NW. A radiocarbon date of about 135 +/- 30 years BP was obtained from a pyroclastic-flow deposit from Cabal�an. Hot springs are found on the E and W flanks.

Biliran
The volcanic island of Biliran, located across the narrow Biliran Strait from the northern tip of Leyte Island, contains many prominent andesitic lava domes, the highest of which is 1301 m Surio. Several Pleistocene K-Ar dates have been obtained from volcanic centers on northern Biliran Island. Fumarole fields are scattered throughout the 20 x 35 km wide island. The only known historical activity was a phreatic explosive eruption and possible debris avalanche at a thermal area in 1939.

Bulusan
Luzon's southernmost volcano, Bulusan, was constructed along the rim of the 11-km-diameter dacitic-to-rhyolitic Irosin caldera, which was formed about 36,000 years ago. It lies at the SE end of the Bicol volcanic arc occupying the peninsula of the same name that forms the elongated SE tip of Luzon. A broad, flat moat is located below the topographically prominent SW rim of Irosin caldera; the NE rim is buried by the andesitic complex. Bulusan is flanked by several other large intracaldera lava domes and cones, including the prominent Mount Jormajan lava dome on the SW flank and Sharp Peak to the NE. The summit is unvegetated and contains a 300-m-wide, 50-m-deep crater. Three small craters are located on the SE flank. Many moderate explosive eruptions have been recorded since the mid-19th century.

Mayon
Symmetrical Mayon, which rises above the Albay Gulf NW of Legazpi City, is the most active volcano of the Philippines. The steep upper slopes are capped by a small summit crater. Recorded eruptions since 1616 CE range from Strombolian to basaltic Plinian, with cyclical activity beginning with basaltic eruptions, followed by longer periods of andesitic lava flows. Eruptions occur predominately from the central conduit and have also produced lava flows that travel far down the flanks. Pyroclastic density currents and mudflows have commonly swept down many of the approximately 40 ravines that radiate from the summit and have often damaged populated lowland areas. A violent eruption in 1814 killed more than 1,200 people and devastated several towns.

Iriga
Mount Iriga (locally known as Mt Asog) is a small andesitic stratovolcano that rises immediately W of Lake Buhi which has satellitic cinder cones of basaltic composition. A large breached crater open to the SE was formed as a result of a major debris avalanche that buried several villages and formed a broad hummocky deposit across the plain south of Lake Buhi. This catastrophic event was at one time considered to have occurred during 1628 CE, but later work has shown that the collapse occurred earlier at some unknown date during the Holocene. An older debris avalanche deposit of similar size was also described SW of the volcano (Paguican et al., 2010). Both debris avalanche deposits cover wide areas of low, waterlogged plains, to a distance of ~16 km for the older and 12 km for the younger. The collapse orientation and deposit constituents for both are consistent with being a response to transtensional faulting and gravity spreading. A cone and lava covering about 9 km2 post-date the younger collapse.

Isarog
The broad isthmus between Lagonoy Gulf and San Miguel Bay in SE Luzon is occupied by Mount Isarog. The andesitic stratovolcano is truncated by a 2.5-km-wide crater that is breached to the east along a narrow valley drained by the Quinarag River. A major debris avalanche deposit extends NW to the coast and into San Miguel Bay. Pyroclastic flows originating from lava dome collapses have occurred during the Holocene, one of which has a calibrated radiocarbon date of about 5,500 years BP. The Maalsom vent displays gas seepages, warm springs, and steaming vents.

Negros-Sulu Volcanic Arc

Kanlaon
Negros-Sulu Volcanic Arc
Kanlaon volcano (also spelled Canlaon) forms the highest point on the Philippine island of Negros. The massive andesitic stratovolcano is covered with fissure-controlled pyroclastic cones and craters, many of which are filled by lakes. The largest debris avalanche known in the Philippines traveled 33 km SW from Kanlaon. The summit contains a 2-km-wide, elongated northern caldera with a crater lake and a smaller but higher active vent, Lugud crater, to the south. Eruptions recorded since 1866 have typically consisted of phreatic explosions of small-to-moderate size that produce minor local ashfall.

Mindanao Volcanic Province

Melebingoy
Mindanao Volcanic Province
M�l�bing�y (previously known as Parker) is a low, vegetated stratovolcano overlooking Sarangani Bay near the southern tip of Mindanao Island. The steep andesitic-dacitic stratovolcano is surrounded by extensive, youthful pyroclastic-flow deposits. The summit is truncated by a 2.9-km-wide caldera with steep-sided walls that rise 200-500 m above heart-shaped Maughan Lake. This volcano was the source of a major explosive eruption in 1641 CE that was previously attributed to Awu volcano on Sangihe Island. The eruption caused darkness over the island of Mindanao, deposited voluminous pyroclastic flows and lahars, and resulted in the formation of the summit caldera. This was the last of three major explosive eruptions during the previous 3,800 years.

Matutum
Mindanao Volcanic Province
The symmetrical Matutum stratovolcano overlooks the city of General Santos in southern Mindanao, NW of Sarangani Bay, Philippines. The summit of the andesitic-to-dacitic volcano is truncated by a 320-m-wide crater that is breached by three gorges and has a 120-m-deep, densely forested floor. Widespread silicic pyroclastic flow deposits surround the volcano; the youngest were dated at about 2,000 years BP. A report stated that Matutum was "smoking" on 7 March 1911 (Neumann van Padang, 1953). The Akmoan and Lianan thermal areas are located on the WSW flank of the volcano.

Makaturing
Mount Makaturing is the central edifice in the Butig Mountains S of Lake Lanao in central Mindanao that includes a complex of volcanic cones and craters stretching 10 km E and 15 km WSW. Eruptions at one time attributed to Makaturing were ascribed to neighboring Ragang volcano to the east by the Catalog of Active Volcanoes of the World (Neumann van Padang, 1953), but PHIVOLCS has listed many eruptions for Makaturing. A dense cover of vegetation suggests long quiescence, but solfataric activity continues.

Ragang
The large Ragang stratovolcano, also called Piapayungan, is SE of Lake Lanao in central Mindanao. A crater about 5 km from the summit on the SW flank towards Latukan volcano is surrounded by mostly unvegetated volcanic material, including a lava flow extending 4 km S; this is likely from the 1916 eruption described by Maso (1917). Ragang is one of several dominantly basaltic volcanoes west of the cordillera in central Mindanao. Historical eruptions, many of which were at one time attributed to neighboring Makaturing volcano, have been recorded since 1765.

Musuan
Musuan, also known as Calayo, is an isolated, low grass-covered andesitic-to-dacitic lava dome and tuff cone that rises above flat farmland in the province of Bukidnon in central Mindanao. Maso (1902) related that in a 1891 document a Jesuit priest had reported that a volcano, along the River Palangui near a waterfall and where the river forms a very narrow canyon with steep high banks, had "burst into eruption some four years ago and constantly emits vapors which burn everything about... there is no flow of lava, but it emits a column of smoke so sulphurous as to prevent any approach." Although Maso (1902) attributed this activity to Musuan, the geographic description does not match, so both the nature and location of this event is uncertain. PHIVOLCS at one time listed eruptions in 1866 and 1867, but had removed those eruptions as of 2020. A strong earthquake swarm occurred nearby in 1976.

Camiguin
The 20-km-long Camiguin Island just off the coast of north-central Mindanao Island consists of four overlapping stratovolcanoes overlying older buried edifices. Mt. Mambajao, the high point of the island, has a youthful morphology with summit and flank lava domes, one of which partially fills a crater breached to the NW. The eroded stratovolcanoes of Mt. Butay and Mt. Ginsiliban form the SE tip of the island and lie at one end of the NNW-SSE trending line of vents cutting across the island. The Binone cinder cone lies along the SE coast. The youngest volcano, Hibok-Hibok (also known as Catarman), lies at the NW end of the island ~6 km NW of Mt. Mambajao. This andesitic-to-rhyolitic volcano contains several lava domes, including Mt. Vulcan on its NW flank. Major eruptions from Hibok-Hibok during 1871-75 and 1948-53 formed flank lava domes and produced pyroclastic flows that devastated coastal villages.

Sangihe Volcanic Arc

Colo
Indonesia
Sangihe Volcanic Arc
Colo volcano forms the isolated small island of Una Una in the middle of the Gulf of Tomini in northern Sulawesi. The broad, low volcano contains a 2-km-wide caldera with a small central cone. Three eruptions have been recorded since the late 1800's, but two of those caused widespread damage over the island. The last eruption, in 1983, produced pyroclastic flows that swept over most of the island shortly after all residents had been evacuated.

Ambang
Indonesia
Sangihe Volcanic Arc
The compound Ambang volcano is the westernmost of the active volcanoes on the northern arm of Sulawesi. The stratovolcano rises 750 m above lake Danau. Several craters up to 400 m in diameter and five solfatara fields are located at the summit.

Soputan
Indonesia
The Soputan stratovolcano on the southern rim of the Quaternary Tondano caldera on the northern arm of Sulawesi Island is one of Sulawesi's most active volcanoes. The youthful, largely unvegetated volcano is the only active cone in the Sempu-Soputan volcanic complex, which includes the Soputan caldera, Rindengan, and Manimporok (3.5 km ESE). Kawah Masem maar was formed in the W part of the caldera and contains a crater lake; sulfur has been extracted from fumarolic areas in the maar since 1938. Recent eruptions have originated at both the summit crater and Aeseput, a prominent NE-flank vent that formed in 1906 and was the source of intermittent major lava flows until 1924.

Lokon-Empung
The Lokong-Empung volcanic complex, rising above the plain of Tondano in North Sulawesi, includes four peaks and an active crater. Lokon, the highest peak, has a flat craterless top. The morphologically younger Empung cone 2 km NE has a 400-m-wide, 150-m-deep crater that erupted last in the 18th century. A ridge extending 3 km WNW from Lokon includes the Tatawiran and Tetempangan peaks. All eruptions since 1829 have originated from Tompaluan, a 150 x 250 m crater in the saddle between Lokon and Empung. These eruptions have primarily produced small-to-moderate ash plumes that sometimes damaged croplands and houses, but lava-dome growth and pyroclastic flows have also occurred.

Mahawu
The elongated Mahawu volcano immediately east of Lokon-Empung volcano is the northernmost of a series of young volcanoes along a SSW-NNE line near the margin of the Quaternary Tondano caldera. Mahawu is capped by a 180-m-wide, 140-m-deep crater that sometimes contains a small crater lake, and has two pyroclastic cones on its N flank. Historical activity has been restricted to occasional small explosive eruptions recorded since 1789. In 1994 fumaroles, mudpots, and small geysers were observed along the shores of a greenish-colored crater lake.

Klabat
Klabat is a symmetrical stratovolcano near the tip of the northern arm of Sulawesi Island, east of the city of Manado. There is a shallow lake in the 170 x 250 m summit crater. No verified reported eruptions are known, but there has been fumarolic activity. A reported eruption in 1683 CE was probably from Tangkoko, 19 km NE.

Tangkoko-Duasudara
The eastern peninsula at the far NE end of Sulawesi near the city of Bitung is occupied by a volcanic complex consisting of two major edifices within a nature reserve. To the north is Tangkoko (also known as Tongkoko), with a large caldera (~3 x 1.5 km) elongated towards the SE from the highest rim point; the rim at the opposite end is more than 400 m lower. Eruptions occurred from the summit crater in the 17th century and in 1801, when the caldera also reportedly contained a cone surrounded by a lake. About 1.5 km down the outer E flank is the Batuangus (or Batu Angus) lava dome, formed in 1801, along with an adjacent vent (Baru Batuangus) that has been the source of all subsequent eruptions. The higher Duasudara (also Dua Suadara) edifice is ~4.5 km SW of the Tangkoko summit. A NE-facing scarp appears to have a hummocky debris flow that reaches the base of Tangkoko.

Ruang
Ruang volcano is the southernmost volcano in the Sangihe Island arc, north of Sulawesi Island; it is not the better known Raung volcano on Java. The 4 x 5 km island volcano is across a narrow strait SW of the larger Tagulandang Island. The summit contains a crater partially filled by a lava dome initially emplaced in 1904. Explosive eruptions recorded since 1808 have often been accompanied by lava dome formation and pyroclastic flows that have damaged inhabited areas.

Karangetang
Karangetang (Api Siau) volcano lies at the northern end of the island of Siau, about 125 km NNE of the NE-most point of Sulawesi. The stratovolcano contains five summit craters along a N-S line. It is one of Indonesia's most active volcanoes, with more than 40 eruptions recorded since 1675 and many additional small eruptions that were not documented (Neumann van Padang, 1951). Twentieth-century eruptions have included frequent explosive activity sometimes accompanied by pyroclastic flows and lahars. Lava dome growth has occurred in the summit craters; collapse of lava flow fronts have produced pyroclastic flows.

Banua Wuhu
The submarine Banua Wuhu volcanic cone lies ~600 m off the western coast of Mahengatang Island, the emergent summit of a large submarine edifice, in the Sangihe Islands. Several ephemeral islands were constructed during the 19th and 20th centuries. An island 90 m high was formed in 1835, but had eroded to only a few rocks by 1848. Another island formed in 1889 was 50 m high in 1894. Five craters were reported during an eruption that built an island in 1904. An island that formed in 1919 had disappeared by 1935. Bathymetry shows shallow water over an area larger than Mahengatang Island towards the W (Haryanto, 2020). Satellite imagery frequently shows two sources of discolored water in the area, and it is a popular location for divers, who report sulfur odors and bubbling.

Awu
The massive Gunung Awu stratovolcano occupies the northern end of Great Sangihe Island, the largest of the Sangihe arc. Deep valleys that form passageways for lahars dissect the flanks of the volcano, which was constructed within a 4.5-km-wide caldera. Powerful explosive eruptions in 1711, 1812, 1856, 1892, and 1966 produced devastating pyroclastic flows and lahars that caused more than 8000 cumulative fatalities. Awu contained a summit crater lake that was 1 km wide and 172 m deep in 1922, but was largely ejected during the 1966 eruption.

Halmahera Volcanic Arc

Tarakan
Halmahera Volcanic Arc
Two cinder cones between Galela Bay and Lake Galela on norther Halmahera, NE of Dukono volcano, were mapped by Supriatna (1980) as basaltic and Holocene. Tarakan Lamo and Tarakan Itji (large and small Tarakan) have well-formed summit craters 800 and 500 m in diameter, and 160 and 125 m deep, respectively.

Dukono
Halmahera Volcanic Arc
The Dukono complex in northern Halmahera is on an edifice with a broad, low profile containing multiple peaks and overlapping craters. Almost continuous explosive eruptions, sometimes accompanied by lava flows, have occurred since 1933. During a major eruption in 1550 CE, a lava flow filled in the strait between Halmahera and the Gunung Mamuya cone, 10 km NE. Malupang Wariang, 1 km SW of the summit crater complex, contains a 700 x 570 m crater that has also had reported eruptions.

Tobaru
Gunung Tobaru, also known as Lolodai, is located in northern Halmahera WSW of Dukono and NNE of Ibu. Supriatna (1980) mapped the little known andesitic volcano as Holocene.

Ibu
The truncated summit of Gunung Ibu stratovolcano along the NW coast of Halmahera Island has large nested summit craters. The inner crater, 1 km wide and 400 m deep, has contained several small crater lakes. The 1.2-km-wide outer crater is breached on the N, creating a steep-walled valley. A large cone grew ENE of the summit, and a smaller one to the WSW has fed a lava flow down the W flank. A group of maars is located below the N and W flanks. The first observed and recorded eruption was a small explosion from the summit crater in 1911. Eruptive activity began again in December 1998, producing a lava dome that eventually covered much of the floor of the inner summit crater along with ongoing explosive ash emissions.

Gamkonora
The shifting of eruption centers on Gamkonora, the highest peak of Halmahera, has produced an elongated series of summit craters along a N-S trending rift. Youthful-looking lava flows originate near the cones of Gunung Alon and Popolojo, south of Gamkonora. Since its first recorded eruption in the 16th century, typical activity has been small-to-moderate explosive eruptions. Its largest recorded eruption, in 1673, was accompanied by tsunamis that inundated villages.

Jailolo
The Jailolo volcanic complex forms a peninsula west of Jailolo Bay on the western coast of Halmahera Island. The stratovolcano at the center of the complex has youthful lava flows on its E flank. Small calderas are located to the W and SW. The westernmost caldera, Idamdehe, truncates an older volcanic edifice. Hot springs occur along the NW coast of the caldera. Kailupa cone forms a small volcanic island off the southern coast of the peninsula. Hot mudflows were reported shortly prior to 1883, but no eruptions are known.

Hiri
Hiri is a 3-km-wide forested island immediately north of Gamalama on Ternate Island, and is the northernmost of a chain of volcanic islands off the western coast of Halmahera. Two conical volcanic edifices are present within a larger caldera open to the W. Apandi and Sudana (1980) mapped it as Holocene in age, but no eruptions have been dated or reported.

Todoko-Ranu
Todoko-Ranu is a large volcanic complex south of Gamkonora in North Maluku, Halmahera, that includes two calderas. The 2 x 2.8 km nested Ranu calderas on the north contains a caldera lake in the smaller one. The lava-filled Todoko caldera is south of the Ranu calderas. The post-caldera Sahu cone, on the S flank of Todoko, is the high point of the complex. Gunung Onu, NW of Ranu caldera, lies at the northern end of the complex. No eruptions have been reported, but it was mapped as Holocene (Supriatna, 1980). Fumaroles are present at Ranu caldera and hot springs are found on Mt. Sahu. Youthful-looking lava flows reach the sea from several locations within the complex.

Kie Matubu
The conical Kie Matubu volcano on the south end of Tidore Island is the highest peak of the North Maluku island chain west of Halmahera. Faral et al. (2022) identified deposits from two eruptions within the past 3,000 years.

Mare
The small volcanic island of Mare, immediately south of Tidore, was mapped as Holocene in age by Apandi and Sudana (1980). The 2 x 3 km island, part of a chain of volcanic islands off the western coast of Halmahera Island, is elongated in a NE-SW direction. A large breached crater at the andesitic volcano is located off the SW tip of the island.

Moti
The 5-km-wide island of Moti, also known as Motir, is part of a chain of volcanic islands off the western coast of Halmahera. It is located north of Makian and south of Mare and Tidore islands, and is surrounded by coral reefs. The truncated, conical island contains a crater on its SSW side. Moti was mapped as Holocene by Apandi and Sudana (1980). A minor eruption was reported in 1774 or shortly before, but Gogarten (1918) indicated that this event was confused with the October 1773 eruption of nearby Gamalama, which could have dropped ash on Moti.

Gamalama
Gamalama is a near-conical stratovolcano that comprises the entire island of Ternate off the western coast of Halmahera, and is one of Indonesia's most active volcanoes. The island was a major regional center in the Portuguese and Dutch spice trade for several centuries, which contributed to the extensive documentation of activity. Three cones, progressively younger to the north, form the summit. Several maars and vents define a rift zone, parallel to the Halmahera island arc, that cuts the volcano; the S-flank Ngade maar formed after about 14,500?13,000 cal. BP (Faral et al., 2022). Eruptions, recorded frequently since the 16th century, typically originated from the summit craters, although flank eruptions have occurred in 1763, 1770, 1775, and 1962-63.

Kie Besi
Kie Besi volcano, forming the 10-km-wide Makian island off the west coast of Halmahera, has been the source of infrequent, but strong eruptions that have devastated villages on the island. The large 1.5-km-wide summit crater, containing a small lake on the NE side, gives the peak a flat-topped profile. Two prominent valleys extend to the coast from the summit crater on the north and east sides. Four cones are found on the western flanks. Eruption have been recorded since about 1550; major eruptions in 1646, 1760-61, 1861-62, 1890, and 1988 caused extensive damage and many fatalities.

Southwestern Pacific Volcanic Regions

Bismarck Sea Volcanic Province

St. Andrew Strait
Papua New Guinea
Bismarck Sea Volcanic Province
The St. Andrew Strait volcano, located in the Admiralty Islands north of Papua New Guinea, consists of a series of overlapping Quaternary cones formed by rhyolitic lava flows and pyroclastic materials on Lou and Tuluman Islands. Volcanism is aligned on a curved arc extending through the 12-km-long Lou Island. The Tuluman Islands, 1.5 km S of Lou Island, were formed during a 1953-1957 eruption. Pam Lin and Pam Mandian Islands farther to the SE along the same arc contain fresh rhyolitic obsidian similar to that found on Tuluman.

Titan Ridge
Papua New Guinea
Bismarck Sea Volcanic Province
SOFAR signals resembling those produced at known submarine eruptions were recorded in January 1972 in the central Bismarck Sea (Johnson et al., 1981). The source of the signals was at the junction of two segments of the N margin of the South Bismarck plate. The more easterly of these segments is a transform fault, whereas the more westerly is an area of oblique active seafloor spreading. The signals were detected by a seismic station on nearby Manus Island, as well as at hydrophone stations on Wake and Midway Islands in the central Pacific. During the eruption in 2026 the "Titan Ridge" name was proposed by local residents. The general story of the Titan (pronounced Tee-Tahn) people is that their island home got devastated and reduced to the Circular Reef (~40 km SSW) due to an uncertain natural phenomenon; they drifted for awhile before they settled, and most of the Titan villages are now mainly along the south coast of Manus Island.

Bismarck Volcanic Arc

Blup Blup
Papua New Guinea
Bismarck Volcanic Arc
The 2 x 3.5 km forested island of Blup Blup contains lava flows with well-defined flow fronts. Weak thermal areas are located on the W and N coasts. Most eruptive activity at the andesitic-dacitic volcano originated from a summit crater about 800 m in diameter, although there may be a lava dome on a ridge to the W and a small satellite cone along the SW coast. Reports of eruptions in 1616 and 1830 are erroneous, but there may have been eruptions during the Holocene (Johnson, 1990 p.c.). Blocks from a submarine debris avalanche lie to the NE of the island.

Kadovar
Bismarck Volcanic Arc
The 2-km-wide island of Kadovar is the emergent summit of a Bismarck Sea stratovolcano of Holocene age. It is part of the Schouten Islands, and lies off the coast of New Guinea, about 25 km N of the mouth of the Sepik River. Prior to an eruption that began in 2018, a lava dome formed the high point of the andesitic volcano, filling an arcuate landslide scarp open to the south; submarine debris-avalanche deposits occur in that direction. Thick lava flows with columnar jointing forms low cliffs along the coast. The youthful island lacks fringing or offshore reefs. A period of heightened thermal phenomena took place in 1976. An eruption began in January 2018 that included lava effusion from vents at the summit and at the E coast.

Bam
The 1.6 x 2.4 km island of Bam is the summit of a mostly submerged volcano in the Schouten Islands off the coast of New Guinea, ~40 km NNE of the mouth of the Sepik River. A steep-walled summit crater that is 300 m wide and 180 m deep is the source of recent eruptions, which have kept the upper half of the cone sparsely vegetated. A NE-trending landslide scarp extends across the upper part of the andesitic volcano from the SW coast, and a large submarine debris-avalanche deposits lies to the S and SW. The younger summit cone partially buries the eastern side of the collapse scarp. A recent lava platform on the N flank supports the small island's only villages. Eruptions recorded since 1872 have all consisted of small-to-moderate explosive activity from the summit crater.

Manam
The 10-km-wide island of Manam, lying 13 km off the northern coast of mainland Papua New Guinea, is one of the country's most active volcanoes. Four large radial valleys extend from the unvegetated summit of the conical basaltic-andesitic stratovolcano to its lower flanks. These valleys channel lava flows and pyroclastic avalanches that have sometimes reached the coast. Five small satellitic centers are located near the island's shoreline on the northern, southern, and western sides. Two summit craters are present; both are active, although most observed eruptions have originated from the southern crater, concentrating eruptive products during much of the past century into the SE valley. Frequent eruptions, typically of mild-to-moderate scale, have been recorded since 1616. Occasional larger eruptions have produced pyroclastic flows and lava flows that reached flat-lying coastal areas and entered the sea, sometimes impacting populated areas.

Karkar
Karkar is a 19 x 25 km forest-covered island that is truncated by two nested summit calderas. The 5.5 km outer caldera was formed during one or more eruptions, the last of which occurred 9,000 years ago. The steep-walled 300-m-deep, 3.2 km diameter, inner caldera was formed sometime between 1,500 and 800 years ago. Cones are present on the N and S flanks of this basaltic-to-andesitic volcano; a linear array of small cones extends from the northern rim of the outer caldera nearly to the coast. Recorded eruptions date back to 1643 from Bagiai, a pyroclastic cone constructed within the inner caldera, the floor of which is covered by young, mostly unvegetated andesitic lava flows.

Hankow Reef
Oral tradition suggests the possible existence of a now-submerged volcano off the coast of Papua New Guinea. Accounts from many villages along the Madang coast report that residents fled from Yomba Island 8-10 generations ago, when the island was destroyed by an eruption accompanied by a tsunami. The location of the former island is uncertain, but most informants placed it in the vicinity of the present-day Hankow Reef (Mennis, 1981), between Bagabag and Crown Islands, NW of Long Island. Binns et al. (2002) surveyed the area, locating two distinct seamounts as well as a caldera SW of the reef; they found no evidence for the existence of the legendary Yomba volcano.

Long Island
The broad profile of Long Island is dominated by two steep-sided stratovolcanoes, Mount Reaumur in the north and Cerisy Peak in the south. Collapse of the basaltic-andesitic volcanic complex produced a large 10 x 12.5 km caldera, now filled by Lake Wisdom. Caldera formation occurred during at least three major explosive eruptions, about 16,000, 4,000, and 300 years ago. The most recent deposited andesitic tephra across the New Guinea Highlands, prompting legends of a "Time of Darkness." Post-caldera eruptions have constructed a small cone, Motmot Island, in the south-central part of Lake Wisdom. Moderate explosive eruptions have occurred during the 20th century from vents at and near Motmot Island.

Umboi
Umboi Island, 50 km in its longest dimension, is the largest of the volcanic islands off the N coast of New Guinea. Dominantly basaltic-andesitic, it is comprised of several coalescing stratovolcanoes cut by a 13 x 17 km caldera whose walls rise up to 1 km above its floor. The caldera is widely breached to the sea on the NE side and contains three youthful post-caldera cones with summit crater lakes, Talo, Soal, and Barik. Talo, displays several thermal areas and has satellitic cones on its flanks. No historical eruptions have been reported, but activity of the post-caldera cones is thought to have continued until the last few hundred years (Johnson et al., 1972).

Ritter Island
Prior to 1888, Ritter Island was a steep-sided, nearly circular island about 780 m high between Umboi and Sakar Islands. Several historical explosive eruptions had been recorded prior to 1888, when large-scale slope failure destroyed the summit of the conical basaltic-andesitic volcano, leaving the arcuate 140-m-high island with a steep west-facing scarp. Devastating tsunamis were produced by the collapse and swept the coast of Papua New Guinea and offshore islands. Two minor post-collapse explosive eruptions, during 1972 and 1974, occurred offshore within the largely submarine 3.5 x 4.5 km breached depression formed by the collapse.

Sakar
Sakar is an incised stratovolcano with a summit crater lake. Deep valleys cut the flanks of the volcano, which is partially surrounded by coral reefs. An older volcano that forms much of the island consists mainly of porphyritic basaltic rocks. A younger andesitic cone with a 1.5-km-wide crater has been constructed within the larger old crater, whose rim is exposed on the N and E. No eruptions have been reported, but warm springs are found along the SW coast, and a pyroclastic cone on the southern flank of the 8 x 10 km island may be of Holocene age (Johnson, 1990 pers. comm.). A large submarine debris-avalanche deposit lies north of Sakar.

Langila
Langila, one of the most active volcanoes of New Britain, consists of a group of four small overlapping composite basaltic-andesitic cones on the lower E flank of the extinct Talawe volcano in the Cape Gloucester area of NW New Britain. A rectangular, 2.5-km-long crater is breached widely to the SE; Langila was constructed NE of the breached crater of Talawe. An extensive lava field reaches the coast on the N and NE sides of Langila. Frequent mild-to-moderate explosive eruptions, sometimes accompanied by lava flows, have been recorded since the 19th century from three active craters at the summit. The youngest and smallest crater (no. 3 crater) was formed in 1960 and has a diameter of 150 m.

Dakataua
The 10.5 x 13.5 km Dakataua caldera anchors the northern tip of the Willaumez Peninsula of New Britain. The latest episode of caldera formation occurred as recently as about 1,150 years ago, and was followed by at least five sub-Plinian or Vulcanian eruptions. A 12-km-wide freshwater lake whose surface is only about 50 m above sea level occupies the caldera. Two vertical fault-bounded blocks form topographic highs at the western and eastern sides of the caldera. A N-S line of post-caldera cones, explosion craters, and part of an arcuate inner caldera rim form a large peninsula that nearly bisects the arcuate caldera lake. The peninsula includes the 350-m-high andesitic Mount Makalia stratovolcano, the largest of the post-caldera cones, which last erupted during the late-19th century. A major submarine debris avalanche deposit NE of the volcano may represent edifice collapse prior to caldera formation. Thermal areas occur at several locations along the central peninsula.

Bola
Bola volcano (also known as Wangore) is a symmetrical stratovolcano located immediately SW of Dakataua caldera on the Willaumez Peninsula. The forested andesitic cone has a 400-m-wide crater with a 100-m-high eastern wall and a low western rim. Three large explosion craters occupy the NE flank. The most recent lava flow issued from the summit crater and flowed to the west. This viscous flow is at least 50 m thick, leaving an irregularity in the profile of the volcano. The summit crater morphology and weak fumarolic activity suggested to Lowder and Carmichael (1970) that the most recent eruption may have been only a few hundred years ago.

Garua Harbour
The Garua (Talasea) Harbour volcanic field consists of a group of lava domes and ash cones of possible Holocene age. These volcanic vents ring the harbor on the west and form Garua Island to the east. Much of the volcanic field, including the two lava domes on Garua Island, consists of rhyolitic rocks. Active hot springs ring the shores of Garua Harbour and are best developed on the north and south sides. Large boiling pools, fumaroles, and small geysers are found on the north shore near Pangalu village. Another large group of boiling pools, fumaroles, and mudpots is located near the Talasea Government Station on the south shore of the bay.

Lolo
Lolo is a nearly symmetrical andesitic stratovolcano, ~3.5 km in diameter, located N of Witori volcano along the N coast of New Britain near Cape Hoskins. It is of very late Pleistocene or Holocene age and overlaps the older Kapberg volcano to the west (Blake and McDougall, 1973). Lava flows are prominent on its flanks, and a well-preserved crater 250 m wide and 60 m deep truncates the summit.

Krummel-Garbuna-Welcker
The basaltic-to-dacitic Krummel-Garbuna-Welcker Volcanic Complex consists of three volcanic peaks located along a 7-km N-S line above a shield-like foundation at the southern end of the Willaumez Peninsula. The central and lower peaks of the centrally located Garbuna contain a large vegetation-free area that is probably the most extensive thermal field in Papua New Guinea. A prominent lava dome and blocky lava flow in the center of thermal area have resisted destruction by thermal activity, and may be of Holocene age. Krummel volcano at the south end of the group contains a summit crater, breached to the NW. The highest peak of the group is Welcker volcano, which has fed blocky lava flows that extend to the eastern coast of the peninsula. The last major eruption from both it and Garbuna volcanoes took place about 1800 years ago. The first historical eruption took place at Garbuna in October 2005.

Witori
The active Pago cone has grown within the Witori caldera (5.5 x 7.5 km) on the northern coast of central New Britain contains the active Pago cone. The gently sloping outer caldera flanks consist primarily of dacitic pyroclastic-flow and airfall deposits produced during a series of five major explosive eruptions from about 5,600 to 1,200 years ago, many of which may have been associated with caldera formation. Pago cone may have formed less than 350 years ago; it has grown to a height above the caldera rim, and a series of ten dacitic lava flows from it covers much of the caldera floor. The youngest of these was erupted during 2002-2003 from vents extending from the summit nearly to the NW caldera wall. The Buru caldera cuts the SW flank.

Sulu Range
The Sulu Range consists of a cluster of partially overlapping small stratovolcanoes and lava domes in north-central New Britain off Bangula Bay. The 610-m Mount Malopu at the southern end forms the high point of the basaltic-to-rhyolitic complex. Kaiamu maar forms a peninsula with a small lake extending about 1 km into Bangula Bay at the NW side of the Sulu Range. The Walo hydrothermal area, consisting of solfataras and mud pots, lies on the coastal plain west of the SW base of the Sulu Range. No historical eruptions are known from the Sulu Range, although some of the cones display a relatively undissected morphology. A vigorous new fumarolic vent opened in 2006, preceded by vegetation die-off, seismicity, and dust-producing landslides.

Hargy
This little-known volcano is one of several major calderas on the island of New Britain. The 10 x 12 km Hargy caldera, whose floor is 150 m above sea level, contains an inner caldera with a steep west-facing wall. A caldera lake on the SE side drains through a narrow gap in the northern caldera wall. The latest caldera-forming eruption of Hargy volcano took place about 11,000 years ago. The dacitic Galloseulo lava cone rises above and partially overtops the western rim of the caldera. A double crater occupies a larger 700-m-wide crater. Numerous small eruptions have taken place at Galloseulo over the past 7000 years, the last occurring about 1000 years ago.

Bamus
Symmetrical Bamus volcano, also referred to locally as the South Son, is located SW of Ulawun volcano, known as the Father. The andesitic stratovolcano is covered in rainforest and contains a breached summit crater filled with a lava dome. There is a cone on the southern flank, and a prominent 1.5-km-wide crater with two small adjacent cones halfway up the SE flank. Young pyroclastic-flow deposits are found on the flanks, and residents describe an eruption that took place during the late 19th century.

Ulawun
The symmetrical basaltic-to-andesitic Ulawun stratovolcano is the highest volcano of the Bismarck arc, and one of Papua New Guinea's most frequently active. The volcano, also known as the Father, rises above the N coast of the island of New Britain across a low saddle NE of Bamus volcano, the South Son. The upper 1,000 m is unvegetated. A prominent E-W escarpment on the south may be the result of large-scale slumping. Satellitic cones occupy the NW and E flanks. A steep-walled valley cuts the NW side, and a flank lava-flow complex lies to the south of this valley. Historical eruptions date back to the beginning of the 18th century. Twentieth-century eruptions were mildly explosive until 1967, but after 1970 several larger eruptions produced lava flows and basaltic pyroclastic flows, greatly modifying the summit crater.

Lolobau
Lolobau volcano has grown over the W rim of a 6-km-wide caldera which formed about 12,000 years ago. The 8 x 13 km island is located just off the coast of eastern New Britain. A small lake occupies the SW part of the caldera. A small lava dome (Hulu) caps Mount Lolobau, which has a 0.8 x 1.1 km summit crater breached to the NE. Flank cones are found along the coast of the largely submerged volcano. Several vents within the caldera, on the E flank of the main edifice, have been active during historical time. The latest eruptions took place during the early 20th century.

Rabaul
The low-lying Rabaul caldera on the tip of the Gazelle Peninsula at the NE end of New Britain forms a broad sheltered harbor utilized by what was the island's largest city prior to a major eruption in 1994. The outer flanks of the asymmetrical shield volcano are formed by thick pyroclastic-flow deposits. The 8 x 14 km caldera is widely breached on the east, where its floor is flooded by Blanche Bay and was formed about 1,400 years ago. An earlier caldera-forming eruption about 7,100 years ago is thought to have originated from Tavui caldera, offshore to the north. Three small stratovolcanoes lie outside the N and NE caldera rims. Post-caldera eruptions built basaltic-to-dacitic pyroclastic cones on the caldera floor near the NE and W caldera walls. Several of these, including Vulcan cone, which was formed during a large eruption in 1878, have produced major explosive activity during historical time. A powerful explosive eruption in 1994 occurred simultaneously from Vulcan and Tavurvur volcanoes and forced the temporary abandonment of Rabaul city.

Tavui
The mostly submarine Tavui caldera lies off the NE tip of the Gazelle Peninsula north of Rabaul caldera. The caldera was first discovered during a bathymetric cruise in 1985. The SW wall of the roughly 10 x 12 km caldera cuts the NE end of the peninsula and extends from Tavui Point at the northern tip of the peninsula SE to Laweo Point. The 7,100-year-old Raluan Ignimbrite, initially thought to have originated from Rabaul, is now thought to have been produced by an eruption of Tavui. A basaltic scoria layer immediately underlies the rhyolitic ignimbrite, and the introduction of basaltic magma was considered to have triggered the rhyolitic eruption. The lack of a major low-velocity region detectable beneath the caldera during a seismic tomography survey suggests that it is not currently active.

Trobriand Volcanic Province

Hydrographers Range
Trobriand Volcanic Province
Latitude: 9°S
The Hydrographers Range is a forested, deeply dissected andesitic volcanic massif extending from the eastern margin of Mount Lamington north to the coast of eastern Papua New Guinea. Most activity took place during the Pleistocene, but perfectly preserved cinder cones and explosion craters on the southern side of the range suggested that some activity took place during the Holocene (Taylor, 1958). Other well-preserved cones are situated in the high country overlooking Songade village on the coast.

Lamington
Trobriand Volcanic Province
Lamington is an andesitic stratovolcano with a 1.3-km-wide breached summit crater containing a lava dome that rises above the coastal plain of the Papuan Peninsula of New Guinea north of the Owen Stanley Range. A summit complex of lava domes and crater remnants tops a low-angle base of volcaniclastic deposits dissected by radial valleys. A prominent broad "avalanche valley" extends northward from the breached crater. Ash layers from two early Holocene eruptions have been identified. In 1951 a powerful explosive eruption produced pyroclastic flows and surges that swept all sides of the volcano, killing nearly 3,000 people. The eruption concluded with growth of a 560-m-high lava dome in the summit crater.

Managlase Plateau
Thirty small volcanic centers of late-Pleistocene to Holocene age are located in SE Papua New Guinea on the Managlase Plateau, south of the Hydrographers Range and SW of the Dyke Ackland Bay. The fault-bounded plateau forms a triangular-shaped area with trachybasaltic lava cones and flows, scoria mounds, cinder cones, and explosion vents of the Uoivi Volcanics, and capped on its eastern side by rhyodacitic ash cones, lava domes, and ashflow deposits of the Manna Volcanics. The date of the most recent eruption is not known, but the trachybasaltic Kururui cinder cone and a nearby explosion crater were active within memory of nearby residents (Ruxton, 1966).

Victory
The dominantly andesitic Mount Victory stratovolcano, forming part of Cape Nelson on the NE coast of Papua New Guinea, is covered by rainforest. The deeply dissected Pleistocene Trafalgar volcano is immediately adjacent to the NE. The summit crater is breached to the SE, possibly due to landslides. Several lava domes are present in the summit area. Four small cones are located on the SW side, and two others occur on the NE flank. The only observed activity was a long-term late-19th to early 20th-century eruption that was frequently seen by passing ships. Pyroclastic flows have destroyed several villages and caused fatalities, and reached the coast.

Goodenough
Goodenough is a roughly circular volcanic island that is the westernmost of the D'Entrecasteaux Islands off the NE tip of Papua New Guinea. Several basaltic andesite and andesitic Holocene eruptive centers are located around the margins of fault-bounded metamorphic rocks that form the central part the island. The youngest volcanic features, which include the Walilagi Cones, are located at the SE end of the island. These well-developed ash cones and blocky lava flows on the N and E flanks of the Bwaido Peninsula may have erupted within the past few hundred years.

Sessagara Hills
The small low-lying andesitic Sessagara Hills volcanic field is located near the mouth of the Uiaka River, south of Collingwood Bay and NE of the Goropu Mountains on the Papuan Peninsula of New Guinea. There are at least two small forest-covered cones, with a small cone and obvious crater ~5 km NE of them and the Waiowa cone ~6 km W. Besides Waiowa (also known as Goropu), Smith (1981) considered some other features in the field to be Holocene; other cones may be of Pleistocene age. The Waiowa pyroclastic cone was formed during 1943-44 by explosive eruptions through Paleozoic to Precambrian metamorphic rocks. Intermittent minor explosions beginning on 18 September 1943 preceded the first major explosion on 27 December. Additional large explosions occurred on 13 February and 23 July 1944, leveling 80 km2 of forest. Following the final activity on 31 August, the small cone included a 500-m-wide, steep-walled crater that later became densely forested and contains a small lake.

Iamalele
Multiple volcanic features and active thermal areas are located on the SW part of Fergusson Island, in the center of the D'Entrecasteaux island group. The Iamalele-Fagululu area contains a series of lava domes and lava flows of probable Holocene age in association with abundant hot springs and fumaroles (Smith, 1981). Two small lava domes are located near Fagululu village, the larger of which is a flat-topped, obsidian-bearing rhyolitic dome. Six other lava domes are clustered around Salt Lake on the W side of the area. Hot springs, boiling springs, fumaroles, and mud pools are found in an area of siliceous sinter near Iamalele village.

Dawson Strait Group
The Dawson Straits, located between eastern Fergusson and western Normanby Islands in the D'Entrecasteaux island group, contains a volcanic field with several centers that define a possible partly submerged caldera. There have been no historical eruptions, but morphology suggests an extremely young age for some lava flows, and the area displays vigorous thermal activity. The most prominent volcanic centers are Mounts Lamonai and Oiau, located about 10 km apart on the SW tip of Fergusson Island. The summit of Lamonai is capped by a steep-walled crater, and rhyolitic lava flows are exposed on the NE side of the cone. The dominantly volcaniclastic Oiau cone has also produced obsidian lava flows. Dobu Island to the south is formed of coalescing volcanic centers and likewise has produced youthful rhyolitic obsidian flows.

Bougainville Volcanic Arc

Billy Mitchell
Bougainville Volcanic Arc
Billy Mitchell, a small pyroclastic shield immediately NE of Bagana volcano, has produced some of the largest Holocene eruptions in Papua New Guinea. The andesitic-to-dacitic volcano is truncated by a 2-km-wide caldera containing a shallow lake with a small island near its S shore. Two major explosive eruptions, one about 900 years ago and the other about 370 years ago, produced dacitic pyroclastic-fall deposits that cover most of the northern half of Bougainville Island. The younger eruption may have been responsible for formation of the nearly vertical, steep-walled summit caldera. Pyroclastic-flow and -surge deposits extend 25 km to the E coast of Bougainville Island.

Balbi
Bougainville Volcanic Arc
The complex andesitic Balbi stratovolcano on Bougainville Island includes a large number of coalesced cones and lava domes. Five well-preserved craters occupy a NW-SE-trending ridge north of the summit cone, which also contains a crater. Three large valleys with steep headwalls dissect the flanks. The age of the most recent eruption is not known precisely. An oral tradition of a major eruption during the 19th century is thought to be in error, but could refer to minor eruptive activity. Fumaroles are located within 600-m-wide Crater B and on its W flank.

Takuan Group
The Takuan volcano group in southern Bougainville Island consists of three closely spaced, NW-SE-trending andesitic-dacitic stratovolcanoes. Two of these are relatively uneroded and have probably been active during the Holocene, and a third, extensively eroded volcano is probably Pleistocene in age (Blake and Meizitis, 1967). Along with Loloru volcano, the Takuan volcanoes are post-caldera cones constructed along the rim of the Pleistocene Laluai caldera. The 2210-m NW-most volcano, Mount Takuan, is the highest of the group and is a lava cone that has fed viscous lavas flows to the south, similar to those at Bagana volcano. The central volcano contains a large lava dome in its breached summit crater; this dome may represent the most recent activity of the Takuan volcano group. Older, but still well-preserved lava flows are found on the flanks of this volcano.

Bagana
Volcano type: Lava cone
Bagana volcano, in a remote portion of central Bougainville Island, is frequently active. This massive symmetrical cone was largely constructed by an accumulation of viscous andesitic lava flows. The entire edifice could have been constructed in about 300 years at its present rate of lava production. Eruptive activity is characterized by non-explosive effusion of viscous lava that maintains a small lava dome in the summit crater, although occasional explosive activity produces pyroclastic flows. Lava flows with tongue-shaped lobes up to 50 m thick and prominent levees descend the flanks on all sides.

Loloru
Loloru, the SE-most volcano on Bougainville Island, is the source of a broad ignimbrite apron that covers much of the southern part of the island. The summit consists of two nested calderas, and a forested andesitic lava dome that restricts a crescent-shaped lake to the eastern side of the younger caldera. The smooth flanks of the pyroclastic shield are dissected by radiating deep valleys. A pristine lava flow occurs on the SE flank. Loloru is constructed within the 10 x 15 km Pleistocene Laluai caldera. The topographically higher Taroka group of volcanoes to the NW and the Takuan group to the north also were constructed within the caldera and deflected the bulk of Loloru ignimbrites to the south. The most recent of several major Holocene explosive eruptions took place about 3,000 years ago.

Solomon Volcanic Province

Kana Keoki
Solomon Islands
Solomon Volcanic Province
Bathymetry and petrologic evidence indicated the presence of an active dacitic submarine volcano SW of Rendova Island (Taylor, 1987). Kana Keoki Seamount, located along the Ghizo Ridge south of the convergent margin between the Indo-Australian and Pacific plates, rises to within about 700 m of the surface from a depth of 3,700 m and is surrounded by a volcaniclastic apron.

Coleman Seamount
Solomon Islands
Solomon Volcanic Province
The research vessel "Moana Wave" (University of Hawaii) discovered a young submarine volcano SE of Kana Keoki seamount during a November 1985 to January 1986 cruise. The volcano, named Coleman Seamount, was constructed over the E end of the inactive Woodlark spreading center, S of the convergent boundary between the Indo-Australian and Pacific plates.

Simbo
Solomon Islands
Simbo is a small island in the western Solomons with three truncated andesitic volcanic centers. The only Potassium-Argon date (2.3 +/- 1 million years ago from Mount Patukio) suggests a Pliocene-to-Pleistocene age for the island (Solomon Islands Geological Survey, 1982). The southern half of the island is thermally active. It contains fault-related fumarolic areas and hot springs near saltwater Lake Ove along the western coast and along the eastern coast near Mount Patukio, which has a steep-walled summit crater. Grover (1955) noted native accounts of the explosive enlargement of the Ngusunu explosion crater along the SW coast of the island one to two generations prior to 1955, probably after a visit by Guppy in 1882. Press reports mentioned an eruption in the early 1900s that forced the evacuation of villages beside Lake Ove, immediately adjacent to Ngusunu crater.

New Georgia at 8.9�S
An unnamed seamount was mapped during a 1979 cruise about 9 km NE of Kavachi (Okugrin, 1985), near the SE end of the New Georgia Islands at about 8.9�S. The seamount appeared to have been recently active, with porphyritic and aphyric andesitic rocks dredged from that location. Another seamount 7 km NW of Kavachi was capped by corals, and a small peak was noted on the SW flank of the seamount (see map after Okugrin, 1985, in Exon and Johnson, 1986).

Kavachi
Named for a sea-god of the Gatokae and Vangunu peoples, Kavachi is located in the Solomon Islands south of Vangunu Island. Sometimes referred to as Rejo te Kvachi ("Kavachi's Oven"), this shallow submarine basaltic-to-andesitic volcano has produced ephemeral islands up to 1 km long many times since its first recorded eruption during 1939. Residents of the nearby islands of Vanguna and Nggatokae (Gatokae) reported "fire on the water" prior to 1939, a possible reference to earlier eruptions. The roughly conical edifice rises from water depths of 1.1-1.2 km on the north and greater depths to the SE. Frequent shallow submarine and occasional subaerial eruptions produce phreatomagmatic explosions that eject steam, ash, and incandescent bombs. On a number of occasions lava flows were observed on the ephemeral islands.

Savo
The 6 x 7 km island of Savo, off the NE coast of Guadalcanal Island, consists of a forested andesitic-to-dacitic stratovolcano with a shallow, elliptical 1 x 1.5 km summit crater. Young lava domes are located on the crater floor and the NE rim, and older domes occur on the flanks. Pyroclastic flows and mudflows traveled down valleys from the summit crater to form debris fans along the coast. Thermal areas located in the summit crater, the S to SE flanks, and offshore include areas of steaming ground, fumaroles, small geysers, and hot springs. Spanish explorers observed the first recorded eruption in 1568. Pyroclastic flows during the climactic phase killed almost all inhabitants of the island, and oral traditions also note the expansion of the island on the northern side. Other eruptive episodes occurred during the mid-17th century and during the 1830s to 1840s.

Vanuatu Volcanic Arc

Tinakula
Vanuatu Volcanic Arc
The small 3.5-km-wide island of Tinakula is the exposed summit of a massive stratovolcano at the NW end of the Santa Cruz islands. It has a breached summit crater that extends from the summit to below sea level. Landslides enlarged this scarp in 1965, creating an embayment on the NW coast. The Mendana cone is located on the SE side. The dominantly andesitic volcano has frequently been observed in eruption since the era of Spanish exploration began in 1595. In about 1840 an explosive eruption apparently produced pyroclastic flows that swept all sides of the island, killing its inhabitants. Recorded eruptions have frequently originated from a cone constructed within the large breached crater. These have left the upper flanks and the steep apron of lava flows and volcaniclastic debris within the breach unvegetated.

Motlav
Vanuatu
Vanuatu Volcanic Arc
The elongated island of Motlav, also referred to as Mota Lava, is comprised of at least five Pleistocene basaltic stratovolcanoes capped by two well-preserved late-Pleistocene to Holocene pyroclastic cones, Tuntog and Vetnam. Tuntog is a largely pyroclastic composite cone at the SW end of the island with a 500-m-wide summit crater. Vetman, in the center of the island, is a pyroclastic cone truncated by a summit crater that is breached on the southern side. The 411-m high point of Motlav is a remnant of older volcanics along the central ridge of the 12-km-long, NE-SW-trending island.

Suretamatai
Vanuatu
Suretamatai volcano (also known as Soritimeat) forms much of Vanua Lava Island, one of the largest of Vanuatu's Banks Islands. The younger lavas overlie a number of small older stratovolcanoes that form the island. In contrast to other large volcanoes of Vanuatu, the dominantly basaltic-to-andesitic Suretamatai does not contain a youthful summit caldera. A chain of small stratovolcanoes oriented along a NNE-SSW line gives the low-angle volcano an irregular profile. The youngest cone, near the northern end of the chain, is the largest and contains a lake of variable depth within its 900-m-wide, 100-m-deep summit crater. Activity reported during the 19th century consisted of moderate explosive eruptions.

Gaua
Vanuatu
The roughly 20-km-diameter Gaua Island, also known as Santa Maria, consists of a basaltic-to-andesitic stratovolcano with an 6 x 9 km summit caldera. Small vents near the caldera rim fed Pleistocene lava flows that reached the coast on several sides of the island; littoral cones were formed where these lava flows reached the ocean. Quiet collapse that formed the roughly 700-m-deep caldera was followed by extensive ash eruptions. The active Mount Garet (or Garat) cone in the SW part of the caldera has three pit craters across the summit area. Construction of Garet and other small cinder cones has left a crescent-shaped lake. Eruptions have been frequent since the onset of activity from a vent high on the SE flank in 1962.

Ambae
The island of Ambae, also known as Aoba, is a massive 2,500 km3 basaltic shield that is the most voluminous volcano of the New Hebrides archipelago. A pronounced NE-SW-trending rift zone with numerous scoria cones gives the 16 x 38 km island an elongated form. A broad pyroclastic cone containing three crater lakes (Manaro Ngoru, Voui, and Manaro Lakua) is located at the summit within the youngest of at least two nested calderas, the largest of which is 6 km in diameter. That large central edifice is also called Manaro Voui or Lombenben volcano. Post-caldera explosive eruptions formed the summit craters about 360 years ago. A tuff cone was constructed within Lake Voui (or Vui) about 60 years later. The latest known flank eruption, about 300 years ago, destroyed the population of the Nduindui area near the western coast.

Ambrym
Volcano type: Shield(pyroclastic)
Ambrym is a large basaltic volcano with a 12-km-wide caldera formed during a major Plinian eruption with dacitic pyroclastic flows about 1,900 years ago. A thick, almost exclusively pyroclastic sequence, initially dacitic then basaltic, overlies lava flows of a pre-caldera shield volcano. Post-caldera eruptions, primarily from Marum and Benbow cones, have partially filled the caldera floor and produced lava flows that ponded on the floor or overflowed through gaps in the caldera rim. Post-caldera eruptions have also formed a series of scoria cones and maars along a fissure system oriented ENE-WSW. Eruptions have been frequently reported since 1774, though mostly limited to extra-caldera eruptions that would have affected local populations. Since 1950 observations of eruptive activity from cones within the caldera or from flank vents have occurred almost yearly.

Lopevi
The small 7-km-wide conical island of Lopevi, known locally as Vanei Vollohulu, is one of Vanuatu's most active volcanoes. A small summit crater containing a cinder cone is breached to the NW and tops an older cone that is rimmed by the remnant of a larger crater. The basaltic-to-andesitic volcano has been active during historical time at both summit and flank vents, primarily along a NW-SE-trending fissure that cuts across the island, producing moderate explosive eruptions and lava flows that reached the coast. Historical eruptions at the 1413-m-high volcano date back to the mid-19th century. The island was evacuated following major eruptions in 1939 and 1960. The latter eruption, from a NW-flank fissure vent, produced a pyroclastic flow that swept to the sea and a lava flow that formed a new peninsula on the western coast.

East Epi
The submarine East Epi group of basaltic and dacitic cones are located within a possible 10-km-diameter caldera off the NE coast of southern Epi Island in Vanuatu. Three cones (1-1.5 basal diameter), known as Epi A, Epi B (or Cioan), and Epi C, are located along the northern rim of the inferred caldera, though Beier et al. (2018) suggest an alternate to the post-caldera formation model. A few smaller cones are south of Epi B. Ephemeral islands were formed during eruptions at Epi B in 1920 and 1953. Explosive activity was reported in 1958 and 1960, discolored water was often seen during 1971-1974 and 1988, a new vent was detected in 1979, and explosive activity occurred in 1999, 2002, 2004, and 2023. The summit was at 34 m below sea level at the time of a 2001 survey, and a research cruise in 2013 (R/V Sonne SO-229; Haase et al, 2013) sampled six cones, including "very fresh pumice and lava bombs" from Epi B and "relatively old-looking" material from the others. The SO-229 cruise also recovered rhyodacitic pumice with mafic streaks, similar to that sampled by previous cruises, and described Epi B as "covered by massive blocks of pumice."

Kuwae
The largely submarine Kuwae caldera occupies the area between Epi and Tongoa islands. The 6 x 12 km caldera contains two basins that cut the NW end of Tongoa Island and the flank of the Tavani Ruru volcano on the SE peninsula of Epi Island. Native legends and radiocarbon dates from pyroclastic-flow deposits have been correlated with a 1452 CE ice-core peak thought to be associated with collapse of Kuwae caldera; however, others considered the deposits to be of smaller-scale eruptions and the ice-core peak to be associated with another unknown major South Pacific eruption. The submarine Karua cone in the east-central part of the caldera has formed several ephemeral islands since it was first observed in eruption during 1897.

Nguna-Emau
The islands of Nguna, Pele, and Emau (or Emao), north of Efat� Island (also known as Vate), have been variously mapped as Pleistocene and Pleistocene to Holocene. Eruptions in the late Pleistocene to Holocene constructed composite basaltic cones with well-preserved craters. Largely submarine calderas of varying sizes have been inferred towards the north, ranging from a large caldera whose southern rim is defined by Nguna, Pele, and Emao to a smaller caldera, but their submarine morphology is difficult to define. Pumiceous deposits of the Efat� Pumice Formation cover much of Efat� island and record a major trachydacitic explosive eruption about 1 million years ago that originated from a submarine vent somewhere north of the island.

Traitor's Head
The Traitor's Head peninsula north of Cook Bay on eastern Erromango Island is comprised of three Holocene volcanic cones that are the youngest on the 50-km-long island. Mounts Rantop, Nagat, and Oulenou are small basaltic-to-andesitic stratovolcanoes with well-preserved morphologies. Rantop is the largest, but Oulenou is the most youthful looking, with an unbreached crater. A low plateau to the NW is underlain by ash deposits distributed by southeasterly trade winds. The volcanoes initially formed an offshore island that was joined to the mainland by uplift after volcanism ceased. A submarine vent offshore between the tip of the peninsula and Goat Island, 5 km to the NE, erupted in 1881, the only recorded activity of the Erromango volcanoes.

Yasur
Yasur has exhibited essentially continuous Strombolian and Vulcanian activity at least since Captain Cook observed ash eruptions in 1774. This style of activity may have continued for the past 800 years. Located at the SE tip of Tanna Island in Vanuatu, this pyroclastic cone has a nearly circular, 400-m-wide summit crater. The active cone is largely contained within the small Yenkahe caldera, and is the youngest of a group of Holocene volcanic centers constructed over the down-dropped NE flank of the Pleistocene Tukosmeru volcano. The Yenkahe horst is located within the Siwi ring fracture, a 4-km-wide open feature associated with eruption of the andesitic Siwi pyroclastic sequence. Active tectonism along the Yenkahe horst accompanying eruptions has raised Port Resolution harbor more than 20 m during the past century.

Gemini-Oscostar
The submarine Gemini-Oscostar volcanic field lies near the southern end of the Vanuatu (or New Hebrides) Volcanic Arc, ~100 km S of Aneityum Island. Water discoloration and bursts of very dark water were observed from Oscostar seamount (also known as Eastern Gemini) from a passing ship on 18 February 1996. Overflights as late as 22 February noted periodic explosions that ejected black material to about 20 m above sea level. It consists of an elongated NNE-SSW-trending ridge of submarine volcanoes with satellitic cones. Several basaltic samples and one andesitic rock dredged in 1989 were described as glassy, vesicular, and extremely fresh.

Matthew Island
France - claimed by Vanuatu
Matthew Island is composed of two low andesitic-to-dacitic cones separated by a narrow isthmus. The Matthew name originates from an English mariner who sighted the island in 1788. Only the triangular eastern portion of the 0.6 x 1.2 km island was present prior to the 1940s, when construction of the larger western segment began; it consists primarily of lava flows. The western cone contains a crater that is breached to the NW and is filled by a lava flow whose terminus forms the NW coast.

Hunter Island
France - claimed by Vanuatu
Hunter Island, the SE-most volcano of the New Hebrides arc, is a 1-km-wide island consisting of a composite andesitic-to-dacitic cone topped by explosion craters and a lava dome. The island was named after the English trading ship that reported sighting it in 1798. A 100-m-deep, steep-sided crater occupies the NW part of the island, which contrasts with the southern cone, whose summit is filled by a lava dome. Several poorly documented eruptions have been noted since the 19th century. Large streams of lava were reported to be pouring from two craters on the eastern side of the island in 1895; the latest eruption apparently took place from the northern tip. Fumarolic and solfataric areas are located at the northern tip of the island and the NE and SE coasts.

Fiji Volcanic Arc

Taveuni
Fiji
Fiji Volcanic Arc
Taveuni, the third largest of the Fiji islands, is known as the "Garden Island" due to its rich volcanic soils. The massive, elongated basaltic shield volcano includes approximately 150 volcanic cones along a NE-SW rift that extends the length of the 40-km-long island. A few cones in the central part occur to the west of the axial rift zone. At least 58 eruptions have occurred since the first known human settlements around 950-750 BCE; all of these eruptions affected the southern two-thirds of the island. A period of voluminous eruptions between about 300 and 500 CE caused abandonment of the southern part the island until about 1100 CE. The latest known eruption produced a lava flow at the southern tip sometime between about 1450 and 1650 CE.

Nabukelevu
Fiji
Fiji Volcanic Arc
The andesitic-to-dacitic Nabukelevu lava-dome complex occupies the SW end of Kadavu Island at the S end of the Fiji archipelago. The high point of the complex is Mt. Washington, an andesitic lava dome. Flat-lying dacitic lava flows are found at Cape Washington along the W coast and at Talaulia Bay on the NE coast. NNE-trending faults cut the complex in several locations and define its E boundary. The dome complex is cut by several collapse scarps, which were the source of debris avalanches that have incorporated human artifacts and remains. Debris avalanches have entered the sea on the both the N and S sides of the volcano. Onshore and offshore deposits as well as native legends indicate that several eruptions have occurred during the Holocene. Block-and-ash flows related to dome growth have occurred within the past few hundred years.

Tonga-Kermadec Volcanic Regions

Northeast Lau Basin Volcano Group

Niuafo'ou
Tonga
Northeast Lau Basin Volcano Group
Niuafo'ou ("Tin Can Island") is a low 8-km-wide island that forms the summit of a largely submerged basaltic shield volcano in the north central Lau Basin about 170 km W of the northern end of the Tofua volcanic arc. The circular island encloses a 5-km-wide caldera that is mostly filled by a lake whose bottom extends to below sea level. The inner walls of the caldera drop sharply to the lake, named Big Lake (or Vai Lahi), which contains several small islands and pyroclastic cones on its NE shore. Eruptions recorded since 1814, mostly from circumferential fissures on the west-to-south side of the island, have often damaged villages. A major eruption in 1946 forced evacuation of most of its 1,200 inhabitants.

Tafu-Maka
Tonga
Northeast Lau Basin Volcano Group
Two submarine volcanoes, Tafu and Maka, lie along a NE-SW-trending ridge segment in the southern part of the NE Lau Spreading Center (NELSC). The NELSC is a back-arc spreading center in the northeast part of the Lau Basin. Tafu (Tongan for "source of fire") rises to about 1,400 m below sea level at the NE end of the ridge segment, and Maka (Tongan for "rock") reaches 1,560 m below sea level at the SW end. A November 2008 NOAA Vents Program expedition discovered submarine hydrothermal plumes consistent with very recent (days to weeks?) lava effusion from Maka; a return visit in May 2009 documented the freshly emplaced lava flow.

West Mata
Tonga
West Mata, a submarine volcano rising to within 1,174 m of the ocean surface, is located in the northeastern Lau Basin at the northern end of the Tofua arc, about 200 km SW of Samoa and north of the Curacoa submarine volcano. Discovered during a November 2008 NOAA Vents Program expedition it was found to be producing submarine hydrothermal plumes consistent with recent lava effusion. A return visit in May 2009 documented explosive and effusive activity from two closely spaced vents, one at the summit, and the other on the SW rift zone.

Niuatahi
Niuatahi is a nearly circular caldera ~15 km in diameter, with a floor at a depth of about 2 km (Arculus, 2012). A young cone (Motu Tahi) in the SE sector rises 730 m above the floor to a summit depth of about 1,270 m. The volcano is in the Northeast Lau Basin, ~40 km W of the edifices along the Tofua Volcanic Arc, and 25 km E of the central ridge of the Northeast Lau Spreading Center. The composition of the cone and surrounding floor is predominantly dacite. Towing with seafloor cameras over the cone and various parts of the caldera in 2012 resulted in the discovery of at least three sources of hydrothermal particle venting on the cone's summit and adjacent to the inner caldera walls. The Tonga Ministry of Lands, Environment, Climate Change and Natural Resources named the volcano Niuatahi, which means 'sea' in Tongan, with the small cone of Motutahi meaning 'island in the sea'; it had previously been given an unofficial research cruise designation of "Volcano O."

Dugong
This volcano was discovered during an Australian research cruise in 2008. The overall edifice is 45 km in diameter, with a 5-km-diameter summit caldera.

Lobster
Active hydrothermal venting was noted when this volcano was first discovered in 2008 by an Australian research expedition.

Tofua Volcanic Arc

Tofua Arc at 21.1�S
Tofua Volcanic Arc
A large submarine volcano rises to within 65 m of the ocean surface west of Tongatapu Island. The volcano was informally named Volcano 1 by scientists on the bathymetric survey that mapped it in 2003. The summit of the andesitic-to-dacitic seamount is cut by a large 4.5 x 7 km caldera, with two young scoria cones forming the high point. A chain of explosion craters up to 100 m deep cut the flank of one of the scoria cones, and thick deposits of ash and scoria cover the caldera floor nearby. The lack of organic sediments between volcaniclastic deposits exposed in one portion of the caldera wall suggest it was constructed within the past 200 years. Diffuse low-temperature hydrothermal vents and vigorous gas discharge occurs near the explosion craters.

Tofua Arc at 21.3�S
Tofua Volcanic Arc
During a submarine eruption in 1907 pyroclastic material was ejected to 100 m above the ocean surface, and pumice rafts were produced. The eruption was located (on Admiralty Chart 2421) ~48 km SW of Tongatapu Island. The location given in this catalog has been shifted 5 km N relative to the 1907 report, to a seamount that rises to within 100 m of the ocean surface, because the previous spot corresponds to sloping terrain at 1,800 m depth on a 1982 bathymetric map. A second eruption from this area was reported in late 1932. This seamount may be the SE part of a larger edifice extending about 15 km NW, informally designated as "Volcano 2" (R/V Sonne 167 survey).

Tofua Arc at 20.9�S
An unnamed submarine volcano is located along the Tofua Volcanic Arc 35 km NW of the Niu Aunofo lighthouse on Tongatapu Island. The first documented eruptions took place in 1911 and 1923; an ephemeral island was formed in 1999. A submarine eruption in January 2017 produced discolored water visible in satellite imagery.

Hunga Tonga-Hunga Ha'apai
The small andesitic islands of Hunga Tonga and Hunga Ha'apai are part of the western and northern remnants of the rim (~6 km diameter) of a largely submarine caldera located about 30 km SSE of Falcon Island. The topmost sequence of welded and unwelded ignimbrite units from a caldera-forming eruption was 14C dated to 1040-1180 CE (Cronin et al., 2017; Brenna et al. 2022). At least two additional welded pumice-rich ignimbrite units and nonwelded pyroclastic flow deposits, below paleosols and other volcaniclastic deposits, indicated more very large previous eruptions (Cronin et al., 2017; Brenna et al. 2022). Several submarine eruptions have occurred at this caldera system since the first recorded eruption in 1912, including 1937 and S of the islands in 1988. A short eruption in 2009 added land to Hunga Ha'apai. At that time the two islands were each about 2 km long, displaying inward-facing sea cliffs with lava and tephra layers dipping gently away from the caldera. An eruption during December 2014-January 2015 was centered between the islands, and combined them into one larger structure. Major explosive eruptions in late 2021 initially reshaped the central part of the combined island before stronger activity in mid-January 2022 removed most of the 2014-15 material; an even larger eruption the next day sent an eruption plume high into the stratosphere, triggered shock waves through the atmosphere and tsunami across the Pacific Ocean, and left only small remnants of the islands above the ocean surface.

Fonuafo'ou
The ephemeral Fonuafo'ou island in the central part of the Tonga Islands is also known as Falcon Island, named after the British vessel H.M.S. Falcon, which reported a shoal in 1865. Islands up to 6 km long were formed in 1885 and 1927 eruptions; in 1933 the island had a height of more than 145 m. Passing ships often reported "smoke" issuing from the site. The latest explosive activity was reported in 1936. By 1949 the island had eroded beneath sea level, but the summit remains at shallow depths.

Kao
The symmetrical Kao rises steeply from the ocean about 6 km N of Tofua Island in Tonga. It is elongated NNE-SSW and, with the exception of a small flat area on the SSW coast, rises at angles exceeding 35� to the summit, which has a series of small coalescing craters. The lower flanks of the basaltic andesite volcano are densely jungled, but the upper slopes are almost vegetation free. There are no fresh-looking lava flows, although the absence of sufficient time for erosion to produce deep gullies or high sea cliffs suggests a very recent origin. A missionary on a ship anchored at Tofua reported that "smoke" was "pouring forth" from Kao on 10 July 1847.

Tofua
The low, forested Tofua Island in the central part of the Tonga Islands group is the emergent summit of a large stratovolcano that was seen in eruption by Captain Cook in 1774. The summit contains a 5-km-wide caldera whose walls drop steeply about 500 m. Three post-caldera cones were constructed at the northern end of a cold fresh-water caldera lake, whose surface lies only 30 m above sea level. The easternmost cone has three craters and produced young basaltic andesite lava flows, some of which traveled into the caldera lake. The largest and northernmost of the cones, Lofia, has a steep-sided crater that is 70 m wide and 120 m deep and has been the source of historical eruptions, first reported in the 18th century. The fumarolically active crater of Lofia has a flat floor formed by a ponded lava flow.

Lateiki
Lateiki, previously known as Metis Shoal, is a submarine volcano midway between the islands of Kao and Late that has produced a series of ephemeral islands since the first confirmed activity in the mid-19th century. An island, perhaps not in eruption, was reported in 1781 and subsequently eroded away. During periods of inactivity following 20th-century eruptions, waves have been observed to break on rocky reefs or sandy banks with depths of 10 m or less. Dacitic tuff cones formed during the eruptions in 1967 and 1979 were soon eroded beneath the ocean surface. An eruption in 1995 produced an island with a diameter of 280 m and a height of 43 m following growth of a lava dome above the surface.

Home Reef
Home Reef, a submarine volcano midway between Metis Shoal and Late Island in the central Tonga islands, was first reported active in the mid-19th century, when an ephemeral island formed. An eruption in 1984 produced a 12-km-high eruption plume, large amounts of floating pumice, and an ephemeral 500 x 1,500 m island, with cliffs 30-50 m high that enclosed a water-filled crater. In 2006 an island-forming eruption produced widespread dacitic pumice rafts that drifted as far as Australia. Another island was built during a September-October 2022 eruption.

A submarine volcano along the Tofua Volcanic Arc ~45 km NW of Vava'u Island was first observed in September 2001, ~35 km S of Fonualei and 60 km NE of Late volcano. The site of the eruption is at a bathymetric depth of ~300 m. T-phase waves were recorded on 27-28 September 2001, and on the 27th local fishermen observed an ash-rich eruption column that rose above the ocean surface. No eruptive activity was reported after the 28th, but water discoloration was documented the following month. In early November rafts and strandings of dacitic pumice were reported along the coasts of Kadavu and Viti Levu in Fiji. The depth of the summit of the submarine cone following the eruption was determined to be 40 m during a 2007 survey; the crater of the 2001 eruption was open to the E.

Late
The 6-km-wide circular island of Late, along the Tofua volcanic arc about 55 km WSW of Vavau, contains a 400-m-wide, 150-m-deep summit crater with an ephemeral lake. The largely submerged basaltic andesite to andesitic volcano rises 1,500 m from the sea floor, with its conical summit reaching 540 m above sea level. Cinder cones are found north of the summit crater, west and north of a semicircular plateau 100-150 m below the summit, and on the NW coast. A graben-like structure on the NE flank contains two large pit craters, the lower of which is partially filled by a saltwater lake. Eruptions from the NE-flank craters produced explosive activity and possible lava flows in 1790 and 1854.

Tafahi
The small 1.2 x 2.8 km island of Tafahi is a conical stratovolcano about 7 km N of the island of Niuatoputapu in the northern Tonga Islands. It is the northernmost subaerial volcano of the Tofua volcanic arc. The basaltic andesite volcano is elongated N-S, and the summit is located on the SW side of the island. The W side of the volcano is the most dissected, and a narrow fringing reef partially encircles the island. No eruptions have been reported, but its youthful morphology, which resembles that of the larger Kao volcano in the central Tonga Islands, suggests recent activity.

Curacoa
A submarine volcano south of Curacoa Reef at the northern end of the Tofua volcanic arc was first observed in eruption in 1973. Explosive eruptions, which produced large rafts of dacitic pumice, covering an area of more than 100 km2, were observed from the island of Tafahi, 27 km SSW. The eruption site was located about 6.5 km SW of Curacoa Reef. Multiple submarine vents are apparently located in this area; a second eruption was reported in 1979 from a location 13 km N of Tafahi.

Fonualei
The small island of Fonualei (~2 km diameter) contains a fumarolically active crater breached to the SE with a fresh lava flow extending to the sea and forming a rugged shoreline. Steep, inward-facing scarps mark the rim of a partially exposed caldera. Blocky lava flows fill much of the northern caldera moat and reach the sea to the north and east. In contrast to the andesitic and basaltic rocks of other islands of the Tonga arc, Fonualei lavas are of dominantly dacitic composition. Eruptions have been recorded since 1791, with the largest taking place in June 1846, when explosive eruptions produced large pumice rafts, ashfall damaged crops on the island of Vava'u (70 km SSE), and ash was reported by vessels up to 950 km distant. In 1939 explosive and effusive activity occurred from summit and flank vents, and water spouts were reported 1.6 km SE of the island.

Northern Kermadec Volcanic Arc

Raoul Island
New Zealand
Northern Kermadec Volcanic Arc
Anvil-shaped Raoul Island is the largest and northernmost of the Kermadec Islands. During the past several thousand years volcanism has been dominated by dacitic explosive eruptions. Two Holocene calderas exist, the older of which cuts the center the island and is about 2.5 x 3.5 km wide. Denham caldera, formed during a major dacitic explosive eruption about 2200 years ago, truncated the W side of the island and is 6.5 x 4 km wide. Its long axis is parallel to the tectonic fabric of the Havre Trough that lies W of the volcanic arc. Historical eruptions during the 19th and 20th centuries have sometimes occurred simultaneously from both calderas, and have consisted of small-to-moderate phreatic eruptions, some of which formed ephemeral islands in Denham caldera. An unnamed submarine cone, one of several located along a fissure on the lower NNE flank, has also erupted during historical time, and satellitic vents are concentrated along two parallel NNE-trending lineaments.

Monowai
New Zealand
Northern Kermadec Volcanic Arc
Monowai, also known as Orion seamount, is a basaltic stratovolcano that rises from a depth of about 1,500 to within 100 m of the ocean surface about halfway between the Kermadec and Tonga island groups, at the southern end of the Tonga Ridge. Small cones occur on the N and W flanks, and an 8.5 x 11 km submarine caldera with a depth of more than 1,500 m lies to the NNE. Numerous eruptions have been identified using submarine acoustic signals since it was first recognized as a volcano in 1977. A shoal that had been reported in 1944 may have been a pumice raft or water disturbance due to degassing. Surface observations have included water discoloration, vigorous gas bubbling, and areas of upwelling water, sometimes accompanied by rumbling noises. It was named for one of the New Zealand Navy bathymetric survey ships that documented its morphology.

Kermadec Arc at 24.8�S
A large submarine volcano in the Northern Kermadec Arc, ~120 km N of Monowai, is known informally as Volcano 19 from a research cruise designation. The basaltic to basaltic andesite edifice contains a 2.5 x 3.5 km outer caldera and a 1.9-km-wide inner caldera on the west. A cone complex lies in the center of the outer caldera, east of the inner caldera. Hydrothermal fields are located near the summit of the cone complex and at the base of the southern wall of the western inner caldera. Large high-temperature chimney vents discharge clear fluids and black plumes.

Middle Kermadec Volcanic Arc

Wright
New Zealand
Middle Kermadec Volcanic Arc
Two volcanic cones, initially known informally as Volcano W and later named Wright, were discovered during a New Zealand-American submarine vent mapping expedition to the Kermadec arc in 2004. The deep-water basaltic volcanoes, 156 km SW of Curtis Island, both have summits cut by small calderas. Evidence of diffuse hydrothermal venting was observed in 2005 from the SE edifice, which rises to within about 900 m of the ocean surface and contains a cone in its summit caldera. The caldera walls expose pillow lavas, pillow tubes, localized sheet flows, and pillow breccias, with higher proportions of volcaniclastic breccias in the upper portion.

Curtis Island
Middle Kermadec Volcanic Arc
Curtis and nearby Cheeseman Islands are the emergent portions of a submarine volcano along the Kermadec Ridge. The age of the small islands are considered to be Pleistocene, and rocks consist dominantly, if not entirely, of andesitic pyroclastic-flow deposits (Lloyd, 1992). Curtis Island, 500 x 800 m, contains a large fumarolically active crater whose floor is only 10 m above sea level. Reports of possible eruptions probably represent increased thermal activity. Geologic studies have documented 18 m of uplift during the past 200 years, with 7 m occurred between 1929 and 1964 (Doyle et al., 1979). An active submarine magmatic or solfataric vent is believed to exist nearby, but its activity cannot unequivocally be associated with the volcano (Lloyd, 1992).

Macauley
Macauley Island is a rim remnant of a large submarine caldera centered 8 km to the NW. The 2-km-diameter island consists of a low, gently sloping surface of rhyolitic pumice from the caldera-forming eruption truncated by steep cliffs formed of underlying basaltic lava flows. The pre-caldera edifice consisted of two generations of shield volcanoes separated by a period of pyroclastic cone growth. Eruption of the voluminous Sandy Bay Tuff about 6,300 years ago truncated the NW side of the Annexation shield volcano and formed a 12-km-wide, 1.1-km deep caldera. Following formation of the caldera and substantial marine erosion, a partly submarine and partly subaerial eruption centered about 2 km N of present-day Macauley Island produced basaltic scoriae and lava flows. A reported possible eruption in 1825 from "Brimstone Island," 45 km W of Macauley at a location with a depth of about 2,000 m and SW of Giggenbach submarine volcano, is likely a location error and could refer to an eruption from the submarine flank of Macauley caldera (Lloyd et al., 1996).

Giggenbach
Giggenbach, named after volcano gas geochemist Werner Giggenbach, is a basaltic-to-dacitic submarine volcano about 30 km NW of Macauley volcano. The flat summit reaches to within 65 m of the ocean surface, has a 700-m-wide crater containing a central cone, and is cut by numerous small explosion pits and craters. Much of the edifice is covered by dacitic pumice, and several edifice-collapse scarps cut its flanks. Large cones are found on the ENE and SSW flanks, and a chain of eight small cones that fed recent andesitic-dacitic lava flows lies on the west flank. A large hydrothermal vent field was found within the summit crater.

Havre Seamount
Havre Seamount has a caldera capping a 1-km-high edifice. Located on the Kermadec Ridge, it is believed to have erupted in July 2012, the first recorded activity. The caldera has an asymmetric morphology with the N rim comprising mostly a single inner topographic wall, and the S rim comprising both an outer topographic rim and inner wall separated by a 1.1-1.4 km wide terrace. Smaller craters occur on this terrace. Rocks from the caldera wall include aphyric and plagioclase-bearing basalt-andesite, aphyric and plagioclase- and pyroxene-bearing dacite, gabbro, diorite, and pumice (Wright et al., 2006).

Southern Kermadec Volcanic Arc

Clark
Southern Kermadec Volcanic Arc
The submarine Clark stratovolcano lies near the southern end of the Southern Kermadec arc. This basaltic and dacitic edifice consists of a basal substrate of massive lava flows, pillow lavas, and pillow tubes overlain by volcaniclastic sediments. Craters are present along the complex crest. Clark is the southernmost volcano of the submarine chain that displays hydrothermal activity. Diffuse hydrothermal venting and sulfide chimneys were observed near the summit during a New Zealand-American NOAA Vents Program expedition in 2006.

Tangaroa
Southern Kermadec Volcanic Arc
Tangaroa submarine volcano in the southern Kermadec arc rises to within 600 m of the ocean surface. The volcano is elongated in a NW-SE direction and contains smaller cones on its SE to eastern flanks. A larger edifice lies further to the SE. Tangaroa lies between Clark and Rumble V submarine volcanoes near the southern end of the Kermadec arc and is one of more than a half dozen volcanoes in this part of the arc showing evidence for active hydrothermal vent fields.

Rumble V
Rumble V was discovered in 1992 at the southernmost end of the Rumble seamounts on the southern Kermadec Ridge, 17 km ESE of Rumble IV. Andesitic and basaltic andesite rocks have been dredged from this volcano, which rises more than 2,000 m to nearly 400 m below the ocean surface and shows a pristine morphology. A large plume of gas bubbles was acoustically detected rising from the summit in 1992, and subsequent expeditions detected evidence of vigorous hydrothermal activity.

Rumble IV
The submarine Rumble IV volcano was thought to have been active from April to December 1966, based on hydrophone signals (Kibblewhite, 1967), but later evidence indicated that the hydrophone array had been damaged and the signals originated from Rumble III (Hall, 1985). Fresh, glassy andesitic lava was dredged from the summit in 1992 during a New Zealand Oceanographic Institute cruise, and gas bubbles were acoustically detected rising from Rumble IV.

Rumble III
Rumble III seamount, the largest of the Rumbles group of submarine volcanoes along the South Kermadec Ridge, rises 2,300 m from the seafloor to within about 200 m of the surface. Collapse of the edifice produced a scarp open to the west and a large debris-avalanche deposit. Fresh-looking andesitic rocks have been dredged from the summit and basaltic lava from its flanks. It has been the source of several submarine eruptions detected by hydrophone signals.

Rumble II West
Rumble II West, about 12 km NW of Rumble II East, rises 1,800 m from the ocean floor to within 1,200 m of the surface. Bathymetry shows a 2.5-3 km summit caldera about 200 m deep with a central cone. There is evidence of hydrothermal activity, and cones are present on the flanks. Some lava flows on the western flanks originating from near the caldera rim have little or no sediment cover.

Healy
Healy submarine volcano lies along the South Kermadec Ridge and consists of an elongated edifice with a 3 x 4 km wide caldera at the NE end whose rim reaches to 1,150 m below sea level. A smaller caldera lies to the SW, and a cone, Cotton volcano, rises to 980 below sea level at the SW end of the 15-km-long complex. The flat-lying floor of the larger NE caldera lies 250-400 m below the caldera rim. Rhyodacitic pumice deposits mantle the caldera floor and walls, as well as the flanks. Active hydrothermal venting has been observed on the lower part of the southern caldera wall. The roughly 590-year-old sea-rafted Loisels Pumice deposit found in many Holocene beach sequences of North Island, New Zealand, and as far away as the Chatham Islands, 650 km east of New Zealand, is chemically and texturally similar to pumices from Healy caldera.

Brothers
The submarine Brothers volcano, located NE of the Healy submarine volcano, contains an oval-shaped summit caldera 3-3.5 km elongated NW-SE. The high point of the dominantly dacitic edifice lies on the NW caldera rim at about 1,350 m below the ocean surface. The caldera floor is at about 1,850 m depth, and a post-caldera lava dome partially merges with the southern caldera wall. There is significant hydrothermal activity, including a large field of "black smoker" vents on the NW caldera wall and vents on the post-caldera dome.

Taupo Volcanic Arc

Tuhua/Mayor Island
Taupo Volcanic Arc
The 4-km-wide Tuhua/Mayor Island, offshore of North Island in the Bay of Plenty, is the emergent portion of a 15-km-wide peralkaline shield volcano constructed between about 120,000 and 35,000 years ago. A 3-km-wide composite caldera was formed in two or three collapse events, the last of which took place about 6,300 years ago, and was accompanied by a Plinian eruption that produced tephra deposits up to 70 cm thick on the mainland. Post-caldera eruptions generated a series of lava domes and flows emplaced from NNE-trending vents within the caldera that have filled it to depths of at least 180 m. The latest eruption has not been dated, but was considered by Houghton et al. (1992) to have occurred perhaps only 500-1,000 years ago.

Whakaari/White Island
Taupo Volcanic Arc
The uninhabited Whakaari/White Island is the 2 x 2.4 km emergent summit of a 16 x 18 km submarine volcano in the Bay of Plenty about 50 km offshore of North Island. The island consists of two overlapping andesitic-to-dacitic stratovolcanoes. The SE side of the crater is open at sea level, with the recent activity centered about 1 km from the shore close to the rear crater wall. Volckner Rocks, sea stacks that are remnants of a lava dome, lie 5 km NW. Descriptions of volcanism since 1826 have included intermittent moderate phreatic, phreatomagmatic, and Strombolian eruptions; activity there also forms a prominent part of Maori legends. The formation of many new vents during the 19th and 20th centuries caused rapid changes in crater floor topography. Collapse of the crater wall in 1914 produced a debris avalanche that buried buildings and workers at a sulfur-mining project. Explosive activity in December 2019 took place while tourists were present, resulting in many fatalities. The official government name Whakaari/White Island is a combination of the full Maori name of Te Puia o Whakaari ("The Dramatic Volcano") and White Island (referencing the constant steam plume) given by Captain James Cook in 1769.

Okataina
The massive, dominantly rhyolitic Okataina Volcanic Centre (OVC) is surrounded by extensive ignimbrite and pyroclastic sheets produced during multiple caldera-forming eruptions. Numerous lava domes and craters erupted from two subparallel NE-SW-trending vent lineations form the Haroharo and Tarawera volcanic complexes. Lava domes of the Haroharo complex, at the northern end of the OVC, occupy part of the 16 x 26 km Pleistocene Haroharo caldera, which formed incrementally between 300,000 and 50,000 years before present (BP). The oldest exposed rocks on the caldera floor are about 22,000 years old. The Tarawera complex at the southern end of OVC consists of 11 rhyolitic lava domes and associated lava flows. The oldest domes were formed as late as about 15,000 years BP, and the youngest were formed in the Kaharoa eruption about 800 years BP. The NE-SW Tarawera vent lineation extends from the two dacitic cones of Maungaongaonga and Mangakakaramea on the SW to Mount Edgecumbe on the NE. Construction of the Haroharo and Tarawera complexes impounded lakes Rotoiti, Totoehu, Okataina, and Tarawera against the outer margins of the Okataina ring structure. A major hydrothermal area is located at Waimangu; the world-renowned Pink and White Terrace siliceous sinter deposits were destroyed during the major basaltic explosive eruption of 1886.

Taupo
Taupo, the most active rhyolitic volcano of the Taupo volcanic zone, is a large, roughly 35-km-wide caldera with poorly defined margins. It is a type example of an "inverse volcano" that slopes inward towards the most recent vent location. The caldera, now filled by Lake Taupo, largely formed as a result of the voluminous eruption of the Oruanui Tephra about 22,600 years before present (BP). This was the largest known eruption at Taupo, producing about 1,170 km3 of tephra. This eruption was preceded during the late Pleistocene by the eruption of a large number of rhyolitic lava domes north of Lake Taupo. Large explosive eruptions have occurred frequently during the Holocene from many vents within Lake Taupo and near its margins. The most recent major eruption took place about 1,800 years BP from at least three vents along a NE-SW-trending fissure centered on the Horomotangi Reefs. This extremely violent eruption was New Zealand's largest during the Holocene and produced the thin but widespread phreatoplinian Taupo Ignimbrite, which covered 20,000 km2 of North Island.

Tongariro
Tongariro is a large volcanic massif, located immediately NE of Ruapehu volcano, that is composed of more than a dozen composite cones constructed over a period of 275,000 years. Vents along a NE-trending zone extending from Saddle Cone (below Ruapehu) to Te Maari crater (including vents at the present-day location of Ngauruhoe) were active during several hundred years around 10,000 years ago, producing the largest known eruptions at the Tongariro complex during the Holocene. North Crater stratovolcano is truncated by a broad, shallow crater filled by a solidified lava lake that is cut on the NW side by a small explosion crater. The youngest cone, Ngauruhoe, is also the highest peak.

Ruapehu
Ruapehu, one of New Zealand's most active volcanoes, is a complex stratovolcano constructed during at least four cone-building episodes dating to about 200,000 years ago. The dominantly andesitic 110 km3 volcanic massif is elongated in a NNE-SSW direction and surrounded by another 100 km3 ring plain of volcaniclastic debris, including the NW-flank Murimoto debris-avalanche deposit. A series of subplinian eruptions took place between about 22,600 and 10,000 years ago, but pyroclastic flows have been infrequent. The broad summit area and flank contain at least six vents active during the Holocene. Frequent mild-to-moderate explosive eruptions have been recorded from the Te Wai a-Moe (Crater Lake) vent, and tephra characteristics suggest that the crater lake may have formed as recently as 3,000 years ago. Lahars resulting from phreatic eruptions at the summit crater lake are a hazard to a ski area on the upper flanks and lower river valleys.

Western North Island Volcanic Province

Auckland Volcanic Field
Western North Island Volcanic Province
The 600 km2 Auckland Volcanic Field, at the south end of the Northland Peninsula, is overlain by New Zealand's largest city, Auckland / Tamaki Makaurau. This northernmost Quaternary volcanic field of the Auckland Intraplate Province is dominated by intraplate alkali basaltic to basanitic rocks. Fifty-three volcanic centers, comprised of maars, tuff rings, small lava shields, and scoria cones, are within an elliptical zone ~30 km long (N-S) and ~20 km wide (E-W) (Hopkins et al., 2017; Hopkins and Smid, et al., 2020). The first eruptions in the field began about 193,000 years ago, but over half of the volcanoes formed in the past 60,000 years, and there are 19 known eruptions within the last 20,000 years; only Rangitoto has been active during the Holocene (Needham et al., 2011; Hopkins et al., 2017). An eruption between 1400 and 1450 CE built the 6-km-wide Rangitoto Island, the largest volcano in the field, consisting of multiple scoria cones that cap a low shield with a broad apron of lava flows.

Taranaki
Western North Island Volcanic Province
The nearly symmetrical, steep-sided cone of Taranaki (previously known as Egmont), is a large andesitic stratovolcano on the west coast of central North Island. It is surrounded by a ring plain of debris-avalanche and lahar deposits that extend to the coast. Taranaki is the youngest and SE-most of a group of three volcanoes beginning with the Pleistocene Kaitoke Range. Fanthams Peak is located on the S flank, and four lava domes are on the lower N and S flanks. Multiple episodes of edifice collapse have occurred in the past 50,000 years. Explosive activity, sometimes accompanied by pyroclastic flows and lava dome growth, has occurred frequently throughout the Holocene.

Southern Pacific Volcanic Regions

Pacific-Antarctic Ridge Volcanic Province

Hollister Ridge
Pacific-Antarctic Ridge Volcanic Province
Acoustic T-waves from a seismic swarm, possibly associated with magmatic activity, were recorded in 1991 from a location 130 km S of the Eltanin Fracture Zone (Bulletin of the Global Volcanism Network, 1991). The source was near a seamount shallower than 1,000 m in depth near the Pacific-Antarctic Ridge.

Udintsev Transform
Pacific-Antarctic Ridge Volcanic Province
Acoustic signals (T-waves) from a seismic swarm were detected in 1990 from a source along the Udintsev fracture zone at about 143�W, along the segment that corresponds with the Pacific-Antarctic Ridge (Global Volcanism Network Bulletin, 1990). The seismicity may have been linked to volcanic activity.

Salas y G�mez Ridge Volcano Group

Rapa Nui
Salas y G�mez Ridge Volcano Group
The triangular Rapa Nui (also known as Isla de Pascua, or Easter Island), is renowned for its dramatic megalithic statues of hand-carved basalt. The island sits atop the largely submarine Salas y G�mez Ridge, which trends eastward from the East Pacific Rise. It is composed of three principal volcanoes and more than 70 subsidiary vents. Rano Kau at the SW tip includes flat-bottomed crater 1.5 km wide, while Poike volcano is at the E point; both are of Pleistocene age. Terevaka is a broad shield volcano of Pliocene-to-Pleistocene age at the northern point of the island, which is capped by many pyroclastic cones; the last stage of activity consisted of eruptions from multiple rift zones. The latest lava flows, at Hiva-Hiva near the west-central coast, are thought to be less than 2,000 years old.

Southern East Pacific Rise Volcanic Province

Southern EPR at 8�S
Southern East Pacific Rise Volcanic Province
A massive 15 +/- 4 km3 lava flow field covers about 220 km2 of the East Pacific Rise (EPR) axis crest at about 8�S. The high reflectivity of the lava flow indicates a very youthful age. Teleseismically recorded earthquakes in 1964, 1965, and 1969, were of an unusual magnitude. A helium megaplume of a volume consistent with the eruption of a lava flow of this volume was detected several years later at a distant location; its movement was consistent with inferred circulation patterns at mid-ocean depths. These observations led Macdonald et al. (1989) to suggest that part or all of this lava field may have been emplaced within the previous 25 years, during one or more eruptions coincident with the earthquakes and onset of the helium plume.

Southern EPR at 17.5�S (Segment K)
Southern East Pacific Rise Volcanic Province
Lava flows from a very recent eruption were observed in 1994 along segment K of the southern East Pacific Rise. This segment of the mid-ocean ridge north of the Easter microplate displays the broadest cross-sectional area and the shallowest depth (2,566 m) of the southern East Pacific Rise between 13�40' and 18�30'S. Glassy, unsedimented lava flows on the 17.5�S segment of the East Pacific Rise were considered, from biological observations and chemical analyses of the plume and vent fluids, to have been erupted within 2-3 years of a November-December 1993 plume survey. Lava was erupted along two segments, a 4-km-long flow at the southern site and a 5-10 km flow at the northern site. Numerous low- and high-temperature hydrothermal vents are active along this segment of the ridge.

Southern EPR at 18.2�S (Segment J)
The axial crest of Segment J of the Southern East Pacific Rise consists of an asymmetrical shallow graben varying from 250 to 600 m wide with walls about 20 m high. Horst and graben structures expose cooled lava lakes and both active and extinct hydrothermal chimneys. Basaltic lava flow fields, lava pillars, and pillow mounds are found on the floor of the graben. The largest lava flow field is the Moai lava flow at about 18�12'S. Two lava flows have been dated by paleomagnetic evidence at about 1820 and 1890 CE.

Southern EPR at 18.5�S (Segment I)
The narrow axial crest of Segment I of the Southern East Pacific Rise in some places is less than 50 m wide. An axial dome is located along the southern part of the segment. The largest lava flow field in this segment is the Animal Farm flow, named after a thriving low-temperature hydrothermal site discovered during a submersible expedition in 1993. The Animal Farm lava flow was dated by magnetic paleointensity measurements at about 1880-1950 CE, and older flows were dated by similar techniques to the 17th and 19th centuries.

Pitcairn Hotspot Volcano Group

Adams Seamount
Pitcairn Hotspot Volcano Group
Adams Seamount was constructed above the Pitcairn hot spot in the central Pacific, about 90 km WSW of Pitcairn Island. The massive seamount rises about 3,500 m to within 59 m of the ocean surface about 25 km SE of Bounty Seamount. Bounty Seamount, which rises to within 450 m of the oceans surface, appears morphologically more youthful than Adams and water samples indicate continuing hydrothermal activity, two late-Pleistocene Potassium-Argon dates of about 338,000 and 350,000 years were obtained from the flanks. Alkali basaltic rocks were dredged from the flanks of Adams Seamount, whose summit appears to consist of a trachytic lava dome. Several Potassium-Argon dates of Holocene age were obtained from dredges at Adams Seamount (Guillou et al., 1997), the youngest of which was 2,000 +/- 1,000 years. In addition to the Adams and Bounty seamounts, the Pitcairn chain contains about 20 small volcanic cones about 500 m high.

Society Islands Hotspot Volcano Group

Teahitia
France
Society Islands Hotspot Volcano Group
Teahitia is a submarine volcano in the Society Islands whose summit reaches to within ~1,700 m of the surface, 40 km NE of the SE tip of Tahiti Island. Several seismic swarms in the 1980s included volcanic tremor that may have resulted from submarine eruptions (Talandier and Opal, 1984). Rocks dredged in 1986 "exploded" when they reached the surface, suggesting recent lava extrusion that had not yet had time to equilibrate with pressure and temperature conditions on the submerged flanks of the edifice. Two hydrothermal fields each about 400 x 1,000 m exhibiting low-temperature hydrothermal venting were discovered on the flanks during submersible dives in 1986 and 1989.

Rocard
Society Islands Hotspot Volcano Group
Volcano type: Cone
Rocard is a small volcanic seamount about 60 km WNW of Mehetia and 28 km ESE of Teahitia seamount. The summit lies 2,500 m below sea level on a submarine edifice about 8 km in diameter. Seismicity in 1966, 1971, and 1972 may have been caused by submarine eruptions (Talandier and Custer, 1976). Rocks dredged in 1986 "exploded" when they reached the surface, suggesting recent lava extrusion that had not yet had time to equilibrate with pressure and temperature conditions on the submerged flanks of the edifice.

Moua Pihaa
Moua Pihaa is a massive, steep-sided submarine volcano that rises to within 160 m of the ocean surface SW of Mehetia Island. It is the largest of a group of seamounts along the Society Island hot spot chain near Mehetia and Tahiti Islands and rises 3,500 m above the seafloor. It displayed seismicity in 1969 and 1970 considered to have been related to submarine eruptions (Talandier and Custer, 1976).

Mehetia
The 1.5-km-wide, steep-sided island of Mehetia (known as Me'etia or Meket'ia in the Tahitian and Tuamotuan languages, respectively), the youngest and SE-most of the Society Islands, lacks a well-developed fringing coral reef. The ~400-m-high island is the summit of a large volcano that rises 4,000 m from the sea floor. An older edifice is formed of a lava flow sequence overlain by hydromagmatic deposits and Strombolian ejecta. The summit crater, 150 m wide and 80 m deep, has been the source of the youngest lava flows on the island (Binard et al., 1993). Polynesian legends mention "large fires," and the lack of vegetation on some lava flows suggests that the latest activity occurred within the last 2,000 years (Talandier and Custer, 1976). Other recent activity originated from a submarine crater at 2,500-2,700 m depth on the SE flank.

Austral-Cook Hotspot Volcano Group

Macdonald
Austral-Cook Hotspot Volcano Group
Discovered by the detection of teleseismic waves in 1967, Macdonald seamount (also known as Tamarii seamount) rises from a depth of about 1,800 m to within 27 m of the ocean surface at the eastern end of the Austral Islands. The basaltic submarine volcano marks the site of a hotspot that was the source of the Austral-Cook island chain. The summit, named after volcanologist Gordon Macdonald, consists of a flat plateau about 100 x 150 m wide with an average depth of about 40 m. The summit plateau is capped with spatter cones that form steep-sided pinnacles. Most eruptions have been seismically detected, but in 1987 and 1989 pumice emission was observed from research vessels. Pumice rafts observed in the South Pacific in 1928 and 1936 may also have originated here.

Samoan Hotspot Volcano Group

Vailulu'u
Samoan Hotspot Volcano Group
Vailulu'u, a massive basaltic seamount discovered in 1975, rises 4,200 m from the sea floor to a depth of 590 m. Located about one-third of the way between Ta'u and Rose islands at the E end of the American Samoas, it is considered to mark the current location of the Samoan hotspot. The summit contains an oval-shaped crater that is 2 km wide and 400 m deep. Two principal rift zones extend E and W from the summit, parallel to the trend of the hotspot; a third rift extends SE. The rift zones and escarpments produced by mass wasting phenomena give the seamount a star-shaped pattern. On 10 July 1973 explosions were recorded by SOFAR (hydrophone records of underwater acoustic signals). An earthquake swarm in 1995 may have been related to an eruption. Eruptive activity between April 2001 and April 2005 formed a cone almost 300 m high, named Nafanua. Repeated bathymetric mapping surveys showed depth changes, including height and width increases of Nafanua after 2005, that suggest at least intermittent activity during 1999-2017; a 2019 survey showed no further changes since 2017.

Ta'u
Samoan Hotspot Volcano Group
The 10-km-wide Ta'u Island, located at the E end of the Samoan islands, is ringed by sea cliffs. It is the emergent portion of the large Lata shield volcano. A major flank collapse event around 22 ka resulted in the steep scarps on the southern side of the island. Two smaller shields were constructed along rift zones at the NW and NE tips of the island. The NW corner of the island has a tuff-cone complex that ejected large dunite xenoliths and coral blocks. Numerous Holocene post-caldera cones occur at the summit and on the flanks.

Ofu-Olosega
The two triangle-shaped islands of Ofu and Olosega in eastern Samoa, with a combined length of 6 km, are separated by a narrow strait. The islands are formed by two eroded, coalescing basaltic shield volcanoes whose slopes dip to the east and west. Steep cliffs up to 600-m high truncate the northern and southern sides of the islands. The narrow, steep-sided ridge forming the eastern tip of Ofu Island consists of a dike complex. The shield volcano on Ofu is cut on the north by the A'ofa caldera; bathymetry suggests that a caldera may also exist on the Sili shield volcano of Olosega. The Nu'utele tuff cone, forming a small crescent-shaped island immediately off the west end of Ofu Island, is Holocene in age. A submarine eruption took place in 1866 at the opposite end of the two islands, 3 km SE of Olosega, along the ridge connecting Olosega with Ta'u Island.

Tutuila
Volcano type: Tuff cone(s)
The elongated, extensively eroded Tutuila Island in the center of the Samoan Islands consists of five Pliocene-to-Pleistocene volcanoes constructed along two or three rifts trending SSW-NNE. The Pago basaltic-to-andesitic shield volcano in the center of the 32-km-long island is truncated by an eroded, 9-km-wide caldera that encloses Pago Pago harbor on its west. The caldera is now partially filled by cinder cones and trachytic lava domes. ENE-trending dike complexes are prominently exposed on Pago volcano. Following a lengthy period of erosion, submergence, and the construction of a barrier reef, the Leone Volcanics were erupted during the Holocene along a 5-km-long N-S-trending fissure over a broad area at the southernmost part of the island (Stearns, 1944), forming a group of initially submarine tuff cones and subsequent subaerial cinder cones that produced fresh-looking pahoehoe lava flows. An ash layer overlying a cultural deposit in the SW part of the island was radiocarbon dated at about 440 +/- 200 CE (Addison et al., 2006).

Upolu
Samoa
The massive, basaltic shield volcano forming 75-km-long Upolu Island in Samoa is elongated in an E-W direction and was constructed during two periods of extensive eruptions during the Pliocene and Pleistocene. The most extensive activity during the Pleistocene took place along a 20-km segment along the central axis of the island. Following a lengthy period of erosion, the latest lava flows, at least three of which were estimated to be as young as a few hundred to a few thousand years old, were erupted from vents near the crest of the island at its center and western side (Stearns, 1944). One of the youngest flows reached the north-central coast along a roughly 1.5-km-wide front east of Vailele Bay, and another traveled down the Lefaga River channel and reached the SW coast at Lefaga Bay. Apolima Island off the western tip of Upolu is a Holocene tuff cone too young to be fringed by a coral reef, and other reef-free areas along the coastline may be formed by Holocene lava flows.

Savaii
Samoa
Savai'i, the largest and highest of the Samoan islands, consists of a massive basaltic shield volcano constructed along a WNW-ESE-trending rift zone that splits into two rifts on the east side of the 75-km-long, oval-shaped island. Pliocene and Pleistocene shield formation was followed by stream and marine erosion, partial submergence, and growth of coral reefs. Late-stage Pleistocene and Holocene eruptions produced voluminous lava flows that partially buried fringing reefs. Numerous cinder cones and lava cones dot the broad crest of Savai'i, which has a low-angle, dome-like profile and reaches an elevation of 1858 m. Additional cones occur on the north-central flank, and a large number are found in the south-central part of the island. Three eruptions, including two in the 20th century, occurred in historical time, and produced voluminous lava flows that reached the northern coast along broad fronts up to about 15 km wide, destroying several villages and overtopping fringing reefs.

Malumalu
The Malumalu seamount (also called Southeast Bank) is about 50 km SW of Ta'u Island and 90 km SSE of Tutuila in the Samoan Islands. The edifice, at the end of the Mula volcanic ridge that extends back to Tutuila, has basal diameter of about 25 km. Radiometric measurements were done by Sims et al. (2008), who reported that 230Th/238U, 231Pa/235U, and 226Ra/230Th data indicated at least three flows with maximum eruption ages in the last 350,000 years; one flow with excess 231Pa was inferred to be less than 150 ka, and another with excess 226Ra was inferred to be less than 8 ka.

Eastern Australia Volcanic Regions

Southeastern Australia Volcanic Province

Newer Volcanics Province
Australia
Southeastern Australia Volcanic Province
The voluminous Newer Volcanics Province covers a broad 15,000 km2 area of SE Australia with nearly 400 small shield volcanoes and explosive vents of Tertiary-to-Holocene age. Volumetrically the vast proportion of volcanic products consist of flat-lying lava flows, although the most prominent features of the volcanic field are the numerous small scoria cones, tuff rings, and maars that rise above the lava plain. Several vents were active during the Holocene; another vent (Mount Tower) is now considered to be of late-Pleistocene age. Late-Pleistocene to Holocene eruptions are characterized by small volume and low explosivity. The youngest dated eruptions took place at Mount Schank and Mount Gambier about 5,000 years ago, when explosive activity formed several maars and associated lava flows.

Northeastern Australia Volcanic Province

McBride Volcanic Province
Australia
Northeastern Australia Volcanic Province
An area of around 5,500 km2 is covered by the broad lava plains and cones of the McBride Volcanic Province. The 164 volcanic centers form a broad topographic dome. One lava flow traveled 160 km from Undara crater. Lava from the Kinrara cone was Ar-Ar dated at 7,000 +/- 2,000 (Cohen et al., 2017).

Sunda-Banda Volcanic Regions

Inner Banda Volcanic Arc

Wurlali
Inner Banda Volcanic Arc
The andesitic Wurlali stratovolcano was constructed at the northern end of a 5-km-wide caldera on the eastern side of Damar Island in the Banda Sea. Fumarolic activity occurs in the two summit craters and on the SE flanks, producing exploitable sulfur deposits. An explosive eruption was observed in 1892 CE.

Teon
Inner Banda Volcanic Arc
Teon, an elongated andesitic island volcano in the southwestern Banda arc, is also known as Serawerna, the name of its active crater. Another smaller crater is located to the NNE of Serawerna. Explosive eruptions have been recorded since the 17th century; the largest produced pyroclastic flows and surges in 1660 CE that caused damage and fatalities.

Nila
The 5 x 6 km Nila Island in the Banda Sea is comprised of a low-rimmed caldera breached at sea level on the south and east, with a youthful forested cone. Phreatic eruptions from the dominantly andesitic volcano, also known as Laworkawra, have occurred from summit vents and flank fissures. A 1932 eruption from a fissure that extended from the summit to the SE coast produced heavy ashfall that forced abandonment of Rumadai village.

Serua
The 2 x 4 km island of Serua is the emergent summit of a volcano rising 3,600 m above the Banda Sea floor. A truncated central cone surrounded by an old crater wall is capped by the Gunung Wuarlapna lava dome. This andesitic volcano, also known as Legatala, lies near the center of the Banda arc and has had many eruptions recorded since the 17th century.

Manuk
The small steep-sided island of Manuk is the easternmost volcano in the Banda volcanic arc. The truncated andesitic cone rises 3,000 m from the sea floor. No confirmed observed eruptions are known from this uninhabited island, although there was an uncertain report that a member of the 1874 Challenger Expedition saw "smoke" rising from the crater. Highly altered fumarolic areas are located within the crater and on its western rim, and were once the source of sulfur extraction by Chinese traders.

Banda Api
The 3-km-wide island of Banda Api is the northern-most volcano in the Banda arc and has a long period of recorded observation because of its key location in the Portuguese and Dutch spice trade. The basaltic-to-rhyodacitic volcano is located in the SW corner of a mostly submerged 7 km caldera. At least two episodes of caldera formation are thought to have occurred, with the arcuate islands of Lonthor and Neira considered to be pre-caldera remnants. A conical peak rises to about 600 m at the center of the island. Eruptions have been recorded since 1586 CE, mostly consisting of Strombolian eruptions from the summit crater, but larger explosive eruptions have occurred and occasional lava flows have reached the coast.

Sunda Volcanic Arc

Peuet Sague
Sunda Volcanic Arc
Peuet Sague is a large volcanic complex in NW Sumatra. The volcano, whose name means "square," contains four summit peaks, with the youngest lava dome being located to the N or NW. This extremely isolated volcano lies several days journey on foot from the nearest village and is infrequently visited. The first recorded historical eruption took place from 1918-21, when explosive activity and pyroclastic flows accompanied summit lava-dome growth. The active crater is located NE of the Gunung Tutung lava dome and has typically produced small-to-moderate explosive eruptions.

Bur ni Telong
Sunda Volcanic Arc
The conical Bur ni Telong volcano was constructed at the southern base of the massive Bur ni Geureudong volcanic complex, one of the largest in northern Sumatra. The historically active volcano lies 4.5 km from the summit of Geureudong,and its summit crater has migrated to the ESE, leaving arcuate crater rims. Lava flows are exposed on the southern flank. Explosive eruptions were recorded during the 19th and 20th centuries.

Singkut
The Quaternary Singkut caldera is about 7 x 4 km with the S half of the rim topographically distinct. Post-caldera cones have filled much of the crater and the N rim, including Sibayak, Pintau, and Pratektekan. The 900-m-wide Sibayak crater is partially filled on the north by Pintau. A lava flow traveled through a gap in the western crater wall from the summit lava dome of Sibayak; the active geothermal field SE of the summit has abundant solfataras and fumaroles. Area residents record legends of eruptions. Neumann van Padang (1983) cited a report by Hoekstra of ash clouds emitted from the volcano in 1881. The town of Berastagi is within the caldera immediately SE of the younger cones.

Sinabung
Gunung Sinabung is a Pleistocene-to-Holocene stratovolcano with many lava flows on its flanks. The migration of summit vents along a N-S line gives the summit crater complex an elongated form. The youngest crater of this conical andesitic-to-dacitic edifice is at the southern end of the four overlapping summit craters. The youngest deposit is a SE-flank pyroclastic flow 14C dated by Hendrasto et al. (2012) at 740-880 CE. An unconfirmed eruption was noted in 1881, and solfataric activity was seen at the summit and upper flanks in 1912. No confirmed historical eruptions were recorded prior to explosive eruptions during August-September 2010 that produced ash plumes to 5 km above the summit.

Malintang
The broad forested Malintang andesitic-to-dacitic stratovolcano has an irregular summit crater with a 900 x 1,500 m lake. The flanks are relatively uneroded, and it most likely has had significant eruptions within the past few thousand years (Kieh, 2009 pers. comm.). The open caldera may be related to emplacement of a large debris avalanche.

Sorikmarapi
Sorikmarapi is a forested stratovolcano with a 600-m-wide summit crater containing a lake and substantial sulfur deposits. A smaller upper SE flank crater (Danau Merah) also contains a crater lake; these two craters and a series of smaller explosion pits occur along a NW-SE line. Several solfatara fields are located on the E flank. Phreatic eruptions have occurred from summit and flank vents during the 19th and 20th centuries.

Talakmau
The Talakmau (also known as Talamau) volcano rises above the western coastal plain of Sumatra about 70 km NW of Marapi. The andesitic-dacitic complex was constructed along a NE-SW line, with the smaller peaks of Pasaman and Bukit Nilam to the SW. Three craters are aligned along the same trend across the summit area; the NE-most and highest crater is filled by a lava dome. Reports of eruptions, including one with rumblings and "smoke" emission in 1937, are considered doubtful.

Marapi
Gunung Marapi, not to be confused with the better-known Merapi volcano on Java, is Sumatra's most active volcano. This massive complex stratovolcano rises 2,000 m above the Bukittinggi Plain in the Padang Highlands. A broad summit contains multiple partially overlapping summit craters constructed within the small 1.4-km-wide Bancah caldera. The summit craters are located along an ENE-WSW line, with volcanism migrating to the west. More than 50 eruptions, typically consisting of small-to-moderate explosive activity, have been recorded since the end of the 18th century; no lava flows outside the summit craters have been reported in historical time.

Tandikat-Singgalang
This volcanic complex is dominated by the Singgalang stratovolcano and the smaller Tandikat edifice ~4.5 km SSW. They are located ~15 km WSW across the Bukittinggi plain from Marapi volcano. No eruptions are known from Singgalang, which hosts a lake in the summit crater. The summit of Tandikat has a partially eroded 1.2-km-wide crater containing a large central cone capped by a 360-m-wide crater containing a small lake. The only known eruptions are from Tandikat; three events reported in the late 19th and early 20th centuries produced minor explosive activity.

Talang
Talang is part of a large volcanic edifice just NW of Dibawah Lake. An older volcanic peak, Pasar Arbaao, is ~1.5 km W. The steep-sided Talang cone exhibits fumarolic activity but has no crater; it appears to have grown within a larger caldera. Recorded eruptions have mostly involved small-to-moderate explosive activity, first documented in the 19th century, that originated from a series of small craters in a valley on the NE flank.

Kerinci
Gunung Kerinci in central Sumatra forms Indonesia's highest volcano and is one of the most active in Sumatra. It is capped by an unvegetated young summit cone that was constructed NE of an older crater remnant. There is a deep 600-m-wide summit crater often partially filled by a small crater lake that lies on the NE crater floor, opposite the SW-rim summit. The massive 13 x 25 km wide volcano towers 2400-3300 m above surrounding plains and is elongated in a N-S direction. Frequently active, Kerinci has been the source of numerous moderate explosive eruptions since its first recorded eruption in 1838.

Sumbing
Smaller than its prominent namesake on Java, Sumatra's Sumbing volcano has a complicated summit region containing several crater remnants and a 180-m-long crater lake. Its only reported eruptions, in 1909 and 1921, produced moderate explosions. Hot springs occur at the SW foot of the volcano.

Kaba
The Kaba volcanic massif is ~8 km long, elongated WSW-ENE, with a summit area that includes multiple large craters. On the SW is the 1-km-diameter Hitam crater, with the Malintang cone and 400-m crater ~1 km NE, on the flank of the active 1-km-diameter Kaba crater. The smaller Mali crater is connected to Kaba, and Vogelsang cone is just beyond that to the NE. Another large forested cone is SE of the active craters. Most recorded eruptions have originated from the summit craters, and affected only the summit area. However, the upper-NE flank crater Kawah Vogelsang also produced explosions during the 19th and 20th centuries.

Patah
Volcano type: Stratovolcano?
Patah is a heavily forested, dissected Quaternary volcano SE of Dempo volcano. The age of its latest eruptions is not known, although on 1 May 1989 a possible new 150-m-wide crater with active fumaroles was observed by a cargo aircraft pilot in a heavily forested area on the side of a small cone about 3 km SE of Gunung Patah. The exact date of its formation, and its geologic relationship to Patah are uncertain. A crater lake at the summit of another peak, Bukit Belirang (Sulfur Hill), is located 1.5 km S of the fumaroles.

Dempo
Dempo is a stratovolcano that rises above the Pasumah Plain of SE Sumatra. The andesitic complex has two main peaks, Gunung Dempo and Gunung Marapi, constructed near the SE rim of a 3-km-wide amphitheater open to the north. The high point of the older Gunung Dempo crater rim is slightly lower, and lies at the SE end of the summit complex. The taller Marapi cone was constructed within the older crater. Remnants of seven craters are found at or near the summit, with volcanism migrating WNW over time. The active 750 x 1,100 m active crater cuts the NW side of the Marapi cone and contains a 400-m-wide lake at the far NW end. Eruptions recorded since 1817 have been small-to-moderate explosions that produced local ashfall.

Ranau
Ranau is an 8 x 13 km Pleistocene caldera partially filled by the crescent-shaped Lake Ranau. The caldera lies along the Great Sumatran Fault that extends the length of Sumatra. Incremental formation of the caldera culminated in the eruption of the voluminous Ranau Tuff about 0.55 million years ago. A morphologically young post-caldera stratovolcano, Gunung Semuning, was constructed within the SE side of the caldera to a height of more than 1,200 m above the lake surface. The volcano has not been mapped in sufficient detail to determine the age of its latest eruptions, although fish kills and sulfur smells in the late 19th and early 20th centuries may be related to volcanism.

Suoh
The 8 x 16 km Suoh (or Suwoh) depression appears to have a dominantly tectonic origin, but contains a smaller complex of overlapping calderas oriented NNE-SSW. Historically active maars and silicic domes lie along the margins of the depression, which falls along the Great Sumatran Fault that extends the length of the island. Numerous hot springs occur along faults within the depression, which contains the Pematang Bata fumarole field. Large phreatic explosions (0.2 km2 tephra) occurred at the time of a major tectonic earthquake in 1933. Very minor hydrothermal explosions produced two 5-m-wide craters at the time of a February 1994 earthquake.

Krakatau
The renowned Krakatau (frequently misnamed as Krakatoa) volcano lies in the Sunda Strait between Java and Sumatra. Collapse of an older edifice, perhaps in 416 or 535 CE, formed a 7-km-wide caldera. Remnants of that volcano are preserved in Verlaten and Lang Islands; subsequently the Rakata, Danan, and Perbuwatan cones were formed, coalescing to create the pre-1883 Krakatau Island. Caldera collapse during the catastrophic 1883 eruption destroyed Danan and Perbuwatan, and left only a remnant of Rakata. This eruption caused more than 36,000 fatalities, most as a result of tsunamis that swept the adjacent coastlines of Sumatra and Java. Pyroclastic surges traveled 40 km across the Sunda Strait and reached the Sumatra coast. After a quiescence of less than a half century, the post-collapse cone of Anak Krakatau (Child of Krakatau) was constructed within the 1883 caldera at a point between the former Danan and Perbuwatan cones. Anak Krakatau has been the site of frequent eruptions since 1927.

Pulosari
The basaltic-to-andesitic Pulosari stratovolcano at the western end of Java lies south of the 15-km-wide Pleistocene Danau caldera. The summit contains a nearly 300-m-deep crater open to the ENE with active solfataras on its wall. It is SW across a low saddle from the higher Karang volcano, which was constructed on the SE rim of Danau caldera.

Karang
Gunung Karang volcano in westernmost Java was constructed SE of the 15-km-wide Pleistocene Danau caldera. Two craters, Kawah Welirang and Kawah Haji, display fumarolic activity and are found on the eastern flanks, which may be of Holocene age (Bronto 1995, pers. comm.). The forested andesitic and basaltic volcano is the highest of a group of stratovolcanoes in the Danau caldera area and lies across a low saddle from Pulosari volcano.

Perbakti-Gagak
The Perbakti-Gagak volcanic complex, also known as Kiaraberes-Gagak, is a cluster of deeply eroded stratovolcanoes situated immediately SW of Salak volcano. The summit ridge of Gunung Perbakti is elongated in a NW-SE direction, and Gunung Endut volcano rises above a saddle to its SW. Gunung Gagak, to the NW, is capped by pumice and obsidian, with obsidian lava flows extending N and NE. Quaternary rhyolitic lava domes form a NNE-trending chain at the eastern side of the complex. Two 2-km-wide depressions on the northern and southern sides of Perbakti form the headwaters of the Kaluwung Herang and Pamatutan rivers, respectively. The complex is marked by vigorous geothermal activity. Fumaroles, mud pots, and hot springs are located on the S and SE flanks of Perbakti and at the Kiaraberes area, which includes the commercial geothermal field of Awibengkok. Mild phreatic eruptions took place during the Holocene into historical time from flank fumarolic fields.

Salak
The forested Salak volcano was constructed at the NE end of an eroded volcanic range. Satellitic cones occur on the SW flank and at the northern foot, and two large breached craters truncate the summit. One crater is breached to the NE and the westernmost crater was the source of a debris-avalanche deposit that extends 10 km WNW of the summit. Phreatic explosions have been recorded from a solfataric area at 1,400 m on the western flank. Salak volcano has been the site of extensive geothermal exploration.

Gede-Pangrango
The two peaks of the Gede-Pangrango volcanic complex overlook the major cities of Cianjur, Sukabumi, and Bogor, situated to the E, S, and NW, respectively. The summit of Gunung Pangrango, constructed over the NE rim of a 3 x 5 km caldera, forms the high point. Many lava flows are visible on the flanks of the younger Gunung Gede to the SE of Pangrango. The steep-walled summit crater has migrated about 1 km NNW over time. Two large debris-avalanche deposits are present on its flanks, one of which underlies the city of Cianjur. Activity recorded since the 16th century has typically consisted of small short explosive eruptions.

Patuha
The forested andesitic Gunung Patuha rises SW of the plain of Bandung in western Java. Patuha is the northern peak of a roughly 5-km-long N-S volcanic massif, and has a 300 m crater at the summit. A few hundred meters down the SE flank is a 400 x 500 m crater almost completely filled with a shallow greenish lake, Kawah Putih. Sulfur deposits are present around the shoreline and near active fumaroles on the crater walls. A large debris-avalanche deposit extends down the NE flank. The volcano was formed during the late Pleistocene, but no Holocene eruptions are known.

Tangkuban Parahu
Gunung Tangkuban Parahu is a broad stratovolcano overlooking Indonesia's former capital city of Bandung. The volcano was constructed within the 6 x 8 km Pleistocene Sunda caldera, which formed about 190,000 years ago. The volcano's low profile is the subject of legends referring to the mountain of the "upturned boat." The Sunda caldera rim forms a prominent ridge on the western side; elsewhere the rim is largely buried by deposits of the current volcano. The dominantly small phreatic eruptions recorded since the 19th century have originated from several nested craters within an elliptical 1 x 1.5 km summit depression.

Papandayan
Papandayan is a complex stratovolcano at the S end of a curved volcanic massif with Kendang volcano ~9 km away at the N end, Gunung Puntang ~3.5 km NNE, and Gunung Jaya ~6 km NNE. Several episodes of collapse have created an irregular profile and produced debris avalanches that have affected lowland areas. The summit area includes four large craters, including the 1.1-km-wide, flat-floored Alun-Alun crater. A sulfur-encrusted fumarole field occupies the active Kawah Mas ("Golden Crater"). The first reported eruption, in 1772 CE, included a collapse of the NE flank and a debris avalanche that destroyed 40 villages and killed almost 3,000 people. Smaller phreatic eruptions occurred during 1923-25, 1942, and 2002.

Tampomas
Gunung Tampomas is an andesitic stratovolcano overlooking the northern coastal plain of western Java about halfway between Tangkubanparahu and Cereme volcanoes. Youthful-looking lava flows are found on its flanks.

Guntur
Guntur is a complex of several overlapping stratovolcanoes about 10 km NW of the city of Garut in western Java. Young lava flows, the most recent of which was erupted in 1840, are visible on the flanks of the erosionally unmodified Gunung Guntur, which rises about 1550 m above the plain of Garut. It is one of a group of younger cones constructed to the SW of an older eroded group of volcanoes at the NE end of the complex. Guntur, whose name means "thunder," is the only center with recorded activity, with eruptions since the late-17th century. Although it produced frequent explosive eruptions in the 19th century, it has not erupted since.

Galunggung
The forested slopes of Galunggung in western Java SE of Bandung are cut by a 2-km-wide collapse scarp open towards the ESE. The "Ten Thousand Hills of Tasikmalaya" dotting the plain below the volcano are debris-avalanche hummocks from the collapse about 4,200 years ago. An eruption in 1822 produced pyroclastic flows and lahars that killed over 4,000 people. A series of major explosive eruptions starting in April 1982 destroyed a number of villages, killed as many as 30 people, and forced over 60,000 to evacuate. Pyroclastic flows and heavy widespread ash caused significant damage. A large passenger jet that encountered the ash plume on 24 June lost power to all four engines but managed to land safely in Jakarta. The 1982 activity destroyed a 1918 dome and formed the Warirang crater, almost as wide as the valley, about 2 km down from the summit.

Talagabodas
The Gunung Talagabodas stratovolcano lies immediately north of the more well-known Galunggung volcano. Talagabodas, also spelled Telaga Bodas, is one of the older Quaternary volcanoes in an arcuate N-S trending volcano group east of the city of Garut and is built up of andesitic lavas and pyroclastics. Younger pyroclastics from Gunung Putri-Eweranda overlap the Talagabodas products in the north. The crater of Talagabodas has shifted 1.3 km north from the summit crater of Canar and contains a large sulfur-saturated lake. Fumaroles, mud pots, and a warm spring are found around the lake, which has an elevated temperature. The age of the most recent eruption is not known. Changes in lake color occurred in 1913 and 1921, and expanded solfataric activity was reported in 1927. Suffocating gases have frequently killed animals that have wandered into the Pajagalan valley on the NE flank and the Kawah Saat geothermal area south of the crater lake. The Kawah Karaha fumaroles 9 km N are also part of the geothermal system (Tripp et al., 2002).

Ciremai
The symmetrical Ciremai stratovolcano is located closer to the northern coast than other central Java volcanoes. A large crater, elongated in an E-W direction and formed by multiple vents, caps the summit of Gunung Ciremai, which was constructed on the northern rim of the 4.5 x 5 km Geger Halang caldera. A large landslide deposit to the north may be associated with the origin of the caldera, although collapse may rather be due to a voluminous explosive eruption (Newhall and Dzurisin, 1988). Eruptions have included explosive activity and lahars, primarily from the summit crater.

Slamet
Slamet is one of Java's most active volcanoes. It has a cluster of about three dozen cinder cones on its lower SE-NE flanks and a single cinder cone on the W flank. It is composed of two overlapping edifices, an older basaltic andesite to andesitic volcano on the west and a younger basaltic to basaltic andesite one on the east. Gunung Malang II cinder cone on the upper E flank on the younger edifice fed a lava flow that extends 6 km E. Four craters occur at the summit of Gunung Slamet, with activity migrating to the SW over time. Eruptions recorded since the 18th century have originated from a 150-m-deep, 450-m-wide, steep-walled crater at the western part of the summit and have consisted of explosive eruptions generally lasting a few days to a few weeks.

Dieng Volcanic Complex
The Dieng plateau in the highlands of central Java is renowned both for the variety of its volcanic scenery and as a sacred area housing Java's oldest Hindu temples, dating back to the 9th century CE. The Dieng Volcanic Complex consists of multiple stratovolcanoes and more than 20 small Pleistocene-to-Holocene craters and cones over a 6 x 14 km area. Prahu stratovolcano was truncated by a large Pleistocene caldera, which was subsequently filled by a series of cones, lava domes, and craters, many containing lakes. Lava flows cover much of the plateau, but observed activity has been restricted to minor phreatic eruptions. Gas emissions are a hazard at several craters and have caused fatalities. There are abundant thermal features and high heat flow across the area.

Sundoro
Gunung Sundoro, in central Java, is located between the Dieng complex to the NW and Sumbing volcano to the SE. The large Kembang cone is about 2.5 km from the summit on the SW flank. A small lava dome occupies the summit crater, and numerous phreatic explosion vents are present in the summit area. Lava flows extend in all directions from the summit crater. Deposits of a large debris avalanche are located below the NE flank. Pyroclastic-flow deposits dated at 1,720 years before present extend as far as 13 km from the summit. Recorded eruptions typically have consisted of mild-to-moderate phreatic explosions, mostly from the summit crater. Flank vents were also active in 1882 and 1903.

Sumbing
Gunung Sumbing is a stratovolcano that is the SE-most edifice of a chain of volcanoes in central Java that includes Sundoro and the Dieng Complex. Prominent cones are located on the N and SE flanks. An 800-m-wide summit crater is breached to the NE, but is partially filled by a lava dome that extended beyond the original crater rim. Emplacement of the dome followed the production of extensive pyroclastic flows down the NE flank. Activity reported in about 1730 CE may have produced the small phreatic craters found at the summit behind the dome.

Merbabu
Gunung Merbabu is a massive forested volcano north of Merapi in central Java. Three prominent radial valleys extend from the summit toward the NW, NNE, and ESE. The most recent magmatic eruptions originated from a NNW-SSE fissure system that cut across the summit and fed the large-volume Kopeng and Kajor lava flows on the N and S flanks, respectively. Moderate explosive eruptions occurred from the summit crater in 1560 and 1797 CE.

Merapi
Merapi, one of Indonesia's most active volcanoes, lies in one of the world's most densely populated areas and dominates the landscape immediately north of the major city of Yogyakarta. It is the youngest and southernmost of a volcanic chain extending NNW to Ungaran volcano. Growth of Old Merapi during the Pleistocene ended with major edifice collapse perhaps about 2,000 years ago, leaving a large arcuate scarp cutting the eroded older Batulawang volcano. Subsequent growth of the steep-sided Young Merapi edifice, its upper part unvegetated due to frequent activity, began SW of the earlier collapse scarp. Pyroclastic flows and lahars accompanying growth and collapse of the steep-sided active summit lava dome have devastated cultivated lands on the western-to-southern flanks and caused many fatalities.

Lawu
The Lawu volcanic complex includes a deeply eroded volcano to the south joined to a younger edifice to the north considered by van Bemmelen (1949b) to be probably Holocene. No eruptions or dated deposits are known, but it was mapped by Sampurno and Samodra (1997) as Holocene. The southern end of the broad 3-km-long summit of the younger edifice contains eroded crater rims and a lava dome that fed flows 3.5 km down the S flank. A fumarolic area is also located on the S flank. A small cone with a crater is present on the lower SE flank of the older edifice, ~19 km from the summit. An event was reported in November 1885 CE, with booms, rumbling sounds, and "ash rain" later in the day; this was similar to a landslide reported in 1978. A major eruption attributed to Lawu in 1752 CE was actually from Kelud volcano.

Kawi-Butak
The broad Kawi-Butak volcanic massif lies immediately E of Kelut volcano and S of Arjuno-Welirang volcano. Gunung Kawi was constructed to the NW of Gunung Butak. No historical eruptions are known from either volcano, but both are primarily of Holocene age.

Kelud
The relatively inconspicuous Kelud stratovolcano contains a summit crater lake that has been the source of some of Indonesia's most deadly eruptions. A cluster of summit lava domes cut by numerous craters has given the summit a very irregular profile. Satellitic cones and lava domes are also located low on the E, W, and SSW flanks. Eruptive activity has in general migrated in a clockwise direction around the summit vent complex. More than 30 eruptions have been recorded since 1000 CE. The ejection of water from the crater lake during the typically short but violent eruptions has created pyroclastic flows and lahars that have caused widespread fatalities and destruction. After more than 5,000 people were killed during an eruption in 1919, an engineering project to drain the crater lake lowered the surface by more than 50 m. The 1951 eruption deepened the crater by 70 m, leaving 50 million cubic meters of water after the damaged drainage tunnels were repaired. Following more than 200 deaths in the 1966 eruption, a new deeper tunnel was constructed, and the lake's volume before the 1990 eruption was only about 1 million cubic meters.

Penanggungan
Gunung Penanggungan, one of Java's most revered mountains, is a small stratovolcano immediately north of the Arjuno-Welirang massif. Numerous ruins of sanctuaries, monuments, and sacred bathing places dating from 977-1511 CE are found on the northern and western flanks. Lava flows from flank vents descend to all sides and pyroclastic-flow deposits form an apron around it. It was mapped as similar in age to Arjuno-Welirang and Semeru volcanoes by van Bemmelen (1937). Considered to be extinct for at least 1000 years, its last eruption may have occurred about 200 CE.

Arjuno-Welirang
The Arjuno and Welirang volcanoes anchor the SE and NW ends, respectively, of a 6-km-long line of volcanic cones and craters. The complex overlies most of the Gunung Ringgit edifice, whose summit is about 3 km NE from the main ridge. Pyroclastic cones are located on the north flank of Gunung Welirang and along an E-W line cutting across the southern side of Gunung Arjuno that extends to the lower SE flank. Fumarolic areas with sulfur deposition occur at several locations on Welirang.

Semeru
Semeru, the highest volcano on Java, and one of its most active, lies at the southern end of a volcanic massif extending north to the Tengger caldera. The steep-sided volcano, also referred to as Mahameru (Great Mountain), rises above coastal plains to the south. Gunung Semeru was constructed south of the overlapping Ajek-ajek and Jambangan calderas. A line of lake-filled maars was constructed along a N-S trend cutting through the summit, and cinder cones and lava domes occupy the eastern and NE flanks. Summit topography is complicated by the shifting of craters from NW to SE. Frequent 19th and 20th century eruptions were dominated by small-to-moderate explosions from the summit crater, with occasional lava flows and larger explosive eruptions accompanied by pyroclastic flows that have reached the lower flanks of the volcano.

Tengger Caldera
The 16-km-wide Tengger caldera is located at the northern end of a volcanic massif extending from Semeru volcano. The massive volcanic complex dates back to about 820,000 years ago and consists of five overlapping stratovolcanoes, each truncated by a caldera. Lava domes, pyroclastic cones, and a maar occupy the flanks of the massif. The Ngadisari caldera at the NE end of the complex formed about 150,000 years ago and is now drained through the Sapikerep valley. The most recent of the calderas is the 9 x 10 km wide Sandsea caldera at the SW end of the complex, which formed incrementally during the late Pleistocene and early Holocene. An overlapping cluster of post-caldera cones was constructed on the floor of the Sandsea caldera within the past several thousand years. The youngest of these is Bromo, one of Java's most active and most frequently visited volcanoes.

Lamongan
Lamongan, a small stratovolcano located between the massive Tengger and Iyang-Argapura volcanic complexes, is surrounded by numerous maars and cinder cones. The currently active cone has been constructed 650 m SW of Gunung Tarub, the volcano's high point. As many as 27 maars with diameters from 150 to 700 m, some containing crater lakes, surround the volcano, along with about 60 cinder cones and spatter cones. Lake-filled maars, including Ranu Pakis, Ranu Klakah, and Ranu Bedali, are located on the E and W flanks; dry maars are predominately located on the N flanks. None of the maars has erupted during historical time, although several of the youthful maars cut drainage channels from Gunung Tarub. The volcano was very active from the time of its first historical eruption in 1799 through the end of the 19th century, producing frequent explosive eruptions and lava flows from vents on the western side ranging from the summit to about 450 m elevation.

Iyang-Argapura
The massive Iyang-Argapura volcanic complex dominates the landscape between Raung and Lamongan volcanoes in eastern Java. Several Holocene volcanic cones are present, and valleys up to 1,000 m deep dissect the heavily eroded basal Iyang volcano. No major eruptions have occurred within at least the last 500 years, although there was an unverified report of an eruption in 1597 CE. Fumaroles occur in some of the many explosion pits found in the summit crater complex.

Raung
Raung, one of Java's most active volcanoes, is a massive stratovolcano in easternmost Java that was constructed SW of the rim of Ijen caldera. The unvegetated summit is truncated by a dramatic steep-walled, 2-km-wide caldera that has been the site of frequent historical eruptions. A prehistoric collapse of Gunung Gadung on the W flank produced a large debris avalanche that traveled 79 km, reaching nearly to the Indian Ocean. Raung contains several centers constructed along a NE-SW line, with Gunung Suket and Gunung Gadung stratovolcanoes being located to the NE and W, respectively.

Baluran
The small andesitic Baluran, dwarfed by its neighbor Ijen volcano to the SW, occupies the very NE tip of Java. Gunung Baluran contains a wide crater breached to the NE. The volcano lies within a national park and game reserve. It was considered by van Bemmelen (1949b) to be of Holocene age.

Ijen
The Ijen volcano complex at the eastern end of Java consists of a group of small stratovolcanoes constructed within the 20-km-wide Ijen (Kendeng) caldera. The north caldera wall forms a prominent arcuate ridge, but elsewhere the rim was buried by post-caldera volcanoes, including Gunung Merapi, which forms the high point of the complex. Immediately west of the Gunung Merapi stratovolcano is the historically active Kawah Ijen crater, which contains a nearly 1-km-wide, turquoise-colored, acid lake. Kawah Ijen is the site of a labor-intensive mining operation in which baskets of sulfur are hand-carried from the crater floor. Many other post-caldera cones and craters are located within the caldera or along its rim. The largest concentration of cones forms an E-W zone across the southern side of the caldera. Coffee plantations cover much of the caldera floor; nearby waterfalls and hot springs are tourist destinations.

Buyan-Bratan
The most obvious feature of the Buyan-Bratan volcanic complex in north-central Bali is the 11 x 6 km wide Bratan caldera (also known as Catur or Tjatur caldera), which contains three caldera lakes. Several post-caldera stratovolcanoes straddle its southern rim; the largest post-caldera cone, Batukau (Batukaru), is 10 km SW. The cones are well-formed, but covered with thick soils and vegetation; they are thought to have been inactive for hundreds or thousands of years (Wheller, 1986). The Tapak and Lesong cones are not covered by deposits of the youngest dacitic pumice eruptions of nearby Batur volcano, and are thus thought to be less than 23,000 years old. The geothermal field within the caldera has been developed to produce electrical power, and hot springs are located in more than a dozen locations.

Batur
The historically active Batur is located at the center of two concentric calderas NW of Agung volcano. The outer 10 x 13.5 km caldera was formed during eruption of the Bali (or Ubud) Ignimbrite about 29,300 years ago and now contains a caldera lake on its SE side, opposite the Gunung Abang cone, the topographic high of the complex. The inner 6.4 x 9.4 km caldera was formed about 20,150 years ago during eruption of the Gunungkawi Ignimbrite. The SE wall of the inner caldera lies beneath Lake Batur; Batur cone has been constructed within the inner caldera to a height above the outer caldera rim. The Batur stratovolcano has produced vents over much of the inner caldera, but a NE-SW fissure system has localized the Batur I, II, and III craters along the summit ridge. Recorded eruptions have been characterized by mild-to-moderate explosive activity sometimes accompanied by lava emission. Basaltic lava flows from both summit and flank vents have reached the caldera floor and the shores of Lake Batur in historical time.

Agung
Symmetrical Agung stratovolcano, Bali's highest and most sacred mountain, towers over the eastern end of the island. The volcano, whose name means "Paramount," rises above the SE rim of the Batur caldera, and the northern and southern flanks extend to the coast. The summit area extends 1.5 km E-W, with the high point on the W and a steep-walled 800-m-wide crater on the E. The Pawon cone is located low on the SE flank. Only a few eruptions dating back to the early 19th century have been recorded in historical time. The 1963-64 eruption, one of the largest in the 20th century, produced voluminous ashfall along with devastating pyroclastic flows and lahars that caused extensive damage and many fatalities.

Rinjani
Rinjani volcano on the island of Lombok rises to 3726 m, second in height among Indonesian volcanoes only to Sumatra's Kerinci volcano. Rinjani has a steep-sided conical profile when viewed from the east, but the west side of the compound volcano is truncated by the 6 x 8.5 km, oval-shaped Segara Anak (Samalas) caldera. The caldera formed during one of the largest Holocene eruptions globally in 1257 CE, which truncated Samalas stratovolcano. The western half of the caldera contains a 230-m-deep lake whose crescentic form results from growth of the post-caldera cone Barujari at the east end of the caldera. Historical eruptions dating back to 1847 have been restricted to Barujari cone and consist of moderate explosive activity and occasional lava flows that have entered Segara Anak lake.

Tambora
Longitude: 118°E
The massive Tambora stratovolcano forms the entire 60-km-wide Sanggar Peninsula on northern Sumbawa Island. The largely trachybasaltic-to-trachyandesitic volcano grew to about 4,000 m elevation before forming a caldera more than 43,000 years ago. Late-Pleistocene lava flows largely filled the early caldera, after which activity changed to dominantly explosive eruptions during the early Holocene. Tambora was the source of history's largest explosive eruption, in April 1815. Pyroclastic flows reached the sea on all sides of the peninsula, and heavy tephra fall devastated croplands, causing an estimated 60,000 fatalities. The eruption of an estimated more than 150 km3 of tephra formed a 6-km-wide, 1250-m-deep caldera and produced global climatic effects. Minor lava domes and flows have been extruded on the caldera floor at Tambora during the 19th and 20th centuries.

Sangeang Api
Sangeang Api volcano, one of the most active in the Lesser Sunda Islands, forms a small 13-km-wide island off the NE coast of Sumbawa Island. Two large trachybasaltic-to-trachyandesitic volcanic cones, Doro Api and Doro Mantoi, were constructed in the center and on the eastern rim, respectively, of an older, largely obscured caldera. Flank vents occur on the south side of Doro Mantoi and near the northern coast. Intermittent eruptions have been recorded since 1512, most of them during the 20th century.

Wai Sano
The Wai Sano composite volcano at the western end of Flores Island includes a 2.5 x 3.5 km elliptical caldera in the NW part of a larger 9-10 km edifice. The caldera contains Sanonggoang Lake, with a surface more than 200 m below the high point on the southern caldera rim. The Poco Sesok and Poco Dedeng peaks are near the center of the eroded massif. The area has been a target of geothermal investigations, and two solfataras are located at the SE shore of the lake. No eruptions have been reported or dated, but the area was mapped as Holocene (Ratman and Yasin, 1978).

Ranakah
The Anak Ranakah (Child of Ranakah) lava dome was formed in 1987 in an area without previous recorded eruptions at the base of the large older lava dome of Gunung Ranakah. An arcuate group of lava domes extending about 12 km west from Gunung Ranakah to Poco Mandosawa occurs on the outer N flanks of the poorly known Poco Leok caldera on western Flores Island.

Inierie
The symmetrical Gunung Inierie stratovolcano in south-central Flores overlooks the Sawu Sea, and is the highest volcano on the island. A small steep-walled crater is oriented E-W immediately east of the summit, whose upper slopes are unvegetated. A somma wall lies west and NW of Inierie (also known as Rokka Peak). A NNW-SSE-trending chain of volcanoes is just to the NE, including Wolo Bobo; these are part of the Pleistocene Bajawa cinder cone complex. A column of "smoke" is sometimes visible from the crater, as occurred in June 1911. The age of the latest eruption is not known, although the volcano was mapped as Holocene, and an eruption of Wolo Bobo was radiocarbon dated at about 10,000 years ago (Nasution et al., 2000). Hot springs are located on the northern flank of the volcano, and additional geothermal areas are located to the E and NE.

Inielika
Inielika is a broad, low volcano in central Flores Island that was constructed within the Lobobutu caldera. The complex summit contains ten craters, some of which are lake filled, in a 5 km2 area north of the city of Bajawa. The largest of these, Wolo Runu and Wolo Lega North, are 750 m wide. A phreatic explosion in 1905 formed a new crater, and was the volcano's only eruption during the 20th century. Another eruption took place about a century later, in 2001. A chain of Pleistocene cinder cones, the Bajawa cinder cone complex, extends southward to Inierie.

Ebulobo
Ebulobo, also referred to as Amburombu or Keo Peak, is a steep-sided symmetrical stratovolcano in central Flores Island. The Watu Keli lava flow traveled down the N flank to 4 km from the summit in 1830, the first of only four recorded historical eruptions of the volcano.

Iya
Gunung Iya is the southernmost of a group of three volcanoes comprising a small peninsula south of the city of Ende on central Flores Island. The cones to the north, Rooja and Pui, appear to be slightly older and have not shown historical activity, although Pui has a youthful profile (a reported 1671 eruption of Pui was considered to have originated from Iya volcano). Iya, whose truncated southern side drops steeply to the sea, has had numerous moderate explosive eruptions during historical time.

Kelimutu
Kelimutu is a small, but well-known, Indonesian compound volcano in central Flores Island with three summit crater lakes of varying colors. The western lake, Tiwi Ata Mbupu (Lake of Old People) is commonly blue. Tiwu Nua Muri Kooh Tai (Lake of Young Men and Maidens) and Tiwu Ata Polo (Bewitched, or Enchanted Lake), which share a common crater wall, are commonly colored green and red, respectively, although lake colors periodically vary. Active upwelling, probably fed by subaqueous fumaroles, occurs at the two eastern lakes. The scenic lakes are a popular tourist destination and have been the source of minor phreatic eruptions in historical time. The summit is elongated 2 km in a WNW-ESE direction; the older cones of Kelido (3 km N) and Kelibara (2 km S).

Paluweh
Paluweh, also known as Rokatenda, forms the 8-km-wide island of Palu'e north of the volcanic arc that cuts across Flores Island. The broad irregular summit region contains overlapping craters up to 900 m wide and several lava domes. Several flank vents occur along a NW-trending fissure. A large eruption in 1928 included strong explosive activity accompanied by landslide-induced tsunamis and lava dome emplacement. Pyroclastic flows in August 2013 resulted in fatalities.

Egon
Gunung Egon, also known as Namang, sits within the narrow section of eastern Flores Island. The barren, sparsely vegetated summit region has a 350-m-wide, 200-m-deep crater that sometimes contains a lake. Other small crater lakes occur on the flanks. A lava dome forms the southern summit. Solfataric activity occurs on the crater wall and rim and on the upper S flank. Reports of eruptive activity prior to explosive eruptions beginning in 2004 are unconfirmed. Emissions were often observed above the summit during 1888-1892. Strong emissions in 1907 reported by Sapper (1917) was considered by the Catalog of Active Volcanoes of the World (Neumann van Padang, 1951) to be an historical eruption, but Kemmerling (1929) noted that this was likely confused with an eruption on the same date and time from Lewotobi Lakilaki.

Lewotobi
The Lewotobi edifice in eastern Flores Island is composed of the two adjacent Lewotobi Laki-laki and Lewotobi Perempuan stratovolcanoes (the "husband and wife"). Their summits are less than 2 km apart along a NW-SE line. The conical Laki-laki to the NW has been frequently active during the 19th and 20th centuries, while the taller and broader Perempuan has had observed eruptions in 1921 and 1935. Small lava domes have grown during the 20th century in both of the summit craters, which are open to the north. A prominent cone, Iliwokar, occurs on the E flank of Perampuan.

Iliboleng
Iliboleng stratovolcano was constructed at the SE end of Adonara Island across a narrow strait from Lomblen Island. The volcano is capped by multiple, partially overlapping summit craters. Lava flows modify its profile, and a cone low on the SE flank, Balile, has also produced lava flows. Historical eruptions, first recorded in 1885, have consisted of moderate explosive activity, with lava flows accompanying only the 1888 eruption.

Lewotolok
The Lewotolok (or Lewotolo) stratovolcano occupies the eastern end of an elongated peninsula extending north into the Flores Sea, connected to Lembata (formerly Lomblen) Island by a narrow isthmus. It is symmetrical when viewed from the north and east. A small cone with a 130-m-wide crater constructed at the SE side of a larger crater forms the volcano's high point. Many lava flows have reached the coastline. Eruptions recorded since 1660 have consisted of explosive activity from the summit crater.

Ililabalekan
Ililabalekan volcano is situated on a prominent peninsula in SW Lembata (formerly Lomblen) Island. A satellitic cone was constructed on the SE flank of the steep-sided volcano. Four craters, one of which contains a lava dome and two small explosion pits, occur at the summit of Mount Labalekan. No historical eruptions are known from the volcano, although fumaroles are found near its summit.

Iliwerung
Constructed on the southern rim of the Lerek caldera, Iliwerung forms a prominent south-facing peninsula on Lembata (formerly Lomblen) Island. Craters and lava domes have formed along N-S and NW-SE lines on the complex volcano; activity has been observed at vents from the summit to the submarine SE flank. The summit lava dome was formed during an eruption in 1870. In 1948 the Iligripe lava dome grew on the E flank at 120 m elevation. Beginning in 1973-74, when three ephemeral islands were formed, submarine eruptions began on the lower ESE flank at a vent named Hobal; several other eruptions have since taken place at this vent.

Batu Tara
The small isolated island of Batu Tara is located in the Flores Sea ~50 km N of Lembata (formerly Lomblen) Island and the main volcanic arc. A scarp on the eastern side reaches the sea, and vegetation covers the other flanks to within 50 m of the summit. This volcano is noted for its potassic leucite-bearing basanitic and tephritic rocks. The first recorded eruption, during 1847-52, produced explosions and a lava flow.

Sirung
Sirung is located at the NE end of a volcanic massif with multiple centers that extends 14 km NE from the southern end of Pantar Island. The volcano is truncated by a 2-km-wide caldera whose floor often contains one or more small lakes. Much of the volcano is constructed of basaltic lava flows, and the Gunung Sirung lava dome forms the high point on the caldera's western rim. A number of phreatic eruptions occurred from vents within the caldera during the 20th century. Forested Gunung Topaki, the high point of the volcanic chain, has a small summit crater and lies ~3.5 km SW of the active crater area.

Andaman Volcanic Province

Barren Island
India
Andaman Volcanic Province
Barren Island, a possession of India in the Andaman Sea about 135 km NE of Port Blair in the Andaman Islands, is the only historically active volcano along the N-S volcanic arc extending between Sumatra and Burma (Myanmar). It is the emergent summit of a volcano that rises from a depth of about 2250 m. The small, uninhabited 3-km-wide island contains a roughly 2-km-wide caldera with walls 250-350 m high. The caldera, which is open to the sea on the west, was created during a major explosive eruption in the late Pleistocene that produced pyroclastic-flow and -surge deposits. Historical eruptions have changed the morphology of the pyroclastic cone in the center of the caldera, and lava flows that fill much of the caldera floor have reached the sea along the western coast.

Eastern Asia Volcanic Regions

Southeast Asia Volcanic Province

Hainan Volcanic Field
China
Southeast Asia Volcanic Province
The Hainan volcanic field consists of Quaternary lava flows that extend over about 4,100 km2 of northern Hainan Island (also known as Qiong). This field, along with the Leizhou Bandao volcanic field across the Qiongzhou strait to the north on the Leizhou (Liuchow) Peninsula, forms the larger Leiqiong volcanic field (also called the Qionglei volcano group). As many as 58 cones and craters are still evident, primarily near the city of Hainan on the north-central coast of the island. Eruptions were reported in the Lingao and Chengmai areas in the 19th and 20th centuries. Leihuling and Maanshan, two of the best preserved volcanic cones, are oriented along an E-W fracture and are part of a cluster of about 30 cones in the Shishan and Yongzing regions. The Haikou Volcanic Cluster, part of the Leiqiong World Geopark, around the town of Shishan 15 km SE of Hainan city, includes 40 volcanic features.

Ly Son Group
Vietnam
Southeast Asia Volcanic Province
The L� Son (formerly known as C�-Lao R�) volcanic group consists of four subaerial and nine submarine cones about 150 km off the coast of central Vietnam. Three of the subaerial cones form L� Son Island, and the fourth forms An Binh (or Dao Be) Island. The basaltic volcanic field is of Holocene age (Whitford-Stark 1987, pers. comm.).

Ile des Cendres
Vietnam
The Ile des Cendres group of submarine volcanoes off the SE coast of Vietnam includes two submarine cones that built ephemeral islands during an eruption in 1923 and two submarine lava cones of uncertain age. The 1923 eruption produced two small islands, one about 30 m high and about 450 m long, and the other 30 m wide and 30 cm high. A third submarine cone reached to within 20 m of the surface. Additional submarine cones occur between Ile des Cendres and the Vietnam mainland (Bondarenko and Nadezhnyi, 1989). In 1880 there was a reef (named Veteran) reported about 36 km S, described as being 34 km SSE of Grand Catwick Rock (Round Island). It was not found in 1882, but was attributed to a possible volcanic eruption (Catalog of Active Volcanoes of the World), and discolored water was reported in 1928.

Popa
Burma (Myanmar)
Mount Popa, in central Burma (Myanmar), is a large, steep-sided composite cone that rises above a surrounding lava plateau. The main edifice consists of overlapping basaltic and basaltic andesite lava flows, pyroclastic deposits, and scoriaceous material originating from Strombolian eruptions that may have dominated later stages of the volcano's growth. A 1.6-km-wide, 850-m-deep crater is widely breached to the NW as a result of slope failure. A debris avalanche deposit (3 km3) covers an area of 27 km2 N of the breach. The pyroclastic flow and debris avalanche deposits overlie a paleosol 14C dated around 8,500 cal BP, so Belousov et al. (2018) placed the last eruption at approximately 8,000 cal BP. Local legends describe "a great earthquake" when the cone of Popa "rose from the plains" in 442 BCE (Belousov et al., 2018, citing Bell, 1907), but there is no physical evidence of an eruption that recent. The steep Taung Kalat lava plug on the WSW flank is famous for the monastery built on top.

Tengchong
China
The Tengchong volcanic field, located in southern China near the border with Burma (Myanmar), was active during five periods ranging from the early Pliocene to the Holocene. Three main stages produced Pliocene to mid-Pleistocene basaltic rocks, mid- to late-Pleistocene silicic pyroclastic rocks, and Holocene basaltic andesites. The youngest volcanism in the 600 km2 field occurred in two stages during the early and late Holocene. Volcanic cones at the northern end of the field are sparsely vegetated and have clearly visible lava flows. Three basaltic andesite centers, Dayinshshan, Maanshan, and possibly Heikongshan, are of Holocene age. An unconfirmed explosive eruption took place in 1609 CE, and there are unconfirmed reports of eruptions during the Qing Dynasty (1644-1911 CE). The area includes active geothermal fields, the largest and highest temperature of which is the Rehai geothermal field, where more than 20 hydrothermal eruptions have occurred since 1993.

Northern Tibetan Plateau Volcanic Province

Ashikule Volcanic Field
China
Northern Tibetan Plateau Volcanic Province
The Ashikule Volcanic Field contains 10 Pliocene to Holocene pyroclastic cones at the western end of the Kunlun Mountains. Several young trachyandesitic cones lie in the area around Ashi (Aqqikkol) and Wuluke (Ulugkol) lakes. China's most recent eruption was observed by a road-building crew on 27 May 1951, at the Ashishan (also known as Ka-er-daxi or Vulkan) cone. The eruption began with a loud detonation and ejected large blocks, emitting "smoke" for a number of days. An unconfirmed eruption was reported in the 19th century.

Central East Asia Volcanic Province

Honggeertu
Central East Asia Volcanic Province
The Honggeertu volcanic field is located in Nei Mongol Province, NW of Beijing. The basaltic volcanic field consists of a group of six cinder cones extending along an arc for about 10 km that were considered to be of Holocene age by IAVCEI (1973). Liu (1998, p.c.), however, considered the existence of Holocene volcanism at this location to be uncertain.

Arxan-Chaihe
Central East Asia Volcanic Province
The Arxan-Chaihe Volcanic Field, in the central Da Hinggan Mountains of Inner Mongolia in NE China, contains at least 27 volcanic features. The youngest cones, including Yanshan and Gaoshan, produced basaltic lava flows that blocked drainages of the Halahale River and created six lava-dammed lakes. Radiocarbon dates from scoria deposits document eruptions about 2,000-1,900 years ago. The area has been designated as a National Geopark.

Keluo Group
The Keluo volcanic field in NE China is located near the Russian border, S of the Heilongjiang (Black Dragon) River. Like its better known neighbor to the S, the Wudalianchi volcanic field, it contains many high-potassium basaltic cinder cones. Nanshan cone, located at the southern end of the field N of the Keluo River, may be of historical age, based on its youthful appearance, and Gushan may also be Holocene. Other cones to the NE are of Pleistocene to Tertiary. Cinder cones are located at the intersections of regional NE- and NW-trending lineaments, and were erupted through basement volcanic and sedimentary rocks of Jurassic-Cretaceous age, granitic rocks, and pre-Permian metasediments. There are unconfirmed reports of observed activity.

Wudalianchi
The Wudalianchi volcanic field, named for a string of five scenic lava-dammed lakes, consists of 14 cinder cones capping a 500 km2 shield-like lava plateau in NE China. The volcanic field, whose name means "Five Connected Pools" was formed during five eruptive cycles from the early Pleistocene to historical time. Its ancient name was "Nine Hills," which after the historical eruptions now number 14 hills. The cinder cones were erupted through basement sedimentary and granitic rocks and show a preferred alignment along three chains at the intersection of NE- and NW-trending lineaments. In addition to the historical cinder cones of Laoheishan and Huoshaoshan, Xilongmenshan and Donglongmenshan are Holocene in age. The freshly preserved cones of Laoheishan and Huoshaoshan were formed during eruptions in 1720-21. Fissures at the base of the two new cinder cones fed glassy pahoehoe and aa lava flows that covered 65 km2 and formed the five lakes of Wudalianchi at their eastern and northern margins. Renewed eruptions took place in 1776.

Jingpohu
Jingpohu is a Pliocene-to-Holocene volcanic field in the Jingpo Lake area of Heilongjiang Province, NE China. The lake formed when lava flows blocked the Mudan River (Mudanjiang). The NE-striking Dunhua-Mishan fault controls the location of many vents. One alkali basaltic lava flow traveled 100 km down a canyon NW of the lake. Many Holocene trachybasaltic or basanitic cones and lava flows lie on plateaus along the Mudan River, which also contain basanitic and tephriphonolitic rocks. Mantle xenoliths are common. A period of major activity about 5,500-5,200 years ago produced extensive lava flows that covered an area of about 500 km2.

Longgang Group
The Longgang volcanic field covers 1,700 km2 in the Jilin Province of NE China. Basaltic and trachybasaltic lava flows cover a large area containing more than 150 Quaternary cinder cones and eight tuff rings. There is only one known cinder cone of Holocene age, Jinlongdingzi (Gold Dragon Peak); the eruption formed the large scoria cone and deposited tephra over a broad area to the E which was radiocarbon dated at about 1,600-1,700 years ago.

Changbaishan
China-North Korea
Massive Changbaishan stratovolcano (also known as Baitoushan and by the Korean names of Baegdu, Paektu, or P'aektu-san), is located along the China/Korea border. A 5-km-wide, 850-m-deep summit caldera is filled by Lake Tianchi (Sky Lake). The 60-km-diameter dominantly trachytic and rhyolitic volcano was constructed over the Changbaishan (Laoheidingzi) shield volcano. Satellitic cinder cones are aligned along a NNE trend. One of the largest known Holocene explosive eruptions took place here about 946 CE, depositing tephra as far away as northern Japan and forming in part the present caldera; Yang et al. (2021) estimated the total erupted volume to be 40-98 km3. Minor eruptions have been recorded since the 15th century.

Ulleungdo
South Korea
Ulleungdo, also known as Ulreungdo, is a 10-km-wide island about 100 km E of the central Korean Peninsula. The trachyandesitic stratovolcano is truncated by the Nari caldera. A major phonolitic explosive eruption at the beginning of the Holocene from Nari caldera produced pyroclastic flows and deposited ash in central Honshu, Japan.

Halla
South Korea
The massive Halla shield volcano forms much of the 40 x 80 km Cheju (Jeju) Island, which lies 90 km S of the Korean Peninsula. Eruptions during the Pliocene and Pleistocene built a lava plateau above the roughly 100-m-deep continental shelf on which the basaltic-to-trachytic edifice was constructed. A 400-m-wide crater truncates the summit. About 360 late-Pleistocene and Holocene basaltic cones across the flanks were erupted primarily along the long axis of the ENE-WSW-trending island. Most of these are scoria cones, but about 20 along the coast or offshore are Pleistocene-to-Holocene tuff rings and tuff cones; lava domes also occur. The latest two eruptions took place during the 11th century.

Baikal Rift Volcanic Province

Udokan Plateau
Baikal Rift Volcanic Province
The Udokan Plateau volcanic field occupies a broad area about 400 km ENE of the northern tip of Lake Baikal. Quaternary volcanism here represents the latest manifestation of activity dating back to the Miocene covering an area of 3,000 km2 at the eastern margin of the Baikal Rift System. Late Pleistocene to Holocene volcanic centers are concentrated along three major lineaments, and many eruptions were localized along fissures trending NW-SE and NE-SW. Dated Holocene volcanic centers are located on a 20-km-long line at the SW side of the field, but Holocene cinder cones also occur in the NE Udokan Plateau. Seismic activity has been recorded at depths of 15-20 km beneath some of the cones. Basaltic cinder cones dominate the field, but basal trachytic ignimbrites are also overlain by lava domes and flows, and trachytic maars were formed during the final stages of activity. The latest dated eruption took place at Chepe volcano about 2,200 years ago.

Jombolok
Baikal Rift Volcanic Province
A group of small basaltic cinder cones in the East Sayan region of central Asia, about 200 km WNW of the SW tip of Lake Baikal, produced the Jombolok lava field. Six cones are located along a 5-km-long valley segment. Arzhannikov et al. (2016) defined four stages of activity that began about 13,000 years ago. The Stariy and Treshina cones formed during the first stage, followed by the Peretolchin, Atkinson, and Ostanets cones, which produced basaltic flows down the Jombolok and Oka river valleys to a distance of 75 km. A third stage formed the Kropotkin cone and erupted a smaller volume of lava that extended ~2.5 km NE to the Peretolchin cone along the upper reaches of the Khi-Gol and Kadyr-Os valleys. The fourth stage sent lava flows ~1.7 km SW in the upper Khi-Gol valley, transported through lava tubes from an uncertain source. Ivanov et al. (2011) reported calibrated 14C dates for flows from Atkinson to 5180 BCE. The youngest flows were dated by Arzhannikov et al. (2016) using a combination of 14C, dendrochronology, and historical research to 737 +/- 55 CE.

Taryatu-Chulutu
Mongolia
The Taryatu-Chulutu volcanic field lies in north-central Mongolia about 250 km W of Ulaanbaatar. This area, also known as the Hangayn or Tariat volcanic field, is located in a broad region of Miocene-to-Holocene basaltic lavas in the Baikal Rift System SSW of Lake Baikal. Lava flows of four Miocene-to-Holocene age groups form terraces along the Chulutu (Chuloot) River; Pleistocene basalts form the 40-60 m terrace of the Taryatu basin. Six Holocene cinder cones, including Horgo and Dzan Tologai, are concentrated along the Sumein and Gichgeniyn river valleys at the western end of the volcanic field. The 180-m-wide crater of Horgo is breached to the south, in the direction of an associated lava flow. The Holocene cones produced thin, freshly preserved lava flows remarkable for their large numbers of ultramafic xenoliths. The lava flow from Horgo was radiocarbon dated at about 4,930 years ago and dammed the Chulutu River, forming Lake Terkhin-Tsagan-Nur.

Khoid Naiman Nuur
Mongolia
A cone, designated here as Khoid Naiman Nuur ("North Eight Lakes"), is located in the upper reaches of a river valley ~25 km SW from the Orkhan (or Tsutgalan) waterfall, just N of the Khuisiin Naiman Nuur ("Eight Lakes of the Navel") area. Lava flows extend from the cone ~3.5 km S towards the lakes and ~15 km NW then NE down the valley towards the waterfall. Ivanov et al. (2015) noted that the cone and flows were probably Holocene based on their field observations.

Atlantic Ocean Volcanic Regions

Arctic Ridge Volcanic Province

Tjornes Fracture Zone
Iceland
Arctic Ridge Volcanic Province
The offshore Tj�rnes Fracture Zone is an oblique transform zone that separates the northern volcanic zone of Iceland from the Kolbeinsey Ridge, part of the Mid-Atlantic Ridge north of Iceland. A submarine eruption was reported during 1867-1868 at the SE part of the fissure system off the northern coast of Iceland along the Manareyjar Ridge immediately north of Manareyjar Island.

Kolbeinsey Ridge
Iceland
Arctic Ridge Volcanic Province
A submarine eruption was reported in 1372 CE near the Kolbeinsey Ridge NW of Grimsey Island. Kolbeinsey Island, the only subaerial expression of this portion of the Mid-Atlantic Ridge, is a small, rapidly eroding island that formed during the late Pleistocene or Holocene. Dredged glass shards indicate submarine eruptive activity during the late-Pleistocene until at least 11,800 radiocarbon years ago. The island was 700 m long in 1616 CE, but had shrunk to 42 m long and 5 m high by 1985. The Kolbeinsey Hydrothermal Field lies south of the island. Thorarinsson (1965) roughly plotted the location of the 1372 eruption at about 66�40'N. Reidel et al. (2003) note that the location is uncertain, but could lie between the Kolbeinsey Ridge and H�ll Seamount. Other reports of submarine eruptions north of Iceland have an even more uncertain location (1755) or have been discredited (1783 and 1838).

Jan Mayen
Norway
Remote Jan Mayen Island, located in the Norwegian Sea along the Jan Mayen Ridge about 650 km NE of Iceland, consists of two volcanic complexes separated by a narrow isthmus. The large Beerenberg basaltic stratovolcano (Nord-Jan) forms the NE end of the 40-km-long island, which is ringed by high cliffs. The glacier-covered Beerenberg has a 1-km-wide summit crater and numerous cinder cones that were erupted along flank fissures. It is composed primarily of basaltic lava flows with minor amounts of tephra. Reported eruptions from Beerenberg date back to the 18th century. The SW tip of Jan Mayen contains the Holocene Sor-Jan cinder cones, tephra rings, and trachytic lava domes were erupted from short fissures with a NE-SW trend.

East Gakkel Ridge at 85�E
During January-September 1999 global seismic networks detected an earthquake swarm along the East Gakkel Ridge (near 86�N, 85�E). Sonar mapping in May 1999 identified a cone at the western end of a line of volcanoes that corresponded to the average location of the epicenters (Edwards et al., 2001). A survey in July 2007 (Sohn et al., 2008) provided detailed bathymetry and named selected features, including the Oden (location of the 1999 seismicity), Thor, and Loke cones. Both Oden and Loke were covered with a light dusting of pyroclastic material, which was also found throughout the survey area, thought to be products of an eruption during the 1999 swarm.

Iceland Neovolcanic Rift Volcanic Province

Snaefellsjokull
Iceland
Iceland Neovolcanic Rift Volcanic Province
Ice-clad Snaefellsj�kull volcano anchors the western tip of the isolated Snaefellsnes Peninsula in western Iceland. Numerous pyroclastic cones dot the flanks of this stratovolcano, the only large central volcano in this part of Iceland. Lower-flank craters produced basaltic lava flows and upper-flank craters intermediate-to-silicic material. Holocene lava flows extend to the sea over the entire western half of the volcano. Several Holocene silicic eruptions have originated from the summit crater. The latest dated eruption took place about 1750 years ago; several lava flows may be even younger.

Helgrindur
Iceland Neovolcanic Rift Volcanic Province
Helgrindur (also known as Lysuh�ll or Lysukard) is one of Iceland's smallest volcanic systems. It consists of a chain of small alkali olivine basaltic cinder cones and vents along a WNW-ESE line cutting across the central Snaefellsnes Peninsula in western Iceland. The slightly arcuate line of Quaternary vents extends to the northern coast of the peninsula. Helgrindur is the central of three volcanic systems occupying the peninsula. The latest eruption is undated, but the system has been active during the Holocene.

Ljosufjoll
The Lj�sufj�ll volcanic system at the eastern end of the Snaefellsnes Peninsula is composed of a group of alkali olivine basaltic cinder cones and lava flows along short fissures on a roughly 90-km-long WNW-ESE line. The volcanic field is about 20 km wide at the eastern end and narrows to about 10 km on the west. It contains the largest outcrops of silicic rhyolitic and trachytic rocks in the Snaefellsnes volcanic zone, erupted during the mid- to late Pleistocene. Youthful-looking cinder cones and lava flows with morphologically pristine surfaces suggest numerous Holocene eruptions. The latest eruption post-dated the settlement of Iceland, and took place about 1,000 years ago.

Reykjanes
Volcano type: Crater rows
The Reykjanes volcanic system at the SW tip of the Reykjanes Peninsula, where the Mid-Atlantic Ridge rises above sea level, comprises a broad area of postglacial basaltic crater rows and small shield volcanoes. The submarine Reykjaneshryggur volcanic system is contiguous with and is considered part of the Reykjanes volcanic system, which is the westernmost of a series of four closely-spaced en-echelon fissure systems that extend diagonally across the Reykjanes Peninsula. Most of the subaerial part of the system (also known as the Reykjanes/Svartsengi volcanic system) is covered by Holocene lavas. Subaerial eruptions have occurred in historical time during the 13th century at several locations on the NE-SW-trending fissure system, and numerous submarine eruptions dating back to the 12th century have been observed during historical time, some of which have formed ephemeral islands. Basaltic rocks of probable Holocene age have been recovered during dredging operations, and tephra deposits from earlier Holocene eruptions are preserved on the nearby Reykjanes Peninsula.

Krysuvik-Trolladyngja
Volcano type: Crater rows
The Kr�suv�k-Tr�lladyngja volcanic system is described by the Catalogue of Icelandic Volcanoes as an approximately 50-km-long composite fissure swarm trending about N38�E, including a 30-km-long swarm of fissures, with no central volcano. It is one of the volcanic systems arranged en-echelon along the Reykjanes Peninsula west of Kleifarvatn lake. The Fagradalsfjall and Kr�suv�k fissure swarms are considered splits or secondary swarms of the Kr�suv�k?Tr�lladyngja volcanic system. Small shield volcanoes have produced a large portion of the erupted volume within the system. Several eruptions have taken place since the settlement of Iceland, including the eruption of a large basaltic lava flow from the Ogmundargigar crater row around the 12th century. The latest eruption, identified through tephrochronology, took place during the 14th century.

Brennisteinsfjoll
The Brennisteinsfj�ll volcanic system, located east of Kleifarvatn lake, consists of a series of NE-SW-trending crater rows and small shield volcanoes. Postglacial and historical basaltic lavas cover a wide area. An eruption in 1000 CE was dated by its occurrence at the time of a meeting of the Icelandic outdoor parliament at Thingvellier. The most recent eruption took place in the 14th century.

Hromundartindur
Hr�mundartindur is a small volcanic system located south of Thingvallavatn lake and immediately east of the Hengill volcanic system. It lies at a ridge-ridge-transform triple junction at the eastern end of the Reykjanes Peninsula, where the west Iceland volcanic zone changes direction from approximately W-E to SW-NE. The most recent eruptions in the �lkeduh�ls area took place at the end of the latest glacial period, this geothermal field contains numerous hot springs, mud pools, fumaroles, and mineral warm springs. Increased seismic activity and slow uplift beginning in 1994, and continuing for more than 4 years, indicated magma flow into the volcanic system at 7 km depth. Hr�mundartindur was last active about 10,000 years ago.

Hengill
The Hengill volcanic system, cutting through Thingvallavatn lake, consists of a series of NE-SW-trending fissure vents, crater rows, and small shield volcanoes occupying a strongly faulted graben. Hengill is the easternmost of a series of four closely spaced basaltic fissure systems that cut diagonally across the Reykjanes Peninsula and lies at the triple junction of the Reykjanes Peninsula volcanic zone, the Western volcanic zone, and the South Iceland seismic zone. Postglacial lava flows surface much of the volcanic system. The latest eruption was radiocarbon dated about 1,900 years before present. An eruption in the Hellisheidi area once thought to have occurred around 1000 CE at the time of a meeting of the Icelandic parliament at Thingvellir is now known to have occurred at a vent about 5 km away in the Brennisteinsfj�ll volcanic system. The high-temperature Nesjavellir geothermal area NE of the uplifted hyaloclastite ridge forming the Hengill central volcano and the Helllisheidi geothermal field SW of Hengill are major producers of geothermal energy for Reykjavik.

Grimsnes
Gr�msnes is a relatively small volcanic system located SE of Thingvallavatn lake. It is displaced about 15-20 km to the east of the other en-echelon group of volcanic fields of the Western Volcanic Zone extending across the Reykjanes Peninsula. Its lava flows cover 54 km2 and were erupted from a group of 11 fissures that produced a series of NE-SW-trending crater rows. The eruptions of its basaltic lavas were considered to have been restricted to a relatively short interval between about 6,500 and 5,500 years ago, but radiocarbon dating showed that some of the lava flows were emplaced between about 7,400 and 8,900 years ago.

Prestahnukur
The Prestahn�kur volcanic system is located on the W side of the Langj�kull icecap at the west margin of the Western Volcanic Zone, and overlaps with the Hengill volcanic system north of Lake �ingvallavatn. It is about 90 km long and 15 km wide, with a subglacially erupted rhyolite peak and associated rift zones to the N and SW that have erupted during the Holocene. A large part of the volcanic system is underlain by early to mid Pleistocene plateau basalts. Olivine tholeiite basalt lava shields have erupted during the Holocene.

Oddnyjarhnjukur-Langjokull
The Oddn�jarhnj�kur-Langj�kull system includes the Hveravellir central volcano at the northern end of this active volcanic zone that extends NE from the Reykjanes Peninsula. Hveravellir occupies the NE half of the massive Langj�kull icecap, east of the Pleistocene Eriksk�kull table mountain. A summit caldera lies beneath the ice. The Kjalhraun shield volcano east of Langj�kull produced about 11 km3 of lava around 7,800 years ago. Several small shield volcanoes have been constructed along flank fissure zones, producing postglacial lava flows on the N, W, and E sides of Langj�kull. One of the most prominent of these is a small shield volcano at the site of the massive Hallmundahraun lava flow, which covers about 240 km2 and was erupted about 950 CE. The Geysir thermal area lies in the Haukadalur basin, near the southern end of the fissure system. The classic Icelandic shield volcano Skjaldbreidur is also within the southern part of this system, between Thorsj�kull glacier and Thingvallavatn lake; the broad, low-angle volcano produced more than 13 km3 of basaltic lava flows during the early Holocene.

Hofsjokull
Hofsj�kull volcano lies along an east-west-trending area connecting the two principal rift zones of Iceland. It bridges the gap between the Reykjanes-Langj�kull rift on the west, which terminates at Langj�kull, and the eastern zone, which extends NE-ward across east-central Iceland. The roughly 7 x 11 km central caldera lies beneath the western part of the massive Hofsj�kull icecap. A small Holocene shield volcano is located at the SW margin of the icecap. Flank fissures north and east of the icecap have produced basaltic lava flows during the Holocene. Kerlingarfj�ll, a glacially dissected, largely Pleistocene rhyolitic central volcano located SW of the Hofsj�kull icecap, is considered part of this volcanic system. Steep-sided Pleistocene rhyolitic lava domes and numerous hot springs occupy two calderas at the center of the 5 x 7 km wide complex. Fumarolic activity at Kerlingarfj�ll, mostly concentrated in the center of the complex, is the most vigorous in Iceland.

Vestmannaeyjar
The mostly submarine Vestmannaeyjar volcanic system is the southernmost and youngest volcanic center of the Eastern Volcanic Zone that cuts across E-central Iceland. It consists of a roughly 30 x 40 km group of basaltic islands and submarine cones occupying a shallow shelf off the S coast of Iceland, and was the site of two of Iceland's most noted 20th-century eruptions. The island of Surtsey grew from the ocean floor during 1963-67. The island of Heimaey, 20 km to the NE, was the site of eruptions in 1973, during which lava flows partially overran the town of Vestmannaeyjar and threatened its harbor. Twenty-two postglacial eruption sites are known, and all ten subaerial vents on Heimaey are of Holocene age.

Eyjafjallajokull
Eyjafjallaj�kull (also known as Eyjafj�ll) is located west of Katla volcano. It consists of an elongated ice-covered stratovolcano with a 2.5-km-wide summit caldera. Fissure-fed lava flows occur on both the E and W flanks, but are more prominent on the western side. Although the volcano has erupted during historical time, it has been less active than other volcanoes of Iceland's eastern volcanic zone, and relatively few Holocene lava flows are known. An intrusion beneath the S flank from July-December 1999 was accompanied by increased seismic activity. The last historical activity prior to an eruption in 2010 produced intermediate-to-silicic tephra from the central caldera during December 1821 to January 1823.

Katla
Katla volcano, located near the southern end of Iceland's eastern volcanic zone, is hidden beneath the Myrdalsj�kull icecap. The subglacial basaltic-to-rhyolitic volcano is one of Iceland's most active and is a frequent producer of damaging j�kulhlaups, or glacier-outburst floods. A large 10 x 14 km subglacial caldera with a long axis in a NW-SE direction is up to 750 m deep. Its high point reaches 1380 m, and three major outlet glaciers have breached its rim. Although most recorded eruptions have taken place from fissures inside the caldera, the Eldgj� fissure system, which extends about 60 km to the NE from the current ice margin towards Gr�msv�tn volcano, has been the source of major Holocene eruptions. An eruption from the Eldgj� fissure system about 934 CE produced a voluminous lava flow of about 18 km3, one of the world's largest known Holocene lava flows. Katla has been the source of frequent subglacial basaltic explosive eruptions that have been among the largest tephra-producers in Iceland during historical time and has also produced numerous dacitic explosive eruptions during the Holocene.

Tindfjallajokull
Tindfjallaj�kull is one of the oldest late-Quaternary volcanoes of the eastern volcanic zone of Iceland, and has produced rocks of basaltic-to-rhyolitic composition. The NW rim of the 5-km-wide caldera is topped by an icecap. About a dozen small eruptions took place during the late Pleistocene or early Holocene, mostly from vents north and west of the caldera. Although previously thought to be the source of the nearby Th�rsm�rk Ignimbrite deposits, Moles et al. (2019) showed that they originated from Torfaj�kull (about 30 km NE).

Torfajokull
The Torfaj�kull central volcano, located north of Myrdalsj�kull and south of Thorisvatn lake, is cut by a 12-km-wide caldera that formed during the Pleistocene. With about 225 km3 of silicic extrusive rocks exposed, it comprises the largest area of silicic and intermediate volcanism in Iceland. Work by Moles et al. (2019) identified the Ring Fracture Rhyolites as the source of the rhyolitic and trachyandesitic Th�rsm�rk Ignimbrite and the II-RHY-1 tephra, and dated them at 51.3 � 4.2 ka (40Ar/39Ar). The dominantly rhyolitic complex rises about 500 m above surrounding basaltic plains and is elongated WNW-ESE. Most rhyolitic lava flows were erupted subglacially, with silicic hyaloclastites that form ridge and dome-shaped breccias. During postglacial times only a narrow fissure zone at the western end has been active, producing mostly silicic lava flows, domes, and tephras. The most recent silicic eruption produced the Hrafntinnuhraun flow about 900 CE. The fissure system is along trend with and was active at the same time as the basaltic Veidiv�tn fissure system of B�rdarbunga central volcano in 1477 CE. The small Torfaj�kull icecap lies mostly outside the SE rim of the caldera, which is the site of vigorous thermal activity over a broad area of 130-140 km2.

Hekla
One of Iceland's most prominent and active volcanoes, Hekla lies near the southern end of the eastern rift zone. Hekla occupies a rift-transform junction, and has produced basaltic andesites, in contrast to the tholeiitic basalts typical of Icelandic rift zone volcanoes. Vatnafj�ll, a 40-km-long, 9-km-wide group of basaltic fissures and crater rows immediately SE of Hekla forms a part of the Hekla-Vatnafj�ll volcanic system. A 5.5-km-long fissure, Heklugj�, cuts across the 1491-m-high Hekla volcano and is often active along its full length during major eruptions. Repeated eruptions along this rift, which is oblique to most rifting structures in the eastern volcanic zone, are responsible for Hekla's elongated ENE-WSW profile. Frequent large silicic explosive eruptions during historical time have deposited tephra throughout Iceland, providing valuable time markers used to date eruptions from other Icelandic volcanoes. Hekla tephras are generally rich in fluorine and are consequently very hazardous to grazing animals. Extensive lava flows from historical eruptions, which date back to 1104 CE, cover much of the volcano's flanks.

Grimsvotn
Gr�msv�tn, Iceland's most frequently active volcano in recent history, lies largely beneath the vast Vatnaj�kull icecap. The caldera lake is covered by a 200-m-thick ice shelf, and only the southern rim of the 6 x 8 km caldera is exposed. The geothermal area in the caldera causes frequent j�kulhlaups (glacier outburst floods) when melting raises the water level high enough to lift its ice dam. Long NE-SW-trending fissure systems extend from the central volcano. The most prominent of these is the noted Laki (Skaftar) fissure, which extends to the SW and produced the world's largest known historical lava flow in 1783. The 15 km3 basaltic Laki lavas were erupted over 7 months from a 27-km-long fissure system. Extensive crop damage and livestock losses caused a severe famine that resulted in the loss of one-fifth of the population of Iceland.

Bardarbunga
The large central volcano of B�r�arbunga lies beneath the NW part of the Vatnaj�kull icecap, NW of Gr�msv�tn volcano, and contains a subglacial 700-m-deep caldera. Related fissure systems include the Veidiv�tn and Trollagigar fissures, which extend about 100 km SW to near Torfaj�kull volcano and 50 km NE to near Askja volcano, respectively. Voluminous fissure eruptions, including one at Thjorsarhraun, which produced the largest known Holocene lava flow on Earth with a volume of more than 21 km3, have occurred throughout the Holocene into historical time from the Veidiv�tn fissure system. The last major eruption of Veidiv�tn, in 1477, also produced a large tephra deposit. The subglacial Loki-F�grufj�ll volcanic system to the SW is also part of the B�r�arbunga volcanic system and contains two subglacial ridges extending from the largely subglacial Hamarinn central volcano; the Loki ridge trends to the NE and the F�grufj�ll ridge to the SW. J�kulhlaups (glacier-outburst floods) from eruptions at B�r�arbunga potentially affect drainages in all directions.

Tungnafellsjokull
The Tungnafellsj�kull central volcano, located immediately NW of the massive Vatnaj�kull icecap, contains two calderas. One is largely filled by the Tungnafellsj�kull glacier, and the other ice-free caldera to the SE contains Pleistocene rhyolitic lavas. The volcano is largely of Pleistocene age, but postglacial flank fissures on the NE side have produced young basalts. The H�g�ngur central volcano to the SW is part of this volcanic system.

Kverkfjoll
Kverkfj�ll is a large subglacial volcano at the NE end of the Vatnaj�kull icecap. Two elliptical ice-filled calderas, each about 8 x 5 km in size, have been identified. An associated fissure swarm can be traced 60 km to the NE. A half dozen ridges of subglacially erupted pillow lavas are now exposed and extend beyond the glacial icecap to the NE. Subglacial historical eruptions have been recorded since the mid-17th century. Several other historical eruptions once attributed to Kverkfj�ll are now thought to have originated from B�rdarbunga volcano to the west.

Askja
Askja is a large basaltic central volcano that forms the Dyngjufj�ll massif. It is truncated by three overlapping calderas, the largest of which is 8 km wide and may have been produced primarily from subglacial ring-fracture eruptions rather than by subsidence. A major rhyolitic explosive eruption from Dyngjufj�ll about 10,000 years ago was in part associated with the formation of Askja caldera. Many postglacial eruptions also occurred along the ring-fracture. A major explosive eruption on the SE caldera margin in 1875 was one of Iceland's largest during historical time. It resulted in the formation of a smaller 4.5-km-wide caldera, now filled by �skjuvatn lake, that truncates the rim of the larger central caldera. The 100-km-long Askja fissure swarm, which includes the Sveinagja graben, is also related to the Askja volcanic system, as are several small shield volcanoes such as Kollatadyngja. Twentieth-century eruptions have produced lava flows from vents located mostly near �skjuvatn lake.

Fremrinamar
The Fremrin�mar volcanic system, N of Askja and SE of Myvatn lake, includes the central Ketildyngja shield volcano and the Sveinar fissure swarm that extends 130 km to the north coast of Iceland. The Kerlingardyngja shield volcano to the south is early Holocene. The latest eruption produced the Burfellshraun lava flow about 3,200 years ago that covered 75 km2.

Krafla
The Krafla volcanic system in the Northern Volcanic Zone (NVZ) of Iceland is about 100 km long, consisting of a fissure swarm and a central volcano with a 7 x 9 km caldera formed about 110,000 years ago that deposited a rhyolitic welded tuff. It has been moderately active in the Holocene, over three distinct eruptive periods; the current one has lasted about 2,800 years with six volcano-tectonic episodes, each with one or more basaltic fissure eruptions. Lava volumes (DRE) have been in the 0.1-1 km3 range. The Hverfjall and Ludent tuff rings east of Myvatn were erupted along the fissure system. Myvatn lake formed during the eruption of the older Laxarhraun lava flow from the Ketildyngja shield volcano of the Fremrinamur volcanic system about 3,800 years before present (BP); The present Myvatn lake is constrained by the roughly 2,000 years BP younger Laxarhraun lava flow from the Krafla volcanic system. The abundant pseudocraters that form a prominent part of the Myvatn landscape were created when the younger Laxarhraun lava flow entered the lake. The last eruption took place in 1975-1984 CE when nine small basaltic fissure eruptions produced 0.25 km3 of lava.

Theistareykir
The Holocene Theistareykir fissure system, including the basaltic Theistareykjarbunga shield volcano, extends from north of Myvatn lake to the coast of Iceland. This is the northernmost subaerial volcanic system along the Eastern Volcanic Zone of Iceland. The 30 km3 Theistareykjarbunga shield volcano formed slightly after deglaciation; the youngest dated eruption produced the Theistareykjahraun lava flow about 2,400 years ago.

Oraefajokull
Latitude: 64°N
�r�faj�kull, Iceland's highest peak, is a broad glacier-clad central volcano at the SE end of the Vatnaj�kull icecap. A 4 x 5 km subglacial caldera truncates the summit of the dominantly basaltic and rhyolitic volcano. The extensive summit icecap is drained through deep glacial valleys dissecting the SW-to-SE flanks. It is the largest-volume volcano in Iceland, and was mostly constructed during Pleistocene glacial and interglacial periods. Holocene activity has been dominated by explosive summit eruptions, although flank lava effusions have also occurred. A major silicic eruption in 1362 CE was Iceland's largest historical explosive eruption. It and another eruption during 1727-28 were accompanied by major j�kulhlaups (glacier outburst floods) that caused property damage and fatalities.

Esjufjoll
The subglacial Esjufj�ll volcano at the SE part of the Vatnaj�kull icecap, north of �raefaj�kull, consists of the Snaehetta central volcano and a large caldera. Most of the volcano, including the 40 km2 caldera, is covered by ice, but parts of the SE flank are exposed in NW-SE ridges. Most of the exposed rocks are mildly alkaline basalts, but small amounts of rhyolitic rocks are also present. A large j�kulhlaup that came down the Jokulsa a Breidamerkursandi along the coast SE of Vatnaj�kull in the beginning of September 1927 was accompanied by a sulfur odor, and one ashfall event on the Breidamerkurj�kull possibly originated from Esjufj�ll. Although Holocene eruptions have not been confirmed, earthquake swarms that could indicate magma movements were detected in October 2002.

Snaefell
The timing of the most recent activity in the Sn�fell volcanic system, NE of Vatnaj�kull, is unknown. Four Holocene transitional alkalic tephra units in a soil section near the volcano have compositions similar to known Sn�fell eruption products (Oladottir and others, 2011). This stratovolcano is comprised of rhyolites and evolved basalts built in the last 400,000 years. Volcanic fissures trending NE-SW occur out to 10-18 km from the volcano. It lies on a volcanic belt outside the main volcanic zones. The Sn�fell central volcano is Iceland?s highest volcanic peak outside of the large ice caps; it has a small glacier on its summit.

Heidarspordar
The Hei�arspor�ar volcanic system in the Northern Volcanic Zone is about 22 km long, consisting of a fissure swarm and a central volcano. It is embryonic, starting to develop in the marginal area of two adjacent fissure areas, Krafla and Fremrin�mar, producing large-volume eruptions. No geothermal activity is present. Magma composition ranges from olivine-tholeiite through tholeiitic basalt and basaltic andesite to dacite. Characteristic activity consists of effusive basaltic eruptions and small predominantly effusive silicic eruptions. It has shown rather low activity in the Holocene but has produced substantial basaltic lava flows. Two eruptive periods have occurred in Holocene time separated by over 8,000 years. The last eruption took place about 2,200 years ago, producing a lava flow covering about 220 km2 and extending 60 km from source.

Eldey
The Eldey volcanic system is located on the northernmost part of the Reykjanes Ridge and is submarine with the exception of Eldey Island and the skerries (small rocky islands) Eldeyjardrangur, Geirfugladrangur, and Geirfuglasker. Maximum water depth within the system is about 250 m. Characteristic activity consists of explosive submarine basaltic eruptions. Six small eruptions have been located within this system during the last 1,100 years, the last occurring in 1926 CE. Bulletin reports that are included here cover a larger area of the Reykjanes Ridge south of Iceland without a clear source or enough evidence for a separate volcano entry.

Thordarhyrna
The ��r�arhyrna central volcano has been moderately active during the Holocene, with the last eruption occurring in 1903 CE. It is the second and less active central volcano of the Gr�msv�tn-Laki volcanic system, located about 20 km SW of the more active Gr�msv�tn central volcano and connected to it by a subglacial mountain ridge. The volcano has a diameter of 15 km, and is covered by ice 100-600 m thick within the Vatnaj�kull glacier. The last eruption occurred in 1903 CE. The recent activity has been explosive (phreatomagmatic) basaltic eruptions with tephra volumes ranging from 0.01-1 km3, but several rhyolitic nunataks characterize this volcano. Eruptions are accompanied by j�kulhlaups. Being the only second central volcano on a volcanic system with considerable historical volcanic activity, ��r�arhyrna is treated as an independent volcano although the fissure swarm events are shared with the Gr�msv�tn system.

Fagradalsfjall
Although the Fagradalsfjall fissure swarm has previously been considered a split or secondary swarm of the Kr�suv�k?Tr�lladyngja volcanic system, as of September 2022 Icelandic volcanologists managing the Catalogue of Icelandic Volcanoes made the decision to identify it as a distinct separate system. The recent eruptions and related reports have been reassigned here, and other content will be prepared and adjusted as appropriate.

Azores-Terceira Rift Volcanic Province

Pico Fracture Zone
Azores-Terceira Rift Volcanic Province
On 9 July 1865 the crew of a whaling ship observed a submarine eruption. Floating pumice reached the ocean surface, where it formed a large "floating mountain." A strong odor of sulfur was noticed, and dull rumbling sounds were heard at intervals of one hour.

Flores
Portugal
Azores-Terceira Rift Volcanic Province
Flores Island and Corvo Island to its north are located over 200 km W of the other Azores islands, west of the Mid-Atlantic Ridge. Growth of an initially submarine volcano included Pleistocene explosive activity associated with formation of small calderas. The 12 x 17 km island of Flores contains numerous cones and craters. Following a long period of quiescence beginning about 200,000 years ago, several phreatomagmatic craters and associated lava flows erupted during the Holocene. The Caldeira Funda de Lajes tuff ring formed about 3,150 years ago, accompanied by a lava flow that reached the SE coast at Lajes. The Caldeira Comprida tuff ring in Caldeira Seca, west-central Flores, erupted about 2,900 years ago and produced a lava flow that traveled NW to the coast at Faja Grande.

Fayal
Portugal
The island of Fayal, also spelled Faial, is the nearest of the central Azorean islands to the Mid-Atlantic Ridge. The island is composed of a complex large andesitic-to-trachytic stratovolcano that contains a 2-km-wide summit caldera. Thick deposits of trachytic airfall pumice, pyroclastic flows, and lahars related to formation of the caldera cover the island. Formation of the steep-walled 400-m-deep caldera was followed by construction of fissure-fed basaltic lava fields and small volcanoes that form a peninsula extending to the west. This area is covered by the youngest volcanic products on the island. A submarine eruption at Capelinhos during 1957-58 created a new island that soon merged with the western peninsula.

Pico
Portugal
The conical Pico stratovolcano occupies the western end of Pico Island and is the highest volcano in the Azores. The dominantly basaltic edifice lies west of on an older linear volcano with numerous flank cones that forms most of the 46-km-long island. It was constructed over the Montanha volcanic complex on the eastern side of the island and is capped by a 500-m-wide summit crater that is overtopped by a small steep-sided cone. An eruption beginning in 1562 from the Sao Roque Piedade/Planalto da Achada fissure zone produced lava flows that reached the northern coast. Two fissures erupted on the NNW flank and SE flank of Pico volcano in 1718, with lavas reaching the north and south coasts. Lava flows from a fissure on the SE flank in 1720 reached the ocean.

Sao Jorge
The dominantly basaltic S�o Jorge Island is 55 km long and 6.5 km wide. It was formed by fissure eruptions beginning in the eastern part of the island. The western two-thirds of the island contains youthful, fissure-fed lava flows resembling those on neighboring Pico Island. Lava effused from three locations above the south-central coast during 1580, producing flows that reached the ocean. In 1808 a series of explosions took place from vents along the south-central crest of the island; one of the vents produced a lava flow that reached the southern coast. Submarine eruptions have also been reported on several occasions from a submarine ridge to the SE. The 1964 event offshore W of Velas was considered "probable" by Madiera and Brum da Silveira (2003), who also provided 14C dates for several other Holocene eruptions.

Graciosa
The SE end of Graciosa, the northernmost of the central Azorean islands, contains a 0.9 x 1.6 km caldera with active fumaroles. The SE caldera rim is the high point of the 7 x 12 km island. The caldera has been the source of eruptions producing significant tephra falls, pyroclastic flows, lahars, and lava flows. Fumaroles are present in a volcanic cave inside the caldera, and a submarine fumarole occurs off the NW coast. Scoria cones erupted along several widely spaced NE-SW-trending fissures fed a youthful lava field that forms the NW end of the island. The most recent eruption from Pico Tomao, NW of the caldera, produced a lava flow during the mid-to-late Holocene that reached the eastern coast NW of the village of Praia.

Terceira
Terceira Island contains multiple stratovolcanoes constructed along a prominent ESE-WNW fissure zone that cuts across the island. Historically active Santa Barbara volcano at the western end of the island is truncated by two calderas, the youngest of which formed about 15,000 years ago. Comenditic lava domes fill and surround the caldera. Pico Alto lies north of the fissure zone in the north-central part of the island and contains a Pleistocene caldera largely filled by lava domes and lava flows. Guilherme Moniz caldera lies along the fissure zone immediately to the south, and 7-km-wide Cinquio Picos caldera is at the SE end of the island. Historical eruptions have occurred from Pico Alto, the fissure zone between Pico Alto and Santa Barbara, and from submarine vents west of Santa Barbara. Most Holocene eruptions have produced basaltic-to-rhyolitic lava flows from the fissure zone.

Don Joao de Castro Bank
Don Joao de Castro Bank is a large submarine volcano that rises to within 13 m of the ocean surface roughly halfway between Terceira and San Miguel Islands. Pillow lavas form the base of the volcano, which is capped by basaltic hyaloclastites. A submarine eruption during December 1720 produced an ephemeral island that attained a length of 1.5 km and a height of about 250 m before it was eroded beneath the surface two years later. The volcano (also spelled Dom Joao de Castro) was named after the Portuguese hydrographic survey vessel that surveyed the bank in 1941. Two youthful craters, one tephra covered and the other sediment free, are located on the NW flank. The submarine volcano has a shallow fumarole field and remains seismically active.

Picos Fissural Volcanic System
Nearly 200 scoria cones of the Picos volcanic system dot the narrow central zone of Sao Miguel Island between Sete Cidades and Agua de Pau volcanoes. This area of monogenetic fissure-controlled, dominantly basaltic volcanism, much of which post-dates the roughly 5,000-year-old Fogo eruption, cannot be assigned to either volcano and appears related to en-echelon fissures overlying a fracture zone. Thick pumice deposits thought to originate from the Picos system may have originated from vents or a caldera destroyed and now buried by young basaltic volcanism. The most noteworthy of the young vents is Serra Gorda, SE of Siete Cidades, and the cone that produced a lava delta south of Agua de Paul village. The majority of the inhabitants of Sao Miguel Island occupy both coasts below this volcanic zone. At least 18 eruptions have occurred during the past 2,800 years, although the only recorded eruption occurred in 1652 CE. The most recent activity has been basaltic; however, two more-explosive trachytic eruptions occurred during the past 1,100 years.

Sete Cidades
Sete Cidades volcano at the western end of Sao Miguel Island contains a 5-km-wide summit caldera occupied by two caldera lakes. The steep-walled, 500-m-deep caldera was formed about 22,000 years ago, and at least 22 post-caldera eruptions have occurred. A large group of Pleistocene post-caldera trachytic lava domes, lava flows, and pyroclastic-flow deposits is found on the western-to-northern flanks. A nearly circular ring of six Holocene pyroclastic cones on the caldera floor have been the source of a dozen trachytic pumice-fall deposits erupted during the past 5,000 years. Recorded eruptions date back to the 15th century and have occurred both within the caldera and from submarine vents off the west coast.

Agua de Pau
The Agua de Pau stratovolcano in central Sao Miguel Island contains an outer 4 x 7 km caldera formed about 30,000-45,000 years ago and an inner 2.5 x 3 km caldera that was created about 15,000 years ago. The younger caldera is partially filled by the Lagoa do Fogo caldera lake. Several post-caldera lava domes were emplaced on the northern and western flanks, but activity in the caldera did not resume until about 5000 years ago. The 3 km3 Fogo-A plinian pumice fall deposit was emplaced at this time. Numerous flank cinder cones mark radial and concentric fissures, some of which have been active during historical time. The latest trachytic explosive eruption took place during 1563. Prominent hot springs are located on the NW flank.

Furnas
Furnas volcano lies at the eastern end of Sao Miguel Island, immediately west of the older Nordeste shield volcano and its Povoa�ao caldera. There are at least two calderas, a younger one that is 6-km wide and a larger older one that is less topographically distinct. The eastern wall of the 500-m-deep Furnas caldera overlaps the western wall of the Nordeste Povoa�ao caldera. Volcanic activity dates back about 100,000 years. At least 11 trachytic pumice layers, all erupted during the past 5000 years, post-date the caldera. The most prominent post-caldera feature is the Pico do Gaspar lava dome, east of the Lagoa das Furnas caldera lake. A zone of late-Pleistocene to Holocene basaltic-to-trachytic cinder cones and lava domes is located between Furnas and Agua de Pau volcanoes. Two historical eruptions have occurred, one sometime between 1439 and 1443 and the other in 1630. The latter was one of the largest Holocene explosive eruptions in the Azores and caused significant damage and fatalities.

Monaco Bank
Monaco Bank is a submarine volcano constructed along a NW-SE-trending fissure 20 km S of the western tip of Sao Miguel Island. The linear volcano is located along regional tectonic trends connecting Sete Cidades volcano with Santa Mar�a Island, SE of Monaco Bank. The summit rises to within about 200 m of the ocean surface. Submarine eruptions took place during 1911 and 1907, when a submarine cable was ruptured.

Central Mid-Atlantic Rift Volcanic Province

Romanche Fracture Zone
Central Mid-Atlantic Rift Volcanic Province
Several reports of submarine disturbances of possible volcanic origin near the equator were noted by Neumann van Padang et al. (1967, CAVW). Ship captains have reported numerous submarine eruptions during the 18th and 19th centuries over a broad area in this part of the Atlantic, including descriptions of seaquakes, turbulent water, columns of smoke, floating pumice, submarine banks, or small ephemeral islands. These accounts were tentatively collectively assigned by the CAVW to a seamount along the Romanche Fracture Zone, although their locations span a broad area up to 400 km W of the assigned location. Floating "volcanic ash" was collected in 1836 from a site near the Mid-Atlantic Rift, well E of the seamount. The validity of these reports is not clear, although three of these events were considered by the CAVW to possibly represent submarine eruptions.

Ascension
Central Mid-Atlantic Rift Volcanic Province
Ascensi�n Island, just west of the Mid-Atlantic Ridge ~2,250 km E of the eastern-most point of Brazil, is the 12-km-diameter emergent summit of a stratovolcano that rises ~3,000 m above the seafloor. The isolated island has more than 100 youthful cones and lava domes, many aligned along two fissures. Basaltic rocks dominate on the island, but trachytic lava domes are also present, mostly on the eastern side. Two of the youngest lava flows were erupted from flank vents and reached the sea on the N and S coasts. Argon-Argon dating by Preece and others (2018) identified three eruptions within the past 2,000 years. No eruptive activity has occurred since it was visited on Ascensi�n Day in 1501 by the Portuguese navigator Joao da Nova.

Southern Atlantic Volcano Group

Nightingale Island
Southern Atlantic Volcano Group
Nightingale Island, along with the adjacent smaller Middle (or Alex) and Stoltenhoff Islands and associated small islets, are the southernmost of the Tristan da Cunha island group. The heavily eroded island consists of ash and agglomerate units with intervening massive trachytic intrusions and lava flows. Volcanic rocks were K-Ar dated at between 400,000 and 150,000 years, and a radiocarbon date of about 39,000 years BP was obtained from an ash layer overlain by a lava flow. An earthquake swarm lasting 6 hours beginning on 29 July 2004 was followed by observation of large blocks of floating phonolitic pumice that washed up on Tristan da Cunha. The pumice was considered to be from an eruption associated with an earthquake swarm 37-53 km SSE of Tristan da Cunha on the submarine SE flank of Nightingale Island.

Tristan da Cunha
Southern Atlantic Volcano Group
Tristan da Cunha is a 13-km-wide island volcano lying about 500 km E of the crest of the Mid-Atlantic Ridge just south of the latitudes of Buenos Aires and Cape Town. The shield volcano is bounded on most sides by high cliffs. Lava flows dominate both the low-angle base and the steep upper flanks, although pyroclastic cones ringing the central cone are scattered around the lower flanks. Eruptions have occurred from the 300-m-wide summit crater, Queen Mary's Peak, which contains a small lake, and from numerous flank vents, some of which occurred from radial fissures. Radial dike swarms are prominently exposed on all sides of the island. Numerous Strombolian cinder cones occur on the flanks along both concentric ring structures and NNW- and ENE-trending radial fissures. The only historical eruption occurred during 1961 from a north shore vent and forced the evacuation of the island's only settlement.

Bouvet
Norway
The solitary ice-covered shield volcano of Bouvet Island is located just off the Southwest Indian Ridge, east of the triple junction between the African, South American, and Antarctic plates. This basaltic-to-rhyolitic island, also referred to as Bouvetoya, was discovered by and later named for Captain Lozier-Bouvet during his 1739 search for the "great southern continent." About 95% of the uninhabited 10-km-wide island is covered by glaciers. The most prominent feature is the 3.5-km-wide Wilhelmplataet caldera, which is breached to the sea on the NW side. A late-stage rhyolitic lava dome forms the Cape Valdivia peninsula on the N flank. A paleomagnetic investigation was made by Lovlie and Furnes (1978) of a massive basaltic lava flow unit at Cape Meteor; based on oriented drill cores they tentatively inferred a minimum age of 2,000 years.

Walvis Ridge at 33�S
Volcano type: Cone
Hydrophones in the North Atlantic Ocean recorded signals from an explosive eruption in the South Atlantic along the Walvis Ridge about 780 km NE of Tristan da Cunha Island (Haxel and Dziak, 2005). The signals occurred from November 2001 to March 2002 from the N flank of a seamount 170 km NW of W�st seamount and 100 km WNW of Rachel seamount (named by the Walvis Ridge MV1203 Expedition). The signals, similar to those produced by a 2001 submarine eruption of Kick 'em Jenny volcano in the West Indies, reached a peak on 19-20 December 2001.

Northern Africa Volcanic Regions

Western Africa Volcanic Province

Pico Basile
Equatorial Guinea
Western Africa Volcanic Province
Pico Basil� is the largest and highest of three basaltic shield volcanoes forming Bioko Island. Lying on the continental shelf along the Cameroon Line, this volcano is modified by the same NNE faults as Mt. Cameroon across the Gulf of Guinea on the mainland. It contains numerous satellitic cinder cones and is the only Bioko Island volcano with recorded eruptions, although they are poorly documented. Three eruptions, during the late-19th and early-20th centuries, have been reported from SE flank vents.

Tombel Graben
Cameroon
Western Africa Volcanic Province
Young cinder cones and maars are abundant in the low-lying Tombel Graben (also referred to as the Tombel Plain) between Mount Cameroon and Mount Manengouba (within 4�58'N, 9�51'E and 4�33'N, 9�35'E). Mount Koupe, composed of Tertiary syenite, dominates the area. Activity began with the emission of large lava flows over Precambrian metamorphic rocks and Cretaceous sandstones, and concluded with explosive activity forming numerous cinder cones. The 800 km2 volcanic field, which erupted basanitic, basaltic, and trachybasaltic rocks, contains three large lake-filled maars, including Barombi Mbo, a compound maar near the town of Kumba. Legends record an eruption of Le Djungo (also known as Mont Pel�) that destroyed a village; though a small craterless cone is marked along a fault line on a map in Nkono (2009, after Nkouathio et al., 2002) it's unclear what cone is being described by the story, because no noticeably younger or unvegetated cones are apparent in satellite imagery. Two samples taken from the Njombe area in the farthest SW part of the field were K-Ar dated as possible Holocene (Nkouathio et al., 2008), though the error was too large to be definitive.

Cameroon
The massive steep-sided Mount Cameroon rises above the coast of west Cameroon, overlooking the Bight of Biafra, part of the Gulf of Guinea. The dominantly basaltic-to-trachybasaltic edifice forms a volcanic horst constructed above a basement of Precambrian metamorphic rocks covered with Cretaceous to Quaternary sediments. More than 100 small cinder cones, often fissure-controlled parallel to the long axis of the 1,400 km3 edifice, occur on the flanks and surrounding lowlands. A large satellitic peak, Etinde (also known as Little Cameroon), is located on the S flank near the coast. The first known reported activity was in the 5th century BCE by the Carthaginian navigator Hannon. Additional activity has frequently been reported since about 1800 CE, consisting of moderate explosive and effusive eruptions from both summit and flank vents. A 1922 SW-flank eruption produced a lava flow that reached the Atlantic coast, and a lava flow from a 1999 S-flank eruption stopped only 200 m from the sea. Explosive activity from two vents on the upper SE flank was reported in May 2000.

Oku Volcanic Field
Cameroon
Numerous maars and basaltic cinder cones lie on or near the deeply dissected rhyolitic and trachytic Mount Oku massif along the Cameroon volcanic line. The Mount Oku stratovolcano is cut by a large caldera. The Oku volcanic field is noted for two crater lakes, Lake Nyos to the N and Lake Monoun to the S, that have produced catastrophic carbon-dioxide gas release events. The 15 August 1984 gas release at Lake Monoun was attributed to overturn of stratified lake water, triggered by an earthquake and landslide. The Lake Nyos event on 21 August 1986 caused at least 1,700 fatalities. The emission of ~1 km3 of magmatic carbon dioxide has been attributed either to overturn of stratified lake waters as a result of a non-volcanic process, or to phreatic explosions or injection of hot gas into the lake.

Southeast Sahara Volcanic Province

Jebel Marra
Sudan
Southeast Sahara Volcanic Province
The most prominent feature of the vast Jebel Marra volcanic field, located in the Darfur province of western Sudan, is the youthful Deriba caldera. The 5-km-wide, steep-walled caldera, located at the southern end of the field, was formed about 3,500 years ago at the time of the eruption of voluminous airfall pumice and pyroclastic flows that traveled more than 30 km from the volcano. The Jebel Marra volcanic field covers a broad area of the Marra Mountains and contains early basaltic lava flows overlain by thick sequences of pyroclastic-flow deposits. The northern part of the field displays trachytic lava plugs and spines forming residual inselbergs and young basaltic scoria cones and lava flows. Ash eruptions at Deriba caldera may have continued into early historical time (Burton and Wickers, 1966), and fumarolic activity has been observed on the flanks of a small pyroclastic cone within the caldera.

Kutum Volcanic Field
Sudan
Southeast Sahara Volcanic Province
The basaltic Kutum volcanic field, in the northern Darfur area of western Sudan, is located SW of the larger Meidob volcanic field. As with other Saharan volcanic fields, Kutum (also known as the Tagabo Hills or Berti Hills) contains very well-preserved cones, lava flows, and explosion craters. They were considered to be of late-Pleistocene or even Holocene age (Almond, 1974). Franz et al. (1997), however, assigned only Tertiary age ranges for rocks from Tagabo Hills.

Meidob Volcanic Field
Sudan
The alkaline Meidob volcanic field in western Sudan, at the NE end of the Darfur volcanic province, covers an area of 5,000 km2 with nearly 700 Pliocene-to-Holocene vents. The field was constructed over an uplifted Precambrian igneous and metamorphic basement and is elongated in an E-W direction. Basaltic scoria cones and associated lava flows dominate, but trachytic-phonolitic lava domes, tuff rings, and maars are among the youngest volcanic products. Basaltic scoria cones are scattered throughout the field; their lavas have produced a broad lava plateau. The central part of the field consists of younger phonolitic lava flows, trachytic pumice-fall deposits, ignimbrites, and maars. The youngest dated eruptions about 5,000 years ago produced a tuff ring and a lava flow.

Bayuda Volcanic Field
The Bayuda volcanic field is located in the Bayuda Desert of NE Sudan, south of the major Abu Hamed bend of the Nile River about 300 km N of Khartoum. More than 90 eruptive centers along a WNW-ESE line were constructed over Precambrian and Paleozoic granitic rocks near the center of the Bayuda Desert. Most vents are cinder cones that produced lava flows which breached the cones. About 10% of vents in the field are explosion craters, the largest of which, named Hosh ed Dalam, is 1.3 km wide and up to 500 m deep. The youngest basalts appear to post-date the last period of moist climate in Sudan, which ended as recently as about 5,000 years ago. One of the least eroded lava flows was dated at about 1,100 years ago.

East Central Sahara Volcanic Province

Tarso Toh
Chad
East Central Sahara Volcanic Province
The Tarso T�h Pleistocene-to-Holocene volcanic field in the NW part of the arid Tibesti Range of Chad contains 150 scoria cones and two maars. Basaltic lava flows fill valleys and plains over an area of 80 km in an E-W direction and 20-30 km in a N-S direction in the area north of the more well-known Tarso Toussid� Volcanic Complex. The flows were erupted over a basement of Precambrian schists on the east and Paleozoic sandstones on the west. Sediments within the Begour maar were radiocarbon dated at 8300 +/- 300 years (Hagedorn and Jakel, 1969).

Tarso Tousside
Chad
East Central Sahara Volcanic Province
Tarso Toussid�, a broad volcanic massif at the western end of the Tibesti Range, is capped by the Toussid� stratovolcano, constructed at the western end of the 14-km-wide ignimbritic Pleistocene Yirrigue caldera. The 6,000 km2 massif was constructed over a basement of Precambrian schists on the east and Paleozoic sandstones on the west. The summit contains numerous fumaroles and very youthful lava flows (Vincent, 1992 pers. comm.). Fresh-looking trachytic and trachyandesitic lava flows cover an area of 200 km2 and extend as far as 25 km from the summit on the western side. The steep-sided, 1-km-deep, 8-km-wide Trou au Natron caldera cuts the SE rim of Yirrigue caldera and is one of the youngest features of the massif. Ehi Timi and Ehi Sosso volcanoes, and the smaller 1.5-km-wide explosion crater of Doon Kidimi, are located on the NE-to-ESE flanks of the massif.

Emi Koussi
Chad
Volcano type: Shield(pyroclastic)
The large Emi Koussi volcano at the SE end of the Tibesti Range, a 60 x 80 km massif constructed over a basement of Cretaceous and Paleozoic sandstones, forms the highest summit of the Sahara. Two nested calderas, 12 x 15 km, truncate the dominantly trachytic volcano, whose high point lies on the southern caldera rim of the low-angle pyroclastic shield volcano. The calderas contain several explosion craters, lava domes, and young scoria cones, along with lava flows of recent and pre-modern age (Geze et al., 1959). The Era Kohor (Trou au Natron du Koussi) caldera on the SE floor of the 2nd caldera is 2-3 km wide and 350 m deep. The latest activity in the calderas produced three maars, and numerous basaltic cinder cones; associated lava flows have been constructed both within the calderas and on their outer flanks. The Yi-Yerra thermal area is located on the S flank.

Tarso Voon
The broad summit of Tarso Voon volcano, located in the west-central part of the Tibesti Range, is truncated by a shallow 14 x 18 km wide caldera. Ignimbrite deposits surround the caldera to distances of 15-35 km. It was constructed over a basement of Precambrian schists. Youthful-looking Quaternary basaltic lava flows have been erupted from vents near the caldera rim over a 180-degree area extending counterclockwise from the NE and from Ehi Mousgau, a 3100-m-high stratovolcano located to the NW. The Soborom solfatara field, the largest in the Tibesti Range, is located in an area of volcano-tectonic uplift 5 km west of the caldera rim. Its fumaroles, active mud pots, and boiling waters are visited by Tibesti peoples for medicinal uses.

West Central Sahara Volcanic Province

Todra Volcanic Field
Niger
West Central Sahara Volcanic Province
The Todra Volcanic Field covers about 1,000 km2 in the Tuareg shield in the southern A�r region of Niger. Activity began with the eruption of about 30 trachytic and phonolitic volcanoes through Precambrian basement rocks. This was followed by the formation of about 130 basaltic cones that typically produced valley-filling lava flows. A series of NW-SE faults control cone locations. The date of the latest eruption is not known, but may have been as recent as a few centuries ago.

Tahalra Volcanic Field
Algeria
West Central Sahara Volcanic Province
Longitude: 5°E
The large E-W elongated Tahalra volcanic field covers an area of about 1,800 km2 in the Hoggar Province of southern Algeria. It lies WSW of the town of Tamanrasset and was active from the Miocene to the Holocene, producing alkaline Strombolian cones and lava flows. The field was constructed over Precambrian metamorphic and plutonic rocks of the Tuareg shield. A dozen trachytic-to-rhyolitic lava domes and spines formed during the Pliocene, and Pliocene-to Pleistocene activity formed about 100 small basaltic (mostly basanitic) cones. The most recent activity, during the Pleistocene and Holocene, produced about 20 maars and cones along the northern margin.

Atakor Volcanic Field
Algeria
The massive Atakor volcanic field is the largest in the Hoggar (or Ahaggar) volcanic province of southern Algeria and covers an area of 2,150 km2. Quaternary basaltic (mostly basanitic) scoria cones and lava flows lie near older trachytic and phonolitic lava domes and volcanic necks that form some of the most dramatic scenery of northern Africa. The latest stage of activity began around 1.95 million years and continued almost to the present. Lava flows cover Holocene lake sediments dated at about 10,000 BP and alluvial terraces in which Neolithic artifacts have been found. Pottery has been found within lava flows in the Tahifet area, and oral traditions of the Tuareg people suggest that eruptions were witnessed. Sporadic fumaroles and persistent small-scale seismicity have been reported.

Manzaz Volcanic Field
Algeria
The Manzaz volcanic field, north of the Atakor volcanic field in the Hoggar (Ahaggar) volcanic province of Algeria, consists of a large number of scoria cones and associated lava flows. The field covers an area of 1,500 km2, overlying Precambrian metamorphic and plutonic rocks of the Tuareg shield. Many cones are breached, and the dominantly basaltic and basanitic volcanic products are rich in peridotite and pyroxenite xenoliths and megacrysts. The youngest volcanoes rest on Neolithic terraces and are of Holocene age.

Cape Verde Hotspot Volcano Group

Fogo
Cabo Verde
Cape Verde Hotspot Volcano Group
The island of Fogo consists of a single massive stratovolcano that is the most prominent of the Cape Verde Islands. The roughly circular 25-km-wide island is truncated by a large 9-km-wide caldera that is breached to the east and has a headwall 1 km high. The caldera is located asymmetrically NE of the center of the island and was formed as a result of massive lateral collapse of the older Monte Armarelo edifice. A very youthful steep-sided central cone, Pico, rises more than 1 km above the caldera floor to about 100 m above the rim. Pico, which is capped by a 500-m-wide, 150-m-deep summit crater, was apparently in almost continuous activity from the time of Portuguese settlement in 1500 CE until around 1760. Later lava flows, some from vents on the caldera floor, reached the eastern coast below the breached caldera.

Brava
Cabo Verde
Cape Verde Hotspot Volcano Group
Brava Island, 18 km W of Fogo, is the westernmost of the southern Cape Verde islands. The 10-km-wide island contains 15 morphologically youthful craters located along two or three lineaments intersecting along the crest of the island. Most of the younger eruptions originated from the interaction of phonolitic magmas with a large groundwater reservoir contained within an older volcanic series characterized by thick welded ignimbrites and block-and-ash flow deposits. Carbonatitic lavas are also found.

Canary Volcanic Province

La Palma
Spain
Canary Volcanic Province
The 47-km-long wedge-shaped island of La Palma, the NW-most of the Canary Islands, is composed of two large volcanic centers. The older northern one is cut by the steep-walled Caldera Taburiente, one of several massive collapse scarps produced by edifice failure to the SW. On the south, the younger Cumbre Vieja volcano is one of the most active in the Canaries. The elongated volcano dates back to about 125,000 years ago and is oriented N-S. Eruptions during the past 7,000 years have formed abundant cinder cones and craters along the axis, producing fissure-fed lava flows that descend steeply to the sea. Eruptions recorded since the 15th century have produced mild explosive activity and lava flows that damaged populated areas. The southern tip of the island is mantled by a broad lava field emplaced during the 1677-1678 eruption. Lava flows also reached the sea in 1585, 1646, 1712, 1949, 1971, and 2021.

Hierro
Spain
Canary Volcanic Province
The triangular island of Hierro is the SW-most and least studied of the Canary Islands. The massive shield volcano is truncated by a large NW-facing escarpment formed as a result of gravitational collapse of El Golfo volcano about 130,000 years ago. The steep-sided scarp towers above a low lava platform bordering 12-km-wide El Golfo Bay, and three other large submarine landslide deposits occur to the SW and SE. Three prominent rifts oriented NW, NE, and S form prominent topographic ridges. The subaerial portion of the volcano consists of flat-lying Quaternary basaltic and trachybasaltic lava flows and tuffs capped by numerous young cinder cones and lava flows. Holocene cones and flows are found both on the outer flanks and in the El Golfo depression. Hierro contains the greatest concentration of young vents in the Canary Islands. Uncertainty surrounds the report of an eruption in 1793. A submarine eruption took place about 2 km SSW off the southern point of the island during 2011-12.

Tenerife
Spain
The large triangular island of Tenerife is composed of a complex of overlapping Miocene-to-Quaternary stratovolcanoes. The NE-trending Cordillera Dorsal volcanic massif joins the Las Ca�adas volcano on the SW side of the island with older volcanoes, creating the largest volcanic complex of the Canary Islands. The origin of the 10 x 17 km Las Ca�adas caldera, partially filled by the Teide stratovolcano, has been variably considered to be due to collapse following multiple major explosive eruptions or as a result of a massive landslide (in a manner similar to the earlier formation of the massive La Orotava and Guimar valleys), or a combination of the two processes. The most recent stage of activity beginning in the late Pleistocene included the construction of the Pico Viejo and Teide edifices. Tenerife was perhaps observed in eruption by Christopher Columbus, and several flank vents on the Canary Island's most active volcano have been active during historical time.

Gran Canaria
The circular 60-km-wide island of Gran Canaria in the middle of the Canary archipelago includes three major volcanic structures, and has been modified by caldera collapse, gravitational edifice failure, and extensive erosion resulting in steep-walled radial gorges called barrancos. Although the island is largely Miocene-to-Pliocene, middle Quaternary scoria cones and lava flows are found in the northern and eastern parts of the massive shield volcano, which is cut by a major NW-SE-trending rift zone that extends across the island and fed flows primarily to the NE. Basaltic cones and lava flows of Holocene age are situated within a NW-trending zone from Berrazales to Bandama, and at Las Isletas, a peninsula on the NE coast. One cinder cone was radiocarbon dated at about 3,000 years before present, and other cones and flows may be less than 1,000 years old.

Fuerteventura
Pleistocene and Holocene cinder cones and lava flows cover large portions of elongated Fuerteventura Island at the SE end of the Canary Islands. The youngest lavas are found at the northern and central portions of the arid, sparsely vegetated island. Malpais de la Arena, the Northern Malpais, and the Lobos Island areas at the northern tip of Fuerteventura are the sites of broad fields of cinder cones and lava flows. The Malpais Chico, Malpais Grande, and Malpais de Jacomar areas on the south-central part of the island represent smaller zones of youthful volcanism, as do the volcanoes of Pajara, which were constructed on the older plutonic massif west of the axis of the island. No recorded eruptions are known, although the appearance of lava flow surfaces in the central part of the island suggests late Holocene activity.

Lanzarote
The 60-km-long island of Lanzarote at the NE end of the Canary Islands contains the largest concentration of youthful volcanism in the Canaries. Pleistocene-and-Holocene cinder cones and lava flows erupted along NE-SW fissures are found throughout the low-altitude arid island and on smaller islands to the north. The largest historical eruption of the Canary Islands took place during 1730-36, when long-term eruptions from a fissure formed the Monta�as del Fuego and produced voluminous lava flows that covered about 200 km2. The lava flows reached the western coast along a broad, 20-km-wide front. The villages of Maretas and Santa Catalina were destroyed, along with the most fertile valleys and estates on the island. An eruption during 1824 produced a much smaller lava flow that reached the SW coast.

Madeira Hotspot Volcano Group

Madeira
Madeira Hotspot Volcano Group
Madeira Island is the emergent top of a massive shield volcano that rises about 6 km from the floor of the Atlantic Ocean and forms the largest island of the 90-km-long Madeira Archipelago. Construction of the volcano along E-W rift zones from the Miocene to about 700,000 years ago was followed by a period of extensive erosion and possible edifice collapse. Two steep-walled amphitheaters open to south in the central part of the island. Late-stage eruptions are scattered throughout the island and lasted until the Holocene, producing scoria cones and intra-canyon lava flows covering rocks of the older eroded edifice. The youngest activity lies in the west-central part of the island, and consists of cinder cones in the upper Sao Vicente valley, a series of intra-canyon flows, and a tephra layer on top of the Paul da Serra plateau dated at about 6,500 years ago.

European Volcanic Regions

Western European Volcanic Province

Chaine des Puys
Western European Volcanic Province
The Cha�ne des Puys, prominent in the history of volcanology, form a N-S-trending chain of basaltic and trachytic cinder cones, basaltic maars, and trachytic lava domes in France's Massif Central that has been active into the Holocene. Construction of the present-day Cha�ne des Puys began about 70,000 years before present (BP), and was largely completed by the beginning of the Holocene. Holocene eruptions constructed lava domes such as the Puy de D�me, whose growth was accompanied by pyroclastic flows, cinder cones that fed lengthy lava flows, and maars. The latest well-documented activity took place about 6,000 BP near Besse-en-Chandesse and included the powerful explosions that formed the Lac Pavin maar. The dating of younger tephras has not yet been confirmed, and reports of eruptions as late as 1,000 BP have been discredited.

Olot Volcanic Field
Western European Volcanic Province
The Olot volcanic field (also known as the Garrotxa volcanic field) occupies the NE corner of Spain south of the Pyrenees Mountains about 90 km NNE of Barcelona. The field consists of a large number of Strombolian pyroclastic cones and associated alkali basaltic lava flows, and is part of the NE Volcanic Province, which includes the Ampurd�n and Selva areas to the SE. The pyroclastic cones are preferentially located at the intersection of E-W and NW-SE faults that cut sedimentary and metamorphic basement rocks. The latest dated eruption occurred during the early Holocene, and stratigraphic evidence suggests that more recent eruptions have occurred.

Calatrava Volcanic Field
The Calatrava volcanic field lies in central Spain near Ciudad Real. The more than 300 basaltic-to-foiditic pyroclastic cones, maars, and lava domes cover an area of more than 5,000 km2. The field is mostly of Pliocene or late-Pleistocene age, although late-stage phreatomagmatic activity at Columba volcano was dated at the mid-Holocene. It lies in a continental rift setting and contains several lake-filled maars. Fumarolic activity was recorded in the Sierra de Valenzuela area during the 16th-18th centuries.

Central European Volcanic Province

West Eifel Volcanic Field
Germany
Central European Volcanic Province
The West Eifel Volcanic Field of western Germany, SW of the city of Bonn, is a dominantly Pleistocene group of 240 scoria cones, maars, and small stratovolcanoes covering an area of about 600 km2. The smaller, but better known, East Eifel Volcanic Field is about 40 km NE. Individual vents spread across a broad NW-SE-trending area extending about 50 km from the towns of Ormont on the NW to Bad Bertrich on the SE. Eruptions originated from a mantle plume through Devonian sedimentary and metamorphic rocks. Two-thirds of the volcanic centers in the field are scoria cones; lava flows have been produced from about half of them. About 30% of the centers are maars or tuff rings, many of which are occupied by lakes. About 230 eruptions have occurred during the past 730,000 years. The latest eruptions formed the Ulmener, Pulvermaar, and Strohn maars around the end of the Pleistocene and the beginning of the Holocene.

Italian Peninsula Volcanic Provinces

Colli Albani
Italy
Italian Peninsula Volcanic Provinces
The Colli Albani (Alban Hills) complex immediately SE of Rome contains a large Pleistocene stratovolcano with a 10 x 12 km caldera formed during an eruptive period with six major explosions that produced at least 280 km3 of ejecta between about 560,000 and 350,000 years ago. Subsequent eruptions occurred from a new 5-km-wide central cone and from many phreatomagmatic craters and cones within the Artemisio-Tuscolana caldera and on its outer flanks. The post-caldera eruptions have buried the western side of the caldera rim. The largest of the post-caldera craters is Lake Albano, a 2.5 x 4 km compound maar constructed at the WSW margin of the caldera in multiple stages dating back to about 69,000 years ago. The age of the most recent eruptions from the Albano maar is not known precisely; variable dates range from about 36,000 years ago to perhaps the Holocene, when several possibly non-volcanic lake overflow lahars occurred. Reported eruptions during the Roman period are uncertain, but subsequent seismic swarms lasting up to two years have been recorded.

Campi Flegrei
Italy
Italian Peninsula Volcanic Provinces
Campi Flegrei is a 13-km-wide caldera that encompasses part of Naples and extends to the south beneath the Gulf of Pozzuoli. Episodes of significant uplift and subsidence within the dominantly trachytic caldera have occurred since Roman times. The earliest known eruptive products are dated 47,000 years BP. The caldera formed following two large explosive eruptions, the massive Campanian ignimbrite about 36,000 BP, and the over 40 km3 Neapolitan Yellow Tuff (NYT) about 15,000 BP. Following eruption of the NYT a large number of eruptions originated from widely scattered subaerial and submarine vents. Most activity occurred during three intervals: 15,000-9,500, 8,600-8,200, and 4,800-3,800 BP. The latest eruptions were in 1158 CE at Solfatara and in 1538 CE when the Monte Nuovo cinder cone was built.

Vesuvius
Italy
One of the world's most noted volcanoes, Vesuvius (Vesuvio) forms a dramatic backdrop to the Bay of Naples. The active cone was constructed within a large caldera of the older Monte Somma edifice, thought to have formed incrementally beginning about 17,000 years ago. The Monte Somma caldera wall has channeled lava flows and pyroclastic flows primarily to the south and west. Eight major explosive eruptions have taken place in the last 17,000 years, often accompanied by large pyroclastic flows and surges, such as during the 79 CE Pompeii eruption. Intermittent eruptions since 79 CE were followed by a period of frequent long-term explosive and effusive eruptions between 1631 and 1944. The large 1631 eruption produced pyroclastic flows that reached as far as the coast and caused great destruction. Many towns are located on the flanks, and several million people live within areas that could be affected by eruptions.

Ischia
The Ischia volcanic complex forms a rectangular, 6 x 9 km island immediately SW of the Campi Flegrei area at the western side of the Bay of Naples. The eruption of the trachytic Green Tuff ignimbrite about 56,000 years ago was followed by caldera formation. The high point on the island, Monte Epomeo, is a volcanic horst composed of the Green Tuff ignimbrite deposit that was submerged after its eruption and then uplifted. Volcanism on the island has been significantly affected by tectonism that formed a series of horsts and grabens; at least 800 m of uplift has formed as a result of resurgent doming during past 33,000 years. Many small monogenetic volcanoes were formed around the uplifted block. Volcanism during the Holocene produced a series of pumiceous tephras, tuff rings, lava domes, and lava flows, and a major collapse of Mount Epomeo produced a large submarine debris-avalanche deposit. The latest eruption, in 1302 CE, produced a spatter cone and the Arso lava flow, which reached the NE coast.

Aeolian Volcanic Arc

Palinuro
Aeolian Volcanic Arc
Palinuro seamount in the Tyrrhenian Sea north of the Eolian Islands rises nearly 3,000 m to within 70 m of the surface and has an open summit crater. A marine ash layer (PL-1) radiocarbon dated (calibrated) at 9,990 +/- 90 years ago is chemically and stratigraphically similar to two ash layers on land in southern Italy; it was tentatively correlated to Palinuro seamount activity (Siani et al., 2004).

Panarea
Aeolian Volcanic Arc
The mostly submerged Panarea volcanic complex lies about midway between Stromboli and Lipari in the eastern part of the Aeolian Islands. Panarea, the smallest island in the Aeolian Archipelago, lies on the western side of a shallow platform whose shelf margin is at about 130 m depth. A series of small islands breach the surface to form the Central Reefs, the rim of a crater 2 km E of Panarea, whose shallow submerged floor contains Roman ruins. The submerged Secca dei Pesci lava dome lies at the SE end of the platform, and the rhyolitic Basiluzzo lava dome rises 165 m above the surface at the NE end, along a ridge trending towards Stromboli volcano. The complex was constructed in two main stages: an initial effusive activity phase that produced lava domes, and an explosive stage. The youngest subaerial airfall-tephra deposits are dated to about 20,000 years ago; a date of less than 10,000 BP on a lava flow is uncertain. Vigorous hydrothermal activity has continued at fumarolic fields at several locations on the submerged platform; submarine hydrothermal explosions have been observed.

Lipari
Lipari, the largest of the Aeolian Islands, is located immediately north of Vulcano Island. The irregular-shaped island contains numerous small stratovolcanoes, craters, and lava domes on a basement of submarine volcanic deposits. Lipari was formed in three major eruptive cycles, the first of which took place from about 223 to 188 thousand years ago (ka) from N-S-trending fissures on the western side of the island. The second eruptive period from about 102 to 53 ka included the formation of the Monte San Angelo and Costa d'Agosto stratovolcanoes in the center of the island. The third eruptive cycle (40 ka to the present) included the Monte Guardia sequence, erupted at the southern tip of the island between about 22,600 and 16,800 years ago, and Holocene rhyolitic pyroclastic deposits and obsidian lava flows at the NE end of the island. The latest eruption, at Monte Pilato on the NE tip of the island, formed the Rocche Rosse and Forgia Vecchia obsidian lava flows, which have been dated variously from about 500 to 1230 CE. Objects made of obsidian from Lipari have been found throughout southern Italy.

Stromboli
Spectacular incandescent nighttime explosions at Stromboli have long attracted visitors to the "Lighthouse of the Mediterranean" in the NE Aeolian Islands. This volcano has lent its name to the frequent mild explosive activity that has characterized its eruptions throughout much of historical time. The small island is the emergent summit of a volcano that grew in two main eruptive cycles, the last of which formed the western portion of the island. The Neostromboli eruptive period took place between about 13,000 and 5,000 years ago. The active summit vents are located at the head of the Sciara del Fuoco, a prominent scarp that formed about 5,000 years ago due to a series of slope failures which extends to below sea level. The modern volcano has been constructed within this scarp, which funnels pyroclastic ejecta and lava flows to the NW. Essentially continuous mild Strombolian explosions, sometimes accompanied by lava flows, have been recorded for more than a millennium.

Vulcano
The word volcano is derived from Vulcano stratovolcano in Italy's Aeolian Islands. Vulcano was constructed during six stages over the past 136,000 years. Two overlapping calderas, the 2.5-km-wide Caldera del Piano on the SE and the 4-km-wide Caldera della Fossa on the NW, were formed at about 100,000 and 24,000-15,000 years ago, respectively, and volcanism has migrated north over time. La Fossa cone, active throughout the Holocene and the location of most historical eruptions, occupies the 3-km-wide Caldera della Fossa at the NW end of the elongated 3 x 7 km island. The Vulcanello lava platform is a low, roughly circular peninsula on the northern tip of Vulcano that was formed as an island beginning more than 2,000 years ago and was connected to the main island in about 1550 CE. Vulcanello is capped by three pyroclastic cones and was active intermittently until the 16th century. Explosive activity took place at the Fossa cone from 1898 to 1900.

Marsili
The Marsili seamount is a 50-km-long volcanic ridge in the southern Tyrrhenian Sea within a back-arc basin about 75-85 km NW of the Aeolian arc volcanoes. Near-source tephra layers obtained from a core sample were determined by Iezzi et al. (2013) to be approximately 3,000 and 5,000 years old. Accretion of the ridge is thought to have begun around 1 Ma. Recent data also indicate that there is ongoing hydrothermal activity and shallow volcano-tectonic seismicity.

Sicily Volcanic Province

Etna
Sicily Volcanic Province
Mount Etna, towering above Catania on the island of Sicily, has one of the world's longest documented records of volcanism, dating back to 1500 BCE. Historical lava flows of basaltic composition cover much of the surface of this massive volcano, whose edifice is the highest and most voluminous in Italy. The Mongibello stratovolcano, truncated by several small calderas, was constructed during the late Pleistocene and Holocene over an older shield volcano. The most prominent morphological feature of Etna is the Valle del Bove, a 5 x 10 km caldera open to the east. Two styles of eruptive activity typically occur, sometimes simultaneously. Persistent explosive eruptions, sometimes with minor lava emissions, take place from one or more summit craters. Flank vents, typically with higher effusion rates, are less frequently active and originate from fissures that open progressively downward from near the summit (usually accompanied by Strombolian eruptions at the upper end). Cinder cones are commonly constructed over the vents of lower-flank lava flows. Lava flows extend to the foot of the volcano on all sides and have reached the sea over a broad area on the SE flank.

Pantelleria
Sicily Volcanic Province
The island of Pantelleria is constructed above a drowned continental rift in the Strait of Sicily and has been the locus of intensive volcano-tectonic activity. Two large Pleistocene calderas dominate the island, which contains numerous post-caldera lava domes and cinder cones and is the type locality for peralkaline rhyolitic rocks, pantellerites. The 15-km-long island is the emergent summit of a largely submarine edifice. The 6-km-wide Cinque Denti caldera, the youngest of the two calderas, formed about 45,000 years ago and contains the two post-caldera shield volcanoes of Monte Grande and Monte Gibele. Holocene eruptions have constructed pumice cones, lava domes, and short, blocky lava flows. Many Holocene vents are located on three sides of the uplifted Montagna Grande block on the SE side of the island. A submarine eruption in 1891 from a vent ~4 km off the NW coast is the only confirmed historical activity.

Campi Flegrei del Mar di Sicilia
Campi Flegrei del Mar di Sicilia (Phlegraean Fields of the Sicily Sea) is composed of a group of submarine volcanoes SW of Sicily. The volcanoes were constructed within a submarine depression about 1 km deep in the Strait of Sicily between the SW coast of Sicily and the NE tip of Tunisia, forming submarine banks that are capped by cones that rise to near sea level. Submarine eruptions were reported at the Giulia-Ferdinandeo and Pinne banks during the first Punic war (264-241 BCE), and from the 17th to 20th centuries, sometimes producing ephemeral islands. The 1831 eruption at Ferdinandea (also known as Graham in English or Giulia/Julia in French) produced an ephemeral island that was promptly claimed by the navies of France, Britain, Spain, and Italy.

Hellenic Volcanic Arc

Methana
Greece
Hellenic Volcanic Arc
Methana volcano consists of a basaltic andesite to rhyodacitic lava dome complex forming the Methana Peninsula in the Sarronian Gulf on the NE side of Peloponnesus. Potassium-Argon ages for the older part of the complex range from 900,000 to 550,000 years, although activity may have begun during the late Pliocene. A younger phase of activity took place from about 380,000-290,000 years ago, forming a series of lava domes and flows. The youngest dome, Kameno Vouno, on the NW side of the peninsula, was formed in the 3rd century BCE and produced a lava flow that traveled 500 m beyond the coastline. Hot springs are found at several locations along the coast of the peninsula.

Milos
Greece
Hellenic Volcanic Arc
M�los and adjacent small islands have grown from submarine and subaerial volcanism that initially was dominantly andesitic and basaltic, but ended with predominately rhyolitic eruptions. The oldest volcanic rocks are Pliocene submarine rhyolitic pyroclastic-flow deposits overlying basement metamorphic and sedimentary rocks. The latest activity during the late Pleistocene was concentrated in the eastern half of the low, U-shaped M�los Island, forming lava domes and phreatic explosion craters, and on Antim�los Island to the NW, where a composite volcano was constructed. The youngest magmatic eruptions took place about 90,000 years ago, but phreatic explosions, commonly producing overlapping craters rarely more than 1 km in diameter, continued from late-Pleistocene to Recent times. A lahar deposit in SE M�los, east of Fyriplaka tuff ring, buried walls of a Roman harbor town and overlies a coarse ash layer, and was considered to originate from a small phreatic explosion through basement rocks.

Santorini
Greece
Santorini (Thera), in the Aegean Sea, has steep-walled caldera rim with villages that overlook an active volcanic island in the center of a caldera bay. The circular island group is composed of overlapping shield volcanoes cut by at least four partially overlapping calderas. The oldest southern caldera was formed about 180,000 years before present (BP), followed by the Skaros caldera about 70,000 BP, and then the Cape Riva caldera about 21,000 BP. The youngest caldera formed about 3,600 BP (around 1600 BCE) during the Late-Bronze-Age Minoan eruption that forced abandonment of the island. Post-Minoan eruptions beginning in 197 BCE constructed a series of lava domes and flows that form two islands near the center of the caldera. The latest eruption produced a small lava dome and flow in 1950, accompanied by explosive activity.

Nisyros
The easternmost volcano of the Aegean arc forms the 9-km-wide island of Nisyros, which is truncated by a 3-4 km wide caldera. The island was constructed during the past 150,000 years, with three cone-building stages including explosive and effusive andesitic eruptions and effusive and extrusive dacitic and rhyolitic activity. The age of the caldera is variously considered to be less than 24,000 years before present (BP) (Keller et al., 1990) and older than 44,000 years BP (Limburg and Varekamp, 1991). Five large post-caldera lava domes completely fill the western part of the caldera. The NE-most (Boriatiko) and SW-most (Karaviotis) lava domes and flows are significantly younger than the other domes. A sixth post-caldera dome, outside the SW caldera rim, produced lava flows that reached the coast. Historical phreatic eruptions occurred from craters within the caldera between 1422 and 1888. Intense hydrothermal activity continues in the form of many fumaroles on the caldera floor and hot springs along the coast.

Kolumbo
The submarine Kolumbo volcano is about 15 km NE of the center of the Santorini caldera. Although previously considered to be part of a volcanic field associated with Santorini along a fault zone, Klaver et al. (2016) concluded that Kolumbo was a distinct volcanic system with "a deep differentiation history" based on "a signature of high 208Pb/206Pb compared to Santorini". A strong eruption during September-November 1650 CE killed over 60 people, along with livestock, due to toxic gas emissions; ashfall reached mainland Turkey, and an island of pumice rose above sea level but was rapidly eroded. Klaver et al. (2016) describe the current crater as roughly oval-shaped with a diameter of ~1.7 km, with the crater floor at 500 m below sea level, and the highest point of the crater rim at -18 m. A chain of 19 smaller volcanic features extends ~10 km NE from this primary crater.

Western Anatolian Volcanic Province

Kula
Turkiye
Western Anatolian Volcanic Province
The Kula volcanic field, the westernmost area of young volcanism in Turkey, lies about 450 km WNW of its closest Holocene neighbor in central Turkey, the Karapinar volcanic field. The Kula field consists of a broad area of Quaternary alkaline basanitic-to-phonotephritic cinder cones and maars erupted along a roughly E-W line SW of the city of Selendi. Most are Pleistocene in age, between about 1.1 million and 10,000 years old. The initial stage produced lava flows from vents along the ring fracture of caldera identified from satellite images. The second and third stages took place along an E-W graben and produced lava flows with ultramafic xenoliths. Although activity was considered to have continued until the beginning of the Holocene (Yilmaz, 1990), or almost to historical times (Borsi et al., 1972), the age of the most recent eruption is not known.

Hasandag-Keciboyduran Volcanic Complex
Turkiye
Western Anatolian Volcanic Province
The Hasandag-Ke�iboyduran volcanic complex in Central Anatolia includes the massive double-peaked Hasan Dagi stratovolcano, which has undergone four episodes of caldera collapse, the latest of which formed a 4-5 km wide caldera at the summit. The modern edifice within the latest caldera is the youngest of four major basaltic-to-rhyolitic volcanic complexes dating back to the mid-Miocene. Andesitic-to-dacitic lava domes form the two principal summits, of which the westernmost is the highest and is capped by two nested craters. Lava domes and associated pyroclastic-flow deposits cover more than half the flanks. As defined by Uslular et al. (2021), this volcanic field also includes the Pliocene-Quaternary Ke�iboyduran stratovolcano, along with numerous monogenetic features: 11 lava domes (andesitic to rhyolitic), 33 scoria cones (basaltic), one maar (basaltic), and 34 undifferentiated features. Interpretations of Neolithic paintings representing eruptions are controversial, but geologic evidence supports eruptive activity continuing into the Holocene. Uslular et al. (2021) reported a lava dome possibly as young as 9,000 years BP (U-Th/He, citing Friedrichs et al., 2020, and Schmitt et al., 2014).

Erciyes Volcanic Complex
Turkiye
The Erciyes Volcanic Complex at the northern end of the Sultansazligi Basin in central Anatolia is dominated by the massive eroded Erciyes Dagi stratovolcano at the approximate center of a radial monogenetic volcanic field 32 km in diameter, extending further towards the N. Uslular et al. (2021) identified 100 lava domes (dacitic to rhyolitic), 40 scoria cones (basaltic to andesitic), four maars (basaltic andesitic), and 44 undifferentiated features as part of this complex. Growth of the modern edifice began about 900,000 years ago, following Pliocene caldera collapse of the Kocdag complex. The youngest dated rock was from an 83,000-year-old dacitic lava flow, but rhyodacitic eruptions and lava dome growth occurred later at the Perikartin dome. One of the latest documented events was an edifice collapse that produced a large debris avalanche that extended to the east. An early Holocene distal tephra layer in Lebanon was attributed to Erciyes Dagi. Uncertainty remains regarding reported eruptions and their possible depiction on Roman Cappadocian coins. Accounts possibly referring to eruptions could also be attributed to methane releases from a swamp in the Sultansazligi Basin.

Arabia-Central Asia Volcanic Regions

Central Anatolian Volcanic Province

Nemrut Dagi
Central Anatolian Volcanic Province
Nemrut Dagi is the westernmost of a group of volcanoes near Lake Van in eastern Anatolia and the only one that has erupted in historical time. It contains a 9 x 5 km caldera partially filled on its western side by a caldera lake. Post-caldera volcanism, of basaltic to rhyolitic composition, initially occurred along the caldera rim and floor. Pyroclastic flows and the emission of glassy obsidian lava flows accompanied construction of lava domes within the caldera; later activity formed a series of cinder cones and lava domes erupted along N-S-trending fissures on the northern flank. The most recent activity has been concentrated along a NNW-trending fissure cutting the eastern caldera floor and extending beyond the north caldera rim; nearly two dozen cinder cones and lava domes were constructed on the caldera floor. Ash layers in Lake Van document numerous Holocene eruptions, and an eruption in 1441 CE from a N-flank fissure involved compositionally bimodal lava flows.

Tenduruk Dagi
Central Anatolian Volcanic Province
Tend�rek Dagi, also known as Tend�r�k Dagi, is an elongated shield volcano that rises above the Dogubayazit plain, near the Iranian border south of Mount Ararat. An E-W summit ridge, developed north of an arcuate caldera structure exposed only on the southern side, contains two well-developed cones. The higher western cone is capped by a steep-walled crater with a trachytic spine at its eastern edge. The flatter eastern crater contains a warm lake. The shield volcano developed during a period when highly mobile lava flows from the western crater covered an area of 500 km2. Following summit caldera formation, numerous flank eruptions took place from N-S-trending fissures, producing viscous trachytic lava domes and flows as well as fluid basaltic pahoehoe flows that extend 10-20 km N and S. The latest activity formed two major basaltic lava flows from large cones on the NE and SE flanks. An eruption took place from a vent on the SE flank about 2500 years ago, and a gas-and-ash eruption took place in 1855.

Ararat
Mount Ararat, also known as Agri Dagi, is Turkey's highest and largest volume volcano. The overall massif extends ~25 km NW-SE, and 18 km NE-SW, with another large volcano, Kucuk Ararat (or Lesser Ararat), ~11 km SE. Construction of the Greater and Lesser Ararat volcanoes was followed by a period of extensive flank eruptions, many erupted along N-S fissures. The initial stage of flank eruptions produced a cluster of cinder cones and dacitic-rhyolitic lava domes surrounding Greater Ararat and a series of pyroclastic cones and domes on the W flank of Lesser Ararat. There are also large pyroclastic cones lower on the flanks of the two volcanoes. A small cone ~8 km SW of Lesser Ararat appears to be the source of a dark lava-flow field covering ~80 km2 towards the S. Ararat appears to have been active during the 3rd millennium BCE; pyroclastic-flow deposits overlie early Bronze Age artifacts and human remains. Karakhanian et al. (2002) reported historical evidence for a phreatic eruption and pyroclastic flow at the time of a July 1840 earthquake and landslide.

Caucasus Volcanic Province

Elbrus
Caucasus Volcanic Province
Elbrus, the highest peak of the Caucasus Mountains of SW Russia, is a large glaciated stratovolcano. The summit area has two distinct peaks about 1 km apart, with a 250-m-wide crater on the eastern cone, separated by a low saddle from the western peak. Eruptive products cover 260 km2; its longest lava flow traveled 24 km down the NNE flank. Vlodavetz (in Blumenthal et al., 1964, CAVW) hypothesized that the most recent lava flows were 2,000-3,000 years old based on morphological appearance. Gushchenko (1979) noted explosive activity and a lava flow across a glacial moraine, and dated it at around 2,000 years ago. Weak solfataric activity has been reported near the summit, and hot springs are present on the flanks.

Kazbek
Georgia
Caucasus Volcanic Province
The glacier-covered Kazbek stratovolcano in the Caucasus Mountains of Georgia, just south of the border with Russia, has produced long lava flows down flank valleys. The summit cone and the latest lava flows are of post-glacial age, and the latest andesitic-dacitic lava flow was radiocarbon dated at about 6,000 years ago. Gushchenko (1979) listed an 800-700 BCE eruption.

Samsari Volcanic Center
Georgia
The Samsari Volcanic Center consists of more than 20 volcanoes extending about 40 km N-S along the Samsari Ridge, part of the Dzhakheti Highland of southern Georgia, about 90 km WSW of Tbilisi. The most prominent volcanoes are Shavnabada in the north, the Samsari Caldera, and Didi-Abuli in the south. K-Ar dates obtained by Lebedev et al. (2003) showed that the oldest rocks were about 400 ka, from Didi-Abuli; the Samsari caldera was active around 200 ka. One sample from Tavkvetili volcano, a feature with a well-preserved crater at the far northern edge of the range, dated to <30 ka. A lava flow from Godorebi volcano, just north of Didi-Abuli, had a similar date.

Aragats
Armenia
Aragats is a large andesitic-to-dacitic stratovolcano in NW Armenia about 40 km NW of the capital city of Yerevan. The main edifice is dissected by glaciers and is of Pliocene-to-Pleistocene age. Satellitic cones and fissures are located on all sides of the volcano and were the source of large lava flows that descended its lower flanks. Several of these were considered to be of Holocene age, but later Potassium-Argon dating indicated mid- to late-Pleistocene ages. The youngest lower-flank flows have not been precisely dated, but are constrained as occurring between the end of the late-Pleistocene and 3000 BCE (Kharakanian et al., 2003). A 13-km-long, WSW-ENE-trending line of craters and pyroclastic cones cuts across the northern crater rim and is the source of young lava flows and lahars; the latter were considered to be characteristic of Holocene summit eruptions.

Ghegham Volcanic Ridge
Armenia
The Ghegham Volcanic Ridge, located in west-central Armenia between the capital city of Yerevan and Lake Sevan, contains as many as 127 volcanic centers, lava domes and pyroclastic cones, of Pleistocene-to-Holocene age. The volcanoes and associated lava flows cover a 65-km-long, 35-km-wide area west of Lake Sevan and south of the Hrazdan River and are concentrated along three NNW-SSE-trending alignments. Lava flows from the central and eastern clusters flowed into Lake Sevan. Initial explosive eruptions in the volcanic field were followed by the extrusion of rhyolitic obsidian lava domes and flows. The latest activity produced a series of andesitic and basaltic andesite cinder cones and lava flows. The central and eastern portions of the field contain large areas of Holocene eruptions with morphologically fresh lava flows devoid of vegetation.

Vaiyots-Sar
Armenia
The Vaiyots-Sar pyroclastic cone is located in the southern Armenia province of Vayots Dzor in the western Vardenis Volcanic Highland south of Lake Sevan (Karakhanian et al., 2002); previous names such as Dar-Alages or Daly-Tapa are of Russian origin. Near the north end of the approximately 5 x 8 km flow field the 1.5-km-diameter cone rises about 300 m above the surrounding lavas, identified by Sviatlovsky (1959) as post-glacial. Oswald (1906) noted that steep escarpments of Nummulitic limestones were ~6 km NE of the cone across an lava-flow field. At the southern end of the flow field a fissure-fed lava flow several thousand years ago dammed the Arpah River near the town of Vyke and then flowed NW for 6 km; the flows overlie a late Pleistocene terrace and have little soil development (Karakhanian et al., 2002). The youthful-looking Smbatassar cinder cone, 17 km NW of Vaiyots-Sar, appears to be the source vent for Holocene lava flows that traveled 11 km N and 17 km S down two valleys (Karakhanian et al., 2002).

Porak
Armenia-Azerbaijan
The mid-Pleistocene Porak volcano lies in the Vardenis volcanic highland about 20 km SE of Lake Sevan. The volcanic field straddles the Armenia/Azerbaijan border, and lava flows extend into both countries. The flanks contain 10 satellitic cones and fissure vents. It was constructed along the active Pambak-Sevan strike-slip fault, which has bisected the mid-Pleistocene Khonarassar volcano, separating its two halves by about 800 m. Two large lava flows traveled up to 21 km north and NW, and fresh-looking lava flows form peninsulas extending into Lake Alagyol. Fifth century BCE petroglyphs were interpreted to depict volcanic eruptions (Karakhanian et al., 2002). Porak is referred to in a cuneiform inscription as Mount Bamni, and stratigraphic and archeological evidence indicates that an explosive eruption also producing a lava flow occurred at the time of a military battle dated to 782-773 BCE.

Tskhouk-Karckar
Armenia-Azerbaijan
The Tskhouk-Karckar volcano group of cones and lava flows is located in the NW and central part of the Syunik Volcanic Upland along the Armenia/Azerbaijan border about 60 km SE of Lake Sevan. It was constructed within offset segments of the major Pambak-Sevan-Syunik strike-slip fault trending SE from Lake Sevan. Eight pyroclastic cones produced three generations of Holocene lava flows (Karakhanian et al., 2002). Abundant petroglyphs, burial kurgans, and masonry walls were found on flows of the older two age groups, but not on the youngest. Lava flows from these cinder cones overlie petroglyphs dated to the end of the 4th millennium and beginning of the 3rd millennium BCE and are themselves used in gravesites dated to 2770 BCE +/- 140 years. Following these eruptions, the area was not repopulated until the Middle Ages.

Damavand
Iran
The Damavand stratovolcano is located 70 km NE of Iran's capital city of Tehran and 70 km S of the Caspian Sea. A younger cone has been constructed during the past 600,000 years over an older edifice, remnants of which were previously interpreted as a caldera wall. Flank vents are rare, and activity at the dominantly trachyandesite volcano has been concentrated at the summit vent, which has produced a series of radial lava flows. Lava effusion has dominated, pyroclastic activity has been limited, and the only major explosive event produced a welded ignimbrite about 280,000 years ago. The youngest activity, from the summit vent, produced a series of lava flows that cover the W side of the volcano. The youngest dated lava flows were emplaced about 7,000 years ago. No recorded eruptions are known, but hot springs are located on the flanks, and fumaroles are found at the summit crater.

Northern Arabia Volcanic Province

Karaca Dag
Northern Arabia Volcanic Province
Karaca Dag (also known as Karacalidag) is a broad basaltic shield volcano in SE Turkey about 100 km N of the Syrian border. The volcano lies on the Arabian foreland about 150 km SW of the boundary with the Anatolian Plate and has been active since the Pliocene along a N-S-trending set of fissures and craters associated with the nearby Akcakale graben. Potassium-Argon dates of mid-Pleistocene age have been obtained from lava flows, but Landsat imagery suggests that some lava flows, particularly those on the E flank, may perhaps be only a few thousand years old (Pearce et al., 1990).

Harrat Ash Shaam
Syria-Jordan-Saudi Arabia
Northern Arabia Volcanic Province
The massive Harrat Ash Shaam volcanic province, which extends from Syria through Jordan and into northern Saudi Arabia, contains many smaller volcanic fields. Activity began during the Miocene; a younger eruptive stage, at the SE end of the field, occurred during the late Pleistocene and Holocene (Brown et al., 1984). Al Harrah, a large basaltic volcanic field in northwestern Saudi Arabia, covers an area of 15,200 km2 and forms the southern third of the harrat across a 210-km-long, roughly 75-km-wide area. Other fields include the Jabal ad Druze, Es Safa, Golan Heights, and the Kra Lava Field where radiocarbon dating indicated an eruption at 2,670 BCE � 200 years. Although a "boiling lava lake" eruption has been in the volcanological literature since 1925, a translation of the original source of that report by Wetzstein (1860) clearly shows that he was describing solidified crater floor surface features and lava flows.

Western Arabia Volcanic Province

Harrat Lunayyir
Saudi Arabia
Western Arabia Volcanic Province
Harrat Lunayyir is a basaltic volcanic field in NW Saudi Arabia, east of the Red Sea port of Umm Lajj. It contains about 50 volcanic cones that were constructed over Precambrian crystalline rocks along a N-S axis. Harrat Lunayyir is one of the smallest of the Holocene lava fields of Saudi Arabia, but individual flow lobes radiate long distances from the center of the Harrat, and flows reached the Red Sea in two places. Lava flows are basaltic to basanitic in composition, and the Holocene flows are alkali olivine basalts. One of the cones may have erupted around the 10th century CE or earlier. A seismic swarm in May 2009 was interpreted to be consistent with intrusion of an 8-km-long dike to shallow crustal levels.

Harrat Ithnayn
Saudi Arabia
Western Arabia Volcanic Province
The 4000 km2 Harrat Ithnayn volcanic field contains scattered shield volcanoes and scoria cones. It merges with the much larger Harrat Khaybar volcanic field to the south. The field overlies Cambrian sandstones and Precambrian basement rocks. Vents form a general N-S pattern, but are more scattered than those of Harrat Khaybar. Harrat Ithnayn rocks are of basaltic and basanitic composition and lack the silicic components present in neighboring Harrat Khaybar. The youngest lava flows from Harrat Ithnayn are less than 4500 years old. An uncertain report of an historical eruption in 1800 CE is considered unlikely by Camp et al. (1991), who mapped no eruptive products younger than about 1500 years.

Harrat Khaybar
Saudi Arabia
Harrat Khaybar, one of Saudi Arabia's largest volcanic fields, covers an area of more than 14,000 km2 N of Madinah (Medina). A 100-km-long N-S linear vent system contains felsic lava domes, tuff rings, the Jabal Qidr stratovolcano, and numerous small basaltic cones. At least seven lava flows are less than 4,500 years old, and another eight are less than 1,500 years old. In the latter category is the 55-km-long Habir lava flow as well as Jabal Qidr stratovolcano, the only stratovolcano in the Harrats of western Saudi Arabia. An eruption was reported in early Mohammedan times during the 7th century CE. Lavas from Harrat Khaybar overlap older lavas of Harrat Kura to the west and merge with lavas from Harrat Ithnayn to the north.

Harrat Kishb
The 5,900 km3 Harrat Kishb volcanic field, located E of a N-S-trending line of volcanic fields in central Saudi Arabia, is comprised of basaltic scoria cones, tuff rings and maars, and phonolitic lava domes and flows. Most of it is of Pleistocene age; Holocene flows are restricted to three areas in the western half of the field. Jabal Aslaj cone and its associated lava flows contain abundant granitic blocks from basement rocks and ultramafic nodules. Jabal Hil is a large scoria cone with a 300-m-wide crater that was filled and overtopped by a lava lake. Among the several tuff rings and maars is the 800 x 600 m wide Al Wabah maar in the west-central portion of the field. The most recent products, including the scoria cones and lava flows of Jabal Aslaj and Jabal Hil and the Jabal Shalman lava-dome, lava-flow, and scoria-cone complex, are stratigraphically younger than a pluvial period dated about 6500-4000 years before present.

Harrat Rahat
Harrat Rahat, Saudi Arabia's largest lava field, covers 20,000 km2 and extends for 300 km S of Madinah (Medina). Four coalescing lava fields erupted from offset NNW-trending vent systems comprise the field, which has an average width of 60 km. Lava flows extend as far as 100 km W of the axis of the field. Basaltic scoria cones dominate, but the volcanic field has also produced silicic trachy-basaltic to trachytic rocks. Small shield volcanoes and lava domes with associated pyroclastic flow and surge deposits are also present. Activity has migrated to the north over time, resulting in eruptions near Madinah. The best-known eruption took place in 1256 CE, when a 0.5 km3 lava flow erupted from six aligned scoria cones and traveled 23 km to within 4 km of Madinah.

Southwest Arabia Volcanic Province

Harrat al Birk
Southwest Arabia Volcanic Province
The Harrat al Birk volcanic field, also known as Harrat Hayil or Hubhub al Sheikh, is the only Saudi Arabian volcanic field that lies directly along the Red Sea coast. It covers an 1800 km2 area west of the town of Abha and separates the Tihamat ash Sham and Tihamat 'Asir coastal plains. Volcanic activity dates back to the Miocene and concluded with the formation of Holocene cinder cones (Brown et al., 1984). The Quaternary lava flows are of basaltic to trachybasaltic composition and contain ultramafic inclusions. Cinder cones are scattered throughout the volcanic field, with a few late-stage cones (Ba'a and Qishr) NE of the main lava field. Isolated patches of freshly eroded ash surround a vent at Jabal Ba'a, east of the main field, suggesting an eruption during the last century.

Jabal Yar
Southwest Arabia Volcanic Province
Jabal Yar, the southernmost young volcanic field in Saudi Arabia, is a small olivine basaltic field along the Red Sea coast at the SW tip of Saudi Arabia. It contains three groups of volcanoes, Qummatain, Djar'atain-Harra, and 'Ukwatain. Hot springs occur south of Djar'atain and between it and 'Ukwatain. A single historically documented eruption took place at the beginning of the 19th century.

Harra of Arhab
Yemen
The Quaternary Harra of Arhab in Yemen, north of the capital city of Sana'a, consists of a 1,500 km2 basaltic plateau capped by a few small stratovolcanoes and about 60 scoria cones, two of which have erupted in historical time. Cones in the volcanic field (also known as the Sana'a or the Sana'a-Amran volcanic field) are commonly aligned along a NNW trend above a 100-250-m-thick volcanic plateau. Pliocene-to-Holocene volcanic rocks have a dominantly basaltic-to-hawaiitic composition and overlie the northern end of an area of extensive Oligocene-Miocene basaltic-to-rhyolitic rocks that extends to the SW tip of the Arabian Peninsula. Baker et al. (1997) include outcrops of Quaternary volcanism south of the main area of lava flows, such as Jabal al Marha, as part of this system, but note that they can be difficult to distinguish from Oligocene flood basalts. The latest eruption took place between about 400 and 600 CE and produced a lava flow that traveled 9 km.

Jabal Haylan
Yemen
The Jabal Haylan area contains a 75-km-long chain of tuff cones and associated olivine basaltic lava flows in eastern Yemen. The chain crosses a NW-SE-trending fault extending between the highlands and desert lowlands to the east. One of the lava flows covers alluvial terraces that accumulated behind man-made dams from about 800-1200 BCE (Catalog of Active Volcanoes of the World).

Harras of Dhamar
Yemen
The lava fields surrounding the town of Dhamar are part of a volcanic field extending 80 km E that includes several stratovolcanoes and many youthful volcanic cones. Basaltic lava flows overlie older rhyolitic flows. Residents near Dhamar "spoke of a volcanic eruption that must have taken place in 1937 near the town" (von Wissmann, 1942; Rathjens and von Wissmann, 1942; cited in Neumann van Padang, 1963); this supposed activity has not been confirmed, located, or described by later work.

Harra Es- Sawad
The Harra es-Saw�d (or Shuqra) volcanic field in southern Yemen extends for nearly 100 km along the Gulf of Aden, east of the city of Shuqra (Shaqra). The field is oriented WSW-ENE and contains about a hundred cones that have sent lava flows across a 40 x 95 km area of faulted basement limestones. Most of the volcanic field is Holocene in age (Cox et al., 1977), and in many cases the flows and cones are essentially uneroded. The only recorded event was a major, but poorly documented, eruption in 1253 CE.

Balhaf-Bir Ali Volcanic Field
The Balhaf-Bir Ali Volcanic Field along the Gulf of Aden in southern Yemen contains cinder cones associated with vesicular lava flows and scoria cones. The 500 km2 field lies along the Gulf of Aden about 120 km SW of the city of Al Mukalla. Lava flows covered much of the area and created an irregular shoreline. One fresh-looking basaltic flow may be of historical age (Catalog of Active Volcanoes of the World). The At-Tab�b tuff cone along the coast rises about 200 m from the sea and has a 1.5-km-wide crater partially filled by a cinder cone and associated lava flows. An adjacent tuff cone to the east contains a lake.

Bir Borhut
Near the villages of Hleime and Al Ghayl, along the Wadi Hadhramout valley about 45 km from the coast of Yemen, is what appears to be a pyroclastic volcanic cone and extensive dark lava flows. Although Theodore Bent did not reach the volcano while traveling through the region in 1894, he described it as a solfataric area and source of brimstone. Arabic reports exist of an active volcano in eastern Hadramaut that erupted in the 10th century; emissions were reported in 1813 (Neumann van Padang, 1963). Geologic maps of the Arabian Peninsula show Quaternary mafic volcanic rocks in this area, which lies south and west of the Wadi al Masilah river valley. Small cones are present in the coastal lava fields, including a cone with two craters about 10 km NE of the town of Qusay'ir.

Eastern Africa Volcanic Regions

Red Sea Rift Volcanic Province

Jebel at Tair
Red Sea Rift Volcanic Province
The basaltic Jebel at Tair volcano rises from 1,200 m depth in the south-central Red Sea, forming an oval-shaped island about 3 km long. It is the northernmost known Holocene volcano in the Red Sea and lies SW of the Farisan Islands. Youthful basaltic pahoehoe lava flows from the steep-sided central vent, Jebel Duchan, cover most of the island, draping a circular cliff cut by wave erosion of an older edifice and extending beyond it to form a flat coastal plain. Pyroclastic cones are located along the NW and S coasts, and fumarolic activity occurs from two uneroded scoria cones at the summit. Radial fissures extend from the summit, some of which were the sources of lava flows. Explosive eruptions were reported in the 18th and 19th centuries, prior to an eruption in 2007-2008.

Zukur
Red Sea Rift Volcanic Province
Zukur (Zugar), the northernmost large island of the Zukur-Hanish island group in the southern Red Sea, is formed of Holocene basaltic pyroclastic cones and spatter cones that issued youthful-looking pahoehoe lava flows. This island group lies in shallow waters S of the Red Sea median trough. Products of phreatic eruptions form small islands and coastal cones. Late-stage trachytic lava domes produced viscous lava flows. Vents on Zukur are aligned along a NE-SW trend.

Hanish
The Hanish Islands are formed from a series of volcanic vents along a NE-SW trend, and include the Holocene Great Hanish, Little Hanish, and many other small islands and submarine shoals. The Zukur-Hanish island group lies in shallow waters S of the Red Sea median trough. Spatter cones, cinder cones, and ash cones line the crest of the 20-km-long Great Hanish Island. Short lava flows reach the coast on both sides of the island. Initial eruptions were phreatic, followed by the formation of basaltic cinder cones, spatter cones, and fluid lava flows.

Zubair Group
The 5-km-long Jebel Zubair Island is the largest of a group of small islands and submerged shoals that rise from a shallow platform in the Red Sea rift. The platform and eruptive vents forming the islands and shoals are oriented NNW-SSE, parallel to the rift. An early explosive phase was followed by a brief period of marine erosion, then by renewed explosive activity accompanied by the extrusion of basaltic pahoehoe lava flows. This latest phase of activity occurred on the morphologically youngest islands of Zubair, Centre Peak, Saba, and Haycock. Historical explosive activity was reported from Saddle Island in the 19th century. Spatter cones and pyroclastic cones were erupted along fissures that form the low spine of Zubair Island. Eruptions that began in late 2011 built two new islands, increasing the total number in the group to 12.

Afar Rift Volcanic Province

Dallol
Ethiopia
Afar Rift Volcanic Province
Volcano type: Explosion crater(s)
Numerous phreatic explosion craters are present across the Salt Plain NNE of the Erta Ale Range in one of the lowest areas of the desolate Danakil depression. The most recent of these craters, Dallol, lies 48 m below sea level and was formed during an eruption in 1926. Colorful hot brine springs are found in the Dallol area. Another phreatic explosion was observed in January 2011.

Alid
Eritrea
Afar Rift Volcanic Province
Alid is an isolated, dissected volcano in the central Danakil depression. Elongated in an E-W direction perpendicular to the orientation of the Alid graben, it consists of a structural dome of uplifted sedimentary rocks rising 700 m above the graben floor, which was produced by intrusion of a silicic magma body. The dome is capped by steep-sided basaltic-to-rhyolitic lava flows. Late-stage eruptions during the late Pleistocene ejected rhyolitic pumice. A 2 x 3 km graben cuts the top of the dome, and the crater that produced the Plinian eruption occupies the western third of the summit depression. Vast lava fields of probable Holocene age originating from fissure vents bank up against the flanks to the NW and SE. Small cones and craters that were the source of the flows are localized along NNW-trending fissures. Fumarolic activity continues from broad areas on the northern summit and flank.

Gada Ale
Ethiopia
Gada Ale (also known as Kebrit Ale), the most prominent volcano at the northern end of the Erta Ale Range, is formed of interstratified lava flows and hyaloclastites. Fumarolic activity is continuing, and the summit crater contains a small lake with hot mud. Like other Erta Ale Range volcanoes, Gada Ale is considered to be of Holocene age (Barberi and Varet, 1970). A fissure on the SE flank has produced spatter cones and a cinder cone; the latter fed lava flows that reach to Lake Bakili. The symmetrical Catherine tuff ring is located along this same SE trend west of Lake Bakili, and other tuff rings occur on the east side of the lake. A 2-km-wide salt dome to the west has uplifted lava flows as much as 100 m, and the structure of Gada Ale itself appears to be related to salt diapir uplift.

Alu-Dalafilla
Ethiopia
The summit region of Alu, ~5 km NW of the Dalafilla stratovolcano, is an ellipsoidal volcanic horst, elongated NNW-SSE, and formed primarily of older basaltic lava flows. Recent fractures along the axis of the Erta Ale range cut the main horst of Alu and areas to the SSE. Fumarolic activity is located on the numerous parallel faults. Fissure vents west of the horst have fed silicic lava flows, and voluminous youthful basaltic lava flows to the east extend north as far as Lake Bakili. Dalafilla, also referred to as Gabuli, is a steep-sided cone that rises 300 m above surrounding lava fields due to extrusion of viscous, silicic lava flows. Basaltic lava flows from regional fissures surround the volcano. Fumarolic activity occurs in the 100-m-wide summit crater and has weathered surrounding lava flows. The first historical eruption of Alu-Dalafilla took place in 2008, when lava flows from vents between the two edifices traveled NE.

Bora Ale
Bora Ale is a complex volcano located near the center of the Erta Ale Range. The earliest activity formed submarine lava flows partially covered by Quaternary reef deposits. A 4-km-wide shield volcano SW of the main cone is cut by curvilinear faults; youthful chains of spatter cones follow this same pattern and form concentric semi-circles. The summit is located on the NE side of the massif and consists of a silicic stratovolcano that is the largest of the Erta Ale Range. It has produced steep-sided viscous lava flows that have traveled up to 5 km. Strong fumarolic activity occurs within a 300-m-wide summit crater. Regional faulting has fed very recent basaltic lava flows from a NNW-trending fissure that cuts the stratovolcano.

Erta Ale
The Erta Ale basaltic shield volcano in Ethiopia has a 50-km-wide edifice that rises more than 600 m from below sea level in the Danakil depression. The volcano includes a 0.7 x 1.6 km summit crater hosting steep-sided pit craters. Another larger 1.8 x 3.1 km wide depression elongated parallel to the trend of the Erta Ale range is located SE of the summit and is bounded by curvilinear fault scarps on the SE side. Basaltic lava flows from these fissures have poured into the caldera and locally overflowed its rim. The summit caldera usually also holds at least one long-term lava lake that has been active since at least 1967, and possibly since 1906. Recent fissure eruptions have occurred on the N flank.

Hayli Gubbi
Hayli Gubbi is the southernmost volcano of the Erta Ale Range. Recent tectonism has created a NW-SE graben across the summit, with a 380-m-diameter scoria cone at the summit and a 260-m-diameter crater displaying fumarolic activity. A sequence of fissure vents and lava fields extends 6 km NW to the southern caldera of Erta Ale. Additional dark flows that originated from the summit area cover the W and NE flanks, and SE before turning E at the base on the shield. More fissure vents extend ~3.5 km SSE within the graben to another small shield. From there, the line of vents continues, along with a lava field that spreads across the Afrera Plain, to a distance of 25 km from the summit crater. Barberi and Varet (1970) reported that those basaltic flow fronts covered sediments in the plain which Roubet et al. (1969) described as lacustrine limestones and diatomites deposited around 8,200 years BP above hyaloclastite formations. This places the eruption of the SE-most flows sometime within the last 8,000 years, but no additional information about how recent they might be is known; in appearance they are similar to very recent flows from the Erta Ale shield. On 15 July 2025 a dike intrusion that originated at the Erta Ale N caldera pit craters produced active fissure vents and lava flows within and on the S flanks of the south caldera; another set of fissure vents were active 4 km SE from the caldera rim, within 2 km of the Hayli Gubbi crater. A large explosive eruption on 23 November 2025 excavated the previous summit cone and created a second large crater (~200 m in diameter) in the summit area, and a third smaller crater.

Ale Bagu
Ale Bagu, also known as Ummuna, is an elongated stratovolcano located SW of Erta Ale volcano. In contrast to other volcanoes of the Erta Ale Range, it is located SW of the axis of the range, and is mantled by basaltic pyroclastic rocks. Summit craters are elongated along a NNW-SSE trend. The main crater is a steep-walled, 750 x 450 m depression occupied by a steep-sided lava cone that has fed trachytic lava flows over the crater floor. Silicic lavas from the axial regional fissure extend to the NW and SE.

Nabro
Eritrea
The Nabro stratovolcano is the highest volcano in the Danakil depression of northern Ethiopia and Eritrea, at the SE end of the Danakil Alps. Nabro, along with Mallahle, Asavyo, and Sork Ale volcanoes, collectively comprise the Bidu volcanic complex SW of Dubbi volcano. This complex stratovolcano constructed primarily of trachytic lava flows and pyroclastics, is truncated by nested calderas 8 and 5 km in diameter. The larger caldera is widely breached to the SW. Rhyolitic obsidian domes and basaltic lava flows were erupted inside the caldera and on its flanks. Some very recent lava flows were erupted from NNW-trending fissures transverse to the trend of the volcanic range.

Mallahle
Ethiopia-Eritrea
Mallahle is the central of three NE-SW-trending stratovolcanoes (along with Asavyo and Nabro) in the Danakil horst SW of Dubbi volcano. These volcanoes, plus Sork'Ale, form the Bidu Volcanic Complex. The volcano is truncated by a steep-walled 6-km-wide caldera, and is formed of rhyolitic lava flows and pyroclastics. Basaltic lava flows cover the slopes. Recent obsidian flows are found on the NW flank, and older obsidian flows were erupted on the northern caldera floor. Flank spatter and scoria cones are most numerous on the western side of the volcano. Extensive ignimbrite deposits associated with the collapse of Mallahle and Nabro volcanoes cover the countryside.

Sork Ale
Ethiopia-Eritrea
Sork Ale is a silicic stratovolcano located in the Danakil horst SW of Dubbi volcano. Also known as Asdaga, it was constructed perpendicular to the NE-SW orientation of three larger stratovolcanoes (Nabro, Mallahle, and Asavyo) with which it forms the Bidu Volcanic Complex at the southern end of the Danakil Alps. A small, roughly 1-km-wide, 300-m-deep steep-walled caldera is found at the summit. Basaltic lava flows are prominent on the E side of the volcano, and satellite vents are located on the SE flank. The International Association of Volcanology and Chemistry of the Earth's Interior (1973) listed Sork Ale as probably active during the last 2000 years, but Wood (1980, pers. comm.) considered Holocene activity unlikely. The flanks are extensively dissected on the SW to NE sides, but less dissected flows form the eastern-to-southern flanks.

Asavyo
Asavyo, also known as Bara?Ale, is the SW-most of three large silicic stratovolcanoes (along with Mallahle and Nabro) constructed along a NE-SW-trending line in the Danakil horst. A large 12-km-wide caldera truncates the summit. Basaltic lava flows cover the flanks, which merge into the Mogorros plains to the south. Although the age of the volcano is not known precisely, Asavyo was considered to have erupted during last 2,000 years (IAVCEI, 1973). A large post-caldera cone was constructed near the center of the caldera, and smaller pyroclastic cones occur within the caldera and on its flanks.

Mat Ala
Mat Ala is a low shield volcano in the southern Tat Ali Range, east of Afder� volcano. A 300-m-deep, 2.5 x 3.5 km wide caldera is found at the summit of the volcano, whose flanks are cut by numerous N-S-trending faults. Mat Ala has been active during the Holocene, and fumarolic activity occurs along a fissure SW of the volcano.

Tat Ali
Tat Ali volcano is the dominant feature of the Tat Ali Range, east of Lake Afrera. The low Holocene shield volcano has an elongated summit depression and has produced a variety of rock types, ranging from basalts to pantellerites. NNW-SSE-trending fissures cutting the volcano have fed basaltic lava flows; those NE of Lake Afrera are of prehistorical age. Late-stage volcanism produced youthful basaltic lava flows on the floor of the summit depression, which is also the site of prominent fumarolic activity.

Borawli
Borawli stratovolcano rises above the eastern shore of Lake Afrera, also known as Lake Giulietti. The upper part of the conical edifice consists of trachytic lava flows overlying older basaltic flows. Young pantelleritic obsidian domes south of the volcano are the probable source of rounded pumice fragments found around Lake Afrera.

Dubbi
Eritrea
Dubbi, located east of the Erta Ale Range and south of the crystalline basement rocks of the Danakil Alps, is a large volcanic massif that rises above the western shore of the Red Sea. About 20 small cinder cones are located at the summit, and extensive basaltic lava fields to the north and NE, known as the Edd lava field, cover an area of 2700 km2 and reach the Red Sea coast. The two most-recent eruptive centers are fissure systems that extend NW-SE and NNE-SSW. The former produced lava flows that reached the Red Sea in 1400 CE. The second created 19 small craters at the summit in 1861. Ash fell more than 300 km from the volcano. Two villages were destroyed and more than 100 people were killed during Africa's largest eruption in historical time. Lava flows from the 1861 eruption traveled as far as 22 km and reached the coast.

Ma Alalta
The Ma Alalta stratovolcano, also known as Pierre Pruvost, is located well to the west of the Danakil depression at the foot of the regional Ethiopian scarp, between two large horsts of uplifted basement blocks. A large trachytic and rhyolitic stratovolcano at the center of the complex contains nested oval-shaped summit calderas, 8 x 5 km and 5 x 2.5 km. Ignimbrite deposits, perhaps associated with formation of the larger caldera, extend beyond the volcano primarily to the NE and SE. Young basaltic lava flows were erupted on the NW, SE, and E flanks. Recent silicic activity has produced pantelleritic obsidian domes and lava flows on the southern flank. Fumarolic activity continues at one of the domes.

Alayta
The massive Alayta shield volcano covers an area of 2700 km2 in the western Danakil depression SW of Lake Afrera. A series of very recent craters is aligned along the NNW-trending axis of the basaltic-to-trachytic shield. The lava field, covered by very fresh flows, was erupted from N-S fissures along the east side of the shield volcano and laps up against the western flank of Afder� volcano. Two historical eruptions that were formerly attributed to Afder� actually originated from Alayta. One of those eruptions, in 1907, produced a large lava flow from a SE-flank vent. Fumarolic activity occurs at two locations in the southern part of the complex.

Dabbahu
Dabbahu (also known as Boina, Boyna, or Moina) is a Pleistocene-to-Holocene volcanic massif forming an axial range of the Afar depression SSW of the Alayta massif. Late-stage pantelleritic obsidian flows, lava domes, and pumice cones form the summit and upper flanks. The volcano rises above the Teru Plain and was built over a volumetrically dominant base of basaltic-to-trachyandesitic lava flows of a shield volcano. Late-stage basaltic fissure eruptions also occurred at the NW base of the volcano. Abundant fumaroles are located along the crest of the volcano and extend NE towards Alayta. The first historical eruption took place from a fissure vent on the NE flank in September 2005, producing ashfall deposits and a small pumice dome. More than 6000 people were evacuated from neighboring villages.

Dabbayra
Dabbayra, the westernmost volcano of the Afar depression, was constructed along an offshoot of the Ethiopian escarpment, SW of the Teru plain. In contrast to structural trends in other parts of Afar, Dabbayra (also known as Bar-Ali) consists of a basaltic shield volcano elongated ENE-WSW. The only silicic volcanic rocks are a NNW-trending line of lava domes and lava flows near the crest of the volcano.

Manda Hararo
As the southernmost axial range of western Afar, the Manda Hararo complex is located in the Kalo plain, SSE of Dabbahu volcano. The massive 105-km-long and 20-30 km wide complex represents an uplifted segment of a mid-ocean ridge spreading center. A small basaltic shield volcano is located at the N end of the complex, S of which is an area of abundant fissure-fed lava flows. Two basaltic shield volcanoes, the larger of which is Unda Hararo, occupy the center of the complex. The dominant Gumatmali-Gablaytu fissure system lies to the S. Voluminous fluid lava flows issued from these NNW-trending fissures, and solidified lava lakes occupy two large craters. The small Gablaytu shield volcano forms the SE-most end of the complex. Lava flows from Gablaytu and from Manda overlie 8,000-year-old sediments. Hot springs and fumaroles occur around Daorre lake. The first historical eruptions produced fissure-fed lava flows in 2007 and 2009.

Groppo
Groppo was identified by IAVCEI (1973) as a small alkali rhyolitic stratovolcano located in the western Afar near the Ethiopian escarpment, NE of Dessye. However, the nearest volcanic feature, identified in satellite imagery about 15 km NW from the given location, is a dark lava-flow field about 2.5 x 4.5 km in size, surrounding two small cones; two other smaller breached cones are nearby. The largest cone is about 300 x 500 m long, and 45 m high.

Afdera
Afder� is an isolated rhyolitic stratovolcano located between the Erta Ale, Tat Ali, and Alayta ranges. It lies at the intersection of three fault systems. Young rhyolitic lava domes are aligned N-S at its southern foot. Only a few late-stage satellitic cones are of basaltic composition. Eruptions were reported in 1907 and 1915 (Catalog of Active Volcanoes of the World). However, on morphological grounds it appears to be substantially older than adjacent volcanoes, and the reported eruptions were probably from Alayta volcano to the west. The age of the most recent eruption is not known, although the S-flank rhyolitic lava domes are too young to be dated by the Potassium-Argon method.

Manda Gargori
The Manda Gargori rift, located north of the town of Aisa Aita NE of Borawli volcano and SE of Kurub volcano, is the youngest rift segment in the Afar depression and is only one third the width of the adjacent Manda Hararo-Goba'ad rift system to the west. Two older lava flows from the Manda Gargori rift have Pleistocene potassium-argon dates. Youthful-looking lava flows, some of which may have been subaqueous, have been emitted from NNW-trending fissures. A hyaloclastite tuff ring is also present, and a rhyolitic lava dome surrounded by two basaltic lava flows is located north of Uddummi lake. No historical activity has been reported at the dominantly basaltic Manda Gargori rift, but human footprints have been observed in a fresh ashfall deposit, and the eruptive activity is considered to be of historical age.

Manda-Inakir
Ethiopia-Djibouti
Manda-Inakir consists of a series of NW-trending fissure vents and pyroclastic cones along the Ethiopia-Djibouti border. The elongated complex represents an uplifted mid-ocean ridge spreading center now exposed above sea level. An elongated dome of basement rocks is cut by two axial rifts, the northern of which was active during historical time. Basaltic cinder cones along the rift's marginal faults have produced lava flows on the flanks of the structural dome, yielding a shield-like morphology. An eruption in 1928 or 1929 at the SE end near the town of Korili (in Djibouti) produced the Kammourta cinder cone and a lava flow.

Mousa Alli
Ethiopia-Eritrea-Djibouti
The Mousa Alli volcanic complex is a large Holocene stratovolcano constructed along the border between Ethiopia, Eritrea, and Djibouti. The trachytic-to-rhyolitic volcano is the most prominent topographic feature in this area. Rhyolitic lava domes and lava flows are found in the summit region, which is truncated by a caldera.

Gufa
Eritrea-Djibouti
The Gufa volcanic field, located along the Eritrea-Djibouti border, consists of a group of basaltic scoria cones and lava flows, aligned E-W, NE of the large Mousa Alli stratovolcano. A second E-W chain of cones is located to the N of the principal chain, most of which lies in Eritrea, and fed long lava flows that descend northward, toward the Red Sea.

Assab Volcanic Field
The Assab volcanic field near the Red Sea coast in southern Eritrea forms a spectacular range of basaltic cinder cones and associated lava flows. The massive lava field covers a 55 x 90 km area, and flows reached the Red Sea along a broad front. The vents of the Assab volcanic field, also known as Ado Ale or Ud'ale, were constructed along a broad E-W line that extends to the coastal city of Assab.

Ardoukoba
Djibouti
The Ardouk�ba (Asal) Rift in Djibouti, trending NW from the Red Sea, contains a broad area of youthful fissure vents between Lake Asal and the Ghoubbat al Kharab gulf. It is subaerially exposed over 12 km between these two bodies of water and contains numerous basaltic cinder and spatter cones. The silicic centers of Eger Alayta and Asa Aleyta, on the N and S sides, are remnants of a Pleistocene silicic center that has been disrupted and spread apart. Magma-water interaction has produced tuff cones, some of which form islands or are breached by the sea. The most recent lava flows are younger than lake sediments deposited 5,300 years ago. These lavas were thought to have been erupted during the past 3,000 years (Delibrias et al., 1975). The fissure erupted in 1978, producing a small cinder cone and lava flows that covered part of the rift floor near the Red Sea.

Kurub
The small Holocene shield volcano, also known as Kurub Koma, Kurub Koba, or Curub, lies in the Saha Plain, SE of the Manda Hararo complex in the South Danakil region. The easternmost lava flow was potassium-argon dated at about 0.3 million years. Wind-blown sand fills the summit crater of the very recent basaltic volcano. Initial subaqueous activity occurred along NNW-trending fissures. Fumarolic activity observed in the 1930s was not seen during field work in the 1970s.

Main Ethiopian Rift Volcanic Province

Dama Ali
Main Ethiopian Rift Volcanic Province
Dama Ali is a broad 25-km-wide shield volcano that rises above the NW shore of Lake Abbe in eastern Ethiopia. Nested circular craters are located at the summit of the dominantly basaltic volcano, which also displays an older caldera rim. An arcuate chain of rhyolitic lava domes occupies the northern, western, and southern flanks. Youthful basaltic lava flows surround these domes and cover the flanks, and recent flows also cover the young sediments of the Kalo and Abhe basins. The Asmara basaltic pyroclastic cone located in the southern Kalo basin SW of the base of the volcano was considered to have had activity during the last 2,000 years (IAVCEI, 1973). It is considered the most likely source of an eruption reported to have occurred in 1631 (Gouin, 1979). Major fumarolic activity occurs in the summit crater, and abundant hot springs are found on the volcano.

Yangudi
Main Ethiopian Rift Volcanic Province
Yangudi volcano, lying in the Addado graben of the northern Main Ethiopian Rift, is a complex rhyolitic stratovolcano with an elliptical summit caldera. A trachytic lava flow originating in the caldera covers part of the southern flank of Yangudi, also known as Angudi, Jangudi, or Langudi. Rhyolitic obsidian domes on the NW flank are surrounded by younger basaltic lava flows. Very recent scoria cones and lava flows are located south of Yangudi along the eastern graben faults.

Gabillema
Gabillema is a rhyolitic stratovolcano along the axis of the Addado graben. The volcano was constructed at the intersection of the central Afar rift zone with the northern end of the Main Ethiopian Rift. Rhyolitic lava domes are located on the flanks, and a 5 x 17 km basaltic lava field that covers the Ado Bad plain north of the volcano originated from a broad area of fissure vents and spatter cones on the north side of Gabillema. Young lava flows also occur south and east of the volcano, the latter along E-W fissures. This period of rejuvenation, perhaps not directly related to Gabillema, has included rhyolitic as well as basaltic volcanism.

Ayelu
Ayelu is a vegetated rhyolitic stratovolcano, located south of the Asbahri plain in the southern Afar region. On its eastern side, 2145-m-high Ayelu is cut by regional faults and is overlain by ignimbrites erupted from Adwa volcano immediately to the east. It was constructed by a series of thick rhyolitic lava flows, creating a higher and steeper-sided volcano than Adwa. Hot springs are located on the western flank.

Hertali
Hertali is a basaltic fissure vent that fed lava flows at the S end of the Awash plain, about 50 km NNE of Dofen volcano. It was considered by Mohr and Wood (1976) to have been active during the late Pleistocene to Holocene on the basis of its youthful-looking morphology.

Liado Hayk
The Liado Hayk (Liado Lake) volcanic field consists of a dozen closely spaced maars and cinder cones with associated lava fields in the Awash plain NE of Dofen volcano. The morphology of the cones and maars suggested a late Pleistocene or Holocene age (Wood, 1979 p.c.).

Adwa
Adwa (also known as Aabida, Amoissa, or Dabita), is a broad stratovolcano in the southern Afar area immediately east of the younger vegetated Ayelu volcano. It has a roughly 3 x 4 km caldera that originated following eruption of voluminous ignimbrites, with a trachytic dome extruded in the eastern part of the caldera. Scoria cones are located on the floor of the caldera and on its NW and SW flanks. Extensive young basaltic lava flows cover the flanks and overlap a sedimentary plain to the SE. Many fumaroles occur within the caldera. Satellitic pyroclastic cones and lava domes were considered to be only a few hundred years old (Mohr 1980, pers. comm.). Dark lava flows originating from cones about 4 km from the caldera rim on the SW flank cover more than 50 km2.

Dofen
The Dofen shield volcano rises 450 m above the Awash plain in the northern Main Ethiopian Rift. Numerous cinder cones, constructed along a 10-km-long, N-S-trending line, occur on the flanks of the dominantly rhyolitic volcano. The northern cones are younger, have well-preserved morphologies, and display strong fumarolic activity. A major fumarole in a wide S-flank crater has precipitated large amounts of sulfur. The latest eruptions occurred during the Holocene (WoldeGabriel 1987, pers. comm.), and it is known as the "smoking mountain".

Beru
An area of Holocene basaltic lava flows is located along the Main Ethiopian Rift at Beru, between Fentale and Kone (Gariboldi) volcanoes.

Fentale
Fentale is a volcanic complex at the N end of the Main Ethiopian Rift that includes a main stratovolcano and caldera with various subsidiary features. Products are primarily rhyolitic obsidian lava flows with minor tuffs. Welded pantelleritic ash flows accompanied formation of a 2.5 x 4.5 km elliptical summit caldera, with steep-sided walls, that trends WNW-ESE, perpendicular to the rift. Post-caldera vents lie along the same orientation. Lava flows that appear to be more recent are present on the NE and SW flanks, and dark trachytic and obsidian lava flows occur on the caldera floor. Sometime during about 1770-1808 CE basaltic lava flows effused from a 3.5-km-long fissure on the S flank; there were also lava flows in the caldera. During 2015 there was a seismic swarm and deformation NE of Fentale, caused by a dike intrusion that Temtime et al. (2020) determined was about 6 km long (striking N29�E) and 2 m wide, with a depth range of 5.4-8 km below the surface (volume change of about 33 x 106 m3).

Kone
The Kone volcanic complex (also known as Gariboldi) is composed of a series of silicic calderas and young basaltic cinder cones and lava flows about 30 km SW of Fentale volcano in the Main Ethiopian Rift. As many as eight silicic calderas are accompanied by ignimbrite outflow sheets. Kone, the youngest caldera, is an elliptical 5 x 7.5 km structure trending E-W and oriented perpendicular to the rift. The rim rises about 100 m above the caldera floor; the eastern rim overlaps with a smaller elliptical caldera. Regional fissures trending roughly N-S cut across the caldera and its flanks. The youngest basalts were erupted during the first half of the 19th century from vents along a hinge line between the smaller eastern caldera (Korke) and the larger western one. A dark lava flow from a cone near the center of the southern caldera (Birenti), extended 12 km SW, where the caldera rim had been eroded, and surrounded older cones.

Boset
The Boset volcanic complex includes the Boset-Gudda (Great Boset) and Boset-Bericha (Little Boset) composite volcanoes rising above the floor of the Ethiopian Rift valley. Initial basaltic-to-trachytic activity at Gudda followed by rhyolitic effusive and explosive eruptions resulted in the formation of a caldera, a remnant of whose rim is found on the NW flank. Elsewhere, post-caldera activity produced very recent pantelleritic obsidian fissure-fed lava domes and flows that buried the caldera wall. Flank eruptions from fissures parallel to the rift produced voluminous pantelleritic lava flows. Bericha has produced similar very recent obsidian flows and associated pumice flows. Fissures connecting the edifices have erupted basaltic lava flows.

Bishoftu Volcanic Field
The Bishoftu volcanic field, also known as Debre Zeit, consists of an area of fissure-fed Holocene lava flows, cinder cones, tuff rings, and maars. Several of the maars are filled by lakes, which are popular recreational destinations from the nearby capital city of Addis Ababa. Most of the craters and cones are aligned NE-SW, parallel to the direction of the Ethiopian Rift Valley. The 750 x 1000 m Haro Maja tuff ring and its neighbor, lake-filled Kilole, are offset to the east. The cones and maars of the volcanic field were erupted through rhyolitic welded tuffs.

Melkassa
The Melkassa (or Sodore) volcanic field is an extensive 15 x 25 km group of about 30 Pleistocene and Holocene pyroclastic cones and lava flows that covers the floor of the E side of the Ethiopian Rift Valley, around the town of Melkassa, between the Boset volcanic complex and Gedamsa caldera.

Gedemsa
The Gedemsa caldera covers 7 x 9 km along the Main Ethiopian Rift E of Lake Koka and SW of Wonji Sugar Estate Farm. The steep-sided edifice has walls 100-200 m high whose upper part consists primarily of rhyolitic lava flows, formed by the eruption of a series of trachytic ignimbrites, It is also cut by many NNE-SSW-trending regional faults, particularly on the E side. Late-Pleistocene to Holocene volcanics form a chain of rhyolitic lava flows and pumice deposits, known as Ittisa, that rises above the floor of the caldera. A large 1-km-wide crater is located at the eastern part of the chain. A Holocene lava dome or flow is found on the SW flank. Small basaltic spatter cones have formed inside the caldera rim. Weak fumarolic activity was reported at two locations.

Bora-Bericha-Tullu Moye
The Bora-Bericha-Tullu Moye (BBTM) volcanic complex includes three main silicic edifices and at least 11 smaller cones within the Main Ethiopian Rift. Tullu Moye is a youthful trachytic-to-rhyolitic pumice cone with a 700-m-wide summit crater. A large silicic lava flow at Giano was erupted about two centuries ago from a regional fissure. Flank fissures have produced silicic lava flows as recently as about 1900 CE. Many large lava flows can be seen N of the Tulle Moye cone, extending for about 20 km in an arc between Gedamsa and the Bericha cone to the SE shore of Koka Lake. The silicic Bora and Bericha pumice cones are SE of Koka Lake. Bora has a 1.5-km-wide summit crater; the more conical Bericha is capped by a small summit crater and has a 1-km-wide crater on its S flank. Small silicic pyroclastic cones are found on the E flanks of both. All volcanic products in this area are considered to be Holocene, and there is ongoing fumarolic activity.

East Ziway
A large area of basaltic cinder cones and lava flows lies within about 5 km of the SE shore of Lake Ziway, and also forms islands along its E shore. About 80 vents were formed along the East Ziway segment of the Wonji Fault Belt. The youngest lava flows have been unaffected by the latest tectonic faulting along the Ethiopian Rift.

Butajiri-Silti Field
The Butajiri-Silti volcanic field consists of a large group of basaltic cinder cones, maars, and lava flows in an 80-km-long, NE-SW-trending area near the western margin of the Ethiopian Rift. At least 13 maars, many filled by lakes, are located near the town of Debre Zeit, SE of the capital city of Addis Ababa. The maars were erupted through Pleistocene rhyolitic lava flows and tuffs. Eruptions of the younger basaltic cinder cones were contemporaneous with those that produced the maars. Some of the lava flows associated with the cinder cones were considered very young by Di Paola (1972).

Aluto
Aluto, between lakes Zway and Langano (Mirrga), is a stratovolcano with multiple vents aligned along NNE-SSW and E-W fissures along a narrow graben between the two lakes. This silicic volcanic center lies along the regional Wonji Fault Belt and has produced abundant pumice-flow and pumice-fall deposits, along with lesser rhyolitic lava flows. Obsidian lava flows erupted from craters along the fissures have descended the flanks in all directions. Cinder cones, lava domes, phreatic explosion craters, and thermal springs are structurally controlled. The oldest known eruptions produced the Hulo-Seyno Ignimbrite about 155,000 years ago. The latest eruptions produced obsidian flows and pumice breccias about 2,000 years ago. Eruptive products overlie recent basaltic lava flows to the west. Strong fumarolic activity continues.

Shala
The Shala (also known as O'a) caldera along the central Main Ethiopian Rift forms the eastern portion of the 15 x 25 km Lake Shala. Formation of the caldera about 240,000 years ago was accompanied by the eruption of two ignimbrite deposits, the first of which was strongly welded. The only post-caldera activity consists of two pyroclastic cones to the N, one silicic and the other basaltic, and a group of tuff rings, spatter cones, and lava flows of Holocene age near the SW shore of the lake. These were erupted along the Corbetti-Shalla segment of the Wonji Fault Belt, which extends N from Corbetti caldera. Fumarolic activity continues on all sides of the lake.

Corbetti
Corbetti is one of the largest calderas (15.6 x 10.9 km) within the Main Ethiopian Rift (MER). As summarized by Colby et al. (2022), it has followed an evolutionary pattern similar to other caldera volcanoes within the MER, beginning with a shield-building phase of peralkaline rhyolite lava flows, followed by at least one caldera-forming eruption, the inferred deposits of which are dated to ca. 182 � 28 ka (Hutchison et al., 2016). Subsequent volcanism focused around three post-caldera edifices (Artu, Urji, and Chabbi) and a rhyolitic cone (Biftu Tuff Cone), situated outside the south-eastern caldera wall.... The eroded remains of Artu cone partly cover the northeastern section of the caldera, and younger products from Chabbi shield entirely cover the eastern portion of the caldera wall." The Wendo Koshe Younger Pumice (WKYP) has been 14C dated by Rapprich et al. (2016) to around 396 BCE; stratigraphic correlations indicate more recent eruptions, including four obsidian lava flows (Rapprich et al., 2016) and possibly two smaller explosive eruptions (Colby et al., 2022). Additional undated deposits are present between the WKYP event and the formation of the Biftu Tuff Cone after 5425 BCE (Colby et al., 2022).

Bilate River Field
The Bilate River basin west of Lake Awasa contains a group of lake-filled maars and tuff rings of Pleistocene and probable Holocene age (WoldeGabriel 1987, pers. comm.). Active hot springs and fumaroles are located in this area.

Northern Lake Abaya Volcanic Field
The Northern Lake Abaya volcanic field consists primarily of small Quaternary cones and basaltic lava flows between Doguna volcano to the north, Chericha to the E, Lake Abaya to the south, and the Hobitcha caldera to the west. The 3.5-km-long rhyolitic dome area immediately SE of the Hobitcha caldera trachytic ridge includes recent obsidian flows from vents at Hako and Salewa Dore (Corti et al., 2013).

Kenyan Rift Volcanic Province

Korath Range
Kenyan Rift Volcanic Province
Volcano type: Tuff cone(s)
The Korath Range is an isolated group of about 20 tuff cones and lava flows in southern Ethiopia that were erupted along the Turkana Rift, which extends north from Kenya. Many of the cones issued lava flows from their flanks that traveled up to about 5 km. The apparent youngest flow issued from the central crater and flowed through a breach in its rim. The absolute age of the dominantly basanitic-tephritic lava flows is unknown, but a shell adhering to the youngest flow was radiocarbon dated at 7,900 years before present (BP) (Brown et al., 1969). Davidson (1983) indicated an age between 30,000 and 7,900-9,500 BP.

Lake Turkana North Island
Kenya
Kenyan Rift Volcanic Province
Volcano type: Tuff cone(s)
The 2-km-wide North Island in Lake Turkana is the northernmost and smallest of three volcanic islands in the lake. It is primarily composed of trachyandesitic-to-trachytic phreatomagmatic deposits from overlapping eroded tuff cones or tuff rings. The center of the island consists of a young tuff ring about 1 km in diameter nested inside an older tuff ring. Two fresh unvegetated lava flows that reach the lake shore from the central tuff ring form lava deltas on the N and W sides of the island; the northern delta is about 900 m wide. The two blocky lava flows are younger than a terrace that formed less than 10,000 years ago during the last major high-water level (Key and Watkins, 1988). Geothermal activity occurs along a curvilinear ridge on the S portion of the island and on wave-cut platforms and beaches on the SW shoreline.

Lake Turkana Central Island
Kenya
Central Island in the middle of Lake Turkana, also known as Crocodile Island, is composed of more than a dozen craters and cones, three of which are filled by small lakes. The two largest lakes partially fill craters up to 1 km wide and about 80 m deep. An E-W chain of small explosion craters cuts the E side of the 3-km-wide island. Several small islands to the SE represent partially submerged crater rims, and other cones and lava plugs lie beneath the lake surface near the island. The youngest tuffs and lavas may be as young as Holocene (Karson and Curtis, 1992). Fumarolic activity is concentrated along the NE-to-SE rim of the central crater, and sprays of sulfur from the fumaroles were observed by visitors in the 1930s. In 1974 intense emission of molten sulfur and steam clouds were seen from the mainland.

Marsabit
Kenya
Marsabit is a massive basaltic shield volcano located 170 km E off the center of the East African Rift. There are 22 maars and 180 cinder cones on its slopes, most of which are concentrated along NW- and NE-trending belts that cut across the thickly vegetated summit region. The main phase of shield construction occurred during the Pliocene. Quaternary activity shifted to explosive activity that formed maars accompanied by further extensive effusion of lava flows. The youngest dated lava flow has a Potassium-Argon age of 68,000 +/- 16,000 years, but more recent activity has also occurred. The youngest lava flows are unvegetated, and Key (1987) mapped the post-shield cinder cones as Pleistocene-to-Recent in age.

Lake Turkana South Island
The southernmost and largest of the three volcanic islands in Lake Turkana, South Island (sometimes referred to as Hohnel Island), contains numerous tuff cones. Early stage cone formation may have been associated with a high stand of Lake Turkana dated at about 10,000 years ago, and later subaerial activity postdates the last high stand of the lake about 3,200 years ago. The island is within a volcanic horst that extends 10 km to the N beneath the lake surface. Dominantly basaltic lava flows erupted from a N-S fissure extending the 11-km length of the island are morphologically similar to Holocene flows from The Barrier volcano at the S end of Lake Turkana. An eruption from a scoria cone on the island was witnessed during Count von Teliki's 1888 expedition.

The Barrier
The Barrier volcanic complex separates Lake Turkana from the broad Suguta Trough to the S, the site of a former lake. The volcano is comprised of four overlapping shield volcanoes, with the youngest, Kakorinya, located over the axis of the East African Rift. Kalolenyang volcano lies W of Kakorinya, and Likaiu West and Likaiu East are located to the ENE. A 3.8-km-wide summit caldera was formed at Kakorinya about 92,000 years ago. Youthful-looking trachytic and phonolitic lava domes and flows erupted within the caldera and along its ring fracture fill much of the caldera floor. Early Holocene fissure-related scoria cones and lava flows dot the S and N flanks. Solfataric fields are located within the caldera and on the W and S flanks. Historical eruptions from Teleki's and Andrew's cones on the N and S flanks, respectively, have produced basaltic explosive activity and lava flows during the 19th and 20th centuries.

Namarunu
The largely Pliocene Namarunu trachytic shield volcano is topped by cones and lava flows of upper Pleistocene and Holocene age. Voluminous basaltic effusive and explosive activity took place during the early Holocene on the lower N, E, and S flanks along the axis of the East African Rift. The activity produced fissure-controlled subaerial basaltic scoria cones and lava flows, and partially or completely sub-lacustral tuff cones, tuff rings, and pillow lavas. Olivine basalts erupted from a breached scoria cone at the summit. The youngest eruptions postdated the drying out of Lake Sugata about 3,000 years ago. Some could be as recent as the recorded eruptions at The Barrier volcano to the north (Dunkley et al., 1993). Hot springs are located on some of the young volcanic cones on the rift valley floor and on the E side of the rift along the base of the Tirr Tirr Plateau.

Segererua Plateau
A large number of late-Pleistocene to Holocene basaltic cones, lava flows, and maars occur along a roughly 50-km-long NE-SW trend on the Segererua and Rusarus Plateaus and areas to the SW. This volcanic region is located well E of the East African Rift, S of the massive Marsabit shield volcano. The two plateaus host most of the vents and are bounded by the Milgis River to the N and the Merille River to the S. Other vents lie to the SW, east of the Kauro River, and another large area of basaltic lava flows lies to the W.

Emuruangogolak
The broad Emuruangogolak shield volcano is situated at a narrow constriction in the Gregory Rift and almost completely straddles it. A 5 x 3.5 km summit caldera formed about 38,000 years ago. Since then trachytic and basaltic lava flows were erupted on the northern and southern flanks and within the caldera. A NNE-SSW-trending chain of lake-filled basaltic maars extends along the floor of the rift from the lower flanks of the volcano. Young lava flows were also erupted from vents along rift valley faults. Well-preserved cones erupted along rift-parallel faults cutting the volcano; the latest eruption produced a trachytic lava flow dated from secular magnetic variation measurements at about the beginning of the 20th century. Fumarolic activity and hot steaming ground occurs along NNE-trending fissures within the caldera and along the lower NW flanks.

Silali
The 30-km-wide Silali trachytic shield volcano, the largest Quaternary volcano in the northern Gregory Rift, completely straddles the East African Rift. The 5 x 8 km summit caldera with 300 m deep walls is thought to have formed incrementally about 63,000 years ago, related to eruption of the Kantenmening basaltic and trachytic lava flows. A series of summit-area lava benches formed by eruptions from circumferential fissures is morphologically similar to Galapagos Islands volcanoes. The N, E, and S flanks are cut by a prominent broad rift zone 10 km wide and 30 km long, with numerous pyroclastic cones. Lava domes on the upper E flank formed during the late Pleistocene and early Holocene, until about 7,000 years ago. Youthful cones are common on the caldera floor and on the N and NE flanks; the youngest lava flows may be little more than a few hundred years old (Williams et al. 1984). Geothermal activity occurs within the caldera and on the upper E flanks.

Paka
The dominantly Pleistocene Paka shield volcano in the Gregory Rift contains a small 1.5-km-wide summit caldera. Eruption of large volumes of trachytic pyroclastic rocks around the end of the Pleistocene and the beginning of the Holocene formed a NW-trending ridge of pyroclastic cones across the summit region; collapse of this area formed the summit caldera and associated craters. A second large crater SE of the caldera is 0.5 x 1 km wide and contains a pumice cone. The summit caldera is narrowly breached on the N side, which has funneled post-caldera lava flows in this direction. The three youngest post-caldera pyroclastic cones on the NE flank may be only a few hundred years old. A series of viscous trachytic lava flows were erupted from vents on the lower flanks. Young fissure-fed basalts were also erupted to the S, between Paka and Korosi volcanoes. Surficial geothermal activity is widespread at Paka, both within the summit caldera and on extensive portions of the N flank.

Korosi
The trachytic Korosi shield volcano lies at the N end of Lake Baringo. Unlike other rift valley volcanoes, it does not contain a summit caldera. Lava domes on the N flanks have fed trachytic lava flows. The major stage of volcanism spanned a period between 0.4 and 0.1 million years ago, and included the eruption of voluminous fluid basaltic lava flows and pyroclastic cone formation along a NNE-trending fissure cutting across the axis of the shield volcano. This was followed by the eruption of trachytic lava domes and pumice/scoria cones. The youngest activity, consisting of fissure-fed basaltic lava flows on the lower N flanks between Korosi and Paka, was probably coeval with the latest eruptions on Ol Kokwe to the S, which are only a few hundred to a few thousand years old (Dunkley et al. 1993). Fumaroles and hot steaming ground occur around the summit cones and NW flanks over an area of 30 km3.

Ol Kokwe
The elongated Ol Kokwe Island in the center of Lake Baringo SW of Korosi volcano consists of young basaltic scoria cones that cap a trachytic shield volcano. N-S-trending faults cut the complex, producing W-facing scarps. Smaller islands to the N and S are faulted basaltic lava flows; Parmalok Island to the SW is a breached trachytic tuff cone that fed a small lava flow. The latest eruptive activity was estimated to have occurred within the past thousand years (Smith 1991, pers. comm.). Hot springs, boiling mud pools, and fumaroles are present along the faults on the NE peninsula of the island and are frequently visited by tourists.

Nyambeni Hills
The broad NE-SW-trending Nyambeni shield volcano is capped by numerous phonolitic lava domes, basaltic cones, and lava flows of late-Pleistocene to Holocene age (Hackman et al., 1989). The basaltic cinder cones are the youngest features. They are clustered in a NE-trending belt along the crest of the shield, in a N-S-trending area including the Mula Hills, and in the Giaki area.

Menengai
The massive Menengai shield volcano occupies the floor of the East African Rift. Construction of a 30 km3 shield volcano beginning about 200,000 years ago was followed by the eruption of two voluminous ash-flow tuffs, each preceded by major pumice falls. The first took place about 29,000 years ago and produced a large caldera. The second, producing about 30 km3 of compositionally zoned peralkaline trachytic magma about 8000 years ago, was associated with formation of the present-day 8 x 12 km summit caldera. More than 70 post-caldera lava flows cover the caldera floor, the youngest of which may be only a few hundred years old. No historical eruptions are known. Fumarolic activity is restricted to the caldera.

Elmenteita Badlands
The Elmenteita Badlands, located between Lake Elmenteita (N) and Eburru volcano (S), is an area of pyroclastic cones and lava flows of varying ages. Large basaltic lava flows and ash cones post-date the 10,000-year-old high-stand of Lake Elmenteita (Thomson and Dodson, 1963).

Homa Mountain
Homa Mountain is a large carbonatitic complex with a flat-topped summit that forms a broad peninsula on the E shore of Lake Victoria. This dominantly Miocene-to-Pleistocene complex contains numerous flank vents, including the carbonatitic and ultramafic Lake Simbi maar on the lower E flank. The Chiewo, Got Ojawa, and Got Oloo vents on the S and W sides of Homa Mountain were formed during the latest stage of carbonatitic activity. Legends of inhabitants near the Lake Simbi maar suggest that it may have been formed in historical time.

Ol Doinyo Eburru
Eburru volcano is elongated E-W perpendicular to the Gregory Rift NW of Lake Naivasha. The main edifice is eroded, but young partly vegetated rhyolitic domes occur on the E flank and are probably of Holocene age (Thompson and Dodson, 1963). Pleistocene phonolitic and trachytic lava flows are overlain by rhyolitic obsidian lava flows forming much of the N and NE slopes of the main massif. A prominent late-Pleistocene rhyolitic lava flow from a SE-flank vent extends almost to Lake Naivasha. Extensive fumarolic activity occurs at cinder cones and craters constructed along dominantly N-S faults cutting the massif.

Olkaria
The Olkaria volcanic complex, located immediately S of Lake Naivasha and W of Longonot volcano, comprises up to 80 individual alkali rhyolite centers. A thick, geochemically diverse basal complex is overlain by a dominantly silicic lava-dome and lava-flow complex constructed within a largely obscured 11 x 7.5-km-wide caldera that formed about 20,000 years ago following the eruption of welded alkali rhyolite ignimbrites. The youngest known eruption originated from the Ololbutot fissure on the SW side of the complex and produced a 5 km3 lava flow and a pumice flow that has a radiocarbon age of about 180 years. Fumarolic activity occurs at the Njorowa Gorge, and at the Orengingnai and Olkaria (Orgaria) pumice cones. Olkaria is the site of a large 50-80 km3 high-temperature geothermal field.

Longonot
The trachytic Longonot stratovolcano SE of Lake Naivasha in the Gregory Rift valley contains a 8 x 12 km caldera. Formation of the caldera accompanied large explosive eruptions about 21,000 years ago. A large central cone that was constructed within the caldera, which forms the summit, is truncated by a circular, 1.8-km-wide crater. Post-caldera lavas are found on the caldera floor and the volcano's flanks, marking a late stage of effusive eruptions. A well-preserved satellitic cone is located on the NE flank. Masai tradition records a lava flow on the N flank during the 19th century. Similarly youthful-looking lava flows occur on the SW flank.

Suswa
The phonolitic-to-trachytic Suswa volcano in the Kenyan Rift, ~50 km WNW of Nairobi, is notable for its 8 x 12 km caldera. Construction of an early shield volcano was followed by eruption of voluminous Pleistocene pumice and lava flows that accompanied incremental formation of the caldera. The post-caldera lava cone of Ol Doinyo Onyoke ("The Red Mountain," also known as Ol Doinyo Nyukie) is on the south side of the caldera. A large elongated summit crater is truncated on the north by a ring graben. This unusual 5-km-wide circular graben at the center of the older caldera isolates a tilted island block of caldera-floor lava flows. Some lava flows from flank vents remain unvegetated and may be only a century or so old, but have not been dated.

Ol Doinyo Lengai
Tanzania
The symmetrical Ol Doinyo Lengai is the only volcano known to have erupted carbonatite tephras and lavas in historical time. The prominent stratovolcano, known to the Maasai as "The Mountain of God," rises abruptly above the broad plain south of Lake Natron in the Gregory Rift Valley. The cone-building stage ended about 15,000 years ago and was followed by periodic ejection of natrocarbonatitic and nephelinite tephra during the Holocene. Historical eruptions have consisted of smaller tephra ejections and emission of numerous natrocarbonatitic lava flows on the floor of the summit crater and occasionally down the upper flanks. The depth and morphology of the northern crater have changed dramatically during the course of historical eruptions, ranging from steep crater walls about 200 m deep in the mid-20th century to shallow platforms mostly filling the crater. Long-term lava effusion in the summit crater beginning in 1983 had by the turn of the century mostly filled the northern crater; by late 1998 lava had begun overflowing the crater rim.

Chyulu Hills
The 100-km-long NW-SE-trending Chyulu Hills volcanic field is located 150 km E of the Kenya Rift. It contains several hundred small cones and flows, including numerous recent cinder cones. Two of these, Shaitani and Chainu, erupted during the mid-19th century. Volcanic activity began about 1.4 million years ago with eruptions in the northern Chyulu Hills and migrated to the SE, where a large number of Holocene cones are found. Many of the cinder cones are aligned along dominantly NW-trending older faults and younger NNE-trending fissures. The silica contents of the lava flows increased with time. Early flows consisted of foidites; later Holocene lava flows are basanites and alkali basalts. Six tephra deposits from Lake Chala were attributed by Martin-Jones et al. (2020) to Pleistocene eruptions in the Chyulu Hills (~87-16.8 ka), along with one Holocene mafic cryptotephra 14C dated at about 4.2 ka.

Meru
Tanzania
Meru has a conical profile when viewed from the west, but there is a 4-km-wide collapse crater to the E. The summit collapse is associated with the early Holocene Momella event that resulted in debris avalanche and lahar deposits as far as the W flank of Kilimanjaro. Cones and lava domes are located on all sides; a maar field is present on the lower N flank. Activity from the Ash Cone, inside the open crater, was reported around 1878 and in 1910 CE. A second vent between it and the headwall produced lava flows that cover much of the caldera floor. Kisaka et al. (2021) identified three late Pleistocene explosive eruptions during 31-38 ka BP (cal 14C).

Mega Volcanic Field
The Mega Volcanic Field in southern Ethiopia is present on both sides of the 100-km-long NW-SE Mega escarpment, and covers about 1,400 km2. Franceschini et al. (2020) provides an excellent review of this field, from which most of this summary is taken. The field includes 114 monogenetic centers, primarily cinder cones and some maars; the largest maar is the 2.3-km-diameter El Sod. Uneroded lava flows often partially overly deeply eroded lava flows. Large lava flows are usually associated with cinder cones, but fissure-fed flows in the Megado area exhibit oriented spatter ramparts. One of the largest lava flows extends more than 10 km SW from the Mega escarpment and covers about 25 km2; it has a very fresh, black, glassy appearance of the surface, and minimal vegetation. Two samples analyzed by Franceschini et al. (2020) yielded 40Ar/39Ar ages of 0.116 � 0.005 and 0.044 � 0.008 Ma; two other samples indicated very recent Holocene ages. These are the first age dates available for this field, and are in agreement with the morphological interpretation of some young cinder cones and lava flows.

Albertine Rift Volcanic Province

Fort Portal Volcanic Field
Uganda
Albertine Rift Volcanic Province
The carbonatite lavas and tuffs of the Fort Portal Volcanic Field in Uganda, NE of Mount Ruwenzori between Lake Albert and Lake Edward, consists of a group of tuff cones and maars covering an area of about 145 km2. About 50 volcanic vents, some of which now contain crater lakes, were erupted through Precambrian gneiss in an WSW-ENE-trending area north of the town of Fort Portal. Several additional vents are located in the Kasekere (Rusekere) area to the NE. Radiocarbon dates of about 4,700-4,000 years ago were obtained from ash deposits in the volcanic field. Holmes (1950) noted that Kasensankaranga Crater in the Fort Portal area means "spewer of roasted material," implying observed activity.

Ndali-Kasenda Volcanic Field
Uganda
Albertine Rift Volcanic Province
The Ndali-Kasenda Volcanic Field (also known as Kwatya) is located in the Western Rift Valley, N of the equator and E of the Ruwenzori Mountains about halfway between Lake Edward and Lake Albert. The numerous tuff cones and lake-filled maars are part of a group of Quaternary volcanic fields in western Uganda. Leaf fragments obtained from basal sediments cored from Lake Kifuruka were radiocarbon dated to 11,560 cal BP (9610 BCE) (Kiage et al., 2020). No eruption dates are known.

Nyamulagira
DR Congo
Africa's most active volcano, Nyamulagira (also known as Nyamuragira), is a massive high-potassium basaltic shield about 25 km N of Lake Kivu and 13 km NNW of the steep-sided Nyiragongo volcano. The summit is truncated by a small 2 x 2.3 km caldera that has walls up to about 100 m high. Documented eruptions have occurred within the summit caldera, as well as from the numerous flank fissures and cinder cones. A lava lake in the summit crater, active since at least 1921, drained in 1938, at the time of a major flank eruption. Recent lava flows extend down the flanks more than 30 km from the summit as far as Lake Kivu; extensive lava flows from this volcano have covered 1,500 km2 of the western branch of the East African Rift.

Nyiragongo
DR Congo
The Nyiragongo stratovolcano contained a lava lake in its deep summit crater that was active for half a century before draining catastrophically through its outer flanks in 1977. The steep slopes contrast to the low profile of its neighboring shield volcano, Nyamuragira. Benches in the steep-walled, 1.2-km-wide summit crater mark levels of former lava lakes, which have been observed since the late-19th century. Two older stratovolcanoes, Baruta and Shaheru, are partially overlapped by Nyiragongo on the north and south. About 100 cones are located primarily along radial fissures south of Shaheru, east of the summit, and along a NE-SW zone extending as far as Lake Kivu. Many cones are buried by voluminous lava flows that extend long distances down the flanks, which is characterized by the eruption of foiditic rocks. The extremely fluid 1977 lava flows caused many fatalities, as did lava flows that inundated portions of the major city of Goma in January 2002.

Karisimbi
DR Congo-Rwanda
Karisimbi is a complex basanitic-to-trachytic volcano with a symmetrical sharp-peaked summit. The 2-km-wide Branca caldera, located SE of the summit, is filled by viscous lava flows and two explosion craters. The large 1.2-km-wide Muntango pit crater is located south of the summit. A broad lava plain, formed from lava flows erupted within the caldera and along a chain of cones, extends SW. More than 100 cones erupted along a NNE-SSW zone that extends to the shores of Lake Kivu. The youngest Potassium-Argon date obtained is about 10,000 years before present (de Mulder, 1985). The youngest eruptions produced a group of dome-shaped vents east of the caldera, which fed viscous lava flows that traveled as far as 12 km E, and lava flows from the SW-flank lava vents.

Mugogo
DR Congo
Volcano type: Cone
The small Mugogo cone was built during a 1957 eruption. Although initially thought to be a flank vent related to the Visoke stratovolcano, ~11 km S, geochemical analysis by Condomines et al. (2015) found that the lava flows were more similar to Nyamulagira and Nyiragongo to the W, rather than Visoke.

Rukwa Rift Volcanic Province

Ngozi
Tanzania
Rukwa Rift Volcanic Province
Ngozi caldera is the most prominent volcanic feature of the Poroto Ridge, a transverse structure at the northern end of the Karonga basin. The trachytic-to-phonolitic volcano contains a 3-km-wide caldera with a 1.5 x 2.5 km lake in the southern part of the caldera that is bounded by steep-walled cliffs 150-300 m high. Numerous pyroclastic cones are situated along the ridge. Eruption of the Kitulo Pumice, radiocarbon dated at about 10,200 cal. years before present, is though to be related to formation of the caldera. The youngest activity appears to have originated from the caldera and from youthful-looking pyroclastic cones to the north; the youngest known eruption produced a pyroclastic flow that swept at least 10 km S about 500 years ago.

Rungwe
Rukwa Rift Volcanic Province
Rungwe volcano, the largest in the Karonga basin NW of Lake Malawi (Lake Nyasa), is cut by a 4-km-wide caldera that is breached to the WSW. Hummocky terrain from a debris-avalanche deposit produced by collapse of the summit and western flank extends at least 20 km SW of the volcano. The trachytic caldera is largely filled by a series of youthful-looking uneroded and sparsely vegetated pumice cones, lava domes, and explosion craters. The latter are also found on the southern and northern flanks. A large area of basaltic cones and lava flows are found on the NW flank, and youthful-looking lava flows extend SW from vents inside the caldera. Explosive and effusive eruptions were produced during the Holocene; the largest explosive eruption took place about 4,000 years ago, and the most recent about 1,200 years ago.

Kyejo
Late-stage activity of the Kyejo (Kieyo) trachytic stratovolcano, NW of Lake Malawi (Lake Nyassa), consisted of the formation of numerous maars and cinder cones. This stratovolcano is elongated in a NW-SE direction and has been active since the mid-Pleistocene. Maars, some of which contain lakes, surround the area, and young basaltic cinder cones and lava flows cover an extensive area to the south. The latest eruption around 1800 CE took place from two tephritic cones, Sarabwe and Fiteko, that were constructed along a NW-trending fissure. The eruption produced lava flows that traveled 8 km and overran several villages.

Somalian-Antarctic Volcanic Regions

Madagascar-Comoros Volcanic Province

La Grille
Union of the Comoros
Madagascar-Comoros Volcanic Province
La Grille is a basaltic shield volcano at the N end of Grand Comore Island (Ngazidja). Unlike the larger Karthala volcano to the S, it lacks a summit caldera but has an abundance of pyroclastic cones. The cones were erupted along fissures paralleling the irregular N-S summit ridge and from radial fissures that reach as far as the coast. Recent lava flows, some perhaps as young as a few hundred years, have reached the sea from fissures on the lower W, N, and E flanks.

Mayotte
Madagascar-Comoros Volcanic Province
Mayotte, located in the Mozambique Channel between the northern tip of Madagascar and the eastern coast of Africa, consists two main volcanic islands, Grande Terre and Petite Terre, and roughly twenty islets within a barrier-reef lagoon complex (Zinke et al., 2005; Pelleter et al., 2014). Volcanism began roughly 15-10 million years ago (Pelleter et al., 2014; Nougier et al., 1986), and has included basaltic lava flows, nephelinite, tephrite, phonolitic domes, and pyroclastic deposits (Nehlig et al., 2013). Lava flows on the NE were emplaced from about 4.7 to 1.4 million years, and on the south from about 7.7 to 2.7 million years. Mafic activity resumed on the north from about 2.9 to 1.2 million years and on the south from about 2 to 1.5 million years. Several pumice layers found in cores on the barrier reef-lagoon complex indicate that volcanism likely occurred less than 7,000 years ago (Zinke et al., 2003).

Karthala
Union of the Comoros
The southernmost and largest of the two shield volcanoes forming Grand Comore Island (also known as Ngazidja Island), Karthala has two overlapping 3-4 km summit calderas generated by repeated collapse. Elongated rift zones extend NNW and SE from the summit of the basaltic shield, which has an asymmetrical profile that is steeper to the S. The lower SE rift zone forms the Massif du Badjini, a peninsula at the SE tip of the island. More than twenty eruptions have been recorded since the 19th century from the summit caldera and vents on the N and S flanks, producing many lava flows that reached the sea on both sides of the island. An 1860 CE lava flow from the summit caldera traveled ~13 km to the NW, reaching the W coast to the N of the capital city of Moroni.

Fani Maore
Activity that began in May 2018 consisted of seismicity and ground deformation occurring offshore E of Mayotte Island (Lemoine et al., 2019). One year later, in May 2019, a new subaqueous edifice, named Fani Maor�, and associated lava flows were observed 50 km E of Petite Terre during an oceanographic campaign.

Reunion Hotspot Volcano Group

Piton de la Fournaise
Reunion Hotspot Volcano Group
Piton de la Fournaise is a massive basaltic shield volcano on the French island of R�union in the western Indian Ocean. Much of its more than 530,000-year history overlapped with eruptions of the deeply dissected Piton des Neiges shield volcano to the NW. Three scarps formed at about 250,000, 65,000, and less than 5,000 years ago by progressive eastward slumping, leaving large embayments open to the E and SE. Numerous pyroclastic cones are present on the floor of the scarps and their outer flanks. Most recorded eruptions have originated from the summit and flanks of Dolomieu, a 400-m-high lava shield that has grown within the youngest scarp, which is about 9 km wide and about 13 km from the western wall to the ocean on the E. More than 150 eruptions, most of which have produced fluid basaltic lava flows, have occurred since the 17th century. Eruptions in 1708, 1774, 1776, 1800, 1977, and 1986 originated from fissures outside the scarps.

Amsterdam-St. Paul Hotspot Volcano Group

Boomerang Seamount
Amsterdam-St. Paul Hotspot Volcano Group
Boomerang Seamount, an active submarine volcano 18 km NE of Amsterdam Island, was first discovered during a bathymetric survey in 1996. It rises to within 650 m of the ocean surface and has a 2-km-wide summit caldera that is 200 m deep. Rift zones that extend to the SE and N give it an arcuate shape. A basaltic volcano, it lies along the axis of the Southeast Indian Ridge and marks the site of the Amsterdam-St. Paul hotspot. This hotspot may have been the source of the Ninetyeast Ridge submarine volcanoes on the Australian Plate prior to its "capture" by the Southeast Indian Ridge, after which volcanism was restricted to the Antarctic Plate. Very short half-life radionuclide dating of fresh volcanic glass samples recovered during the 1996 expedition indicated that it had erupted only about 5 months earlier (Johnson et al., 2000). Water column temperature anomalies above the seamount suggest the presence of hydrothermal activity within the caldera.

Amsterdam Island
Amsterdam-St. Paul Hotspot Volcano Group
The elliptical 7 x 10 km Amsterdam Island is the northernmost subaerial volcano on the Antarctic Plate. The basaltic volcano is located near the axis of the East Indian Ocean Ridge adjacent to the Indian Plate. Amsterdam volcano was formed during two episodes of cone growth accompanied by the formation of small calderas. The caldera of the youngest eruptive center, 2 km ENE of the earlier one, contained a lava lake that fed several stages of lava outflows. Minor late-stage eruptions formed more than two dozen scoria cones and many small lava flows. No observed eruptions are known, although the fresh morphology at Dumas Crater on the NE flank suggests it may have occurred as recently as a century ago (Nougier, 1982).

St. Paul
The uninhabited triangular island of St. Paul is located near the axis of the East Indian Ocean Ridge, 80 km S of Amsterdam Island. It is composed of an older tuff cone surmounted by a basaltic stratovolcano with a 1.8-km-wide caldera. The entire NE half of the volcano was submerged following collapse along a NW-trending fault. This breached the central caldera, leaving an 80-m-deep bay connected to the ocean by a narrow channel. Geothermal areas are located near the caldera rim and along the margins of the caldera bay. The only recorded eruption took place in 1793 from a vent on the lower SW flank.

Marion Hotspot Volcano Group

Prince Edward Island
South Africa
Marion Hotspot Volcano Group
Uninhabited 5 x 10-km-wide Prince Edward Island lies opposite Marion Island at the N end of a submarine plateau on the Antarctic Plate immediately S of the SW Indian Ocean Ridge. It is a low-angle remnant of a large shield volcano formerly centered off the current NW shore of the island. Pleistocene and Holocene scoria cones and tuff cones are located throughout the unglaciated island, which was active contemporaneously with nearby Marion Island. Fifteen of the scoria cones and four tuff cones on the coastal plain were active during the Holocene.

Marion Island
South Africa
Marion Hotspot Volcano Group
Marion Island lies at the SW end of a submarine plateau immediately south of the SW Indian Ocean Ridge, opposite Prince Edward Island. The low profile of the 24-km-wide dominantly basaltic and trachybasaltic volcano is formed by two young shields that rise above a flat-topped submarine platform. The island includes about 150 cinder cones, smaller scoria cones, and coastal tuff cones. The earliest dated eruptions took place about 450,000 years ago, but much of the island is covered by Holocene aa and pahoehoe lava flows, and more than 130 scoria cones formed during the Holocene. Many of these appear younger than the 4,020 BP peat layer overlying one of the flows (Verwoerd, 1981). Unvegetated lava flows appear to be only a few hundred years old (Verwoerd, 1967). An eruption in 1980 produced explosive activity and lava flows from a 5-km-long fissure that extended from the summit to the west coast.

Crozet Hotspot Volcano Group

Ile de l' Est
Crozet Hotspot Volcano Group
Ile de l'Est, the easternmost island in the Crozet archipelago, is a glacially eroded basaltic stratovolcano. A metamorphosed gabbroic complex is cut by a dense network of dikes and cone sheets that fed younger volcanic rocks. The 10 x 19 km island is the oldest of the Crozet Islands, but contains five younger oxidized scoria cones, most of which are on its E flank. The young scoria cones may be Holocene (LeMasurier and Thomson, 1990).

Ile de la Possession
Crozet Hotspot Volcano Group
�le de la Possession, located immediately W of Ile de l'Est in the Crozet archipelago, consists of a stratovolcano intruded by ring and cone dikes and modified by block faulting, marine erosion, and uplift. The structural center of the volcano is located on the W side of the 14 x 19 km island, which has an irregular shoreline. The stratovolcano was formed during at least five stages dating back to the Miocene. The eruption of plateau basalts from a rift system during stage IV was followed by a glacial period and then by the eruption of scoria cones and lava flows. The young scoria cones are of probable Holocene age and are distributed over much of the island, concentrated at the structural center on the W side and along a series of N-S and NE-trending fractures. The Mont Branca cone on the W flank has been estimated by Bellair (1964) to be not more than a few centuries old.

Ile aux Cochons
The 8 x 10 km Ile aux Cochons, at the W end of the Crozet Islands, is a single stratovolcano with a small summit caldera and more than 60 scoria cones. The production of phreatomagmatic breccias interbedded with thin lava flows was followed by block faulting and the eruption of scoria cones and lava flows along four radial fracture systems. Bellair (1964) considered the Morne Rouge cone on the E coast to be younger than a cone on Possession Island estimated to be several hundred years old.

Kerguelen Hotspot Volcano Group

McDonald Islands
Australia
Kerguelen Hotspot Volcano Group
The McDonald Islands are located on the Kerguelen Plateau about 75 km W of Heard Island. The largest island, McDonald, is composed of a layered phonolitic tuff plateau cut by phonolitic dikes and lava domes. A possible nearby active submarine center was inferred from phonolitic pumice that washed up on Heard Island in 1992. Volcanic plumes were observed in December 1996 and January 1997 from McDonald Island. During March 1997 the crew of a vessel that sailed near the island noted vigorous steaming from a vent on the N side of the island along with possible pyroclastic deposits and lava flows. A satellite image taken in November 2001 showed the island to have more than doubled in area since previous reported observations in November 2000.

Heard
Kerguelen Hotspot Volcano Group
Heard Island on the Kerguelen Plateau in the southern Indian Ocean consists primarily of the emergent portion of two volcanic structures. The large glacier-covered composite basaltic-to-trachytic cone of Big Ben comprises most of the island, and the smaller Mt. Dixon lies at the NW tip of the island across a narrow isthmus. Little is known about the structure of Big Ben because of its extensive ice cover. The active Mawson Peak forms the island's high point and lies within a 5-6 km wide caldera breached to the SW side of Big Ben. Small satellitic scoria cones are mostly located on the northern coast. Several subglacial eruptions have been reported at this isolated volcano, but observations are infrequent and additional activity may have occurred.

Kerguelen Islands
The Kerguelen Islands are composed primarily of Tertiary flood basalts and a complex of plutonic rocks. The trachybasaltic-to-trachytic Mount Ross stratovolcano at the S end was active during the late Pleistocene. The Rallier du Baty Peninsula on the SW tip of the island contains two youthful subglacial eruptive centers, Mont St. Allouarn and Mont Henri Rallier du Baty. An active fumarole field is related to a series of Holocene trachytic lava flows and lahars that extend beyond the icecap (Ballestracci and Nougier, 1984). Gagnevin et al. (2003) dated a trachytic ignimbrite that was considered to represent the last major eruptive event on the Kerguelen Archipelago at 26,000 +/- 3000 years.

Pleistocene Volcanoes | VOTW 5.4.0, 7 Aug 2026

Northern Victoria Land
A large number of isolated basaltic scoria cones are located throughout Antarctica's northern Victoria Land near the western coast of the Ross Sea, not clearly associated with the larger stratovolcanoes. One lava flow on the southern side of Cosmonaut Glacier, SW of Mount Overlord, spilled onto the glacier and diverted it, but has not yet been removed by erosion or covered by ice. Nathan and Schulte (1968) inferred a possible age for the lava flow of less than a thousand years, but not greater than 50 ka. Potassium-Argon dates from Overlord (see separate volcano entry) indicate an age of about 7 million years (Kyle, 1977, pers. comm.; LeMasurier and Thomson, 1990). There is no clear evidence of Holocene activity from any of these poorly-studied basaltic rocks, called the "Local Suite" by Nathan and Shulte (1968).

Adare Peninsula
The Adare Peninsula is a complex of overlapping shield volcanoes forming the northernmost volcanic pile of the Hallet Volcanic Province. Hamilton (1972) considered uneroded cinder cones at Cape McCormick to be of Holocene age, but similar-looking Antarctic cones have proved to be as old as Tertiary. Most Potassium-Argon dates for the Adare Peninsula range from 6-13 million years ago (Ma), but one possibly anomalous date of 1.14 Ma was obtained, and a sample from Cape Roget was dated at 2.27 Ma (LeMasurier and Thomson, 1990).

Mount Rittmann
Mount Rittmann, a roughly 8 x 5 km caldera under the Aviator Glacier in the Melbourne Volcanic Province, has been dated at between about 4 and 0.07 million years ago (Martin et al., 2010). Active fumaroles, heated ground, and ice and snow hummocks occur near the caldera rim.

Franklin Island
Franklin Island is a 2 x 7.6 km remnant of a shield volcano whose vent was located to the east. IAVCEI (1973) assigns a Quaternary age. The only radiometric date available is a Potassium-Argon date of 4.8 +/- 2.0 Ma (LeMasurier and Thomson 1990). Bathymetric mapping in 2004 identified the Franklin Volcanic Field, a regional high with clusters of submarine cones extending 80 km long and up to 40 km wide (Smith, 2004).

Beaufort Island
Beaufort Island is an eroded remnant of a Quaternary volcano (Calkin and Nichol 1972). LeMasurier and Thomson (1990) indicate its age is unknown.

Terror
Mount Terror is a large basaltic shield volcano forming the eastern portion of Ross Island with numerous pyroclastic cones and lava domes. The youngest dated rocks are 0.82 million years ago (Ma) from the lower slopes of Terror and 0.8 Ma from the summit of Terra Nova, a large basaltic cone on the W flank (LeMasurier and Thomson, 1990).

Taylor Valley
Taylor Valley contains numerous basaltic cinder cones, the youngest of which is Potassium-Argon dated 1.57 million years ago. Similar Pliocene volcanism took place in the Wright Valley to the north (LeMasurier and Thomson 1990).

Hut Point Peninsula
Hut Point Peninsula consists of a 20-km-long line of basaltic scoria cones south of Erebus. Potassium-Argon dates range from 1.34 to 0.44 million years ago (LeMasurier and Thomson, 1990). Martin et al. (2010) listed a 0.5 Ma date.

White Island
White Island is a mostly ice-covered volcanic complex at the northern end of the island consisting of two shield volcanoes and overlying pyroclastic cones. The youngest Potassium-Argon date obtained was 0.17 million years ago and there is no evidence of Holocene activity.

Black Island
A series of basaltic pyroclastic cones and trachytic lava domes form Black Island, in the Ross Sea west of White Island. Potassium-Argon dates of 3.4 Ma were obtained (LeMasurier and Thomson 1990). Martin et al. (2010) reported dates of 3.8-1.69 million years.

Transantarctic Mountain Foothills
Volcano type: Unknown
Elevation: m
Latitude: 78°S
Volcanic rocks in the Transantarctic Mountain Foothills have been radiometrically dated at between 14 and 0.9 million years (Martin et al., 2010).

Mason Spur
An older trachytic volcanic complex at Mason Spur is overlain by a younger sequence consisting of a trachytic dome, tuff rings, and numerous basanite and tephrite cinder cones. Several lava flows drape over the bluffs, and may be less than 100,000 years old (LeMasurier and Thomson, 1990).

Discovery
Mount Discovery is a central volcano that Potassium-Argon dating indicates formed about 5.3 million years ago. The youngest flank cones have been dated at about 1.87 million years ago (LeMasurier and Thomson, 1990).

Waesche
Mount Waesche is the southernmost of a N-S chain of volcanoes in central Marie Byrd Land, 20 km SW of Pliocene Mount Sidley. The Waesche shield was constructed around 1.0 Ma on the SE rim of the 10-km-wide Chang Peak caldera; pre-caldera Chang Peak lavas were erupted about 1.6 Ma. Satellitic cinder cones, some aligned along radial fissures, are located on the SW flank. The youngest dated products suggest a pulse of effusive activity between about 200,000 and 100,000 years ago.

Siple
Mount Siple is a shield volcano that forms an island along the Pacific Ocean coast of Antarctica's Marie Byrd Land. The massive 1,800 km3 volcano is truncated by a 4-5 km summit caldera and is ringed by tuff cones at sea level. A possible eruption cloud observed on satellite images on 18 September and 4 October 1988 was considered to result from atmospheric effects, after low-level aerial observations revealed no evidence of recent eruptions. Trachytic rocks at the summit have been Ar-Ar dated to about 227,000 and 169,000 years old.

Toney Mountain
Toney Mountain in east-central Marie Byrd Land is a 50-km-long volcanic massif with a 3-km-wide summit caldera and several satellitic cinder cones. Several small cinder cones occur along the crest of the massif, which is almost entirely covered by glaciers. A felsic sample from the summit area gave a Potassium-Argon date of 500,000 years.

Peter I Island
The 11 x 19 km Peter I Island in the Bellingshausen Sea opposite Ellsworth Land is a shield-like volcano with a 100-m-wide circular crater at its summit.The island was discovered by the Russian explorer Bellingshausen in 1821; extensive summer pack ice and its isolated location far from regular shipping lanes have restricted visits. Dated samples range from 350,000 to 100,000 years old (Prestvik et al. 1990).

Bursey
Two coalescing shield volcanoes with 4-5 km diameter summit calderas, Hutt Peak on the east and Koerner Bluff on the west, form Mount Bursey. Potassium-Argon dates indicate both volcanoes were constructed during the Miocene; the youngest dated rock is 490,000 years old, from a cone on the Hutt Peak caldera rim (LeMasurier and Thomson, 1990).

Obiglio
Mt. Obiglio is a strombolian-phreatomagmatic cone on Grant Island with a Potassium-Argon date of 0.51 million years ago (LeMasurier and Thomson, 1990).

Shepard Island
Shepard Island consists of a group of tuff cones and a possible lava dome. The youngest dated rock at Worley Point has a Potassium-Argon date of 0.42 million years ago (LeMasurier and Thomson 1990).

Crary Group
The Crary Mountains consist of two large shield volcanoes, Mount Frakes and Mount Steere, and the smaller Mount Rees and Boyd Ridge volcanoes. Mount Steere is dissected, but the younger Mount Frakes is relatively undissected has had flank vent activity as late as 1.7 million K-Ar years ago (LeMasurier and Thomson, 1990).

Murphy
Mount Murphy is a glacially dissected basaltic-trachytic shield volcano that formed during the Miocene. A Potassium-Argon date on a cone of 900,000 years indicates that flank activity resumed much later during the Pleistocene (LeMasurier, 1972; LeMasurier et al., 1990).

Beethoven Peninsula
The Beethoven Peninsula contains nine nunataks consisting of basaltic lava flows and associated hyaloclastites. No primary volcanic edifice is preserved and it is not clear whether the exposures represent individual volcanic vents or a volcanic field. The youngest dated rocks are less than one million years old (LeMasurier and Thomson 1990).

Seal Nunataks Volcanic Field
The Seal Nunataks are a group of 16 isolated nunataks emerging from the Larsen Ice Shelf east of Graham Land Peninsula. Most of the larger nunataks are considered to represent separate volcanic vents erupted in a shallow-water environment. Fumarolic activity was reported from Murdoch and Dallman cones in 1982, and fresh-looking pyroclastics and a lava flow at Dallman (not observed in 1979) were seen on the ice surface three years later (Gonz�lez-Ferr�n, 1983). Fumarolic activity was observed at Christensen in 1893, and Lindenberg was observed in eruption in 1893. Baker (1968) saw cinders on the ice surface, suggesting a 20th-century eruption, and similar observations were reported in 1985 and 2010, but these events may have been due to aeolian tephra redistribution. A 1988 British expedition noted that tephra away from nunataks was found only in ice-cored moraines, suggesting a glacial rather than pyroclastic origin. They noted no fumarolic activity, although water vapor resulting from radiant heating of ice-cored moraines was observed.

Brabant Island
Isolated exposures of the Bahia Bouquet Formation occur on Brabant Island; a Potassium-Argon date of less than 1 million years was obtained from a rock at the northern end of the island. The region has been poorly studied (LeMasurier and Thomson, 1990).

Tabarin Peninsula
Volcano type: Shield?
Extensive plateau basalts on the southern Tabarin Peninsula may have erupted from fissures, small centers, or a large shield volcano. Basalts and tuff breccias are also found on Jonassen, Andersson, Rosamel and Dundee Islands. The only radiometric ages are 1.1 and 0.9 million years ago from rocks on the Tabarin Peninsula (LeMasurier and Thomson, 1990).

Argo Point
Argo Point is a small scoria cone on the Jason Peninsula for which Potassium-Argon dates of 1.4 and 0.9 million years ago have been obtained (LeMasurier and Thomson, 1990).

Livingston-Greenwich Islands
Several small eroded tuff cones remnants and volcanic plugs are located on northern Livingston and Greenwich Island. Dated samples from two location are younger than 500,000 years ago (LeMasurier and Thomson, 1990).

Domuyo
Volc�n Domuyo is an Argentinian stratovolcano of late-Pleistocene or possibly Holocene age (Moreno 1985, pers. comm.). At least 14 dacitic lava domes and other eruptive centers were constructed within a broad 15-km-wide caldera, and at least another five lie outside the caldera. The largest of the latter is Volc�n Chanque-Mall�n on the ESE flank. It is truncated by a 4-km-wide caldera and contains a resurgent dome.

Cochiquito Volcanic Group
A small group of volcanoes lies N of the town of Buta Ranquil, near where the R�o Grande and R�o Barrancas join to form the R�o Colorado. Volc�n Cochiquito is an alkaline basaltic stratovolcano with eight satellitic cones. Volc�n Sillanegra (or Malal) is pyroclastic cone complex with two craters and basaltic aa lava flows located east of the R�o Grande. Its age was estimated to be Holocene (Gonz�lez-Ferr�n, 1995). Volc�n Ranquil del Sur is a small stratovolcano south of the R�o Barranca with an estimated Pleistocene-Holocene age that contains a 600-m-wide crater and produced andesitic pyroclastic material and lava flows. However, Folguera et al. (2006) describe Chochiquito as being erupted along a normally reactivated reverse fault in the Chos Malal belt, part of a group of basaltic domes and lava flows ranging from 3.2 to 1.5 Ma (citing dates in Linares and Gonzalez, 1987). Other researchers (e.g. Ramos and Folguera, 2011) map the area as older Pleistocene volcanics not part of the larger volcanic fields nearby.

Trolon
Trolon (also called Trocon) volcano lies in Argentina NE of the Caldera del Agrio, and is grouped here together with the Cerro Bayo cone, 10 km ESE. This dacitic-andesitic lava-dome complex has two summit craters and a pyroclastic cone that fed andesitic lava flows that traveled to the east. Gonz�lez-Ferr�n (1995) estimated an age of Pleistocene-Holocene.

Laguna Marinaqui
Volc�n Laguna Mari�aqui is a minor volcanic center about 45 km S of Copahu� and 40 km ENE of Tolguaca volcanoes. It consists of two eroded open craters, 2 km apart along a NE-trending fault, that produced andesitic pyroclastic material and lava flows with columnar jointing; Gonz�lez-Ferr�n (1995) identified them as Holocene. The nearby Cerro Chapulul cinder cone, on a plateau ranging from 2,000-2,300 m elevation, was also considered Holocene by Moreno (1985, pers. comm.). However, the entire area was mapped by Stern (1989) as Pleistocene

Tralihue
The dominantly Pleistocene Tralihue and Pino Solo volcanic centers lie NW of the Pleistocene Pino Hachado caldera in the Nequ�n Andes of Argentina, east of the main Andes drainage divide. Initial trachyandesitic eruptions were followed by the eruption of small lava domes and basaltic pyroclastics along a NW-trending fracture during postglacial time. The area was mapped by Stern (1989) as Pleistocene based on K-Ar dates older than 2 Ma.

Cerro Pantoja
Cerro Pantoja is an eroded dominantly basaltic volcano of Pleistocene age along the Chile-Argentina border. Though a cinder cone on the Argentinian side was described as Holocene by Moreno (1985, pers. comm), later work by Lara et al. (2001) mapped it as Pliocene-Pleistocene. It lies SSW of Lake Constancia, which is located immediately west of the Argentinian border, and has a dramatic steep-sided summit pinnacle.

Tupungato
The northernmost of the central Chile volcanoes, conical Tupungato is a Pleistocene stratovolcano capped by a about 0.8 million years ago lava dome complex (Moreno and Naranjo 1991).

Nevado de los Piuquenes
The Pleistocene volcano Nevado de los Piuquenes is the southernmost volcano of the Tunpungato-Tupungatito volcano group. A 5.5-km-wide amphitheater is open to the east (Moreno and Naranjo 1991).

Northern Mendoza Volcanic Field
The northern part of the Pleistocene Mendoza volcanic field contains more than 80 volcanic centers, mostly basaltic cinder cones, but also the Diamante stratovolcano, a small shield volcano, and tuff rings and tuff cones. The small Infiernillo volcanic field of late-Pleistocene to Holocene age at the SW part of the larger volcanic field is listed separately in this compilation.

Llancanelo Volcanic Field
The Pliocene-Pleistocene Llancanelo Volcanic Field lies west of the saline lake of the same name in the Mendoza province of Argentina. The field includes scoria cones, tuff cones, and tuff rings. Often described as covering an area of 10,700 km2, that zone includes the Cerro Nevado and Northern Mendoza volcanic fields.

Sordo Lucas
Sordo Lucas (Alto del Padre) is a highly eroded stratovolcano of Pleistocene age (Moreno and Naranjo, 1991).

Cerro Nevado
The Cerro Nevado Volcanic Field is located north of Payun Matru and west of Llancanelo volcanic field. The exact bounds vary depending on the researcher, with the area between the Cerro Nevado stratovolcano and Payun Matru being considered part of Payun Matru, Cerro Nevado, or the Llancanelo volcanic fields, or simply generically within the Payenia Volcanic Province. K-Ar ages reported by Ramos and Folguera (2011) are around 1.32 Ma.

Puelche Volcanic Field
The Pleistocene Puelche volcanic field is the largest cluster of Quaternary rhyolitic lava flows known to date in the Southern Volcanic Zone of the Andes.

Auca Mahuida Volcanic Field
Auca Mahuida is a large basaltic shield volcano described by Folguera and Ramos (2011) as having a well-preserved central crater and an andesite plug. Most of the lavas, recently date using Ar-Ar, are in the 0.8-1.7 Ma range.

Sierra Nevada
Sierra Nevada is a late-Pleistocene glaciated stratovolcano with a 7-km-long E-W zone of fissure vents that lies about 15 km NE of Llaima volcano. The age of Sierra Nevada has been considered to be late-Pleistocene (Moreno and Naranjo, 1991) or late-Pleistocene to Holocene (Gonz�lez-Ferr�n, 1995). Naranjo (pers. comm., 2004) noted that no eruptions have occurred during the Holocene. The volcano has erupted dominantly andesitic to basaltic lava flows and pyroclastic material and has produced pyroclastic flows and lahars.

Pino Hachado
The Pino Hachado caldera in the Nequ�n Andes of Argentina was constructed along one of the branches of the major regional Liquine-Ofqui fault system. The 12-km-wide caldera is 150 m deep. Following the eruption of dacitic and rhyolitic ignimbrites, post-caldera trachyandesitic lava flows were erupted. Radiometric dates of about 1.6 and 1.2 million years were obtained on post-caldera rocks.

Cerro Trautr�n
Cerro Trautr�n in Chile lies at the NW end of an area of Pleistocene volcanism along the Chile/Argentina border. The high point of the complex, Cerro Norte Divortium, lies along the border SE of Cerro Trautr�n, which has K-Ar dates of about 0.8 and 0.5 million years (Lara et al., 2001).

Cerro Maich�n
Lava flows at Cerro Maich�n were K-Ar dated at about 0.9 +/- 0.7 million years (Lara et al., 2001).

Quinchilca
The Quinchilca complex south of Villarica volcano is a Pleistocene stratovolcano with a caldera and post-caldera lava domes. A K-Ar date of 0.8 +/- 0.6 million years was obtained by Lara et al. (2001).

Cuernos del Diablo
Cuernos del Diablo is a partially glacially eroded basaltic stratovolcano. Numerous satellitic pyroclastic cones and associated basaltic lava flows were formed during the Holocene, principally on the SW flank and from the summit to the NW base of the volcano. Fumaroles were observed on a flank cone in 1931. Although no historical eruptions are known, some of these cones may have formed during historical time (Gonz�lez-Ferr�n, 1995). However, Lara et al. (2001) mapped this volcano as Plio-Pleistocene, and cited a K-Ar age date of 0.7 +/- 0.4 Ma from SERNAGEOMIN-BRGM (1995).

Rio Murta
Basaltic lava flows were emplaced on valley floors along the R�o Murta, about 30 km SE of Hudson volcano. The river follows a glacially carved valley cut into granitic rocks of the North Patagonian Batholith. The columnar-jointed lava flows include pillow lavas, lava tubes, and subglacial and sublacustral deposits. They have been considered to be of Holocene age due to lack of erosion and only locally subglacial emplacement. Guivel et al. (2005), however, found that two of three Potassium-Argon dates suggested an age of 850,000-900,00 years, but that a third sample too young to date precisely could be consistent with a Holocene age.

Sara Sara
Glacier-covered Sara Sara, between Laguna Parinacocha and the R�o Ocona, is the westernmost Quaternary volcano in Per�. The andesitic stratovolcano was the source of lava flows with prominent levees that traveled ~15 km E into the R�o Ocona valley. Upper-slope lava flows with a fresh-looking morphology and ash layers in peat deposits at its base suggest a possible Holocene age. However, Reyes-Hardy et al. (2024) cite a geological map by Reyes et al. (2020) indicating a Pleistocene age, along with the Instituto Geof�sico del Per� website (November 2024), which reports that the last eruption was 14000 BCE.

Chachani Volcanic Complex
The andesitic-dacitic Chachani Volcanic Complex, located immediately north of Arequipa, consists of a 320 km2 group of Pleistocene lava domes, a stratovolcano complex, and a flank shield volcano. The central Nevado Chachani edifice contains multiple vents along an arcuate line, including a well-defined summit crater at the western end. Two early Pleistocene ignimbrites were erupted from now-buried vents of older edifices. Pleistocene lava domes form the northern end of the complex. Thin lava flows from Chachani overlie glacial moraines. The 8-km-wide lava shield of Pampa de Palacio on the SW side produced a well-preserved lava flow field that represents the youngest products of the complex. In a comprehensive review of the Chachani volcanic cluster, Aguilar et al. (2022) found that the Cabreria cone on the S flank had most recent eruption, 40Ar-39Ar dated at 56.5 +/- 31.6 ka.

Yura Volcanic Field
The Yura volcanic field includes six monogenetic centers in the NW Arequipa basin off the W flank of the Chachani stratovolcano. 40Ar/39Ar dating and stratigraphy showed that phreatomagmatic, Strombolian, and effusive eruptions from these centers (Yura Viejo, Ccapua, Uyupampa, El Chiral, Patacocha, and Nicholson) took during 195-54 ka (Aguilar et al., 2022). Cerro Nicholson, the southernmost feature of the group, erupted through the 1.65 Ma Arequipa Airport Ignimbrite, which originated from a now-buried site beneath the Chachani volcanic complex; andesitic bombs surround the crater at the summit of the scoria cone.

Huambutillo-Rumicola
Landform: Unknown
Volcano type: Unknown
A K-Ar date of about 0.59 +/- 0.25 Ma was obtained from Huambutillo volcano at the eastern end of the Cuzco valley about 20 km SE of Cuzco. Nearby Rumicola volcano was dated at about 7.2 Ma, but this was considered to be in error, and the volcano to be of likely Quaternary age (Bonhomme et al., 1988).

Solimana
The eroded Solimana volcano has not erupted since the Pleistocene, but has an active fumarole.

Nevados Firura
The Nevados Firura volcanic complex consists of a 10-12 km long, NE-SW-trending cluster of small stratovolcanoes. The highest peak is 5500-m-high Nevado Firura itself, which lies to the NE of Cerro Soncco Orcco and Cerro Jahsaya. Little is known about this andesitic volcanic complex, but morphologically youthful lava flows extend into vegetated and settled areas. The age of Nevados Firura was considered to be Holocene (de Silva and Francis, 1990), but later work showed that the young-looking lava flows on the flank of the volcano were dated at about several hundred thousand years (Worner 2006, pers. comm.).

Cerros Purupuruni
The Cerros Purupuruni are a group of lava domes of probable Pleistocene age (de Silva 2007, pers. comm.).

Tacora
The andesitic Tacora volcano is located in northern Chile just S of the border with Peru. It overlies a flat-lying ignimbrite platform forming the Arica Altiplano. About 6 km NNW from the summit the older Chupiqui�a is at the end of a line of smaller edifices, with seven distinct peaks, extending N into Peru for ~10 km. Solfataric and fumarolic activity has been reported on the E side of the volcano (Casertano, 1963, CAVW), along with hot springs; sulfur mines are present in the saddle with Chupiqui�a. Hantke (1939) cited reports of eruptions in 1930 and 1937 that are not listed in other sources, but Moreno (1985, pers. comm.) did not indicate Holocene eruptions.

Tambo Quemado
Bolivia
A low pyroclastic shield near the Rio Lauca forms Cerro Volc�n Tambo Quemado on the Bolivian Altiplano. The volcanic complex (also known as Cerro Quemado or Volc�n Sacabaya) displays fumarolic activity and was estimated to be of Holocene age by some based on appearance, but no eruption dates are known. An ignimbrite shield is capped by an elongated NNE-SSW-trending vent area about 2 x 3.5 km in diameter formed by three large overlapping craters. The youngest crater lies at the southern end of the summit region and contains a blocky lava dome. Wind has redistributed tephra deposits to the E and S, forming aeolian sand dunes.

Laguna Jayu Khota
Bolivia
Two small maars are located in the central Altiplano of Bolivia, north of Salar de Uyuni and east of Salar de Coipasa. Laguna Jayu Khota, at one time considered to be a meteorite impact crater, was formed by basaltic-trachyandesite explosive volcanism. Nekhe Khota maar lies 4 km SW of Jayu Khota; both were considered by de Silva and Francis (1991) to be of probable Holocene age, but no eruption dates are known. Phreatomagmatic eruptions produced basaltic-trachyandesite pyroclastic deposits containing granitic xenoliths. The maars lie along a transverse lineament; the alkali basaltic cone of Chiar Kkollu is located nearby where this lineament intersects the regional trend.

Jatun Mundo Quri Warani
The Jatun Mundo Quri Warani (also known as Nuevo Mundo) silicic lava dome and flow complex between Potos� and Uyuni in Bolivia is capped by pumice cones. Two viscous dacitic lava flows erupted along a N-S fault were associated with block-and-ash flows to the E. A later Plinian eruption produced an airfall tephra deposit that extends as far as the Bolivian mining center of Potos�, 200 km E. It was considered to be of late Pleistocene or Holocene age by de Silva (2007, pers. comm.), and is the youngest volcanic center of the vast Los Frailes ignimbrite plateau in the eastern Cordillera of Bolivia. However, no eruption dates are known.

Pampa Luxsar
The Pampa Luxsar lava field consists of a 45 x 45 km area of coalesced lava flows at the SW margin of Bolivia's Salar de Uyuni, east of the Andean volcanic front. Several generations of lava flows and cones are present, but the youngest flows were considered to be Holocene or late Pleistocene (de Silva 2007, pers. comm.). The lava field partially or completely surrounds the older dissected stratovolcanoes of Cerro Luxsar and Cerro Uquila.

Cerro del Azufre
Cerro del Azufre is the largest and youngest volcanic center of the 30-km-long, NW-trending Azufre-Inacaliri Volcanic Chain just W of the Bolivian border, S of Salar de Ascot�n. The northern edifice forms the high point of the andesitic volcano, with a southern peak just to the SE towards the Apacheta-Aguilucho Volcanic Complex on the same massif. Abundant late-Pleistocene lava flows extending down the northern flanks partially overlie a debris avalanche deposit now largely buried by the Salar de Ascot�n. The Chanka dacitic lava-dome complex occupying the lower W flank has been K-Ar dated at 1.5 million years. Two dacitic lava domes on the SE flank, Pabell�n and Chac-Inca, mark the most recent effusive activity. There are also youthful-looking craters on the main edifice. Though many features appear young, recent Ar-Ar ages (see review by Godoy et al., 2022) were all older than about 80,000 years old.

Ollague
Volc�n Ollag�e, also known as Oyahu�, is a massive andesitic stratovolcano with a summit dacitic lava dome. A large Pleistocene debris-avalanche deposit extending westward separates the Salar de San Mart�n from the Salar de Ollag�e. Three youthful-looking silicic lava flows mark late post-collapse eruptions, but show evidence of glaciation and are thought to pre-date the last glacial advance at about 11,000 years ago (Freeley et al., 1993). A youthful-looking scoria cone on the lower WSW flank, La Poru�ita, was initially considered to be of Holocene age (Gonz�lez-Ferr�n, 1995), however W�rner et al. (2000) later obtained Potassium-Argon dates of 420,000 to 680,000 years. Active sulfur mines on the upper western and southern flanks are reached by a road that climbs to about 5500 m elevation. No historical eruptions have been recorded; activity has been restricted to periods of intense fumarolic activity, and a persistent steam plume emanates from a fumarole on the south side of the summit dome.

San Pedro-San Pablo
The composite volcano of San Pedro in the arid Atacama desert of northern Chile has a basaltic andesite-to-dacitic edifice and is 6 km W of the older San Pablo. The youngest cone was constructed within an arcuate escarpment left by the collapse of an older edifice, which produced a large debris avalanche to the west, perhaps accompanied by a major pumice eruption. Thick dacitic lava flows with steep-sided fronts mantle the upper portion of the younger cone. Reports of variable reliability mention eruptions in the 19th and 20th centuries, but no corresponding deposits have been identified. The youthful-looking La Poru�a scoria cone on the W flank produced an 8-km-long lava flow, but Worner et al. (2000) obtained a Helium surface-exposure age of 103,000 years from a juvenile block of the lava flow. Gonz�lez-Maurel et al. (2019) obtained 40Ar/39Ar ages using unaltered groundmass from fresh La Poru�a samples of 92 � 34 and 110 � 11 ka; for San Pedro, an 40Ar/39Ar groundmass age of 96 � 8 ka was measured.

Cerro Overo
Cerro Overo is located on the lower NE flank of Chiliques volcano, west of the Salar de Aguas Calientes. The 600-m-wide, 50-m-deep maar crater was determined to have a maximum eruption age of 77 � 7.8 ka based on U-Th/He in zircon from entrained felsic xenoliths (cited in van Alderwerelt, 2017). The 55-m-high La Alb�ndiga Grande lava dome, about 2 km SW from Cerro Overo, has a similar composition and was considered by van Alderwerelt (2017) to be of similar age from the same magma source. Both erupted through the Atana ignimbrite.

Negros de Aras
Negros de Aras (or El Negrillar) is a monogenetic volcanic field ~20 km N of Socompa volcano and W of the Cord�n de P�lar. There are 44 scoria cones and 22 additional lava flow source vents within a 190 km2 area (Aguilera et al., 2022). Though this has been interpreted to be a Holocene field by some researchers (Moreno 1985, pers. comm.; de Silva and Francis, 1991), others believe it is older (Gardeweg, 1993, pers. comm.). Aguilera et al. (2022) did not consider any of the scoria cones to be younger than the 100 ka La Poruna cone (~250 km N). The major Holocene debris avalanche from Socompa overlies some lava flows at the W margin of the complex.

Copiapo
Volc�n Copiap� in Atacama province SW of Nevados Ojos del Salado volcano is a dominantly Miocene-Pliocene stratovolcano. Eight andesitic pyroclastic cones are located primarily on the SE flank of the 6052-m-high volcano. The most recent cone, Volc�n San Rom�n, lies 7 km north of Copiap� and was considered to be of probable Pleistocene age, related to late-stage reactivation of Pleistocene-Holocene fissures cutting the Ojos del Salado region (Gonz�lez-Ferr�n, 1995). This dacitic-to-andesitic volcano was reported by Von Wolff (1929) to display solfataric activity.

Tuzgle
The Cerro Tuzgle stratovolcano rises ~1 km above the surrounding land surface in the Northern Puna of Argentina, ~120 km E of the main volcanic arc of the central Andes. Activity began with the eruption of a rhyodacitic ignimbrite, followed by construction of a lava dome complex on the rim of an existing caldera. Andesitic lava flows covered much of the dome complex and later partially filled the crater. Several edifice-collapse events have occurred. The youngest flows were erupted onto the SW flank from a summit vent, with older flows down multiple other flanks. Schwab and Lippolt (1976) obtained a K-Ar date of 0.1 Ma on what they believed to be the youngest lava. However, de Silva and Francis (1991) and Gonz�lez-Ferr�n (1995) considered the latest activity to be Holocene, and Coira and Kay (1993, Fig. 2B) placed the youngest flow at the Pleistocene-Holocene boundary. Giordano et al. (2013) listed the "Young Lava Flow" as Pleistocene.

Antofagasta Volcanic Field
This volcanic field has produced multiple monogenetic back-arc mafic centers within the Antofagasta de la Sierra Basin, a tectonic depression NE of Cerro Blanco volcano in the Southern Puna region of Argentina. The field contains several basaltic andesite scoria cones and lava flows, which Francis (1982) and de Silva and Francis (1991) suggested may only be a few thousand years old. The youngest cones, De La Laguna and Alumbrera, are roughly in the middle of the field. A sample from De La Laguna Ar-Ar dated by Risse et al. (2008) to 0.34 � 0.06 Ma was considered to be a mixed age with older phenocrysts; another sample from a morphologically young flow at the La Falda cone (~20 km NW of Laguna) was assigned an estimate of less than 0.1 Ma with zero-age values. In their stratigraphic and morphological study, Baez et al. (2016) also considered Alumbrera to be the younger than De La Laguna, and noted that ventifact analysis suggested "a probable Holocene age" for the most recent activity. However, no radiometric age dates confirming Holocene eruptions are known.

Cerro Pucara
Cerro Pucara is a volcanic field with pyroclastic cones of Pleistocene age, with nearby ages of 1.0-0.6 million years (de Silva 2007, pers. comm.). The Pataca Kollu cones are considered part of this volcanic field.

Patilla Pata
The International Association of Volcanology and Chemistry of the Earth's Interior data sheets (1973) classified Patilla Pata volcano in Bolivia NW of Sajama volcano as being active during the past 2000 years, but de Silva (2007 pers. comm.) noted no evidence from analysis of satellite images for Holocene activity in this area. Patilla Pata has undergone extensive glacial erosion. The andesitic stratovolcano has also produced basaltic lava flows.

Nevado del Sajama
Nevado del Sajama, rising to 6542 m about 20 km E of the Chilean border, is Bolivia's highest mountain. The prominent glacier-clad edifice consists of an andesitic stratovolcano overlying andesitic-to-rhyodacitic lava domes. Sajama borders Volc�n Cholcani on the SE, and flank centers occupy the saddle between the two peaks. The steep-sided volcano towers about 2200 m above its base, and glaciers descend to about 5600 m. The age of the most recent activity has variously been considered to be Holocene, Pleistocene-Holocene, or Pleistocene, but de Silva (2007 pers. comm.) noted no evidence of Holocene activity.

Volcan Larancagua
Volc�n Larancagua is Plio-Pleistocene in age (Moreno, 1985).

Caquena
The Caquena andesitic lava domes are Potassium-Argon dated around 194,000 to 264,000 years before present (Worner et al. 1988).

Vilacollo
Lava flows from the Vilacollo cinder cones are Potassium-Argon dated around 285,000 years before present (Worner et al. 1988).

Acotango
Acotango, along with Volc�n Humarata to the north and Cerro Capurata (also known as Cerro Elena Capurata) to the south, comprises the Nevados de Quimsachata volcano group. Quimsachata means "three" in the Andean Aymar� language, and 5730-m-high Humarata, Acotango, and 5990-m-high Cerro Capurata straddle the Chile-Bolivia boundary along a roughly N-S line. The 6052-m-high Acotango stratovolcano is the central and highest of the three stratovolcanoes. It is in a fairly advanced stage of dissection, but a morphologically youthful lava flow on its northern flank suggested Holocene activity (de Silva and Francis, 1991). Later higher resolution imagery implied a Pleistocene age (de Silva 2007, pers. comm.). Humarata, with a summit crater breached to the ESE, and Capurata, a complex of lava domes and associated pyroclastic-flow deposits, may also have been active during the Holocene.

Lexone
The eroded Lexone volcano contains a group of young lava domes in northern Chile SE of Tacora volcano. The domes were initially considered from morphological evidence to be of Holocene age (Moreno 1985, pers. comm.), but K-Ar dates of about 60,000-70,000 years were obtained from the young chain of lava domes (Clavero 2004, pers. comm.).

Nevado Anallajsi
The International Association of Volcanology and Chemistry of the Earth's Interior data sheets (1973) listed Nevado Anallajsi volcano in Bolivia north of Sajama volcano as being active during the past 2000 years, but de Silva and Francis (1990) noted no evidence from analysis of satellite images for Holocene activity in this area. The andesitic-to-dacitic compound volcano overlies an ignimbrite plateau. Younger basaltic lava flows were erupted from a north-flank vent, but Woerner (2006 pers. comm.) indicated there was certainly no Holocene activity at Anallajsi.

Arintica
Volc�n Arintica is the central and most prominent cone of a large volcanic complex that rises north of the Salar de Surire. The complex includes Cerro Puquintica (also called Poquentica), 7 km to the east, Cerro Calajata, 3 km to the SW, and the dacitic Calajata lava dome at the SW end of the complex. The volcanoes are extensively dissected, but the latest activity at 5597-m-high Arintica produced a postglacial lava flow from a relatively well-preserved summit crater that descended the SE flank (de Silva and Francis, 1991). Later higher-resolution imagery indicated this lava flow was a collapse deposit and the volcano had a probable Pleistocene age (de Silva 2007, pers. comm.). Potassium-Argon ages of 637,000 and 486,000 yrs were obtained by W�rner et al. (2000), who suggested that based on the elevation and location of the volcano, the summit may not have been glaciated and that consequently the lack of glaciation may not denote Holocene activity. Cerro Puquintica (Poquentica) is considerably older than Arintica and rises to 5760 m.

Rochaculla-Inca Camacha
These volcanoes display hydrothermal alteration (IAVCEI, 1973) and are of possible Pleistocene age (de Silva, 2007 pers. comm.).

Cerro Tatajachura
Cerro Tatajachura stratovolcano of Pliocene-Pleistocene age was the source of voluminous andesitic lava flows (Gonzalez-Ferran, 1995).

Cerro Cariquima
Cerro Cariquima is a youthful-looking stratovolcano, but could be Pliocene in age (Worner, 2006 pers. comm.) Similar appearing volcanoes elsewhere in this part of the Andes were K-Ar dated at about 3 million years. An unnamed cinder cone corresponding to the location of Cerro Pina on the lower NE flank was classified by IAVCEI (1973) as being active during the past 2000 years. Worner (2006 pers. comm.) however indicated there was no young volcanism in this area, and de Silva and Francis (1991) noted no evidence from satellite imagery of young volcanism here.

Porquesa
The massive Porquesa lava-dome complex produced small-volume ignimbrites dated at 0.15 and 0.29 million years ago (Worner et al., 2000).

Cerro Napa
Cerro Napa has a Potassium-Argon date of 1.38 million years (Worner et al., 2000).

Copa-Ocana
Pleistocene stratovolcanoes (Moreno, 1985). Group of cones on a plateau-like area that includes Cerro Copa and Oca�a about 15 km NE of Irruputuncu volcano.

Aucanquilcha
The world's highest permanent human habitation is situated below a sulfur mine in the summit region of Cerro Aucanquilcha, one the largest volcanoes of northern Chile. Several distinct cones are located along a 10-km-long, E-W ridge that forms the broad summit. A Pleistocene debris-avalanche deposit is a prominent feature on the lower NW flank. Extensive Pleistocene glacial moraines surround the stratovolcano, but postglacial lava flows overlie these moraines on the upper southern flanks (de Silva and Francis, 1991). W�rner et al. (2000) obtained surprisingly old Potassium-Argon dates of 400,000 to 780,000 years from the youngest flows on the NE and SW flanks, and eruptive activity appears to have ended during the late Pleistocene. It presently displays fumarolic activity.

Cerro San Agustin
The International Association of Volcanology and Chemistry of the Earth's Interior data sheets (1973) considered the andesitic-to-dacitic Cerro San Agust�n stratovolcano to have been active during the past 2000 years, but de Silva and Francis (1991) noted no evidence from analysis satellite images of Holocene activity in this area, and de Silva (2007 pers. comm) considered the volcano to be of Pleistocene age.

Escala
Endogenous extrusions at the andesitic Escala lava dome in SW Bolivia occurred during the Holocene (Kussmaul et al., 1977). Later analysis of higher-resolution satellite imagery showed no evidence of Holocene domes in this area (de Silva 2007, pers. comm.).

Cerro Moiro
The International Association of Volcanology and Chemistry of the Earth's Interior data sheets (1973) listed Cerro Moiro (also known as Cerro Negro) in SW Bolivia as being active during the past 2000 years, but de Silva and Francis (1991) found no evidence from satellite image analysis of Holocene activity. Later higher-resolution satellite imagery suggested a possible Pleistocene age (de Silva 2007, pers. comm.). The andesitic scoria cone was constructed on a rhyolitic ignimbrite plateau.

Ca�apa
Ca�apa is an andesitic-dacitic stratovolcano of Plio-Pleistocene age (Gonzalez-Ferran, 1995). De Silva (2007 pers. comm.) considered the volcano to be of Pleistocene age.

Cerro Ascotan
The correct name is Ascot�n (Moreno, 1985 pers. comm.), not Acost�n (IAVCEI, 1973). De Silva (2007 pers. comm.) considered the volcano to be of Pleistocene age.

Paniri
Cerro Paniri is a complex stratovolcano located about 30 km SE of San Pedro volcano. The summit contains three craters separated by about 4 km along a NW-SE trend. The age of this andesitic-to-dacitic volcano was considered to be Pleistocene-Holocene (Gonz�lez-Ferr�n, 1995), but de Silva (2007 pers. comm.) considered it to be of probable Pleistocene age.

Cerro del Leon
Cerro del Le�n is an andesitic stratovolcano 40 km SE of the San Pedro-San Pablo volcanoes. It is flanked by two massive dacitic lava domes, 2.6 km3 Chillahuita to the SE and 26 km3 Chao to the NW, in the saddle between Cerro del Leon and Paniri volcanoes. Gonz�lez-Ferr�n (1995) considered Le�n to be of Pleistocene-Holocene age. The massive Chao lava dome and flow is the world's largest of its type. The 14.5-km-long dacitic lava flow has distal margins that are 350-400 m high and dramatic 30-m-high flow ridges on its surface. The age of the flows was considered to be post-glacial (Guest 1981, pers. comm.), but Argon-Argon dates indicate only that it is less than 100,000 years old (de Silva and Francis, 1991), and based on comparison with nearby dated flows, it was considered to be of Pleistocene age (de Silva, 2007 pers. comm.). The eruption of less than 1 km3 of dacitic pyroclastic flows preceded the initial lava extrusion, which formed the 22 km3 compound main flow. Eruption of a small amount of rhyolitic airfall and growth of a pumice cone was followed by effusion of the final 3 km3 of lava.

Deslinde
Listed as Quaternary by Guest (1969), and not Holocene by Moreno (1985).

Volcan Linzor
Volc�n Linzor is a 5680-m-high stratovolcano along the Chile/Boliva border. This andesitic volcano was considered to be Pleistocene-Holocene age by Gonz�lez-Ferr�n (1995). De Silva (2007 pers. comm.) noted no evidence for Holocene activity at Linzor, which lies west of Laguna Colorada.

Jorcada
Volc�n de Jorcada is an elongated fissure-controlled volcanic massif extending between the Pastos Grandes caldera and Laguna Colorada in Bolivia. More than 50 craters, small stratovolcanoes, and lava domes are located along four fissures covering an area of 230 km2. Eight small andesitic-to-dacitic stratovolcanoes with craters 0.2-1.5 km wide are located along the southernmost fissure. A second fissure, oriented NW-SE and 10 km long, contains ten volcanic centers with craters with widths of 0.2-1.2 km. A third fissure, trending NE, produced seven rhyodacitic lava domes. Activity has migrated to the north, with the youngest fissure, on the NW side of the complex, estimated to be of probable Holocene age (Gonz�lez-Ferr�n, 1995). De Silva (2007, pers. comm.) dated this youngest fissure at 95,000 years BP. This NW-trending fissure, 7 km long, contains 27 small basaltic andesite craters.

Quetena
Lava effusions along fissures at Quetena were considered to have occurred during the Holocene (Kussmaul et al., 1977). De Silva (2007 pers. comm.) indicated that volcanism in this area is pre-Holocene and may be Pleistocene or older.

Sunequera
Fernandez et al. (1973) noted that well-preserved craters favor activity in historical time, however de Silva (1990, pers. comm.) indicates that Sunequera is a pre-Holocene shield volcano with craters that are glacial cirques.

Uturuncu
Uturuncu, located SE of Quetana, has two active sulfur-producing fumarole fields near the summit. Though postglacial lava flows were noted by Kussmaul et al. (1977), de Silva and Francis (1991) stated that inspection of satellite images showed no evidence for postglacial activity. Although lava flows display well-preserved flow features, youthful-looking summit flows show evidence of glaciation. Lava flows are mainly andesitic and dacitic, and no pyroclastic deposits have been reported. Large-scale ground deformation was observed beginning in May 1992 (Pritchard and Simons, 2002), indicating, along with seismicity detected in 2009-10 (Jay et al., 2012), that a magmatic system is still present.

Cerro Chascon
The lava dome of Cerro Chascon and the associated rhyolitic Cerro Runtu Jarita lava flow are located within the moat of Bolivia's Pliocene Pastos Grandes caldera. The roughly circular, flat-topped Cerro Chascon is located immediately NW of Laguna Khara. Cerro Runtu Jarita forms a roughly N-S-trending chain of small silicic lava bodies that probably represents the surficial expression of a subsurface dike. Minor eruptions of rhyolitic tephra preceded extrusion of the Cerro Runtu Jarita lavas. The age of Cerro Chascon was considered to by Holocene (de Silva and Francis, 1991), but new K-Ar dates give ages of 0.88-0.93 Ma (Watts et al., 1999).

Apagado
Pleistocene stratovolcano (Moreno 1985).

El Volcan
El Volc�n is one of several stratovolcanoes located east of the vigorous G�iseres del Tatio geothermal field. Lava flows at the base of the volcano are dacitic, while those at the upper part are andesitic-to-dacitic. It was considered by Gonz�lez-Ferr�n (1995) to be of Pleistocene-Holocene age, but de Silva (2007 pers. comm) assigned it a probable Pleistocene age.

Cerros de Tocorpuri
Cerros de Tocorpuri (or Volc�n Tocorpuri) is a stratovolcano complex on the Chile-Bolivia border with a youthful-looking rhyolitic lava dome, Cerro la Torta, at its western foot. The international border swings around the eastern rim of a 1.4-km-wide crater that truncates the summit; the crater lies wholly within Chile. It was considered by Gonz�lez-Ferr�n (1995) to be of Pleistocene-Holocene age. Cerro la Torta has been considered to be of Holocene age due to its youthful morphology, but its age is not known precisely and Potassium-Argon dating indicates only that it is less than a million years old. Comparison with similar dated domes nearby suggests it is of Pleistocene age (de Silva, 2007 pers. comm.). The circular, roughly 5 km3 Cerro la Torta was erupted from a central vent and is surrounded by a flat-topped surface with wrinkled flow ridges. The flow terminates in steep, talus-covered margins about 150 m high. Lava extrusion was preceded by minor silicic explosive eruptions.

Volcan Tatio
A chain of dominantly Pliocene-to-Pleistocene volcanoes including Cerro Deslinde, Cerro Volc�n, Cerros del Tatio, and Volc�n Tatio is ~9 km E of a depression that contains some of the most dramatic thermal features of the Andes. Although no Holocene eruptions are known from El Tatio itself, it was included in the Catalog of Active Volcanoes of the World (Casertano, 1963) based on this geothermal activity. The 30 km2 Hoyada de Los Geisers del Tatio geothermal field contains 85 fumaroles and solfataras, 62 hot springs, 40 geysers, 5 mud volcanoes, and extensive sinter terraces. Geothermal energy exploration has been conducted, but remoteness of the location has precluded development. Listed as Quaternary by Guest and Sanchez (1969), and not Holocene by Moreno (1985).

Poquis
Erupted on Pliocene ignimbrite plateau (IAVCEI). Late Pleistocene (Moreno, 1985).

Curutu
Curut� is late Pleistocene (Moreno, 1985).

Losloyo
Upper Pleistocene (Moreno 1985)

Potor
One of a group of upper Pleistocene volcanoes (Moreno 1985).

Hecar
stratovolcano north of Lascar volcano; no evidence for Holocene activity (de Silva and Francis 1991).

Laguna Verde
Laguna Verde, located west of Colachi volcano, is one of a cluster of young stratovolcanoes north and east of Lascar. Laguna Verde was considered to be of Pleistocene-Holocene age (Gonz�lez-Ferr�n, 1995), but de Silva (pers. comm., 2007) indicated it was of probable Pleistocene age. The andesitic volcano collapsed to the north, producing a debris avalanche that dammed the Quebrada Portor, forming a lake.

Cerro de Rio Negro
Complex stratovolcano north of the Salar de Aguas Calientes; no evidence for Holocene activity (de Silva and Francis 1991).

Cerro Zapaleri
Cerro Polques is of probable Pliocene age, although some component could be Pleistocene (de Silva, 2007 pers. comm.).

Miscanti
Pleistocene (Moreno, 1985).

Laco
Laco is a central dome surrounded by satellite craters, perhaps Pleistocene in age. Radiometric dates range from 2.17 to 1.8 million years (de Silva, 2007 pers. comm.).

Incaguasi
Landform: Unknown
Volcano type: Unknown
Pleistocene (Moreno 1985)

Capur
Pleistocene stratovolcano (Moreno 1985).

Aguas Delgadas
Aguas Delgadas volcano is listed as active during the past 2000 years (IAVCEI 1973), but no Holocene volcanoes are listed in this area by de Silva and Francis (1990). The volcanoes Cerro Bayo and Corrida de Cori, very near to the listed location of Aguas Delgadas, are classified as Pleistocene.

Tumisa
Potassium-Argon dates 1.2 to less than 0.4 Ma (Gonzalez-Ferran, 1995).

Lejia
Pleistocene (Moreno 1985).

Piedra Parada
Piedra Parada is a large stratovolcano with summit craters and lava flows that retain integrity in the upper part of the edifice and is of likely Pleistocene age (de Silva, 2007 pers. comm.).

San Francisco
San Francisco volcano has K-Ar dates of 1.34 and 1.32 million years ago (Gonzalez-Ferran, 1995).

Cerro de la Niebla
Cerro de la Niebla is a compound volcano of possible Pleistocene age (de Silva, 2007 pers. comm.).

El Azufre
Landform: Unknown
El Azufre has a somewhat youthful morphology and could be of Pleistocene age (de Silva, 2007 pers. comm.).

Tres Cruces
The massive Tres Cruces complex of Pliocene-Pleistocene age covers an area of about 1000 km2 along the Chile-Argentina border (Gonzalez-Ferran, 1995). The Indio lava dome on the SW side of the complex was K-Ar dated at about 0.35 million years.

Los Patos
Los Patos is a large eroded stratovolcano of possible Pleistocene age (de Silva, 2007 pers. comm.).

Nevado Queva
Late-Quaternary flows with no radiometric age date (Hormann et al., 1973). De Silva (2007, pers. comm.) assigned a likely Pleistocene age.

Tocomar
The Tocomar volcanic center was the source of two major phreatomagmatic and phreatic eruptions during the Pleistocene. The Tocomar Ignimbrite of rhyolitic composition covers an area of 50 km2. It is located along the Calama-Olacapato-Toro fault zone south of Tuzgle and NE of Nevado Queva volcanoes.

Gemelos-Saladillo
The late-Pleistocene Los Gemelos scoria cones were constructed along the Calchaqui fault, NW of Salta. The basaltic trachyandesitic cones produced a lava flow about 35,000 years ago that traveled to the west and then was deflected south. Monogenetic cones at El Saladillo to the NW of Los Gemelos produced a lava flow that traveled to the SE and south.

Antofalla
Volc�n Antofalla is a 6409-m-high Argentinian stratovolcano west of the Salar de Antofalla. The andesitic-to-rhyolitic main edifice is surrounded by a circular ring of smaller satellitic stratovolcanoes. Sapper (1917) reported "smoke" clouds from Volc�n Antofalla in 1901 and 1911, but detailed study showed that its youngest rocks were erupted during the early Pleistocene (Richards et al., 2006). Younger small-volume monogenetic volcanism took place on the SW and western flanks later in the Pleistocene.

Cerro Galan
Caldera-forming eruption took place about 2.6 million years ago, latest ring fracture eruptions may have taken place in last few tens of thousands of years (Francis 1982).

Cerro Colorado
Cerro Colorado is a stratovolcano of possible Pleistocene age (de Silva, 2007 pers. comm.).

Incapillo
The Plio-Pleistocene Icapillo caldera and lava-dome complex is the southernmost ignimbritic caldera of the Central Andes. The 5 x 6 km wide caldera formed during a rhyodacitic eruption about 510,000 years ago. About 40 rhyodacitic lava domes surround the caldera.

Inacalari
The andesitic stratovolcano Cerro Inacalari is located about 25 km SE of Cerro del Azufre along the Chile-Bolivia border. Satellite imagery shows a small lake in the 400-m-diameter summit crater. It's age was estimated by Gonzales-Ferron (1995) as Pliocene-Pleistocene.

Petacas
Cerro de Las Petacas is a lava dome in the Departamento Cauca about 7 km NE of Animas and 18 km NE of Do�a Juana volcanos. Though Von Wolff (1929) described many morphologically fresh cones nearby (Von Wolff, 1929), satellite imagery shows no distinct volcanic features. Little work has been done, so the age of the most recent eruption is not known; it is not listed as an active volcano by the Servicio Geologico Colombiano.

Santa Rosa
Eroded Pleistocene andesitic shield volcano (Herd 1982). Deposits from near the base of the volcano were dated as 2.3 � 0.1 Ma (K-Ar whole rock) according to Thouret (1989).

Nevado del Quindio
Nevado del Quind�o is a Pleistocene stratovolcano located south of Santa Isabel volcano and NW of Nevado del Tolima volcano. The vent area is eroded by glaciers (Herd 1982).

San Augustin-Isnos
A back-arc volcanic field with many pyroclastic cones lies in the Department of Huila, near the towns of San August�n and San Jose de Isnos, overlies an ignimbrite plain. Disappearance of the San August�n culture between the 2nd century BCE and the first century CE has been attributed to invading armies or volcanic activity (Borrero et al., 2007).

Cutanga
The Cutanga caldera, about 25 km S of the Sotara volcano, was considered by Kroonenberg et al. (1982) to be a possible source of Plio-Pleistocene rhyolitic ignimbrite deposits in the uppermost Magdalena Valley. The area was mapped as Quaternary volcanics by Gomez Tapias et al. (2015, see San�n et al, 2022).

Animas
Las Animas is located about 11 km NE of Dona Juana volcano and 12 km SW of Petacas volcano, according to the Pasto Observatory. Included in Latter Quaternary volcano list.

Merenberg-Pensil Volcanic Field
A back-arc volcanic field in the La Plata and La Argentina area of the Department of Huila contains the small Merenberg volcano and its 1.5-km-wide caldera, along with several pyroclastic cones, including El Morro (Borrero and Castillo, 2006).

Chalpatan
The Chalpatan caldera is of Plio-Pleistocene age (Beate 1992, pers. comm.). A single Potassium-Argon age of 2.0 million years ago has been obtained (INECEL 1987).

Chiltazon
Pleistocene stratovolcano (Beate 1992, pers. comm.)

Iguan
Iguan is a Pleistocene stratovolcano with an avalanche caldera open to the WNW (Beate 1992, pers. comm.).

Yanaurcu de Pinan
Yanaurcu de Pi��n is a stratovolcano of Pleistocene age (Beate 1992, pers. comm.).

Pilavo
Pilavo is Pleistocene stratovolcano (Beate 1992, pers. comm.).

Cotacachi
The steep-sided Pleistocene stratovolcano Cotacachi rises above Cuicocha caldera to the south.

Cusin
Cus�n is a Pleistocene stratovolcano with a caldera open to the NW (Beate 1992, pers. comm.).

Casitagua
Casitagua is a Pleistocene stratovolcano with a caldera containing lava domes SW of Pululagua volcano (Beate 1992, pers. comm.).

Pambamarca
Pambamarca is a Pleistocene stratovolcano with two lava domes on the SE flank (Beate 1992, pers. comm.).

Pasochoa
Pasochoa is a Pleistocene stratovolcano with an avalanche caldera open to the NW (Beate 1992, pers. comm.).

Cerro Puntas
Cerro Puntas is a Pleistocene stratovolcano with an avalanche caldera open to the west (Beate 1992, pers. comm.).

Ilalo
Ilal� is a low, eroded Pleistocene stratovolcano immediately SE of Quito. A single Potassium-Argon age of 1.62 +/- 0.16 million years ago has been obtained (INECEL 1980).

Pan de Azucar
Pan de Az�car is a large, probably alkalic volcano in the jungle NNW of Sumaco volcano and east of the town of Baeza. The 3482-m-high volcano was only relatively recently discovered on satellite images and was considered to be Holocene in age because it is otherwise not likely to be so well preserved in a region with heavy rainfall (Hall 1987, pers. comm.). Later work suggested that the volcano was substantially older than neighboring Sumaco volcano and was of probable late-Pleistocene age (Eissen, 2006, pers. comm.).

Santa Cruz
Santa Cruz is a small stratovolcano of Pleistocene age with a caldera open to the north (Beate 1992, pers. comm.).

Sincholagua
Sicholagua is an eroded Pleistocene volcano NNE of Cotopaxi volcano (Beate 1992, pers. comm.).

Ruminahui
Rumi�ahui is a Pliocene or Pleistocene stratovolcano with a summit caldera NE of Cotopaxi volcano (Hall 1987, pers. comm.).

Corazon
Coraz�n is an early to mid Pleistocene stratovolcano with a summit caldera (Hall 1977). Late Pleistocene lavas are also present.

Chalupas
The 18-km-wide Pleistocene Chalupas caldera is the source of the about 90 km3 Chalupas ignimbrite, the largest known in the northern Andes during the Quaternary (Beate, 1989). The Pleistocene Quilindana stratovolcano is located within the caldera. The youngest intracaldera lava flow are unaffected by glaciation.

Putzalagua
Putzalagua is a Pleistocene lava dome near Latacunga (Hall 1987, pers. comm.).

Sagoatoa
Sagoatoa is an eroded Pleistocene stratovolcano with flank cones (Beate 1992, pers. comm.).

Igualata
Igualata is an eroded Pleistocene stratovolcano between Chimborazo and Tungurahua volcanoes (Hall 1987, pers. comm.).

Llimpi
Llimpi is a small late Pleistocene stratovolcano NE of Tungurahua volcano (Hall 1987, pers. comm.).

Puyo
A group of nine scoria cones NE of Puyo are aligned along a NW-SE fissure. A 40Ar-39Ar date of 190 +/- 7 ka was obtained by Hoffer et al. (2008).

Carihuairazo
Carihuairazo is an eroded Pleistocene stratovolcano truncated by edifice collapse, leaving a caldera breached to the NE. A younger volcano, Pu�alica, was constructed between about 18,000 and 14,000 years before present 5 km east of Carihuairazo (Clapperton 1990). A landslide and lahar in 1698 produced debris that reached the town of Ambato (Hall 1987, pers. comm.).

Calpi
A group of tuff cones and lava flows of Pleistocene age is located SW of Chimborazo volcano (Beate 1992, pers. comm.).

Altar
Altar is a large stratovolcano of Plio-Pleistocene age with a caldera breached to the west (Hall 1987, pers. comm.). Indian legends report that the top of Altar collapsed after seven years of activity in about 1460, but the caldera is considered to be older than this (Catalog of Active Volcanoes of the World, Hall, 1977).

San Diego
Although the San Diego maar has been known and described by Servicio Geologico Colombiana, along with dating by Toro (1988) that placed the most recent activity in the late Pleistocene-early Holocene, work by Borrero et al. (2016) provides a more comprehensive understanding of this volcano. The NNE-elongated crater is about 1.5 x 2.1 km and contains a lake about 230 m below the crater rim. A cone feature located immediately NE of the maar is the remains of a dacitic dome with landslides on the flanks. They determined that the volcanic features were all the result of a single monogenetic eruptive period that began with the vent opening and incremental growth of the original crater, followed by additional widening of the maar. Effusion of the dome was the last stage of active volcanism. A paleosol below the young maar sequence was 14C dated at 20,056 � 93 years cal BP, and the dome was slightly younger at 18 ka BP based on fission track dating of apatite.

El Escondido
Identified by the Servicio Geologico Colombiano in a press release in February 2015, this area of a partially collapsed crater and lava domes is covered in thick vegetation. SGC scientists tentatively estimated that the last eruption was 30 ka, but noted that there are hot springs in the area.

South East Range
Saint Kitts and Nevis
The South East Range in central St. Kitts is a young volcano with a partly preserved summit crater less than one million years old (Robertson, 2005). The Ottley's Level and Monkey Hill lava domes lie on the flanks of the volcano.

Northern Centres
Netherlands
The Northern Centres volcanic complex consisting of five adjacent volcanic centers forming the NW end of St. Eustatius Island is less than 1 million years old (Smith and Roobol, 2005).

Silver Hills
The Silver Hills volcanic complex at the northern end of Montserrat was active about 2.58-1.16 million years ago (Hincks et al., 2005).

Centre Hills
The andesitic Centre Hills lava-dome complex was active about 0.95-0.55 million years ago (Hincks et al., 2005).

Septentrional Chain
The Septentrional Chain (Northern Chain) of volcanoes at the NW end of Basse Terre consists of andesitic-to-dacitic lava domes and flows that were active from about 3.5 to 1.2 million years ago (Komorowski et al., 2005).

Axial Chain
The Axial Chain in central Basse Terre is a 15-km-long chain of stratovolcanoes that were active about 1.25 to 0.45 million years ago (Komorowski et al., 2005). The youngest eruptions took place at the southern end of the chain, at Sans Toucher volcano. The Bouillante geothermal field was developed along the coast in submarine volcaniclastic rocks.

Bouillante Chain
The Bouillante Chain along the west-central coast of Basse Terre consists of a N-S-trending chain of phreatomagmatic craters and offshore submarine cones that were active about 0.8-0.25 million years ago (Komorowski et al., 2005). The Bouillante geothermal field and numerous submarine hot springs attest to its recent activity.

Monts Cara�bes
The Monts Cara�bes volcanic complex at the southern tip of Basse Terre was active about 0.5 million years ago (Komorowski et al., 2005).

Terre de Bas
Terre de Bas Island, located in the Les Santes Islands off the southern coast of Basse Terre, were active about 1.9-0.6 million years ago (Komorowski et al., 2005).

Foundland
Foundland volcano at the SE tip of Dominica is Pliocene-to-Pleistocene in age. An andesitic lava flow was K-Ar dated at 1.12 million years (Lindsay et al., 2005a).

Pitons de Carbets
The Pitons de Carbets volcanic complex SE of Montagne Pel�e, was active during the Pliocene and Pleistocene. The early edifice was cut by a major flank-collapse leaving a breached caldera open to the west, inside which a group of lava domes known as the Pitons were constructed.

Trois Ilets Peninsula Group
A series of small volcanoes was constructed at the SW tip of Martinique about 1-2 million years ago (Komorowski et al., 2005). This group includes the Rocher du Diamant, a lava-dome remnant forming a small island off the south coast of the peninsula.

Morne Garu
Saint Vincent and the Grenadines
Morne Garu stratovolcano, south of Soufri�re St. Vincent volcano was active during the Pleistocene. A young Ar-Ar date of 0.011 +/- 0.014 suggests that activity may have overlapped with that of Soufri�re St. Vincent volcano (Robertson, 2005b).

Grand Bonhomme
Saint Vincent and the Grenadines
The Grand Bonhomme volcanic centre, along with adjacent South-East volcanics, form much of the southern half of St. Vincent Island. K-Ar dates range from 2.5-1.2 million years (Robertson, 2005b). Pyroclastic cones are found along the southern tip of the island as part of the South-East volcanics and on the western flank of the Grand Bonhomme volcanic centre.

Greater Antilles Volcanic Arc

Morne la Vigie
Haiti
Greater Antilles Volcanic Arc
Morne la Vigie, a well-preserved nepheline basaltic scoria cone in the Saut d'Eau area north of Port-au-Prince, was dated at about 1.5 million years and represents the youngest volcanism in Haiti (Wadge and Wooden, 1982; Haiti Bureau of Mines and Energy brochure).

Thomazeau
Haiti
Greater Antilles Volcanic Arc
Nepheline basaltic pyroclastic cones near the village of Thomazeau, ENE of Port-au-Prince, represent, along with Morne la Vigie to west, the youngest volcanism in Haiti, dated at about 1.5 million years (Wadge and Wooden, 1982; Haiti Bureau of Mines and Energy brochure). Three volcanic episodes happened successively at Thomazeau, and morphologically, the youngest cone is well preserved, with an easily distinguished lava flow.

San Juan
Dominican Republic
Basaltic lava flows of late-Pliocene to late-Pleistocene age up to 10 km long were erupted from scattered cinder cones in the San Juan valley of the western Dominican Republic (Wadge and Wooden, 1982).

Dos Hermanos
Dominican Republic
The Cerro los Frailes vent, south of the San Juan Los Pozos fault, is adjacent to Dos Hermanos volcanic field, which consists of lava domes and flows of trachy-andesitic composition and is of late-Pliocene to late-Pleistocene age (Wadge and Wooden, 1982).

Valle Nuevo
Dominican Republic
The Valle Nuevo volcanic field, north of the San Juan Los Pozos fault, consists of late-Pliocene to late-Pleistocene age contains rocks of rhyolitic-to-basaltic composition (Wadge and Wooden, 1982).

Ipala
Ipala is a small stratovolcano that extends across the Ipala graben and rises 750 m above the graben floor. Its summit is truncated by a 1-km-wide crater whose steep, 150-m-high walls contain a lake. A prominent cone, Monte Rico, is located on the S flank; it and other cones on the N flank lie along a N-S-trending fracture that continues well beyond the volcano's S flank. The E flank is cut by a 17-km-long, NNE-SSW fissure that produced a line of cinder cones and basaltic lava flows covering about 20 km2. Diaz reported that in 1865 CE Ipala ejected ash from 24 January to June; he listed no source and the report seems improbable (Incer, 1988 unpublished manuscript).

Chiquimula Volcanic Field
The Chiquimula volcanic field occupies a fault-bounded basin underlain by Cretaceous plutonic rocks in the Chiquimula Valley of SE Guatemala. Initial eruptions during the Pleistocene produced basaltic lava flow fields along the N-S-trending fault, forming the eastern edge of the Ipala graben. These were followed by the eruption of widespread lava flows NW of Chiquimula town that covered about 12 km2. The most recent eruptions produced basaltic cinder cones and lava flows near the northern edge of Chiquimula town. The cinder cones were constructed along a N-S-trending fracture, with Cerro Grande, the largest, at the northern end and Cerro Chiquito, the youngest, at the southern end. The sparsely vegetated lava flows from Cerro Chiquito were considered by Williams et al. (1964) to be possibly less than 1,000 years old based on their appearance; there are no reports of eruptive activity and no radiometric ages are known.

Siete Orejas
Siete Orejas is an andesitic stratovolcano with a large caldera breached to the south. The volcano overlooks Quetzaltenango, Guatemala's second largest city. A broad irregular summit profile gives the volcano its name, which means "Seven Ears." The latest eruption produced a widespread airfall pumice and pyroclastic-flow deposit that is stratigraphically constrained to between 126,000 and 85,000 years ago. Volc�n Chicabal, immediately to the west, was constructed within a 4-km-wide breached scarp of unknown origin; the age of this stratovolcano is unknown, but it has a well-preserved summit crater containing a crater lake.

Santo Tomas-Zunil
Volc�n Santo Tom�s (also known as Volc�n Pecul) is a large eroded stratovolcano across a valley SE of Santa Mar�a volcano. The summit is capped by late-Quaternary andesitic tephra. A winding ridge connects it to Volc�n de Zunil, 4.5 km NE, a stratovolcano that forms the topographic high point of the Santo Tom�s-Zunil complex. Solfataras and thermal springs are located on the ridge's W side. Zunil is along the SW rim of the 4-km-wide, 600-m-deep Tzanjuyub caldera, which is breached to the S by the R�o Masa. Several dacitic-rhyolitic lava domes are located on the caldera's N flank and the NW flank of Volc�n de Zunil. The youngest dome, Cerro Zunil, was last active about 84,000 years ago (K-Ar dating). No Holocene eruptions are known from this complex, although it was included in the Catalog of Active Volcanoes of the World (Mooser et al., 1958) based on its geothermal activity.

Cuxliquel
A Quaternary lava-dome complex lies in the center of a semi-arcuate depression of uncertain origin near the city of Totonicap�n. A small symmetrical lava dome, Cerro de Oro, is located on the ESE flank of the larger edifice, 3029-m-high Cuxliquel. The headwaters of the R�o Samal� trace an arcuate path around the dome complex beginning on its SE side around to the north side and then to the SW. Thick Los Chocoyos pyroclastic-flow deposits from the eruption that formed Atitl�n caldera to the SE fill much of the basin and extend down the R�o Samal� to the SW.

San Pedro
Volc�n San Pedro is the oldest of three stratovolcanoes constructed within the roughly 85,000-year-old Atitl�n III caldera, with a forested cone that rises above the SW side of Lake Atitl�n. Santiago bay, a narrow 8-km-long inlet of Lake Atitl�n, separates the eastern flank of San Pedro from the slopes of Volc�n Tolim�n. The shallow summit crater is breached to the NW and partially filled by lava. Two cinder cones were constructed in the moat between San Pedro and the SW Atitl�n caldera wall. The age of the most recent activity of San Pedro is unknown, although it is more vegetated and erosionally modified than the Tolim�n and Atitl�n volcanoes, and does not display evidence of fumarolic activity.

Barahona
The silicic Barahona caldera complex, which lies NE of Acatenango volcano and NW of Agua volcano, consists of two overlapping calderas. The northern caldera is 4.5 km in diameter and its floor is the site of the town of Santa Catarina Barahona, after which the complex is named. The southern caldera is about 2 km in diameter. The initial eruptions of the Barahona complex produced the Sumpango group of tephras, which date back to 300,000-250,000 years. The youngest tephra from Barahona is less than 23,000 years old. The rhyolitic and rhyodacitic tephras include 5 plinian deposits and a pyroclastic-flow deposit.

Piedra Grande
A cluster of faulted, heavily eroded andesitic stratovolcanoes is located in the Tecuamburro graben, between the Jalpatagua fault and Tecuamburro volcano. The vent area of Piedra Grande, on the north, lies with 4-km-wide, nested depressions open to the east. Much of the upper part of the andesitic volcano is extensively hydrothermally altered, and a fumarole is present. To the south is El Sordo, a basaltic andesite stratovolcano with a smaller depression breached to the ESE. One lava flow has a Potassium-Argon age of 1.180 +/- 0.080 million years (Ma). To the south the Piedra Grande complex interfingers with El Sordo, an eroded and faulted basaltic cone. To the SW is Los Sitios, a sequence of interfingering andesitic lava flows from two eroded and faulted scoria and cinder cones. One flow has a Potassium-Argon age of 0.800 +/- 0.061 Ma.

Pueblo Nuevo Vi�as
The deeply dissected Pueblo Nuevo Vi�as (also known as Cerro la Gabia) is located between Pacaya and Tecuamburro volcanoes. The andesitic-dacitic stratovolcano has undergone edifice collapse that left a large horseshoe-shaped caldera breached to the NE and a debris-avalanche deposit that is overlain by the village of Pueblo Nuevo Vi�as. Four cinder cones are located on the NE flank, and lava flows cover the western portion of the Cuilapa quadrangle. A Potassium-Argon age of 2.6 +/- 0.3 million years (Ma) was obtained from an older volcano in the complex, and an age of 0.821 +/- 0.118 Ma from a younger stratovolcano (Duffield et al., 1991).

Ixhuatan
The low-angle, eroded Ixhuat�n volcanic complex covers a broad area between Tecuamburro and Moyuta volcanoes, south of the major regional Jalpatagua fault. The dominantly andesitic volcano was assigned a Pliocene-Pleistocene age by Reynolds (1987), and a Potassium-Argon date of 1.160 +/- 0.050 million years was obtained by Duffield et al. (1989) on a lava flow. Silicic pyroclastic-flow deposits are found in the R�o los Esclavos, west of the volcano. The youngest center is a dacitic lava-dome complex at Cerro los Achiotes. The domes and associated ashfall and ashflow deposits partially fill and extend from a horseshoe-shaped caldera that is breached to the SE and may have formed as a result of slope failure. A N-S-trending fault zone that cuts across the volcano was the site of a seismic swarm in 1979-80.

Ayarza
Ayarza is a double caldera that lies about 40 km NE of the active Guatemalan volcanic front. The 5 x 7 km wide figure-8-shaped caldera is filled by the scenic Laguna de Ayarza, which is about 4 km wide in the western caldera and 2 km wide in the eastern caldera. Both calderas, whose steep walls rise nearly 600 m above the lake surface, were formed within several thousand years of each other during major rhyolitic explosive eruptions in the late Pleistocene. The older eastern caldera was associated with eruption of the Mixta pumice fall and ashflow, which were radiocarbon dated at about 27,000 +/- 1600 years before present (BP). The larger western caldera was formed during eruption of the Pinos Altos airfall pumice and Tapalapa ashflows radiocarbon dated at 23,100 +/- 500 years BP. Formation of the double caldera appears to be the last volcanic activity at Ayarza; bathymetry of the lake floor does not show evidence for post-caldera eruptions.

Cerro Alutate
Cerro Alutate is a small Quaternary stratovolcano located well north of the Guatemalan volcanic front, about 20 km north of Lake Ayarza. It is part of the so called Behind-Volcanic-Front region (Walker, 1981; Libbey et al., 2015). Other areas of Quaternary volcanics are found to the NW and NE in a region of mostly Tertiary volcanic rocks, south of the Motagua fault system.

Jumay Volcanic Field
Jumay stratovolcano rises 700 m above the city of Jalapa, just south of the boundary with folded Paleozoic low-grade metamorphic rocks. A shallow crater is located at the summit of the 2174-m-high volcano, which lies at the NE end of the broad area of Quaternary volcanic rocks in SE Guatemala. Widespread basaltic lava flows occur on the NW flank of the volcano. The age of the Quaternary volcano is not known precisely.

Cerro Ananopa
Cerro Ananopa is a Quaternary basaltic lava cone and lava flow on the floor of the R�o Motagua valley, WSW of the town of El Jicaro. Scattered basaltic lava flows occur nearby, mostly south of the R�o Motagua, and several Quaternary rhyolitic lava flows were mapped north of the river. These are part of a series of Quaternary volcanic rocks erupted through Paleozoic-to-Mesozoic metamorphic rocks parallel to the major WSW-ENE-trending Motagua fault system, which cuts both sides of the R�o Motagua valley.

Guistepeque Volcanic Field
G�istepeque Volcanic Field consists of Quaternary cinder cones and lava cones north of Suchit�n volcano. The basaltic cones are located within the N-S-trending Ipala graben, and several of the cones were consequently constructed along N-S-trending fissures within the graben.

Cerro Redondo
El Salvador-Guatemala
Cerro Redondo is the central feature of a Quaternary volcanic field immediately W of Lake Guija near the border with El Salvador. Two overlapping basaltic shield volcanoes were constructed along a N-S line west of the lake. Small lava fields, capped by cinder cones and small lava domes, are located E, W, and NE of the shield volcanoes. Unlike in other volcanic fields in SE Guatemala, many of the cones in this area show random orientations unrelated to regional trends.

San Diego
Basaltic cinder cones and forested lava flows along the east side of Lake G�ija, which straddles the border between El Salvador and Guatemala, is named after its largest feature, Volc�n de San Diego. A large basaltic lava flow from the San Diego cinder cone dammed the drainage and was responsible for the formation of Lake G�ija. Although Williams and McBirney (1955) estimated that the latest eruption occurred within the past few thousand years, none of the eruptions have been dated.

Guazapa
Guazapa is a massive, eroded Pleistocene stratovolcano ~20 km NNE of the city of San Salvador. The basaltic volcano has no trace of its original summit crater, and deep canyons cut its flanks. Several pyroclastic cones and lava flows of similar composition found at the base of the volcano were thought to be Holocene by Williams and Meyer-Abich (1955). The Macanze scoria cone, ~4 km SE from the base of the edifice, was considered to have probably been active only a few thousand years ago; however, Weber and Wiesemann (1978) did not map Holocene vents in this area.

Apastepeque Field
The Apastepeque volcanic field, N of the city of San Vicente, consists of a dense cluster of about two dozen volcanic features, including lava domes, cinder cones, and maars. Andesitic-to-dacitic lava domes were emplaced in some locations following dacitic pumice eruptions; after the more siliceous eruptions ended, a series of basaltic cinder cones formed. Some of the basaltic eruptions concluded with the formation of maars up to 100 m deep, including those now occupied by lakes such as Laguna de Apastepeque and Laguna Chalchuap�n. No eruption dates are known.

Conchagua
Conchagua (also known as Cochague) is a conical edifice consisting of two overlapping stratovolcanoes, Ocotal and Banderas, overlooking the Gulf of Fonseca at the SE tip of El Salvador. It is elongated WSW-ENE, and the eastern and southern flanks descend into the sea. Cerro de La Banderas has a large horseshoe-shaped crater open to the NE, and though it appears younger, Ar-Ar dating by Quezada and Garcia (2008) was 0.41 +/- 0.1 Ma. To the WSW, the slightly higher Cerro del Ocotal, at 1225 m, was dated at 0.15 +/- 0.02 Ma. Ocotal has multiple peaks and the flanks are more dissected. Eruptions reported for the years 1522, 1688, 1868, 1892, and 1947 are erroneous, and may refer to landslides associated with earthquakes, an interpretation supported by Rapprich et al. (2010).

Conchaguita
Conchag�ita volcano occupies a small, 4-km-wide island in the Gulf of Fonseca across a narrow strait from Conchagua volcano. Late-stage eruptions formed a small, sharp-topped cone with a 100-m-wide summit crater at the southern end of the low 505-m-high island, and a youthful peninsula also extends from the island's eastern side. A crescent-shaped crater open to the west is located at the northern end of the island.

Utila Volcanic Center
Located in the Caribbean Sea off the northern coast of Honduras, the Utila Volcanic Center is described by Kepezhinskas et al. (2020) as a monogenetic volcano in the Central American Volcanic Arc back-arc region, where a single eruption (less than 200,000 years BP) produced a suite of basaltic lavas and palagonite lapilli tuff that contain kaersutite-bearing gabbroic xenoliths. Although McBirney and Bass (1969) described the basaltic rocks on the eastern end of the island as Holocene, the timing of the eruption is uncertain. Both Calibri (also called Stuert or Stuart) Hill and Pumpkin Hill are tuff cones within an area of basaltic lava flows (Kepezhinskas et al., 2020).

Masahuat Volcanic Field
Cerro Masahuat is an eroded Pleistocene stratovolcano that lies at the NW corner of a major bend in the R�o Lempa SE of Lake Guija. The R�o Lempa surrounds Cerro Masahuat on all but the SE side and has cut a gorge through volcanic rocks of similar age to Masahuat that cover a broad area across the river to the north, east of Lake Guija.

Cerro las Tablas
Cerro las Tablas, also known as Cerro la Gloria or El Amate, consists of two low overlapping stratovolcanoes of Pleistocene age located at the SW corner of a major bend of the R�o Lempa, NE of Coatepeque caldera. This Cerro las Tablas, distinct from the Cerro las Tablas of the Cerro Sing�il volcanic field, lies at the SW end of a chain of Pleistocene volcanoes extending to the NE that includes Cerro las Visiones, Cerro Pacho, and Cerro Agua Helada.

Los Limones Volcanic Field
Los Limones volcanic field consists of a group of five cinder and lava cones of Pleistocene age located near the R�o Lempa north of Guazapa volcano.

Cerro Lolotique
A broad area of Quaternary volcanic rocks surrounds the town of Nueva Guadalupe, north and NW of Chinameca volcano. Loma Larga and Cerro Lolotique form west- and south-facing escarpments, respectively, that overlook Nueva Guadalupe and the town of Chinameca. Although the Pan-American highway traverses the flanks of the two escarpments, geologic studies have focused on the more dramatic neighboring volcanoes of the San Miguel-Tecapa cluster, and relatively little is known of the geologic history of this area.

Cerro Yayantique
Located about 11 km E of the Laguna Aramuaca maar, Cerro Yayantique is the most prominent and least-eroded feature in a broad area of Pleistocene volcanic rocks in the SE corner of El Salvador west of the NW arm of the Gulf of Fonseca. Mapped as Pliocene by Weber and Wiesemann (1978).

La Union Norte Volcanic Field
A broad area of isolated small volcanic cones of Pleistocene age is located in the La Uni�n Department of eastern El Salvador near the border with Honduras, west of the R�o Goascoran and north of the city of Santa Rosa de Lima.

Cerro Cacahuatique
Cerro Cacahuatique is a massive Pleistocene stratovolcano located in the interior valley of El Salvador about 30 km NNE of San Miguel volcano. The volcano (also spelled Cerro Cacaguatique) rises 1000 m above its base and is deeply dissected, although it still retains its subdued conical form. A large erosional caldera, formed through a breach on the SE side, truncates the summit.

Cerro Buena Vista
Cerro Buena Vista is an eroded Pleistocene stratovolcano located in the Jucuar�n Range in the SE corner of El Salvador. The 750-m-high volcano lies near the Pacific coast, SW of Laguna de Olomega. A broad crater roughly 1 km wide is breached to the WSW.

Isla Zacatillo
Isla Zacatillo lies only 2 km off the eastern tip of El Salvador in the Gulf of Fonseca. The low, roughly 3-km-wide island is crudely rectangular in shape, but has a peninsula extending to the NE. A steep escarpment truncates the western side of the island below its summit. NNW-SSE-trending faults cut lava flows on the island. The smaller nearby island of Mart�n P�rez to the SE is also of Pleistocene age.

Isla Meanguera
Isla Meanguera, located in the Gulf of Fonseca SE of Conchag�ita Island, consists of an elongated line of three small stratovolcanoes of Pleistocene age. A N-S-trending graben cuts the summits of all three volcanoes. A circular crater occupies the summit of the central cone, which forms the island's high point at 493 m.

Monta�a de Izopo
Monta�a de Izopo, a small basaltic shield volcano located about 20 km SE of the capital city of Tegucigalpa, is the highest Quaternary volcano in Honduras. The 2020-m-high volcano rises only 200 m above its base and was constructed along a NE-trending line parallel to the high fault scarps bordering the Zamorano valley. More extensive basaltic lavas were erupted at Santa Elena along this same NE-trending line. Other basaltic lava flows were erupted farther to the NE near Joya Grande and from other parallel NE-trending faults to the east.

Cerro de Hule
A broad, low-angle shield volcano located about 16 km south of the capital city of Tegucigalpa, Cerro de Hule is the second most prominent Quaternary volcano of the central Honduran plateau. Cerro de Hule was constructed at the intersection of two fracture systems and fed basaltic lava flows in all directions. The longest lava flow traveled 10 km to the NE and is now traversed over much of its length by the Carretera del Sur highway.

Cerro Gavilantepeque
Cerro Gavilantepeque is a small Quaternary basaltic shield volcano located about 10 km SSE of Tegucigalpa. Small remnants of lava flows cap adjacent mesas.

El Pedregal
El Pedregal, the most prominent Quaternary volcano in the highlands of central Honduras, is a low-angle basaltic shield volcano constructed on a high plateau of Miocene ignimbrites immediately west of the capital city of Tegucigalpa. A small ephemeral pond occupies a saucer-shaped summit depression. Isolated remnants of basaltic lava flows from El Pedregal and separate vents occur over broad areas primarily to the west, but NW nearly to the village of Zambrano. A small cone near Matasano produced reddish scoria during the only pyroclastic eruption in the Quaternary volcanic fields near Tegucigalpa.

Cerro Calanterique
Volcano type: Lava cone
Cerro Calanterique, located 1.5 km NW of the town of Siguatepeque, SE of Lake Yojoa, is the apparent source of an outcrop of Quaternary basaltic lava on the flat valley floor about 1.5 km west of town.

Rota
The deeply eroded, forested Rota stratovolcano is located between Cerro Negro and the Telica volcanic complex in the central Marrabios Range. The volcano, also known as Orota, is truncated by a 1-km-wide circular crater whose rim is lowest on the southern side. The latest eruption produced thick andesitic lava flows from a NE-trending fissure NW of the summit. Seismic swarms occurred in 1986, 1989, and 1992, but may have been related to regional fracture systems rather than a magmatic system. Two small NNW-SSE-trending lava domes, El Bosque (also known as Lomas San Ignacio del Bosque or Cerro Ojochal) are located on the plain 2 km N. They were constructed along the same trend as other eruptive fissures that extend transverse to the Marrabios Range volcanoes. An extensive lava field in this area was erupted from numerous small cones and maars.

Maderas
Volc�n Maderas is a roughly conical stratovolcano that forms the SE end of the dumbbell-shaped Ometepe island in Lake Nicaragua. The basaltic-to-trachydacitic edifice is cut by numerous faults and grabens, the largest of which is a NW-SE-oriented graben that cuts the summit and has at least 140 m of vertical displacement. The small Laguna de Maderas lake occupies the bottom of the 800-m-wide summit crater, which is located at the western side of the central graben. The SW side of the edifice has been affected by large-scale slumping. Several pyroclastic cones, some of which may have originated from littoral explosions produced by lava flow entry into Lake Nicaragua, are situated on the lower NE flank down to the level of Lake Nicaragua. The latest period of major growth was considered to have taken place more than 3000 years ago, but later detailed mapping has shown that the most recent dated eruptive activity took place about 70,000 years ago and that it has likely been inactive for tens of thousands of years (Kapelanczyk et al., 2012). A lahar in September 1996 killed six people in an E-flank village, but associated volcanic activity was not confirmed.

Esteli
Sparsely vegetated lava flows mostly erupted from fissure vents are located in valleys in the northern interior highlands between the town of Estel� and the border with Honduras. McBirney and Williams (1965) considered basaltic flows in this area to be Quaternary, and possibly Holocene. The flows near Estel� were faulted and slightly tilted during formation of the Estel� structural basin. Other youthful basaltic lava flows, one of which was erupted from the Bonete de Carrao cone, are located between Estel� and Jinotega. Well-preserved cones are also located in the area west and south of Ocotal. Some of the lava flows in northern Nicaragua contain granitic xenoliths and xenocrysts of quartz.

Cerro el Ciguatepe
Cerro el Ciguatepe is one of several Quaternary volcanoes that lie in the Nicaraguan interior highlands, east of the Nicaraguan depression. The steep-sided stratovolcano was constructed east of the R�o Pacora, NE of Lake Managua at the boundary of the flat-lying Tertiary ignimbrite deposits with the fault-blocks bordering the Nicaraguan depression. A small lava flow extends a short distance beyond the base of the cone through a breach in the SW wall of the 1.5-km-wide crater, which has a blocky dome in the center.

Las Lajas
Las Lajas is the largest volcano of possible Quaternary age east of the Nicaraguan graben. The low 7-km-diameter basaltic caldera is breached on the SE side, where a river drains into Lake Nicaragua. Five coalescing andesitic-dacitic lava domes are located in the center of the caldera, and additional domes are present on the outer flanks. McBirney and Williams (1965) was considered Las Lajas to be Holocene based on morphology, and Van Wyk de Vries (1999, pers. comm.) noted that it was of probable Pleistocene age, but that youthful cinder cones on the flanks are similar to those of the Nejapa alignment and may be Holocene. However, Plank et al. (2002) obtained three radiometric dates of Miocene age.

Volcan Azul
Volc�n Azul consists of three trachybasaltic cinder cones on the jungle-covered Atlantic coastal plain of Nicaragua that were first noted by geologists during an aerial overflight in the 1960s. The three cones, located south of the R�o Curinhu�s and west of Pearl Lagoon, each have well-defined, steep-walled craters about 50-60 m across. In contrast to the circular rims of the other two cones, the rim of the easternmost cone is breached to the west. The well-defined craters and unusually low vegetation in an area of heavy rainfall and rapid weathering led Williams and McBirney (1965) to estimate that the cones were probably no more than a few thousand years old. However, K-Ar dating by Janousek et al. (2010) gave a 1.51 +/- 0.20 Ma age. Other trachybasaltic to trachytic Quaternary cones along the central Nicaraguan Atlantic coastal plain are found at Pearl Lagoon and Kukra Hill.

Malpaisillo
Volcano type: Pyroclastic shield
A large but topographically indistinct pyroclastic shield volcano lies in the Nicaraguan depression at Malpaisillo, NE of Las Pilas volcano and NNW of Momotombo volcano. The 10-km-wide Malpaisillo caldera, also known as Cerro el Ch�caro, forms a flat plain on the floor of the graben that contrasts dramatically with surrounding extensively dissected dacitic airfall and ignimbrite deposits. These deposits extend across the graben east of the Marrabios Range and reach into Lake Managua to the SE. They also crop out west and south of the Marrabios Range. A K-Ar age of 0.46 million years was obtained from the Malpaisillo deposit.

Apoyo
The scenic 7-km-wide, lake-filled Apoyo caldera is a large silicic volcanic center immediately SE of Masaya caldera. The surface of Laguna de Apoyo lies only 78 m above sea level; the steep caldera walls rise about 100 m to the eastern rim and up to 500 m to the western rim. An early shield volcano constructed of basaltic-to-andesitic lava flows and small rhyodacitic lava domes collapsed following two major dacitic explosive eruptions. The caldera-forming eruptions have been radiocarbon dated between about 21,000-25,000 years before present. Post-caldera ring-fracture eruptions of uncertain age produced lava flows below the scalloped caldera rim. The slightly arcuate, N-S-trending La Joya fracture system that cuts the eastern flank of the caldera only 2 km east of the caldera rim is a younger regional fissure system structurally unrelated to Apoyo caldera.

Cerro San Jacinto
Cerro San Jacinto, also known as Cerro San Jacinto Viejo, is a small stratovolcano constructed along the eastern margin of the Nicaraguan central graben east of Lake Managua. A large central depression is surrounded on the north and east by a ridge, which is a remnant of an open caldera rim. Though considered to be of possible Holocene age on the basis of youthful morphology (McBirney and Williams, 1965), the volcano is highly dissected relative to the Holocene volcanoes across the Nicaraguan depression to the west. Van Wyk de Vries (1999, pers. comm.) noted that the volcano is substantially older than nearby Las Lajas volcano and is of probable early Pleistocene age.

Tambor Grande
The eroded Tambor Grande caldera is one of several areas of Quaternary volcanic rocks along the Atlantic coastal plain at the SE tip of Nicaragua shown on the geologic map of Nicaragua (INETER, 1995). The two largest areas are located WNW of the coastal city of San Juan del Norte near the headwaters of the R�o Chiripa and WSW of San Juan del Norte, north of the R�o San Juan. Tambor Grande has an easily recognized central caldera and radially eroded flanks. It lies within an area of dense rain forest with some 3000 mm annual precipitation. Several small cones lie south of Rama, near the Escondido River. Considering their well preserved morphology and the heavy rainfall in the Caribbean lowlands of Nicaragua, these structures can be considered to be Pleistocene in age (Incer 2005, pers. comm.). Quaternary basaltic volcanoes are also located along the Atlantic coastal plain across the border in Costa Rica.

Cerro Chopo
The small pyroclastic cone Cerro Chopo (also known by the religious names of Anunciaci�n, Coronaci�n, or Asunci�n) lies south of the main Guanacaste Range and north of the city of Canas. The 250-m-high basaltic pyroclastic cone was constructed over regional ignimbrites and andesitic lava flows. The crater is oriented to the NW and was the source of olivine-basaltic lava flows. Cerro Chopo was roughly estimated by Alvarado (2000) to be of late Pleistocene age (perhaps 40,000-10,000 years old). The interior of the cone, which lies along the well-traveled road from Canas to Tilar�n, has been exposed by quarrying for road construction materials. Another small isolated cinder cone of similar age, Corobici, lies along the R�o Corobici to the west.

Cerro Tilaran
Cerro Tilar�n, also known as Cerro Tovar, is a small andesitic shield volcano that lies at the NW end of the Tilar�n Range west of Lake Arenal, immediately SW of the town of Tilar�n. It is overlain by tephra deposits from Arenal (maximum age about 7,000 years), but an Ar-Ar date of 1 million years was obtained (Alvarado, 2000) and the volcano is of Pleistocene age (Alvarado 2005, pers. comm.). The Tilar�n Range, which lies to the west of the main volcanic chain, is a fault-bounded tectonic block of Miocene-Pleistocene andesitic rocks of the Monteverde formation.

Los Perdidos
The forested Los Perdidos volcano lies at the southern end of a NNW-SSE-trending volcanic chain that includes the Arenal-Chato complex across the R�o Fortuna. Volcanism began during the late Pleistocene at Los Perdidos and migrated northward to the historically active Arenal volcano. Several andesitic lava domes were constructed within and on the rim of a caldera, which have been have been Potassium-Argon dated by Gillot et al. (1994) at about 83,000-99,000 years before present.

Laguna Poco Sol
Volcano type: Explosion crater(?)
Laguna Poco Sol is a 200-m-wide, lake-filled depression that lies near the southern end of a volcanic lineament extending northward to Arenal volcano. The lake has been interpreted as a phreatic explosion crater or possibly a depression associated with a landslide. Lava flows, lahar deposits, tuffs, and volcanic breccias are found near the lake. Thermal activity at the lake and near the R�o Penas Blancas includes mud pots, hot springs, and sulfur deposition.

Cerro San Miguel
Cerro San Miguel is an isolated lava dome that was constructed on the SW flank of the Tilar�n Range near the mouth of the Gulf of Nicoya, NE of the port city of Puntarenas. The dacitic dome covers an area of about 9 km2 and was Potassium-Argon dated at less than 700,000 BP. A series of vertical-to-subvertical concentric fractures cuts the upper part of the dome.

Cerro las Mercedes
Cerro las Mercedes (also known as Cono Mercedes) is a cinder cone of late-Pleistocene age that lies along the Caribbean coastal plain near the border with Nicaragua. The cone lies just west of the R�o San Juan near the point where the Costa Rica-Nicaragua border no longer follows the R�o San Juan and extends westward south of the river. Leucite-bearing bombs and lapilli of potassic alkaline basaltic composition cover an area of about 1 km2.

Cerro Negro
The low Cerro Negro lava shield occupies an isolated position in the center of the Caribbean coastal plain immediately west of the R�o Chirrip� 17 km ENE of the town of Puerto Viejo. Lava flows in the area near this small 136-m-high shield volcano have been dated at from about 24 million years to about 1 million years (Alvarado 2005, pers. comm.).

Lomas de Colorado
Five small Pleistocene shield volcanoes located along the R�os Colorado and Chirrip� form the Lomas de Colorado volcanic field. This group of small alkaline basaltic volcanoes is located near the Caribbean coastline at the NE-most corner of Costa Rica and covers an area of about 50 km2. The highest peak, Cerro Cocor�, is 7 km S of the confluence of the R�o Chirrip� and the R�o Colorado. A lava flow from Cerro Coronel was K-Ar dated at 1.2 million years (Bellon and Tournon, 1978). The westernmost part of the Lomas de Colorado is a hill known locally as Chirrip� Atl�ntico, lying west of the Cocor� lava shield and east of the lengthy north-flowing portion of the R�o Chirrip�.

Tortuguero
Tortuguero is a Pleistocene pyroclastic cone on the Atlantic coastal plain adjacent to the Caribbean Sea (Barquero and Saenz, 1987; Alvarado, 2000). The small basaltic pyroclastic cone was constructed over fluvial sediments along one of the many lagoons common on this part of the coastline. The cone lies near the northern boundary of Tortuguero National Park, a coastal rainforest park rich in birds and wildlife.

Lomas de Sierpe
The Lomas de Sierpe, also known as Cerro Las Lomas Azules, are a group of six small Pleistocene shield volcanoes (Barquero and Saenz, 1987; Alvarado, 2000) covering an area of ~70 km2 on the Caribbean coastal plain between the Tortuguero and Parisimina rivers. The highest of the features is Colon. Some of the volcanoes lie within Tortuguero National Park.

Durika
A group of Pliocene-Pleistocene dacitic lava domes, the D�rika volcanic field (also known as the R�o Lori domes), lies in the Talamanca Range of eastern Costa Rica. A Potassium-Argon date of 900,000 years was obtained from one of the domes (de Boer et al., 1995). The domes lie on the NE side of the crest of the Talamanca Range near the headwaters of the R�o Lori, a tributary of the R�o Coen.

El Valle
Panama
El Valle volcano, 80 km SW of Panama City, is a broad stratovolcano cut by a large compound Pleistocene caldera. The 6-km-wide El Valle de Ant�n caldera was formed about 56,000 years ago in association with eruption of the dacitic El Hato pyroclastic flows. The caldera has steep, 200-300 m high walls overlooking a flat floor underlain by deposits of a former caldera lake and currently occupied by the town of El Valle. A dacitic lava dome complex (Cerro Pajita, Cerro Gaital, and Cerro Caracoral) was constructed along an E-W lineament within the caldera. Major phreatomagmatic Plinian eruptions produced when magma interacted with caldera-lake water as recently as about 34,600 years ago generated pyroclastic flows that reached the Pacific coast, 25 km S. The most recent dated activity was phreatic eruptions about 13,000 years ago, and activity may have continued into the Holocene (IRHE, 1987). Geothermal exploration has taken place to evaluate the energy potential of the caldera.

Tisingal
Panama
Volc�n Tisingal (also known as Cerro Colorado or Cerro Pec�n) lies adjacent to the Costa Rica border in the Talamanca Range of westernmost Panama, NW of Volc�n Bar�. A large andesitic-dacitic stratovolcano was breached to the SW by edifice collapse, leaving a 7-km-wide horseshoe-shaped caldera. Cerro Picacho, on the NE rim of the caldera, forms the 2986 m high point of the volcano. Two large lava domes, andesitic Cerro Totuma and dacitic Cerro Pel�n, were formed in the NW and E sides of the caldera, respectively. Two additional domes, the larger of which is Cerro Pando, lie outside the caldera to the SSW, and another dome, Cerro Punta, is east of the caldera. Potassium-Argon ages for the Volc�n Colorado complex range from 1.66 million years to 0.52 million years.

La Yeguada
La Yeguada, also known as Chitra-Calobre, is a massive volcanic complex in west-central Panam� north of the Azuero Peninsula that was active from the Miocene into the Quaternary. The youngest major feature of La Yeguada is located within a large fault-bounded horst that forms the high point of the volcanic complex east of Laguna La Yeguada. The latest eruptions took place from the northern part of the horst about 220,000 years ago at Cerro Corero lava dome (also known as Cerro de la Charca), north of El Castillo. The youngest feature of the La Yeguada complex is the Media Luna cinder cone, which was erupted through Tertiary ignimbrite deposits at the NW side of the complex. The oldest peat layer within a small lake dammed by a basaltic lava flow originating from the cone was radiocarbon dated at about 300-350 years ago, but later dating has shown that flow was erupted about 45,000 years ago, and that the La Yeguada complex has not had Holocene eruptions. Warm springs are scattered throughout the complex, and the Chitra-Calobre geothermal field is one of three areas in Panam� that have been the object of intensive geothermal exploration.

Apas-Navenchauc
Chiapanecan Volcanic Arc
The 2.9-km-wide Apas caldera was the source of block-and-ash flows, pumice flows, and ash flows that extend primarily to the SW and NW. The SW deposit forms a large fan covering about 140 km2. Deposits from the Apas collapse structure were K-Ar dated at about 0.432 million years. The 1.34-km-wide Pleistocene Navenchauc explosion crater lies immediately NE of the Apas caldera. The Navenchauc lava dome was constructed on the northern rim of the Navenchauc caldera.

Huitepec
The Huitepec lava dome lies immediately west of the city of San Crist�bal de las Casas. The hornblende-andesitic dome has a height of about 520 m and was the source of ash-flow deposits, which crop out about 5 km NW of San Cristobal. These products are generally gray in color, with a phaneritic texture and coarse grains of plagioclase, pyroxene, and amphibole (Mora et al., 2007). The base of the dome has a mean diameter of 5.18 km, covering an area of about 21.2 km2 (Mora et al., 2007). A K-Ar date of about 850,000 years was obtained from the dome. In general, Huitepec dates to about 0.85-1.95 Ma (Mora et al., 2007). Huitepec's composition, like that of other eruptive centers in the Chiapanecan Volcanic Arc, is mostly intermediate, calc-alkaline (Mora et al., 2007).

Mispia
The Misp�a lava dome lies near the center of a cluster of a half-dozen Pleistocene domes SSE of the city of San Crist�bal de las Casas. The Amahuitz lava dome lies to the NE of Misp�a, La Iglesia dome to NNW, La Lanza to the west, and Santont�n and Venustiano Carranza domes to the south.

Papayo
The steep-sided Papayo lava dome and related dacitic lava flows was emplaced in a NE-SW oriented depression south of Telapon and north of Iztacc�huatl in the Sierra Nevada range west of Mexico City. The lava flows extended about 10 km both WSW and ENE from the dome that rises about 230 m above the flows. The lava field covers about 84 km2 and has a volume of about 21 km3. Lavas overlie glacial moraines about 12,000 years old (Nixon, 1989), and on the western side the flows surround the glaciated late-Pleistocene lava and pyroclastic cone of Iztaltetlac. However, a radiometric age (K-Ar) of 118,000 years BP was reported by Macis et al. (2012), along with 80,000 BP for the Teyotl dacitic lava flows immediately south towards Iztacc�huatl.

Los Atlixcos
Los Atlixcos, also known as Cerro el Abra, consists of a broad area of lava flows topped by two large cones at the eastern end of the Mexican Volcanic Belt along the Gulf of Mexico about 80 km NW of the city of Veracruz, near Palma Sola. The two cones, together known as Cerro los Atlixcos, lie 2 km apart with the larger one to the W. A broad area of basaltic lava flows extends primarily to the E and NE, reaching the coast about 9 km from the western cone. The boundaries of the lava shield are defined by the R�o Santa Ana on the NE and the R�o El Tecu�n on the S. Negendank et al. (1985) considered them to be of Holocene age based on morphology. Other Quaternary cones are located to the NW, and a group of cones and silicic lava domes of Tertiary-to-Quaternary age were constructed along the coast to the SE. There are no eruption dates known.

Cofre de Perote
Cofre de Perote is a massive Quaternary andesitic-dacitic volcano at the NNE end of a volcanic chain extending southward to Pico de Orizaba (Citlalt�petl). Lava flows dominated the formation of this broad massif, which is largely of Pleistocene age. Glaciation at the summit has left a steep box-like peak which is sometimes referred to as the "Treasure Chest of Perote." A large escarpment formed in part by multiple edifice collapses cuts the eastern side of the volcano. Numerous cinder cones, likely related to regional monogenetic volcanism, were erupted through NE part of the broad edifice ~12 km from the summit, and are included with the Naolinco Volcanic Field in this catalog.

La Gloria
A broad area of Quaternary volcanic rocks lies in the highland between Cofre de Perote and Las Cumbres volcanoes. Two large arcuate E-facing scarps of uncertain origin, possibly eroded volcanic centers, are the most prominent features of the La Gloria volcanic field. The name originates from the town at its NW base, but is also known as the Desconocido-Tecomales volcanic field after the two large scarp ridges, 9-km-long Desconocido on the N and 6-km-long Tecomales on the S. Numerous pyroclastic cones on both sides of the escarpments are included in the Serd�n-Oriental Volcanic Field for this catalog. The age of the most recent eruptions in this poorly studied region is not known, although some lava flows were classified by Negendank et al. (1985) as Holocene based on their youthful morphology. Carrasco-Nunez et al. (2006) described Holocene debris flow deposits, but characterized the complex as a probable Plio-Pleistocene age chain of aligned vents.

Las Cumbres
Las Cumbres volcanic complex is a Quaternary center ~15 km NNE of Pico de Orizaba The ~3.5 km summit caldera is narrowly breached on the E, and is largely filled by a dacitic lava dome (Cerro Gordo or El Cumbre Grande). Eruptive activity at the main complex ceased during the late Pleistocene. Rhyolitic and obsidian domes to the N and SW, sometimes associated with this complex, are listed as subfeatures of the Serd�n-Oriental Volcanic Field in this catalog.

San Juan
Volc�n San Juan, the NW-most major volcano of the Mexican Volcanic Belt, overlooks the city of Tepic, the capital of Nayarit state. The northernmost of two twin stratovolcanoes is truncated by a 1 x 4 km wide, oval-shaped caldera formed about 15,000 years ago during an eruption that produced thick rhyodacitic pumice-fall deposits. These are up to 9 m thick beneath Tepic and extensively quarried. This major explosive eruption was followed, probably shortly thereafter, by intra-caldera eruptions of andesitic lava domes and flows. Cerro Alto stratovolcano, the 2240 m high point of the San Juan volcanic complex, is an older volcano that rises immediately to the south of San Juan. Reports of historical eruptions of San Juan in 1742 and 1859 are unconfirmed or incorrect (Luhr, 2000).

Las Navajas
Volc�n Las Navajas is a low-profile shield volcano located immediately north of the more prominent Sangang�ey volcano. Las Navajas is truncated by a 4-km-wide circular caldera, associated with eruption of the Las Cuevas ash. The caldera is filled by pantelleritic lava flows that overtopped the caldera rim on the north, east, and SW sides. A major plinian eruption about 200,000 years ago produced widespread airfall pumice and welded pyroclastic flows (collectively known as the La Moderna ash) that first formed a 1-km-wide central crater at the summit of a stratovolcano constructed in the center of Las Navajas caldera and then formed an elliptical caldera 2.5 x 4 km in size on the southern side of the volcano. Two cinder cones and an associated lava flow were subsequently erupted on the northern flank of Las Navajas, and Sangang�ey volcano was constructed on the southern flank, largely burying the southern rim and floor of the second caldera.

Santa Maria del Oro
The scenic lake-filled Santa Mar�a del Oro maar lies between Sangang�ey and Ceboruco volcanoes in the Tepic-Chapala graben. The topographically indistinct outer flanks of the maar give little hint to the dramatic 400 m drop into the Laguna Santa Mar�a crater lake. The roughly 3-km-wide maar was erupted through older Miocene rhyolitic ashflow tuffs of the Sierra Madre Occidental. Little is known of the geology or age of Santa Mar�a del Oro, but it occurs near the alignment of cinder cones extending from Sangang�ey and may have a similar Pleistocene age. Pyroclastic-surge deposits from Santa Mar�a del Oro occur in valleys to the north and in some cases along the walls of the crater.

Tepetiltic
Volc�n Tepetiltic is an andesitic and dacitic stratovolcano truncated by an elliptical 5 x 2.5 km caldera that contains a lake at its NE corner. The caldera, with steep-sided walls elongated NE-SW, originated during a major rhyodacitic eruption that produced Plinian-airfall, pyroclastic-flow, and pyroclastic-surge deposits around the volcano. Caldera collapse was closely followed by emplacement of lava domes on the eastern flank. Two andesitic domes were later emplaced on the caldera floor, and chemically unrelated flank cinder cones were erupted.

San Pedro
The elliptical 7 x 10 km wide San Pedro caldera, located immediately south of the Tepetiltic caldera, is partially filled by the three coalescing Cerro San Pedro lava domes. Construction of a large number of lava domes SE of the current location of San Pedro during the Pleistocene was followed by caldera formation associated with eruption of the Cuastecomate Pumice. The rim of the caldera, which was considered to have formed between about 450,000 and 283,000 years ago, is exposed only on the east side. The dacitic San Pedro lava domes are aligned along a WNW-trending fracture and have been potassium-argon dated at about 41,000 years. Two of the domes have collapsed, forming debris-avalanche deposits that extend as far as 10 km to the NW and SE.

Los Volcanes
A mostly Pliocene volcanic field is located near the town of Los Volcanes, at the southern end of the Atenguillo graben in the Jalisco tectonic block of western M�xico. The 285 km2 field consists of lava cones and flat-topped flows overlying Cretaceous ignimbrites. The youngest products are earliest Pleistocene in age (Potassium-Argon date of 1.56 Ma). The extensional tectonic setting, in a graben of the Jalisco block, has resulted in the eruption of a wide variety of lava types, ranging from potassic minettes and leucitites to calc-alkaline basalts and andesites.

Northern Atenguillo
An extensive Pliocene-Pleistocene volcanic field is located at the northern end of the Atenguillo graben in the Jalisco tectonic block of western M�xico. Pleistocene volcanism has occurred at two locations at the southern and northern ends of the field. Potassium-Argon ages of 0.65 and 0.67 Ma (million years) were obtained from the Las Laja shield volcano at the southern end of the field. Initial phreatomagmatic eruptions at La Laja produced pyroclastic-surge and airfall deposits associated with formation of a tuff ring or tuff cone. Subsequent extrusion of a thick sequence of lava flows formed the symmetrical shield volcano. The flows blocked the R�o Atenguillo, forming an ephemeral 20-km-long lake, and the initial flows produced pillow lavas. El Rosario, the northernmost known Pleistocene vent of the Atenguillo graben, forms an alkali-basaltic lava plateau and has a Potassium-Argon age of 0.64 Ma.

Tequila
Volc�n Tequila is an eroded andesitic-dacitic volcano surrounded by a series of older flank rhyolitic lava domes and obsidian flows ranging from 0.9 to 0.23 Ma in age. A prominent summit spine, similar to that at Sangang�ey, has been dated at 0.21 Ma. The spine occupies a large summit crater open to the NE, which was formed by erosion. After the cessation of activity at the central vent, andesitic lava flows were erupted from vents on the flanks, and a chain of lava domes was formed on the SE flank. At least a dozen cinder cones younger than the central volcano were erupted along a WNW-trending line SW and south of the volcano. These were roughly estimated on the basis of morphology to be older than 40,000 years.

Northern Guadalajara Mesa
A cluster of rhyolitic lava domes lies on the northern end of the Guadalajara Mesa about 20 km N of the city of Guadalajara. This area is located just beyond the SW end of the Jalpa Graben and lies along the boundary between the Pliocene-Quaternary Mexican Volcanic Belt and the mid-Tertiary Sierra Madre Occidental volcanic province. The Northern Guadalajara Mesa lava domes were erupted through Pliocene ignimbrites forming the mesa. The highest dome, Cerro Jacal de Piedra, lies south of Cerro el Chicharr�n. A K-Ar age of 1.4 million years was obtained by Spinnler et al. (2000) from Cerro el Chicharr�n. Two other domes are located along a N-S-trending line to the east.

Sierra la Primavera
The Sierra la Primavera volcanic complex is located immediately west of M�xico's second-largest city, Guadalajara. Following the eruption of rhyolitic lava flows and domes beginning about 120,000 years before present (BP), an 11-km-wide caldera was formed as a result of the eruption of the 20 km3 Tala Tuff about 95,000 BP. La Primavera caldera subsequently filled with water, forming a lake, through which several lava domes were emplaced. The eruption of a series of domes along the margin of the caldera about 95,000 years ago was followed about 75,000 years ago by the eruption of a younger series of ring domes. Uplift and sedimentation filled the lake, and a final series of lava domes was erupted along the southern margin of the caldera beginning about 60,000 BP, with the youngest dome dated at about 30,000 BP. Steam vents and hot springs currently are active throughout the volcanic complex.

Southern Guadalajara
A chain of nine basaltic andesite volcanic centers of Plio-Pleistocene age was constructed along a NW-SE-trending line through the southern portion of the city of Guadalajara. The centers range from small cinder cones, such as Cerro San Bartolo, to larger composite volcanoes. The westernmost cones are partially overlapped by southern Guadalajara's streets and buildings. The largest volcanoes are located at the SE end of the chain. Cerro el Papant�n de Juanacatl�n marks the SE end of the chain. The small stratovolcano Cerro el Molino was constructed SE of Cerro el Papant�n de Juanacatl�n. It is offset slightly to the south of the trend of the rest of the chain, south of a fault block of the Chapala graben.

Acatlan Volcanic Field
The Acatl�n volcanic field, located SW of La Primavera caldera, is a group of andesitic cones, rhyolitic lava domes, and lava flows associated with a caldera system. The Acatl�n Ignimbrite is a compositionally zoned rhyolitic-to-andesitic tuff that covers an area of about 150 km2. The ignimbrite overlies andesitic breccias dated at 0.65 million years. Following eruption of the ignimbrite, a series of rhyolitic and dacitic lava domes and andesitic cinder cones and lava flows were erupted throughout the Acatl�n volcanic field.

Volcan el Cantaro
Volc�n el C�ntaro is the northernmost of a chain of volcanoes rising above the floor of the Colima rift zone. C�ntaro, with Potassium-Argon ages ranging from 1.7 to 1.0 million years, is the oldest volcano of the C�ntaro-Colima volcanic complex, which extends south through Nevado de Colima to the historically active Volc�n de Colima. C�ntaro is erosionally modified, but has many well-preserved andesitic-dacitic lava domes on its northern and eastern flanks. The biotite-bearing rocks of C�ntaro contrast to the more mafic biotite-free rocks of Nevado de Colima and Volc�n de Colima. The southward-migrating volcanism of the C�ntaro-Colima chain is also reflected by a southward-younging progression at C�ntaro itself.

San Sebastian Volcanic Field
The San Sebasti�n Volcanic Field, near the old silver-mining town of San Sebasti�n, is the northernmost of a belt of potassic volcanic fields located west of the main volcanic chain of western M�xico. These geochemically unusual volcanoes are at the conjunction of tectonic regimes involving the rifting of the Jalisco tectonic block and the subduction of the Rivera plate. The field consists of a group of scattered lamprophyric cinder cones erupted predominately through silicic ash-flow tuffs of the southern Sierra Madre Occidental province. The cinder cones and related lava flows, which erupted in a rugged and sparsely populated mountainous area that makes access difficult, range in age from 0.48 to 0.26 million years.

Los Azufres
The Los Azufres volcanic center is one of several silicic volcanic complexes with active geothermal systems that lie north of the axis of the Mexican Volcanic Belt. Located about 200 km NW of Mexico City, the Los Azufres center consists of a 18 x 20 km wide early Pleistocene caldera that was later partially filled by resurgent dacitic-to-rhyolitic lava domes. Two magmatic cycles lasting about 200,000 years each took place between 1.4 and 0.8 Ma (million years), consisting of silicic, followed by basaltic volcanism. The latest magmatic cycle, beginning about 0.6 Ma, involved resurgent doming of the southern part of the caldera, the eruption of chemically diverse basaltic-to-rhyolitic products, and the emplacement of dacitic-rhyolitic lava domes. The latest paroxysmal eruptions produced ignimbrites between 38,000 and 26,000 years ago. Hot springs and fumaroles are located along E-W-trending faults, and Los Azufres is an active producing geothermal field.

Apan-Tezontepec
A large volcanic field of Mesozoic to late-Pleistocene age occupies the central part of the Mexican Volcanic Belt in the NE part of the Valley of Mexico. The Apan-Tezontepec volcanic field covers portions of the states of Hildalgo, Tlaxcala, and M�xico and contains about 300 eruptive centers. The vast majority of these are scoria cones, but shield volcanoes, lava flows, and lava domes are also present. The location of the vents is influenced by regional normal faults. Two of the largest Quaternary volcanoes of the Apan-Tezontepec volcanic field are Chiconautla and 3100-m-high Cerro Gordo, which rises immediately NE of Mexico City. The Tizayuca volcanic field lies at the NW corner of the Apan-Tezontepec volcanic field.

Tlaloc
Tl�loc, at the far northern end of a volcanic chain stretching northward from Popocat�petl, is a stratovolcano of Pliocene-Pleistocene age. Although typically considered to be the oldest volcano of the chain, recent work has documented a major plinian-subplinian eruption radiocarbon dated at about 31,500 years before present. The eruption produced a major pumice-fall deposit and associated pyroclastic flows.

Telapon
Telap�n is a large Pleistocene stratovolcano north of Iztacc�huatal. It lies along a N-S-trending volcanic chain extending from Popocat�petl volcano that is perpendicular to the trend of the Trans-Mexican Volcanic Belt. A dacitic lava flow at the summit was K-Ar dated at about 274,000 years (Cadoux, 2007 pers. comm.).

Acoculco
The Acoculco volcanic complex lies in the NE part of the Mexican Volcanic Belt, where it intersects the Sierra Madre Oriental volcanic province. The Acoculco caldera complex is located about 80 km WNW of the better known Los Humeros caldera. Three major pyroclastic flows were erupted during the late Pliocene and Pleistocene, associated with two circular depressions 28 x 34 and 16 x 21 km in diameter, respectively. The large rhyolitic Cerros las Tetillas lava dome was emplaced during the early Pleistocene. The latest activity consisted of the extrusion of basaltic lava flows during the late Pleistocene. Thermal areas are located within the caldera complex and on its eastern flanks, and the caldera has been considered as a potential area for geothermal development.

Cerro Grande
A group of lava domes and pyroclastic cones of Pleistocene age is located on the western side of Cerro Grande, a Miocene caldera north of La Malinche volcano. Pyroclastic-flow deposits within the caldera are those of the X�ltipan ignimbrite, which originated from Los Humeros caldera to the east about 0.45 Ma (million years ago). A Potassium-Argon age of 0.49 Ma was obtained for the lava domes at Cerro Grande. Post-caldera Pleistocene activity at Cerro Grande covered a broad area on the SW-NW side of the caldera, producing andesitic and dacitic lava domes and basaltic lava cones and pyroclastic cones.

San Martin Pajapan
San Mart�n Pajapan is a composite volcano at the SE end of the Sierra de Santa Martha along the Gulf of Mexico SE of Lake Catemaco. Von Wolff (1929) reported Indian traditions of "smoke" and fire from the volcano, but Nelson and Gonzalez-Caver (1993) noted that the volcano is capped by thick lateritic soils and lacks evidence for recent activity. A K-Ar date of 1.5 +/- 0.2 million years ago (Ma) was obtained from one of the youngest lava flows. K-Ar dates on the adjacent eroded volcanoes of Santa Martha and Yohualtajapan to the NW range from 3.3 to 1.0 Ma. The summits of both these volcanoes are truncated by large depressions open to the north of erosional and slope failure origin. Hundreds of partially eroded cinder cones dot the southern slopes of the Sierra de Santa Martha.

Cocos Ridge Volcanic Province

Isla del Coco
Cocos Ridge Volcanic Province
The 22 km2 Isla del Coco (Cocos Island) lies along the central part of the aseismic Cocos Ridge about 650 km SW of the Costa Rican port of Puntarenas. It is the only subaerial portion of the ridge, which extends from the Gal�pagos hot spot to the Mesoamerican trench. The island was documented by the Spanish pilot Juan Cabeas in about 1526 CE and is known as the site of treasures buried by pirates and ship captains. The roughly rectangular 5 x 7 km island is surrounded on all sides by steep cliffs up to 200 m high. Construction of a Pliocene-Pleistocene shield volcano was followed by caldera formation and the emplacement of a trachytic lava dome. The latest eruptions produced lava flows that originated from NE-trending fissures most prominent on the SW part of the island.

Isla Darwin
Isla Darwin (also known as Culpepper Island) is a small flat-topped island encircled by cliffs that lies NE of the Gal�pagos platform. A single magnetic measurement indicates an age of less than 720,000 years ago.

Isla Wolf
Isla Wolf (also known as Wenman Island) and three nearby smaller islands are the eroded remnants of a shield volcano. The western part of the island and the small low western island may represent caldera-filling lava lake deposits. Remnant magnetism of two samples is reversed, indicating an age between 2.47 and 0.72 million years ago (Cox, 1983). A date of 1.6 +/- 0.07 million years was obtained from Wolf Island (Harpp and Geist, 2002).

Roca Redonda
The tiny flat-topped islet of Roca Redonda, only 50 x 100 m wide, is the remnant of a large shield volcano north of Isabela Island. Shallow submarine fumaroles are present around the island, and a single K-Ar date of essentially zero age (53 +/- 54 ka) was obtained.

Rabida
The most petrologically diverse of the Gal�pagos Islands, the small 2-km-wide R�bida Island consists of a group of lava domes and pyroclastic cones ranging in composition from tholeiitic basalts to trachytes. Potassium-Argon dates from lava flows range from 1.06 to 0.192 million years (Cox, 1983).

Pinzon
The Pinz�n Island shield volcano is covered with lava flows originating from a crater SW of the summit. The most prominent feature is a small steep-walled 1-km-wide caldera NW of the summit. Potassium-Argon dates range from 1.09 to 0.93 million years ago (Cox 1983).

Santa Fe
Santa Fe Island consists of the faulted remnant of a Pliocene shield volcano capped by numerous cinder cones. Potassium-Argon dates range from 3.9-0.72 million years ago (Geist et al., 1986; White et al., 1993). Fumarolic activity was observed in 1970, but not in 1984.

Floreana
The low shield volcano of Floreana Island, also known as Charles Island or Santa Mar�a Island, is densely covered with cinder cones. A 5-km-wide caldera at the center of the island has an irregular floor. Several young lava flows were considered to have been as young as few thousand or even a few centuries old based on their youthful morphology (McBirney and Williams, 1969), but a surface exposure age of 26 +/- 7 ka was obtained on the youngest flow (Kurz and Geist, 1999). An 1813 eruption attributed to Floreana in the Catalog of Active Volcanoes of the World is considered to have actually occurred at Sierra Negra volcano on Isabela Island (Simkin 1980, pers. comm.). The most conspicuous of the cinder cones on the island is Cerro de Pajas, which rises 335 m above its surroundings. It fed a massive pahoehoe lava flow, perhaps the youngest on Floreana, that reached the SW coast over a broad 6.5 km area.

Cerro Prieto
The Cerro Prieto Volcanic Complex is the surface manifestation of the Cerro Prieto Geothermal Field, and 90 km NW of the Gulf of California and 35 km S of the city of Mexicali. As described by Garc�a-S�nchez et al. (2017), the "geothermal field and the Salton Sea in the USA sit in a pull-apart basin that belongs to the trans-tensional tectonic zone that includes the San Andreas Fault system and the Salton Trough basin to the NW and the East Pacific Rise to the SE." Although the only obvious volcanic feature is the small Cerro Prieto dome complex with a 200-m-wide crater at the NE end, the complex, as defined by Garc�a-S�nchez et al. (2017), "consists of seven stratigraphic units emplaced in a brief time span around 78?81 ka. Its activity began with the extrusion of a dacitic lava that came into contact with water-saturated sediments, causing brecciation of the lava. The activity continued with the emplacement of dacitic domes and a dyke that were destroyed by a phreatic explosion emplacing a lithic-rich breccia. This phreatic explosion formed a 300-m-wide and 40-m deep circular crater. The activity then migrated ~650 m to the SW where three dacitic lava domes were extruded and ended with the emplacement of a fissure-fed lava flow." Ages around 100,000 years BP (possibly up to 10,000 years) were reported by de Boer (1979) and Reed et al. (1984), and Cucupas Indian legends described a monster that covered the land with hot rocks, which grew through the soil and emitted fire tongues. Later work by Garc�a-S�nchez et al. (2017) presented "two 40Ar/39Ar whole-rock ages reported by Mac�as et al. (2011) in an internal unpublished report for CFE [with recalculated ages] of 78 � 17 ka for the brecciated dacitic lava and 81 � 13 ka for the dacitic dyke."

San Quintin Volcanic Field
San Quint�n Volcanic Field on the NW coast of Baja California consists of 11 late-Pleistocene pyroclastic cones and related lava flows. Low lava shields, initially submarine, are capped by scoria cones. San Quint�n rocks are similar to intraplate or oceanic island alkalic rocks and differ from other Baja alkalic volcanic suites. It is the only Quaternary volcanic field in Baja California where lower-crustal and upper-mantle xenoliths are found. The field is located at the margins of the Y-shaped San Quint�n Bay, and includes a northern and southern group of cones, Monte Mazo (connected to the mainland by a long tombolo), and Isla San Mart�n (5 km offshore to the west). Lava flows overlie midden deposits thought to be 5-6,000 years old, and Gastil et al. (1975) also considered the southern cones of Picacho Vizcaino and Sudoeste to possibly be less than 3,000 years old. However, Ar-Ar dating (Ortega-Rivera et al., 2004) restricted eruptions to a range of about 180,000 to 20,000 years ago.

Coronado
Volc�n Coronado is a roughly 440-m-high, 2-km-diameter volcanic cone at the northern end of the 7-km-long Coronado Island, 3 km off the E coast of Baja California in the Canal de los Ballenas. The age of the most recent eruptive activity is not known, although fumarolic activity was reported in September 1539 (Medina et al., 1989; original source not referenced).

Tres Virgenes
The Tres V�rgenes volcanic complex contains the only large stratovolcanoes in Baja California, rising above the Gulf of California in the east-central part of the peninsula. Three volcanoes, El Viejo, El Azufre, and La V�rgen, constructed along a NE-SW line, are progressively younger to the SW. The youngest, La V�rgen, is a stratovolcano with both dacitic and andesitic flank lava domes and lava flows. A major Plinian eruption from a SW-flank vent was radiocarbon dated at about 6,500 years, but Helium exposure and Uranium-series dates give a Pleistocene age (30.7 ka) for this event (Schmitt et al., 2006). A stratigraphic review (Avellan et al., 2018) noted that the 30.7 ka age is closer to the expected age of the tephra fall, and that the 22-25.5 ka (as determined by Schmitt et al., 2006) andesitic-dacitic lava flows dispersed around the cone are the youngest units in the complex. Although an ash plume from Tres V�rgenes was reported in 1746 by a Spanish Jesuit priest while navigating the Gulf of California, no tephra deposits from such a recent eruption have been found. A geothermal plant is located at the northern end of the complex near the margin of the Pleistocene El Aguajito caldera.

Cerro Leon
Cerro Le�n, also known as Volc�n Prieto ("Dark volcano"), is a small, roughly 280-m-high cone of early Pleistocene age (~2.5 Ma) that was constructed along the Guaymas lineament on the east coast of northern Baja California (Martin-Barajas and Weber, 2003). The eastern flank of the volcano extends into the Gulf of California. It is part of the Puertecitos Volcanic Province, within the Gulf of California Rift Basin System (Martin-Barajas and Weber, 2003; Oskin and Stock, 2003). This volcanic province is the most extensive in the region and has the longest known volcanic history. It is typically calc-alkaline and largely rhyolitic, but Cerro Leon is predominantly andesitic (Stock, 2000; Gastil et al., 1979; Martin-Barajas and Weber, 2003).

San Ignacio Volcanic Field
The San Ignacio volcanic field lies north of the town of the same name and east of the town of Vizcaino. Miocene tholeiitic basaltic-andesitic lava flows and somewhat magnesian Pliocene-to-Pleistocene andesites emitted from dozens of cinder cones overlie Tertiary sediments (Pallares et al., 2007; Calmus et al., 2003). Surface morphology implies that these Plio-Pleistocene flows were likely highly viscous, compared to their more fluid Miocene counterparts (Pallares et al., 2007). The San Ignacio field dates to about 0.65 to 5 Ma; most of the volcanic activity at this center occurred during the Miocene and early Pliocene (Calmus et al., 2003).

El Aguajito
El Aguajito caldera (also known as Santa Ana caldera) is located along the Gulf of California immediately NE of Tres V�rgenes volcano and NW of La Reforma caldera. The rim of the approximately 10-km-wide resurgent caldera is not exposed, but an arcuate line of andesitic-to-rhyolitic lava domes covers its northern margin. Formation of the rhyolitic caldera was associated with the eruption of ignimbrites, K-Ar dated at 0.76 +/- 0.06 million years ago (Ma), most of which were deposited in the Gulf of California. Rhyolitic lava domes on the northern margin have been dated at 0.5 +/- 0.04 Ma; dacitic lava domes on the southern side of the caldera appear to be older. The regional NNE-SSW-trending Cimarron fault cuts across the center of the caldera. Hot springs are located along the southern caldera margin, and active seismicity was noted during geothermal exploration.

Punta Pulpito
Punta P�lpito is a Pleistocene obsidian dome dated at about 0.5 million years that forms a small peninsula along the Gulf of California, east of the southern tip of Bah�a Concepci�n in southern Baja California. The Saquicismunde geothermal area with hydrothermal springs and steaming ground lies close to the dome, and the larger Los Volcanes geothermal area, lying along the coast about 5 km S, contains 18 fumaroles along a NW-SE alignment.

Cerro Mencenares
The Cerro Mencenares volcanic complex along the Gulf of California is situated at the northern extent of the Loreto Basin, SE of Bahia Concepcion (Dorsey and Umhoefer, 2000). It's eruptive history, which involves three eruptive events, likely played a role in the development of the Loreto Basin. Cerro Mencenares itself is a large stratovolcano; the complex consists of this composite cone and several peripheral centers that cover an area of about 150 km2 (Bigioggero et al., 1995). The volcanic products generally consist of Pliocene to lower Pleistocene andesitic to rhyolitic domes, flows, and pyroclastics (San Juanico Unit), along with dacitic and andesitic-basaltic lava flows (Mencenares Unit) (Dorsey and Umhoefer, 2000; Bigoggero et al., 1995). Younger silicic domes and minor basaltic lava flows make up the San Basilio-San Juan Unit (Bigioggero et al., 1995). The volcanic tuffs and breccias on the flanks of the complex are often interbedded with marine mudstones and limestones (Bigioggero et al., 1995; Dorsey and Umhoefer, 2000).

La Reforma
The early Pleistocene La Reforma caldera lies along the Gulf of California immediately east of Tres V�rgenes volcano and SE of the late Pleistocene El Aguajito caldera. The roughly 9-km-wide caldera contains basaltic, andesitic, and dacitic lava flows, and rhyolitic lava domes. A prominent arcuate caldera rim extends from La Reforma along the NW coast to near Punta Las Cuevas on the SE coast. The age of the caldera was determined (K-Ar) to be between 1.6 and 1.4 million years old (Ma). A 1.09 +/- 0.11 Ma age was obtained on a ring-fracture lava dome. Andesitic lava flows were erupted on the flanks of the caldera both before and after caldera formation.

Kaena
Water discoloration, sulfur odor, possible boiling water, and possible minor floating pumice were observed 60 km NW of the tip of Oahu on 22 May 1956. The seamount at that location has a depth of about 1,200 m at the end of the Kaena Ridge. Macdonald (1959) suggested that a submarine eruption may have occurred, but noted that evidence is less certain than that for the 1955 report of a submarine eruption near Necker Island.

Kohala
The oldest of the volcanoes comprising the island of Hawaii, Kohala forms an oval shield constructed along two NW-SE trending rift zones at the NW tip of the island. Large valleys cut into the NE flanks, including the dramatic Waipio Valley, correspond to the headwall region of the massive Pololu debris avalanche that extended 130 km NE. A caldera that apparently formed during the shield stage was buried by post shield lavas. The youngest volcanic series (the Hawk volcanics) are Potassium-Argon age dated between 0.26-0.06 million years ago.

Kahoolawe
The uninhabited island of Kahoolawe, SW of the island of Maui, consists of a broad, low basaltic shield volcano formed by Pleistocene eruptions along a rift zone that extends SW from a buried, 5-km-wide caldera at the eastern side of the island. The eastern rim of the caldera lies beneath the waters of Kanapou Bay. Two less prominent rift zones trend to the east and north. Much of the island is truncated by steep sea cliffs that expose the thin lava flows making up the volcano. Stearns (1946) and Macdonald and Abbott (1970) considered cinder cones within the caldera on the west side of Kanapou Bay to be of Holocene age, but this age was considered probably too young by Langenheim and Clague (1987), who mapped the cones as Pleistocene or Holocene. Sano et al. (2006) obtained K-Ar dates on the youngest flows of 900,000 to 980,000 years Before Present.

Mahukona
The Pleistocene Mahukona seamount lies between the islands of Hawaii and Kahoolawe, NW of Hualalai volcano. The distinct cone is about 4 km in diameter.

West Maui
The Pleistocene West Maui shield volcano is deeply dissected by spectacular steep-sided valleys that extend from the north and east into the summit caldera. Late-stage cinder cones and lava flows on the W flank were mapped as Recent by Stearns (1946). Mullineaux et al. (1987) indicated that the youngest lava flows are more than 25,000 years old, and the youngest K-Ar dates obtained are older than one million years (Sherrod et al., 2007).

Lanai
The Pleistocene Lanai shield volcano was constructed along three rift zones, the most prominent of which is the NW rift zone. The large submarine Clark debris avalanche extended 150 km S (Moore et al. 1989). A caldera is located at the southern end of the island. Lava and spatter cones were formed along the rift zones. A single Potassium-Argon date of 1.28 +/- 0.4 million years ago has been obtained on Lanai basalts.

East Molokai
East Molokai volcano was constructed along an E-W trending rift zone. The northern half of the volcano is truncated by a cliff more than 1 km high resulting from the massive Wailau debris avalanche that extended more than 100 km N (Moore et al. 1989). The youngest eruptive products formed the small Kalaupapa shield volcano that created a peninsula off the north coast between about 0.57 and 0.35 million years ago (Langenheim and Plague 1987).

West Molokai
The flat West Molokai shield volcano was formed by eruptions along two rift zones at the west end of Molokai Island during the Pliocene and early Pleistocene. The youngest Potassium-Argon date is 1.52 +/- 0.6 million years ago (Langenheim and Clague, 1987).

Koolau
The extensively eroded, elongated Koolau basaltic shield volcano of Pliocene-to-Pleistocene age forms much of the eastern half of Oahu Island. A lengthy NW rift zone is defined by a dike complex that runs the length of the windward coast. The largest documented submarine landslide of the Hawaiian islands produced the Nuuanu debris avalanche, which traveled 230 km NE from its source at the Nuuanu Pali on the NE side of the volcano. After a period of long quiescence activity resumed, forming the Honolulu volcanic series at the SE end of Oahu. The youngest members of the Honolulu Series, which consists of a group of tuff cones, maars, cinder cones, and spatter cones, many with associated lava flows, were considered by Stearns (1946) to be about 5000 years old. The youngest radiometric dates, however, ranged from 31,000 to 43,000 years old (Mullineaux et al., 1987), and more recent work (Ozawa et al., 2005) dated material to about 40,000 years. Sherrod (pers. comm., 2006) noted that earlier estimates of Holocene ages have been shown to be incorrect, and that the Sugarloaf lava flow, thought to be younger than 10,000 years, was dated at 110,000 years.

Waianae
The elongated Waianae shield volcano forms much of western Oahu Island. The Waianae Slump, a landslide formed during multiple events, extends 90 km SW (Moore et al. 1989). The heavily eroded volcano was largely formed during the Pliocene, but late-stage Kolekole volcanics at the SE end of the range are considered to be of Pleistocene age (Langenheim and Plague 1987).

Kauai
Kauai Island is composed of a single large eroded shield volcano with a summit caldera 15-20 km in diameter and two flank calderas. Large Pliocene debris avalanches extended to the north and south. The spectacular Waimea Canyon and Napalm cliffs on the NW coast are products of extensive erosion. Most of the volcano is of Pliocene age; however, rejuvenation of activity during the Pleistocene produced lavas and cones over the eastern two-thirds of the island Potassium-Argon dated 1.40-0.6 million years ago (Macdonald and Abbott 1970).

Niihau
Niihau is the eroded remnant of a Miocene to Pliocene shield volcano. Rejuvenation during the late Pliocene and Pleistocene produced a series of small shield volcanoes, cinder cones and tuff cones.

Kaula
Ka'ula Island is a Pleistocene tuff cone that rests on a broad submerged shield volcano (Macdonald and Abbott, 1970; IAVCEI, 1973).

Vance Segment
The entire Juan de Fuca Ridge is an active spreading center, though there have been no eruptions observed or dates along the Vance Segment. This segment lies between Cleft Segment (the southern-most of the JdfR) to the south, and Axial Seamount to the north.

Central Segment
Central Gorda Ridge between the Jackson Segment to the N and the Phoenix Segment to the S.

Phoenix Segment
Southern Gorda Ridge segment just N of the Escanaba Segment.

Kodiak-Bowie Hotspot Volcano Group

Bowie Seamount
Kodiak-Bowie Hotspot Volcano Group
Final volcanism post-dates the 18,000 years before present upper marine terrace, and is thought to have continued into postglacial time (Herzer, 1971).

Tuzo Wilson Knolls
Kodiak-Bowie Hotspot Volcano Group
Volcano type: Lava dome?
Volcanic rocks from the Tuzo Wilson Knolls were most likely erupted since a drop in the sedimentation rate following sea level rise at end of the last glaciation. They are considered to be the current location of a hotspot that formed the Kodiak-Bowie seamount chain (Chase, 1977). A Potassium-Argon date of 55,000 +/- 55,000 years before present was obtained by Cousens et al. (1985).

Sprague River Valley
The basaltic-to-dacitic Sprague River Valley volcanic field consists of small shield volcanoes, cinder cones, and about two dozen maars active from 5-1.5 million years ago (Sherrod, in Wood and Kienle, 1990). The youngest features are the Saddle Mountain basaltic andesite shield volcano and Taylor Butte, a basaltic cinder cone.

Brushy Butte
Brushy Butte forms a small shield complex immediately east of Timbered Crater, SSE of the Medicine Lake Highlands. The Brushy Butte complex has produced a broad apron of basaltic lava flows with fresh-looking flow features that extends preferentially down the regional gradient to the south as far as the Falls River valley. Soil development and degree of revegetation suggested a Holocene age similar to that of Hat Creek flow to the south (Peterson and Martin, 1980), and Miller (1989) also mapped Brushy Butte as Holocene. The Hat Creek flow, however, has been dated at 24,000 +/- 6,000 years (Clynne and Muffler, 2010). Brushy Butte flows are overlain by the Giant Crater lava flow from Medicine Lake caldera, which has a calibrated age of 12,430 years BP (Donnelly-Nolan, 2010), and Brushy Butte is considered to have formed between about 12,000 and 25,000 years ago (Smith, 2014 pers. comm.).

Twin Buttes
A group of cinder cones near Pleistocene Burney Mountain volcano, including Twin Buttes to the SE, is part of an area of extensive Quaternary volcanism north of the Lassen volcanic center. Twin Buttes at one time was considered to be Holocene (Miller, 1989), late Pleistocene, or early Holocene, but Clynne et al. (2012) assigned an age of 10,000-15,000 years to Twin Buttes. Blocky, partially unvegetated lava flows extend to the north from North and South Twin Buttes, which are located at the SE foot of the Burney Mountain lava dome complex.

Silver Lake Volcanic Field
Lava flows from two isolated cinder cones in the Silver Lake Volcanic Field NW of Lassen Peak blocked drainages, forming three small lakes. The cones lie SW of Burney Mountain and WNW of MaGee Peak. Lava flows from the Silver Lake cinder cone formed Silver Lake to the NE, crescent-shaped Author Lake to the E, and traveled 3.5 km to the SW. The crater of Silver Lake cone is open to the SW. The flat-topped Buckhorn Lake cinder cone to the SE of Silver Lake dammed up Buckhorn Lake, NE of the cone, and produced a lava flow that traveled 3.5 km to the SW. The precise age of these basaltic cones is not known. Although they lie outside the area of glaciation at Lassen, they are considered to be of comparable to the 10,000-15,000 year age of other Lassen area cinder cones (Clynne, 2015, pers. comm.).

Tumble Buttes
A line of cinder cones along a NNW-SSE fissure produced a series of lava flows. Bear Wallow Butte, the source of unvegetated lava flows on its eastern and western flanks, lies at the southern end of the chain. At the northern end is Eiler Butte, constructed on a topographic high, which has also produced blocky lava flows. The most prominent feature is Devils Rock Garden, a thick, blocky andesitic lava flow complex that erupted from Tumble Butte south; it is the youngest of the Tumble Buttes flows and was considered by Miller (1989) to be Holocene. The Devils Rock Garden flow blocks glacial outwash channels and overlies glacial gravels, and thus is younger than about 15,000 years, but was mapped as latest Pleistocene by Clynne and Muffler (2010) and estimated to have been erupted between 10,000-15,000 years ago.

Eagle Lake Field
The Eagle Lake volcanic field occupies the junction of the Cascades, Sierra Nevada, and Basin and Range geologic provinces, and consists of 15 cinder cones and basaltic lava flow vents within a larger Quaternary basaltic field. The vents are aligned along faults defining the Eagle Lake volcano-tectonic depression, and are the southernmost example of late Quaternary back-arc spreading in the NW Great Basin. The Brockman Flat lava flow, the largest of the younger flows, was erupted from a N-S oriented 3-km-long fissure vent along a fault that forms the west boundary of the Eagle Lake basin and created an approximately 63 km2 tube-fed flow field that extended across the Eagle Lake basin to the east side of Eagle Lake. Miller (1989) mapped four Holocene centers west of Eagle Lake; however, recent 40Ar/39Ar dating indicates that the youngest lava flows were erupted during a relatively short interval between about 130 and 125 ka that was unlikely to span more than a few thousand years (Clynne et al., 2017).

Golden Trout Creek
The Golden Trout Creek volcanic field consists of a group of Quaternary alkali olivine basalt cinder cones and lava flows in the Toowa Valley about 25 km S of Mount Whitney. Lava flows erupted through Mesozoic granitic rocks of the Sierra Nevada batholith during episodes dating back to about 743,000 years ago, when the Little Whitney cinder cone and lava flows were erupted. The South Fork cone erupted about 176,000 years ago and produced the largest lava flow in the field, which traveled over 7 km W to the Kern River Canyon. Tunnel Cone to the north of South Fork (Red Hill) cone is undated, but its lava flow is overlain by glacial deposits and it is thought to be only slightly younger than South Fork. The youngest lava flow, from Groundhog Cone, traveled 6 km W down Golden Trout Creek on top of the South Fork flow. Based on a lack of glaciated features, Moore and Lanphere (1983) considered the Groundhog flow to be about 5-10,000 years old. Cosmogenic 36Cl exposure determinations by Browne et al. (2017b) showed a 59-52 ka eruption age for the Groundhog Cone material; this was after the Tahoe glaciation maximum, and subsequent Tioga glaciers did not reach the Toowa Valley floor, so did not affect these deposits.

Coso Volcanic Field
The Coso Volcanic Field, located E of the Sierra Nevada Range at the western edge of the Basin and Range province, consists of Pliocene to Quaternary rhyolitic lava domes and basaltic cinder cones covering a 400 km2 area. Much of the field lies within the China Lake Naval Weapons Center. Active fumaroles and thermal springs are present in an area that is a producing geothermal field. The youngest eruptions were chemically bimodal, forming basaltic lava flows along with 38 rhyolitic lava flows and domes. The latest dated eruption formed the basaltic Volcano Peak cinder cone and lava flow, and was K-Ar dated at 39,000 +/- 33,000 years ago. The youngest lava dome may be Holocene based on geomorphological evidence (Monastero, 1998 pers. comm.).

Lavic Lake
The Lavic Lake basaltic volcanic field was considered to contain four Holocene cinder cones, three in the Lavic Lake area and a fourth in the Rodman Mountains 20 km to the west (Miller, 1989), but later work by USGS scientists revised that evaluation to late-Pleistocene. Pisgah Crater, a 100-m-high cinder cone, is the most prominent feature of the field. Nearby vents were the source of dominantly pahoehoe lava flows that traveled 8 km SE to Lavic Lake and in a narrow lobe over that traveled over alluvial-fan and playa-lake deposits as far as 18 km W of the vent. More recent work indicates a convergence of dates for Pisgah Crater from paleomagnetic, Ar-Ar, and cosmogenic helium at about 25,000 years BP (Reid 2002, pers. comm.). Another very youthful looking, but undated cinder cone and lava field is located in the Sunshine Peak area of the Lava Beds Mountains, south of Pisgah Crater.

Hackamore
Hackamore is a large volcanic field east of Medicine Lake volcano. This Quaternary field covers an area of at least 850 km2 with at least a dozen vents, the youngest of which is about 600,000 years old (Hildreth, 2007).

Big Cave
The Big Cave shield volcano, at the northern end of an area of late-Quaternary volcanism extending north from Lassen Peak, is a small basaltic shield with young pyroclastic cones at the summit and north flank. Big Cave volcano was considered to be of either Holocene (Luedke and Smith, 1981; Miller, 1989) or latest Pleistocene or Holocene age (Sarna-Wojcicki et al., 1983). The inconspicuous low shield volcano, located between Big Lake on the north and Bald Mountain on the south, is surrounded by an extensive now forested lava field. Big Cave was considered by Clynne, 2007 pers. comm.) to probably be of similar age as nearby Cinder Butte volcano, which was dated at 38,000 +/- 7000 years.

Cinder Butte
The Cinder Butte shield volcano and flank pyroclastic cones was listed as latest Pleistocene or Holocene (Sarna-Wojcicki et al. 1983), and as Holocene by Luedke and Smith (1981) and Miller (1989). However, Clynne (in Wood and Kienle 1990) indicated Cinder Butte is slightly older than the Hat Creek lava flow, assigned an age of between 15,000 and 40,000 years (Clynne and Muffler, 2010), and Clynne et al. (2012) assigned an age of 30,000 to 50,000 years to the Cinder Butte cone cluster.

Burney Mountain
Burney Mountain, a large dacitic lava-dome complex, was active about 0.23 million years ago (Clynne, in Wood and Kienle, 1990).

Snow Mountain
The Snow Mountain volcanic center is a large eroded andesitic-to-rhyolitic stratovolcano that was active from about 2 million to 1 million years ago (Clynne, in Wood and Kienle, 1990).

Magee Peak
Magee Peak, an eroded andesitic stratovolcano, was active about 1-2 million years ago (Clynne, in Wood and Kienle, 1990). The andesitic Freaner Peak shield volcano lies across a saddle to the NE.

Blacks Mountain
Blacks Mountain, 25 km east of Hat Creek, is the most prominent of a group of andesitic shield volcanoes and is 1-2 million years old (Clynne, in Wood and Kienle, 1990).

Potato Butte
The Potato Butte cinder cone and lava field, including the Hat Creek lava flow that traveled nearly 30 km from a fissure vent near the town of Old Station, lies immediately north of the Lassen volcanic center. Some flows are younger than the Hat Creek flow, which was initially considered to be Holocene, perhaps as young as a few thousand years (Anderson 1940), although later dating showed the flow to be about 30,000 years old. The younger Potato Butte lavas, once considered to be late Pleistocene or early Holocene, have been K-Ar dated at 65,000-75,000 years old (Clynne et al. 2000). Directly west of Potato Butte is the 61,000-year-old Sugarloaf Peak lava cone.

Latour Butte
Latour Butte, an andesitic lava cone NW of Lassen National Park, was probably active 1-2 million years ago (Clynne, in Wood and Kienle, 1990).

Caribou
The Caribou volcanic field east of Lassen National Park contains about 140 mid-Pleistocene to late-Pleistocene cones and shields that are controlled by Basin and Range extensional faulting. The Caribou volcanic field was active from about 450,000 to 20,000 years ago (Hildreth, 2007). The field includes a long, NW-SE-trending chain of Pleistocene cinder cones immediately west of Bogard Buttes.

Red Lake Mountain
A massive lava Pleistocene lava flow from Red Lake Mountain cinder cone traveled nearly 30 miles (~45 km) to the west. The basaltic flow covers nearly 50 sq miles and has an estimated volume of 1-2 cu miles (Macdonald, 1963). Highway 44 traverses the flow.

Table Mountain
Table Mountain, an andesitic stratovolcano at the NW corner of Lassen National Park, is an andesitic stratovolcano active about 1-2 million years ago. Red Lake Mountain, immediately to the NW of Table Mountain, is the source of youthful-looking basaltic and andesitic lava flows of late-Pleistocene age (Clynne, in Wood and Kienle 1990; Miller 1989).

Black Butte
Black Butte is a late Pleistocene pyroclastic cone west of Lassen National Park (Miller, 1989).

Dittmar
The Dittmar volcanic center is a massive eroded andesitic stratovolcano at the SE part of Lassen National Park that was active about 2.-5-1 million years ago (Clynne, 1990). Dacitic lava domes are located in the Hot Springs and Kings Creek canyons. The younger Mount Harkness stratovolcano lies immediately to the SE of the Dittmar volcanic center.

Sifford Mountain
Sifford Mountain, a basaltic-to-andesitic shield volcano, rises in south-central Lassen National Park. It was probably active during the past 100,000 years (Clynne, in Wood and Kienle, 1990).

Maidu
The massive, highly eroded Maidu volcano center SW of Lassen National Park was active about 2-0.8 million years ago (Clynne, 1990). The hydrothermally altered andesitic stratovolcano also has erupted rhyolitic rocks, and a dacitic lava-dome field lies on the north flank of the volcanic center.

Inskip Hill
Inskip Hill and nearby pyroclastic cones were thought to be of Holocene age, but later mapping indicates a late Pleistocene age (Miller, 1989).

Long Valley
The large 17 x 32 km Long Valley caldera east of the central Sierra Nevada Range formed as a result of the voluminous Bishop Tuff eruption about 760,000 years ago. Resurgent doming in the central part of the caldera occurred shortly afterwards, followed by rhyolitic eruptions from the caldera moat and the eruption of rhyodacite from outer ring fracture vents, ending about 50,000 years ago. During early resurgent doming the caldera was filled with a large lake that left strandlines on the caldera walls and the resurgent dome island; the lake eventually drained through the Owens River Gorge. The caldera remains thermally active, with many hot springs and fumaroles, and has had significant deformation, seismicity, and other unrest in recent years. The late-Pleistocene to Holocene Inyo Craters cut the NW topographic rim of the caldera, and along with Mammoth Mountain on the SW topographic rim, are west of the structural caldera and are chemically and tectonically distinct from the Long Valley magmatic system.

Big Pine Volcanic Field
The Big Pine (Aberdeen) volcanic field in the Owens Valley contains more than 40 vents over a 1,000 km2 region of the Owens Valley. The basaltic field consists of cinder cones that produced lava flows up to 9 km long and a single rhyolitic lava dome. Activity was episodic throughout the Quaternary. Chesterman (1982) considers the latest activity to be of Holocene or late Pleistocene age; other sources attribute the last eruptions to the Pleistocene.

Lava Mountains Volcanic Field
Pliocene-Pleistocene (IAVCEI).

Cima Lava Field
The Cima volcanic field covers an area of about 150 km2 and contains 52 vents of Miocene-to-Pleistocene age. The youngest flows have been mapped as Holocene (Calif Div of Mines & Geol), and a radiocarbon date of 330-480 BP was obtained on the Black Tank cone. Later work suggests that the most recent activity was no younger than about 15,000 BP (Dohrenwend, in Wood and Kienle 1990; Wells et al. 1990). The youngest surface exposure ages obtained by Philipps (2003) were 11,500 and 11,600 years BP.

Amboy
The 70-sq-km Amboy basaltic lava field was erupted onto a flat-lying alluvial valley from Amboy Crater, a prominent cinder cone with four nested craters that rises 75 m above adjacent lava flows at the NE end of the lava field. The dominantly pahoehoe lava field divided the Bristol Dry Lake, occupying a depression between the Bristol and Bullion Mountains, into two playas. The cone and flow were originally considered to be early Holocene in age, but more recent surface exposure dating (Phillips, 2003) has given a 79,000 +/- 5000 yr BP age.

Pinto Basin-Salton Creek
Remnants of Pleistocene or Holocene basaltic flows and pyroclastic deposits lie on alluvium (Chesterman 1982). These volcanics are mapped as Pleistocene (Calif Div Mines & Geol, Luedke and Smith 1981).

Leucite Hills
The Leucite Hills consist of a 2000 km2 area with less than two dozen isolated lava flows, dikes, necks and cinder cones of unusual potassium-rich composition. Their age is about 1.1 Ma.

Sheldon-Antelope
Several Quaternary lava flows along the Nevada-Oregon border issued from small shield volcanoes. The only available Potassium-Argon age is 1.2 million years ago.

Buffalo Valley
A group of cinder cones and lava flows in the Buffalo Valley north of the Oligocene Fish Creek Mountains caldera range in age from 3.05 to 0.92 million years ago (Dohrenwend, in Wood and Kienle 1990).

Steamboat Springs
A small volcanic field of rhyolitic lava domes and flows about 20 km S of Reno, Nevada, ranges in age from 2.53 to 1.14 million years. No eruptive activity has occurred during the Holocene, although it was included in the Catalog of Active Volcanoes of the World (Coombs and Howard, 1960) based on its geothermal activity. The area includes about 50 active hot springs, numerous steam vents, and fumaroles, and is an actively producing geothermal field.

Aurora-Bodie
Aurora-Bodie volcanic field in west-central Nevada near the California border NNE of Mono Lake contains well-preserved cinder cones and lava flows of late Pleistocene age. The most prominent feature, Aurora Crater, is a 25,000 years before present cinder cone surrounded by lava flows. Mud Spring volcano is another late Pleistocene vent with a well-preserved lava flow. Older volcanics of the field include Pliocene andesitic lava domes and Pliocene cones such as Beauty Peak and Mount Hicks.

Lunar Crater
The Lunar Crater volcanic field in central Nevada contains almost 100 Pliocene-Pleistocene volcanic vents cutting across the Oligocene Lunar Lake caldera. The most distinctive feature of the field is Lunar Crater, a 1-km-wide, 130-m-deep maar. Several NE-trending chains of cinder cones occur within the field, which contains lava flows up to 6 km long. The ages of the youngest lava flow, the Black Rock flow, was considered to be early Holocene (Luedke and Smith, 1981), but a cosmogenic exposure age of 38,000 +/- 10,000 years was obtained from the Black Rock flow (Shepard et al., 1995).

Clayton Valley
A solitary cinder cone in Clayton Valley NE of Silver Peak is Potassium-Argon dated about 0.39 million years ago. The breached cone has produced a 2-km-long lava flow partly buried by Quaternary alluvium (Dohrenwend, in Wood and Kienle 1990).

Crater Flat
The Crater Flat volcanic field south of the Miocene Timber Mountain caldera contains five Quaternary cinder cones and lava flows. The youngest, Lathrop Wells scoria cone, was formed about 80,000 years ago (Valentine et al., 2007) and produced lava flows from vents at the S and NE flanks of the cone.

Santa Clara
A Pliocene-to-Quaternary volcanic field north of St. George in SW Utah contains numerous cinder cones and lava flows. The Santa Clara lava flow, originating from two youthful-looking cinder cones above Snow Canyon, is one of many young late-Quaternary lava flows in the Colorado Plateau/Basin and Range region. The sparsely vegetated flow traveled 16 km S down Snow Canyon, excavated through rocks of the colorful Navajo Sandstone. Estimates of the age of the Santa Clara flow have ranged widely from as young as about 1000 years. Sands beneath the flow, however, were dated by optically stimulated luminescence at about 40,000 years, and charcoal just underneath the flow at the same location was radiocarbon dated at about 27,270 +/- 250 yrs BP (Biek et al., 2010). Older Snow Canyon flows of two generations now cap mesa tops as a result of topographic inversion.

Bald Knoll
Bald Knoll is the youngest of a group of basaltic cinder cones on the SW part of the Paunsaugunt Plateau in southern Utah, between the southern end of Bryce Canyon National Park and the western margin of Grand Staircase-Escalante National Monument. The 2135-m-high Bald Knoll has a well-preserved crater and produced a massive youthful-looking lava flow that traveled about 12 km to the SSE. The olivine-basaltic flow fills the floor of Johnson Valley south of Bald Knoll and reaches beyond Ford Pasture into Johnson Canyon. No precise age for the flow is available, but although it was at one point estimated to be several hundred to several thousand years old (Gregory, 1951), Doehling (2008) noted radiometric dates of 0.34 Ma and older on adjacent lava flows and mapped all flows in this area as no younger than late Pleistocene. Buck Knoll and Black Knoll (also known as Corral Knoll) are cinder cones to the west that lie on the western side of Kanab Creek and produced lava flows that traveled as far as 22 km down the Kanab valley.

Kolob
The basaltic Kolob volcanic field on the west margin of Zion National Park contains the youthful-looking Crater Hill cinder cone and associated lava flows at the SW corner of the park and older cones to the north on the upper Kolob Plateau. The latter cones are Pleistocene in age and were erupted through the colorful rocks of the Navajo Sandstone formation, producing lava flows that extended 10-15 km down valleys to the south. Lava flows from Crater Hill blocked drainages, forming the ephemeral Coalpits and Grafton lakes. The latter extended up the Virgin River past the current town of Springdale at the southern entrance into Zion National Park. Crater Hill was at one point considered to be of probable Holocene age, but later work taking into consideration stream downcutting rates suggest an age of about 100,000 years (Biek et al., 2003). An optically stimulated luminescence date of 122.3 +/- 15.73 ka was obtained from sediments in Grafton Lake, formed by the lava flow from Crater Hill.

Mineral Mountains-Cove Fort
The Pleistocene Mineral Mountains-Cove Fort volcanic field includes silicic lava domes in the Mineral Mountains and basaltic and basaltic andesite cinder cones and lava flows of the Cove Fort and adjacent areas. The youngest flows of the Cove Fort field were considered to be of possible early Holocene age (Condie and Barsky, 1972), but Potassium-Argon dates of 300,000 years BP were obtained from the youngest flows (Nash, in Wood and Kienle, 1990).

Smelter Knolls
Smelter Knolls in west-central Utah are a Pliocene rhyolitic lava dome complex. Nearby basaltic volcanism is dated at 0.31 million years ago (Nash, in Wood and Kienle 1990).

Fumarole Butte
The Quaternary basaltic andesite shield volcano Fumarole Butte in west-central Utah is dated 0.9 million years ago. Hot springs are found on the eastern flanks (Nash, in Wood and Kienle 1990).

Willow Peak
The Willow Peak cinder cone is located in the White River National Forest, and can be reached from Coffee Pot Road. Although geomorphically young, this cone is regarded as somewhat older than the Dotsero lava flow (about 4,000 years before present). A lava flow that traveled 5.5 km to the east.

McCoy
A 6.5-km-long basaltic lava flow from two scoria cones is Potassium-Argon dated 0.64 +/- 0.2 million years ago (Larson et al. 1975).

Sentinel Plain
The Sentinel Plain volcanic field covers about 600 km2 along the Gila River with basaltic lava flows. The field was active from 3.3 to possibly 1.3 million years ago (Lynch, in Wood and Kienle 1990).

Springerville Volcanic Field
The Springerville Volcanic Field contains more than 380 vents and lava flows of Pliocene to Pleistocene age. This alkali basalt field contains cinder cones, maars and lava domes, with the youngest dated cones being 0.3 million years ago.

San Carlos
The small San Carlos volcanic field covers about 50 km2 with basaltic cinder cone and lava flow remnants. The field, active from possibly 4.2 to 1.0 million years ago, is located within the San Carlos Apache Indian reservation (Lynch, in Wood and Kienle 1990).

Geronimo
The Geronimo (San Bernardino) volcanic field contains over 140 eruptive centers, mostly pyroclastic cones, in an area of 850 km2. The basaltic field in the SE corner of Arizona was active between 3.2 and 0.3 million years ago (Lynch, in Wood and Kienle 1990).

Potrillo Volcanic Field
The Potrillo volcanic field, in southern New Mexico along the western margin of the Rio Grande Rift, contains more than 150 cinder cones and five maars. Features include Kilbourne Hole, a small shield volcano, and Potrillo maar, which straddles the US-Mexico border. The field was active from 2.65 to 0.8 million years ago (Hoffer, in Wood and Kienle 1990).

Jornada del Muerto
The Jornada del Muerto volcanic field in south-central New Mexico consists of a low shield that was the source of large radial lava flows. The age of the lavas is 0.76 million years (Crumpler and Aubele; in Wood and Kienle, 1990).

Lucero
The Miocene to Pleistocene Lucero volcanic field contains basaltic cinder cones, small shield volcanoes and tuff rings scattered over a 2000 km2 area. The latest eruptions took place only a few tens of thousand years ago (Baldridge, in Wood and Kienle, 1990).

Taylor Volcanic Field
Mapped as Pleistocene or Pliocene flows. Probably early Pleistocene (Lipman and Moench, 1972).

Cat Hills
The Cat Hills volcanic field west of Albuquerque contains about two dozen small cinder cones erupted along a N-S fissure, a small shield volcano and a Pliocene maar. The Cat Hills field was formed about 0.14 million years ago (Ma); the Los Lunas volcano to the SE formed between 1.3-1.1 Ma (Kudo, in Wood and Kienle 1990).

Albuquerque Volcanic Field
The Albuquerque Volcanic Field was erupted along N-S fissures from about 0.17 to 0.7 million years ago, producing spatter cones and lava flows (Kudo, in Wood and Kienle, 1990). Vulcan (or J) cone contains a lava dome split into two by an explosion crater.

Valles Caldera
The 22-km-wide Valles Caldera was formed as a result of two large-volume eruptions that created the widespread Bandelier Tuff ignimbrite plateaus on all sides of the caldera. The lower member of the Bandelier Tuff, the Otawi, was emplaced about 1.7 million years ago (Ma) and resulted in the formation of most of the present-day caldera, including the Toledo embayment at the NE side. The upper member, the Tshirege, is dated about 1.2 Ma, and also deposited voluminous welded pyroclastic flows over about the same area as the Otawi. Post-caldera volcanism has included the emplacement of multiple ring-fracture lava domes and uplift of the caldera floor, forming the Redondo Peak resurgent dome. The El Cajete Pumice, Battleship Rock Ignimbrite, Banco Bonito Rhyolite, and the VC-1 Rhyolite were emplaced during the latest eruption, about 50,000-60,000 years ago. Seismic investigations show that a low-velocity zone lies beneath the caldera, and an active geothermal system with hot springs and fumaroles exists today.

Taos Plateau
The massive Taos Plateau volcanic field covers an area of 7000 km2 along the Rio Grande Rift in north-central New Mexico and was active from about 10 million to 1.8 million years ago. The Red Hill lava flow is of probable Pleistocene age (Dungan et al., 1989).

Ocate
The Ocate (Mora) volcanic field is part of the Jemez Lineament and located east of the Rio Grande Rift in northern New Mexico. It contains numerous basaltic to dacitic flows and cinder cones over a 90 km2 area. The field was active from 8.3-0.8 million years ago, although most activity ended by the Pleistocene (Baldridge, in Wood and Kienle 1990).

Raton-Clayton
The Raton-Clayton volcanic field is a large Miocene-Quaternary field stretching from near Trinidad, Colorado to Clayton, New Mexico. The main pulse of volcanism took place between 4 and 1.8 million years ago. The relatively youthful-looking Capulin Mountain cinder cone was considered to have been active during the Holocene, based on stratigraphic correlations of its lava flow with distant alluvial sequences. However, later work indicated the lava flow was more than 22,000 years old. More-recent cosmogenic helium dating gave an age of 59,100 years for the lava flow (Sayre et al., 1995), who site additional geomorphological evidence for a Pleistocene age for Capulin Mountain. Several other cones and vents nearby, such as Baby Capulin, Twin Mountain, and the Purvine Mesa vents, are younger than Capulin Mountain (Dungan et al. 1989). Although they were erupted during the same geomorphologic period as Capulin Mountain, their precise age is not known.

Isla Isabel
Isla Isabel, a complex of tuff cones and associated lava flows, forms a small 1.5-km-long island located in the Pacific Ocean 30 km off the coast of Narayit state, NW of the city of Tepic, Mexico. Despite its apparent location at the western end of the Mexican Volcanic Belt, the island consists of alkaline basaltic rocks and tephra similar to those of other Mexican island volcanoes and in the extensional province of northern Mexico. The island is a wildlife sanctuary whose rocks and vegetation are covered with guano. Exposures of tuff cone interiors can be found in sea cliffs of the main island and offshore islets. The age of the most recent eruptive activity is not known, but morphology and a negative Argon-Argon age from one sample suggests activity may have continued into the Holocene. One unvegetated lava flow of unknown age is located on the NW side of the island.

Moctezuma Volcanic Field
The Moctezuma volcanic field occupies a 380 km2 area along the foothills of the Sierra Madre Occidental in NW M�xico. An early stage of tholeiitic basaltic volcanism originating from fissures along the eastern boundary of the graben produced a broad mesa within a large graben in the Moctezuma Basin. Younger alkalic basaltic volcanism produced five scoria cones concentrated along a crudely N-S trend in the center of the graben. These produced lava flows that traveled primarily SW. The youngest cone is Cerro Blanco, which produced lava flows to the SW and was Potassium-Argon dated at about 0.53 +/- 0.2 million years.

Camargo Volcanic Field
The Camargo volcanic field is located in the northern Bols�n de Mapim� graben in north-central M�xico, about 150 km SW of Big Bend National Park in Texas. More than 300 volcanic vents, mostly cinder cones and lava cones, are located in a broad 2,500 km2 lava plateau that extends 60 km E-W and 70 km N-S. It is mostly Pliocene, but a Pleistocene age of 1.43 +/- 0.05 Ma was obtained on one sample. The best-studied vent of the field is 1.63 Ma Cerro el Salto (also known as La Olivina), a cinder cone whose spinel-lherzolite xenoliths were once mined for peridot.

Aldama Volcanic Field
An area of Quaternary phonolitic and basaltic pyroclastic cones and lava flows is located along the Gulf of Mexico SE of the Sierra de Tamaulipas. Trachytic and phonolitic eruptions were followed by the emission of young basaltic lava flows from cinder cones. Scattered areas of Tertiary or Quaternary volcanic rocks also lie along a NNW-SSE-trending line on the coastal plain east and NE of the Sierra de Tamaulipas and in areas farther west toward the base of the mountain range.

Los Flores
The Tertiary-to-Quaternary Los Flores volcanic field is located in the rugged limestone peaks of the Sierra Madre Oriental at the conjunction of the states of Tamaulipas, Nuevo Le�n, and San Luis Potos� in eastern M�xico. Basaltic lava flows of the Mexican Basin and Range Province erupted in the valleys formed by late-Mesozoic faulting and folding that formed the NNW-SSE-trending Sierra Madre Oriental. One massive youthful, but undated Quaternary pahoehoe lava flow traveled about 80 km to the SSE down a synclinal valley from Cerro Partido.

Santo Domingo Volcanic Field
The Santo Domingo volcanic field lies in the center of the state of San Luis Potos� in the southern Basin and Range province of central M�xico, ~50 km NE of the Ventura volcanic field. There are a group of four maars in the NW part of the field, along with several alkalic cinder cones and associated lava flows to the SE. The largest maar, La Joya de los Contreras, is 750 x 1,000 m. The Santo Domingo maars are the source of mantle-derived spinel-lherzolite xenoliths and deep-crustal granulite xenoliths.

Ventura Volcanic Field
The Ventura Volcanic Field consists of a group of maars and pyroclastic cones located immediately NE of the city of San Luis Potos� in the southern Basin and Range province of central M�xico. The largest and best-known maar is La Joya Honda, a 850 x 1,100 m, 300-m-deep maar erupted through Cretaceous limestones about 1.1 million years ago. The maars, located near the southern end of the Basin and Range province, are known for their mantle-derived spinel-lherzolite xenoliths and deep-crustal granulite xenoliths. A 10-km-long lava flow also rich in lherzolite xenoliths was erupted from the Cerro Verde cinder cone north of La Joya Honda.

Cerro Grande
Several late-Pleistocene lava flows were erupted near Big Southern Butte. The North Robbers flow was radiocarbon dated 11,940 +/- 300 before present (BP); the Cerro Grande flow was dated at 10,780 +/- 300 BP.

Blackfoot Volcanic Field
The Blackfoot Volcanic Field (BVF) is a Quaternary volcanic field in SE Idaho around Blackfoot Reservoir, within a graben of the Northern Basin and Range Province. It consists of basalt flows that filled in the floors of Gem Valley, the Blackfoot Reservoir basin, Willow Creek drainage, and several other smaller valleys. Although distant from the edge of the Eastern Snake River Plain, the chemical composition of lava flows from the two locations are very similar; McCurry et al. (2011) noted the similarity of mineralogy, geochemistry, and bimodal volcanism. The USGS description states that the BVF is likely related to the Yellowstone hotspot via complex heat transfer away from the main hotspot track. Ages of BVF lavas are scarce, but they are believed to be similar in age to Gem Valley lavas (27.5 +/- 10 ka) (McCurry et al., 2011). In addition to the lava flows, there are three rhyolite domes, ranging in age from 58 +/- 7 ka (Heumann, 2004) to about 1.5 Ma (Luedke and Smith, 1983).

Menan Buttes
North and South Menan Buttes are the two largest of a N-S line of basaltic tuff cones formed by phreatomagmatic eruptions along the Snake River in eastern Idaho. The larger N cone is ~2 km in diameter, and 3 km from the S cone (using crater centers). They were considered to be very late Pleistocene, or more probably, early Recent (Holocene) by Hamilton and Myers (1963). Creighton (1987) cites mapping by LaPoint that indicates a middle to late Pleistocene age, as does King (in Wood and Kienle, 1990).

Yellowstone
The Yellowstone Plateau volcanic field developed through three volcanic cycles spanning two million years that included some of the world's largest known eruptions. Eruption of the over 2,450 km3 Huckleberry Ridge Tuff about 2.1 million years ago created the more than 75-km-long Island Park caldera. The second cycle concluded with the eruption of the Mesa Falls Tuff around 1.3 million years ago, forming the 16-km-wide Henrys Fork caldera at the western end of the first caldera. Activity subsequently shifted to the present Yellowstone Plateau and culminated 640,000 years ago with the eruption of the over 1,000 km3 Lava Creek Tuff and the formation of the present 45 x 85 km caldera. Resurgent doming subsequently occurred at both the NE and SW sides of the caldera and voluminous (1000 km3) intracaldera rhyolitic lava flows were erupted between 150,000 and 70,000 years ago. No magmatic eruptions have occurred since the late Pleistocene, but large hydrothermal events took place near Yellowstone Lake during the Holocene. Yellowstone is presently the site of one of the world's largest hydrothermal systems, including Earth's largest concentration of geysers.

Lava Mountain
The Lava Mountain lava field is the middle of a group of three young basaltic fields located in the High Lava Plains SE of Newberry volcano. In contrast to the small fissure vents of the adjacent Devils Garden lava field, the Lava Mountain field consists of a shield volcano capped by the Lava Mountain pyroclastic cone complex that forms a prominent topographic high. Lava flowed in all directions for distances up to 6 km from the summit cone complex. The age of the lava field is not known directly, but Lava Mountain is thought to have been formed during the same eruption as nearby Four Craters lava field (only 6 km away), whose vents share alignment along the regional fault system extending from Christmas Valley NNW to Quartz Mountain. Both lava fields have similar lava chemistry and paleomagnetic directions, and the Four Craters eruption was dated based on surface exposure evidence by Mackey et al. (2012) to 13 ka.

Four Craters Lava Field
The Four Craters Lava Field is the SE-most of a group of three basaltic lava fields SE of Newberry volcano in the High Lava Plains of central Oregon. The lava field originated from four pyroclastic cones that were constructed along a roughly 4-km-long NW-SE-trending line. The NW-most and highest cone has a well-preserved crater rim. The other cones are breached to the W, SW, and S, respectively. Multiple surface exposure dates place the emplacement of the field at about 13 ka (Mackey et al., 2012).

China Hat-East Butte
China Hat and the adjacent East Butte silicic lava domes, located ESE of Newberry volcano, have K-Ar dates of 800,000 and 870,000 years BP, respectively.

Quartz Mountain
Quartz Butte lava-dome complex, ESE of the China Hat-East Butte lava domes, have a K-Ar date of 1.1 million years.

Fort Rock Volcanic Field
A large group of tuff rings, tuff cones, and maars occupies the Fort Rock-Christmas Lake Valley basin S of Newberry volcano. The 64 x 40 km basin was occupied a Pliocene to late-Pleistocene lake, through which eruptions of basaltic magma occurred along faults cutting diagonally across the basin and adjacent highland. The volcanic field is named for Fort Rock, a wave-cut tuff ring that was breached by erosion. The Table Rock tuff ring and maar complex lies at the SE end of the field. Spectacular maars such as Hole-in-the-Ground and Big Hole are located near Highway 31. Hole-in-the-Ground was formed as recently as between 13,500 and 18,000 years ago.

Silver Creek
The Silver Creek volcanic field covers about 1600 km2 ESE of Newberry volcano and Diamond Craters. Four K-Ar dates in the eastern part of the field range from 3 to 2 million years, but the youngest rocks could be Pleistocene in age (Wood and Kienle, 1990).

Saddle Butte
The Saddle Butte volcanic field in SE Oregon consists of a 1100 km2 area of Pleistocene basalts with a superposed 240 km2 area of younger basalts. The younger flows were considered to be of possible Holocene age (Wood and Kienle, 1990), however Sherrod et al. (1989) mapped the volcanic field as Pleistocene, and a K-Ar date of 0.43 +/-0.09 million years was obtained. Oregon state Highway 78 cuts across the western side of the isolated lava field. The volcanic field is separated from the adjacent Jordan Craters field to the east by the Owyhee River and resembles the lava fields of the Snake River Plain in Idaho. Vents on the flanks of the Sheepshead Mountains at the far western end of the lava field produced lava-tube-fed flows across gently sloping terrain to the east. The most recent flow of the Saddle Butte volcanic field is known for its abundant lava tubes, including the so-called 40-Mile Cave, which is actually part of a tube system that is 13.5 km long.

Lava Butte
The Lava Butte shield volcano, also known as Rocky Butte, lies south of Jordan Craters, and is 0.03-0.09 million years old (Hart and Mertzman, 1983). The slightly older Clarks Butte shield lies to the north and has been dated at 0.25 million years. Another unnamed shield volcano lies to the east of Lava Butte.

Jackies Butte
Jackies Butte, sometimes referred to as Bowden Crater, is a small, relatively unstudied basaltic volcanic field located near the SE corner of Oregon with two small shield volcanoes and two cinder cones. Lava flows cover an area of about 325 km2 E of the Bowden Hills, SE of Burns Junction on Highway 95, and SW of Owyhee Canyon. Smith et al. (1978) estimated a probable age of less than 10,000 years, but no precise age dates have been obtained. Sarna-Wojciki et al. (1983) did not include Jackies Butte in a list of Holocene volcanic fields.

Sinker Butte
A Pleistocene shield volcano and tuff cone in the western Snake River Plain, Sinker Butte, is partially dissected by the Snake River Canyon. Lava flows from the tuff cone flowed up to 10 km to the south. A broad lava shield is overlain by a large tuff cone that is capped with lava flows and welded spatter. Ar-Ar dates of 1.25 and 1.17 Ma were obtained from basalts directly below phreatomagmatic tephra and capping basalts, respectively.

Mountain Home-Kuna Lava Field
This extensive field of Quaternary basalt extends about 95 km between Mountain Home and the Kuna-Melba area southeast of the Boise River Valley (Wood, 1997). Basaltic outcrops have been dated around 2 Ma at Wild Horse Butte and Jackass Butte.

Sutter Buttes
California Coast Ranges Volcano Group
The isolated Sutter Buttes rise above the flat floor of the Sacramento Valley. This andesitic-to-rhyolitic lava-dome complex was active during the Pleistocene. An andesitic central core is surrounded by a ring of dacitic-to-rhyolitic domes.

Tumac Mountain
Tumac Mountain cinder cone north of White Pass was mapped as Holocene by Simmons et al. (1983). However, tephra studies by Schasse (1987) indicated that the last eruption was 20-30,000 years before present.

Goat Rocks
The deeply eroded Goat Rocks stratovolcano was active between about 2.5 and 0.5 million years ago (Ma) (Swanson, in Wood and Kienle 1990). The andesitic volcano was constructed over older products of a major rhyolitic explosive eruption. During the late Pliocene and early Pleistocene the small Hogback Mountain shield volcano was constructed south of White Pass. About 1.0 Ma the Tieton Andesite, the earth's largest known andesitic lava flow, traveled 80 km to the east. Following extensive erosion, mid to late Pleistocene andesites were erupted onto the glaciated Cispus River valley.

Marble Mountain
Marble Mountain, an andesitic shield volcano SE of Mount St. Helens and N of Swift Reservoir, was last active about 160,000 years ago (Wood and Kienle, 1990).

Simcoe
The Simcoe volcanic field, of Pliocene-to-Pleistocene age, lies east and SE of Mount Adams. Small shield volcanoes and cinder cones, many erupted along N-S fissures, range in age to about 500,000 years old.

Boring Lava
The Boring Lava volcanic field, underlying part of the city of Portland, Oregon, and neighboring areas to the east and across the Columbia River in Washington, was active from the Pliocene until about the mid-Pleistocene. The field consists of at least 32 to perhaps 50 small basaltic shield volcanoes and cinder cones, with a large concentration of vents located NW of the town of Boring, Oregon. Larch Mountain shield volcano near the eastern end of the volcanic field is the highest summit. These volcanoes lie about 100 km W of the main Cascade Range volcanoes.

Defiance
Mount Defiance, an andesitic shield volcano, lies south of the Columbia River Gorge and SW of the town of Hood River, Oregon.

Lost Lake Butte
Andesitic Lost Lake Butte shield volcano lies NW of Mount Hood volcano and overlooks Lost Lake.

Wilson
Mount Wilson is the most prominent of a group of Pleistocene shield volcanoes between Olallie Butte and Mount Hood (Sherrod, in Wood and Kienle, 1990). Summit Butte shield volcano lies to the SW and Clear Lake Butte to the NW.

Olallie Butte
Ollalie Butte is a basaltic andesite shield volcano that is older than about 25,000 years before present. North Pinhead cinder cone to the north is younger, but its flows are glaciated, suggesting an age of more than 11,000 years (Sherrod, in Wood and Kienle 1990). Sisi Butte, another shield volcano and other cinder cones are located nearby.

Three Fingered Jack
Three Fingered Jack is a distinctive deeply eroded basaltic andesite shield volcano that forms the highest peak between Mt. Jefferson and the Three Sisters. A pyroclastic cone buttressed by radial dikes forms its sharp-ridged summit. Other Pleistocene shield volcanoes and cinder cones are found to the NW and SW, and Hogg Rock Butte near Santiam Pass is a tuya formed during subglacial eruptions. The Maxwell Butte shield volcano to the SW is less eroded, and erupted between about 80,000 and 40,000 years before present.

Black Butte
Black Butte is a prominent small stratovolcano east of the Cascade Range crest. Despite its youthful profile, Black Butte is older than many other Cascade Range stratovolcanoes because of its position in a rain shadow to the east. Potassium-Argon dates average around 0.45 million years ago (Taylor, 1981). A NW-SE-trending chain of Pleistocene cinder cones lie east of Black Butte, and other Pleistocene cinder cones lie to the south.

Washington
Mount Washington is an eroded Pleistocene basaltic andesite shield volcano capped by a steep-sided central plug that is the most prominent landmark between North Sister and Three Fingered Jack volcanoes. The Cache Mountain cinder cones lie to the NE, and the Hayrick Butte tuya and the Recent cinder cone Hoodoo Butte to the NW. A series of aligned spatter cones on the NE flank along a regional fissure that extends to about 4 km from the summit erupted about 1300 years ago, but ejecta from this chain is petrographically similar to Blue Lake Crater ejecta and is considered to have erupted at the same time (Sherrod et al., 2004).

Black Crater
Black Crater is a Pleistocene basaltic andesite shield volcano SE of Belknap volcano. Trout Creek Butte volcano lies to the SE of Black Crater, and scattered Pleistocene cinder cones lie to the NE.

Scott Mountain
Scott Mountain is a Pleistocene basaltic andesite shield volcano lying SW of Belknap volcano.

Tumalo
The Tumalo volcanic center is the inferred source of large-volume Pleistocene ashflows such as the Desert Spring Tuff, the Bend Pumice and Tumalo Tuff, and the Shevlin Park Tuff. The area contains a large number of rhyolitic domes, such as Melvin Butte, and andesitic cinder cones, such as those in the Triangle Hill area, which are compositionally similar to the Tumalo Tuff (and correlative Bend Pumice) and Shevlin Park Tuff, respectively.

Broken Top
Broken Top is a complex dominantly basaltic andesite stratovolcano immediately SE of South Sister volcano. It is extensively eroded by glaciers, with the summit crater breached to the SE. Intermittent eruptions of andesite, dacite, and rhyolite have produced lava flows, pyroclastic flows, and airfall tephra. A late Pleistocene or early Holocene debris avalanche traveled 7 km N (Hildreth et al., 2012). Cayuse Crater on the upper SW flank is considered to be related to a possible magma reservoir underlying the South Sister area, and is assigned to South Sister rather than Broken Top (Fierstein et al., 2011). A radiocarbon age of 9,520 +/- 100 years before present (BP) from sediment beneath Cayuse Crater scoria is considered to be suspect because of lack of pretreatment and possible contamination by younger material. The scoria overlies glacial till considered to be 11,000-12,500 or as old as 14,000 years BP (Sherrod 1995, pers. comm.).

Williamson Mountain
Williamson Mountain, the highest of a group of small Pleistocene shield volcanoes or large cinder cones SW of Mount Bachelor, is flanked by Elk Mountain to the north and Sixbit Point to the WSW. A N-S-trending chain of cinder cones lies between Elk Mountain and Sixbit Point, and Packsaddle Mountain shield volcano lies west of Sixbit Point.

Irish Mountain
Irish Mountain, a Pleistocene shield volcano SW of Williamson Mountain, was roughly estimated to be 0.25-0.73 million years (Sherrod, in Wood and Kienle, 1990). A N-S-trending chain of cinder cones cuts across Irish Mountain.

Taylor Butte
The Pleistocene Taylor Butte shield volcano lies SW of Irish Mountain. A chain of N-S-trending cinder cones lies SSW of Taylor Butte.

Cultus Mountain

Wuksi Butte-Twin Lakes
The Wuksi Butte-Twin Lakes volcanic field is a 7-km-long N-S trending chain SW of Lookout Mountain consisting of scoria cones at the north and three tuff rings up to 1 km in diameter at the south. At one time considered to be of probable Holocene age (Smith et al.1978), the chain is now thought to have last been active during the latest Pleistocene--lava flows are overlain by a well-developed soil beneath the Mazama ash, suggesting that the volcanic chain is considerably older than 6800 years before present (Scott et al., 1989).

Cupit Mary Mountain
Cupit Mary Mountain, a basaltic andesite shield volcano west of Waldo Lake, has K-Ar dates of 0.3 and 0.68 million years (Sherrod, in Wood and Kienle, 1990).

Fuji Mountain
Fuji Mountain shield volcano SW of Waldo Lake was considered to of Pleistocene age (Sherrod, in Wood and Kienle, 1990). Mount Ray to the ENE, south of Waldo Lake is reversely polarized and older than 0.73 million years.

Maiden Peak
Maiden Peak is the highest and southernmost of a chain of Pleistocene shield volcanoes and pyroclastic cones extending from north of Odell Lake to Charlton Butte. The Twins shield volcano lies across a low saddle north of Maiden Peak, Maklak Mountain lies to the SE of Maiden Peak, and an unnamed volcano that is the site of the WIllamette Pass ski area lies immediately SW of Maiden Peak.

Red Top Mountain
Red Top Mountain and Lakeview Mountain shield volcanoes of Pleistocene age lie between Odell and Crescent Lakes.

Cowhorn Mountain
The glacially modified Cowhorn and Sawtooth Mountain shield volcanoes and adjacent cinder cones lie SW of Crescent Lake. A lava from Sawtooth Mountain, located SW of Cowhorn Mountain was K-Ar dated at 0.56 and 0.52 million years (Sherrod, in Wood and Kienle, 1990).

Cappy Mountain
Cappy Mountain is a large, dissected mid-Pleistocene stratovolcano NNE of Mt. Thielson and south of Crescent Lake with rhyodacitic lavas around its flanks.

Diamond Peak
Diamond Peak, a basaltic andesite shield volcano, dominates the Willamette Pass area. Capped by a pyroclastic cone, Diamond Peak probably erupted in the last 100,000 years. but is older than the last glaciation at about 11,000 years (Sherrod, in Wood and Kienle 1990). An older shield volcano, Mt. Yoran, lies to the NNE and the Diamond Rockpile and Crater Butte cinder cones lie to the south.

Thielsen
The eroded central plug of Mount Thielsen forms a prominent summit spire known as the "Lightning Rod of the Cascades." The heavily eroded volcano is Potassium-Argon dated about 0.29 million years ago (Sherrod, in Wood and Kienle 1990). Pre-Thielsen shield volcanoes lie to the east and NE and pyroclastic cones to the south and SW.

Bailey
Mount Bailey is the southernmost of a N-S chain of volcanoes west of Diamond Lake. Volcanism migrated to the south, with Mount Bailey being late Pleistocene in age, between 100,000 and 11,000 years before present (Sherrod, in Wood and Kienle 1990).

Goose Nest
Goose Nest was considered to be a Holocene andesitic shield volcano and pyroclastic cone south of Crater Lake by Sarna-Wojciki et al. (1983). Sherrod (1995 pers. comm.) noted that mapping by Willie Scott shows it to be older than 13,000 years before present.

Big Bunchgrass
The basaltic Big Bunchgrass pyroclastic cone was considered to be of Holocene age (Sarna-Wojcicki et al. 1983, Smith 1988). The age assignment of Smith was based on lack of observation of Mazama tephra at Big Bunchgrass, but Sherrod (1995 pers. comm.) has found overlying Mazama tephra, and considers Big Bunchgrass to be substantially older than Holocene based on degree of erosion.

Imagination Peak
Imagination Peak pyroclastic cone NW of Pelican Butte was considered to be of Holocene age (Sarna-Wojcicki et al. 1983, Smith 1988), but Sherrod (1995 pers. comm.) considered a Holocene age to be uncertain, based on the lack of a summit crater and possible glaciation. The sharp-topped summit without a crater is morphologically similar to Lone Peak in the southern Cascades of Washington, a tuya constructed through a glacial icesheet or glacial lake.

Pelican Butte
Pelican Butte, one of the largest volcanoes between Crater Lake and Mount Shasta, is a late Pleistocene andesitic shield volcano. Located slightly east of the Cascade Range crest, Pelican Butte is cut by a broad cirque on the NE side and is probably no younger than about 60,000 years before present (Smith, in Wood and Kienle 1990).

McLoughlin
Mount McLoughlin is a large basaltic andesite lava cone containing a pyroclastic core exposed by glaciation that is capped by an armor of andesitic lava flows from summit and flank vents. The latest flows were considered by Maynard (Harris, 1988) to probably be of similar age to the young McKenzie Pass lava flows in the central Oregon Cascades, but Smith (in Wood and Kienle 1990) estimated the age of the youngest flows as about 20-30,000 years.

Brown Mountain
Brown Mountain, SE of Mount McLoughlin, is a forested basaltic andesite shield volcano with fresh, unvegetated lava flows descending as far as the base of the volcano on three sides. The latest flows are estimated by Williams (1942) to be possibly only a few centuries old, but Smith (in Wood and Kienle 1990) brackets the age of Brown Mountain between 60,000 and 12,000 years.

Mountain Lakes
The Mountain Lakes volcanic field, located east of Brown Mountain and NW of Klamath Falls, is a Pliocene-to-Quaternary cluster of andesitic volcanic vents. The volcanic field contains Aspen Butte and Little Aspen Butte, the latter a shield volcano that is the southernmost Quaternary volcano in Oregon (Hildreth, 2007).

Copco Lake
Lava flows from two cinder cones near Copco Lake were dated from morphological evidence as being less than one or two thousand years old (Williams 1949), however Miller (1989) indicated that the Copco Lake volcanics are of late-Pleistocene age.

Goosenest
The Goosenest shield volcano and summit pyroclastic cone were considered by Williams (1949) to be Holocene in age, but Miller (1989) mapped it as late Pleistocene.

Whaleback
Williams (1949) mapped the Whaleback shield volcano and nearby fissure vents as Holocene in age, but Luedke and Smith (1981) mapped the area as Pleistocene and Miller (1989) did not include Whaleback in a summary of Holocene volcanism in California.

Rainbow Mountain
Rainbow Mountain, located between Mt. Shasta and Medicine Lake volcanoes, is a massive andesitic-dacitic stratovolcano of early Pleistocene age.

Squamish
The Squamish volcanic field contains the southernmost vents of the Garibaldi volcanic belt. Late Pleistocene eruptions formed The Castle, a dramatic strongly jointed spire above the town of Squamish formed by ice contact lava extrusion (Mathews, 1958), and Watts Point, on Howe Sound south of Squamish, formed by subglacial valley floor lava extrusion. The dacite flows at Watts Point are Potassium-Argon dated at 0.09 and 0.13 million years (Green et al., 1988).

Satah Mountain
The Satah Mountain Volcanic Field on the Chilocotin-Nechako Plateau in central British Columbia consists of a N-S-trending chain of pyroclastic cones (Hickson 1990, pers. comm.). This long ridge of trachytic lava domes and flows, and basaltic and trachybasaltic pyroclastic cones, extends south from the felsic Itcha Range volcanic complex. The youngest cone is well preserved and could be of comparable age to the 7200-year-old Nazko cone 80 km NE (Charland et al., 1993). However, Ar-Ar dating of multiple cones by Kuehn et al., 2015) found that the youngest was about 1.43 Ma. Kuehn et al. (2015) also interpreted Satah as belonging to the Anahim Volcanic Belt.

Itcha Range
The Itcha Range, one of the Miocene to Pliocene felsic shield volcano complexes of the Anahim Volcanic Belt in central British Columbia, is capped by a large number of basaltic cinder cones of Pliocene to latest Pleistocene age. The highly dissected complex covers an area of 300 km2. Potassium-Argon dates on the younger pyroclastic cones and tuff rings, primarily in the eastern half of the complex, range from 2.2 to 0.8 million years ago (Ma). The youngest lavas are basanite flows in the NW and NE part of the complex. The freshest and best preserved cinder cone in the center of the shield could be much younger, perhaps as young as the 340,000 to 7,100 years before present Nazko cone to the east (Charland et al., 1993). The cone has not been dated and the latest volcanism is most likely of late Pleistocene age (Hickson et al., 1994).

Quesnel Cone Group
A group of pyroclastic cones of Pliocene to Quaternary age are located near Quesnel Lake. The Abbott Creek Cone, about 6.5 km N of Quesnel Lake, was given an Ar-Ar age of 180 ka by Kuehn et al. (2015), confirming the Quaternary activity. However, another outcrop thought to be Quaternary yielded a Jurassic Ar-Ar age (Kuehn et al., 2015).

Chilcotin Group-North
The Chilcotin basalts form an extensive series of flat-lying lava flows of Miocene to Pleistocene age covering the interior of British Columbia (Mathews, 1989). The flow remnants form eroded volcanic outcrops that appear to have been erupted from now-eroded coalescing small shield volcanoes scattered throughout the intermontane region. Most flows are 5-10 m thick, but locally are up to 200 m where they filled palaeovalleys. In some instances thick sequences of pillows are found, while in other localities they form a thin veneer under glacial drift. These basalts are listed here in two groups--a northern group in the Chilcotin Plateau area, and a southern group in the Thompson Plateau. Eroded outcrops of Pleistocene age of the northern Chilcotin group are found at Alixton Creek, Big Bar, Browns Lake, Crows Bar, Dog Creek, Prentice Gulch, and Thaddeus Lake (Hickson et al., 1994).

Chilcotin Group-South
The southern part of the Miocene to Pleistocene Chicotin basalts forming an extensive series of basaltic lava flows covering much of the Thompson Plateau and Okanagan Highland in the interior of southern British Columbia are referred to as the Chilcotin Group-South. These basalts are tectonically and petrologically similar to the Chilcotin basalts to the NW, listed separately in this compilation. The Chicoltin basalts appear to have been erupted from discrete centers, no longer preserved, and form scattered outcrops of thin basaltic flows that are locally thick where they fill palaeovalleys. Five areas of Recent volcanic deposits are mapped north of Princeton and SE of Merritt (Church and McAdam, 1983). Two Potassium-Argon dates of 0.04 million years ago have been obtained on these rocks (Hickson, in Wood and Kienle, 1990), and the Chilcotin basalts are considered to be no younger than late Pleistocene (Hickson et al. 1994). Eroded volcanic outcrops of Pleistocene age in the southern Chilcotin group are found at Kelowna, Lambley Creek, Missezula Lake, Nicola (Chester), Quilchena Creek, and West Kettle River (Hickson et al., 1994).

Baldface Mountain
The Baldface Mountain Volcanic Field is part of the Anahim Volcanic Belt in central British Columbia, between the Itcha Range and Nazko Cone. The youngest Ar-Ar age found by Kuehn et al. (2015) was 0.91 Ma from a hawaiite flow 6 km SE of Baldface Mountain.

Basalt Knob
Mapped as Quaternary?; not likely present when glacial erosion formed inlet (Rossman 1959).

Addington Volcanic Field
The submarine Addington Volcanic Field is about 20 km offshore of Cape Addington on Prince of Wales Island, SW of Iphigenia Bay. This field is a possible source for late Pleistocene tephras deposited in southeast Alaska (Wilcox et al., 2019).

Prindle
Prindle volcano is a small isolated basaltic cinder cone and lava flow in an area of metamorphic and granitic terrain. The cone formed sometime between the early Pleistocene and the about 1900 years before present White River ash that overlies the lava flow; Foster (in Wood and Kienle 1990) considered Prindle to be of Pleistocene age.

Kawdy Metah
The Kawdy Metah volcanic field lies along the Kawdy Plateau north of Level Mountain and contains a group of tuyas and subglacial mounds of Pleistocene age (Hickson et al., 1994).

Dark Mountain
The Dark Mountain volcanic field in the Cassiar Mountains consists of remnants of a group of subglacial mounds now forming volcanic rock outcrops east of Dease Lake and east of the Tuya Butte and High Tuya Lake subglacial volcanic fields (Hickson et al., 1994).

Klastline Group
At least six vents on the Klastline Plateau, the largest of which is the volcanic neck of Castle Rock, are mapped as Quaternary and have produced linear ridges composed of subglacial piles of pillow lava and tuff-breccia (Souther, 1972). Rocks from the nearby Stikine River volcanic field are K-Ar dated from 4.6-5.4 million years ago (Hickson, in Wood and Kienle, 1990).

Hogum Range
The Hogum Range contains a group of at least 7 volcanic necks which are associated with dikes, lava flow remnants, and pyroclastic cones. Some of the cones contain striated boulders, occur in places where they would have been destroyed by Pleistocene glaciers, and are considered to be of Recent age by Lord (1948). Souther (in Wood and Kienle, 1990) indicates that the relationship of intravalley flows to the present topography suggests a Quaternary age. Recent work indicates all activity ceased during the Pleistocene (Hickson et al., 1994).

Alice Arm
Eroded volcanic outcrops of Pleistocene age are found in the Alice Arm area west and north of Tseax River Cone (Hickson et al., 1994).

Maclaren River Volcanic Field
As described by the Alaska Volcano Observatory, the Maclaren River Volcanic Field was first recognized by Brueske et al. (2023) and has been further characterized by Bearden (2023). The field, located east of the Maclaren River on either side of the Denali Highway, includes at least three monogenetic volcanoes that date from the last million years. The three identified features lie along a ~20 mile, NNE-SSW line that approximately traces the position of a tear in the Yakutat plate currently subducting under south-central Alaska. The field occurs in an area informally called ?the Denali gap,? between the Aleutian and Wrangell arc volcanoes, where only minor volcanism has been identified (see also Buzzard Creek and Jumbo Dome). The lavas from the three cones are basaltic to basaltic andesitic in composition.

Nunivak Island
Nunivak Island contains about 60 cinder cones and four maars; the surface of the island is dominated by thin pahoehoe lava flows that form a carapace over Cretaceous sedimentary rocks. The 110-km-wide permafrost-covered island lies about 30 km off the coast of SW Alaska. Widespread lava flows originate from small shield volcanoes and cover much of the island, which has numerous cinder cones and other vents. Two of the maars have about 200 m of relief, with floors near sea level. Eruptions occurred during five broad periods of activity that began 6.1 million years ago and continued until about 150 ka. The bulk of the volcanic field, over 427 km3, was formed during two Pleistocene eruptive periods that ended about 300,000 years ago. The most recent eruptions produced a series of alkalic basalt lava flows and tephra deposits from cinder cones and maars along an E-W zone in the southern part of the island.

Kookooligit Mountains
The Kookooligit Mountains are a 30 x 40 km shield volcano of Pleistocene-to-Holocene age in north-central St. Lawrence Island. The basaltic shield is composed of massive columnar-jointed lava flows overlain by more than 100 small cones (20-60 m high). Most of the cones are aligned E-W along the crest of the elongated shield.

St. George
St. George Island is comprised of Tertiary to late-Pleistocene cones and lava flows (Lee-Wong, in Wood and Kienle 1990). An eruption was reported NE of the island in 1815, but "in spite of these assertations any present volcanic activity must be regarded as doubtful" (Barth 1956).

Togiak Valley
The Togiak volcanics are a late-Pleistocene sequence of thin lava flows that includes the subglacially formed Togiak Tuya (Wood and Kienle, 1990).

Ingrichuak Hills
The Ingrichuak Hills consist of at least five low lava shields of probably Quaternary age (Moll-Stalcup, in Wood and Kienle, 1990).

Selawik Hills
Includes six vents and other scattered lava fields to south of Selawik Hills (IAVCEI) of Tertiary to Pleistocene age.

Espenberg
One of the northernmost areas of Quaternary volcanism in North America, the Espenberg volcanic field, is located at the northern tip of the Seward Peninsula just south of the Arctic Circle. The five maars, the largest known on Earth, were erupted through thick permafrost during the late Pleistocene. They were at one time considered to have been active into the Holocene (from about 120,000 to about 7000 years ago), but later radiocarbon dating indicated that the youngest maar, Devil Mountain, erupted about 17,500 years ago (Beg�t et al., 1996). The compound Devil Mountain maar, consisting of two intersecting craters, is 8 x 6 km wide, and North and South Killeak maars are 4 and 5 km wide, respectively. Whitefish maar is 4.3 km wide. The maars were excavated 100-300 m below the ground surface, with lake surfaces 60-80 m below the surrounding topography. The late-Pleistocene basaltic field also contains five older small shield-like volcanoes.

Sanford
Massive dissected Mount Sanford shield volcano is one of the highest Quaternary volcanoes in the United States. The glacier-covered andesitic volcano towers above the Copper River and has a broad, bulbous top that is surrounded by massive, glacially excavated cirques, most prominent on the SW and SE sides of the summit. The upper part of this little-studied, ice-covered volcano is possibly of Holocene age (Richter, in Wood and Kienle, 1990) and developed on a base of three coalescing andesitic shield volcanoes south, NW and NNW of the summit that began to form about 900,000 years ago. A massive mid-Pleistocene rhyolitic lava flow from a NE-flank vent traveled more than 18 km to the NE. Basaltic lava flows that were erupted from a NE-flank rift zone about 320,000 years ago mark the latest radiometrically dated activity.

Gordon
Mount Gordon is the most prominent of a group of Pleistocene and Holocene cinder cones in the northern Wrangell Mountains SE of Tanada volcano. Most are less than 100 m high, but Gordon is a composite basaltic cinder-lava cone 5 km in diameter and 625 m high. Many of the cones retain their original constructional forms (Richter, in Wood and Kienle, 1990). Construction of the largely ice-covered Gordon was preceded by the effusion of basaltic lava flows, and airfall deposits from the cone cover the area; the precise age is not known.

Capital
The relatively small Capital Mountain andesitic shield volcano, north of Mount Sanford, contains a 4-km-wide summit caldera apparently of non-explosive origin. Shield and intracaldera lavas and dikes are dated 1-1.1 Ma (Richter, in Wood and Kienle 1990).

Drum
The westernmost volcano of the Wrangell volcanic field, Mount Drum was formed during two cycles of activity between about 750 and 250 ka, the last of which included the emplacement of an arcuate ring of ten dacitic lava domes between 350 and 250 ka (Richter et al. 1994). The latest activity resulted in destruction of the southern half of the volcano and the formation of debris avalanches that covered a 200 km2 area during the late Pleistocene.

Tanada
Tanada Peak is an eroded remnant of an andesitic shield volcano with a former 8 x 6 km summit caldera. The 1-2 Ma old shield lavas are mostly eroded away, but younger cones are found to the north and south (Richter, in Wood and Kienle 1990).

Jarvis
Miller and Richter (1994) noted that Jarvis is the high point of a slightly curvilinear, N-trending, 10-km-long, 4,000-m-high ridge. The ridge, covered in snow and ice, consists of a thick sequence of dacitic and andesitic lava flows and capped by either a massive dacite flow or by a series of smaller dacite domes. One K-Ar age on possible basal flows suggests an age of about 1.6 Ma (Richter and Smith, 1976).

Skookum Creek
The Alaska Volcano Observatory describes this volcano as follows, from Miller and Richter (1994): "The Skookum Creek eruptive center is an erosionally dissected complex that may, in part, be as young as Quaternary. It consists principally of a series of rhyolite, rhyodacite, and andesite domes and their associated pyroclastic deposits, with an age of about 3.7 Ma, and an extensive sequence of relatively flat-lying andesite flows, some of which have been dated at 2.8 Ma (Lowe and others, 1982). Both the domes and the flows are intruded by a few rhyodacite and andesitic dikes that appear to originate from a rhyodacite dome near the center of the complex. Relations between the volcanic units of the complex suggest that the flat-lying flows fill a caldera that is defined by the crude arcuate alignment of the domes."

Blue Mountain
The Blue Mountain lava dome cluster immediately west of Upper Ugashik Lake consists of 13 dacitic lava domes. An Ar-Ar date of about 632,000 years was obtained from the highest dome.

Gertrude Creek
An ice-scoured basaltic scoria cone and associated lava-flow apron lies at Getrude Creek about 5 km NE of Becharof Lake. The cone was constructed near the trace of the Bruin Bay fault and was Argon-Argon dated at about 500,000 years BP (Hildreth et al., 2003).

Devils Desk
Devils Desk, which rises 450 m above the top of Hook Glacier to its west, is the eroded neck of a former stratovolcano, most of which has been removed by extensive erosion. Three radial dikes exposed as ridges extend from the volcano toward the east. Devils Desk lies at the NE end of a glacier-mantled range containing small closely spaced volcanic centers that extends from Snowy Mountain, NE of Mount Katmai. The age of Devils Desk volcano is not known precisely. Although it was included in a list of probable Holocene volcanoes (Smith et al., 1978), extensive glacial dissection suggests it could be of Pleistocene age (Motyka et al., 1993), and Hildreth et al. (2003) obtained a Potassium-Argon date of about 245,000 years from a block on the SW face, similar to the age of one of the nearby rear-arc Savonoski cones.

Savonovski River Cluster
A group of small Pleistocene stratovolcanoes and a scoria cone lies behind the volcanic front near the headwaters of the Savonovski River, NW of the Denison to Devils Creek alignment of volcanoes. Dated ages range from about 88,000 to 390,000 years (Hildreth et al., 2003).

Double Glacier
Double Glacier volcano is a Pleistocene lava dome complex forming a nunatak in Double Glacier. Potassium-Argon dates range from 627 to 887 thousand years ago (Reed et al. 1992). Nearby Double Peak, 5 km to the north, was once thought to be a volcano (Coats 1950, IAVCEI 1973), but reconnaissance mapping indicates the peak probably consists of Jurassic plutonic rocks (Reed et al. 1992).

Jumbo Dome
Jumbo Dome is a large cylindrical plug of hornblende andesite 1.6 km long, 1.3 km wide, and 500 m high which intrudes the Devonian Keevy Peak Formation basement and overlying Tertiary Suntrana Formation (AVO, 2005-). Ar/Ar dating by Athey et al. (2006) yielded an age for Jumbo Dome of 1.026 +/- 0.057 Ma.

Sergief
Sergief is a small stratovolcano on SW Atka Island whose age is poorly known. The SW part of the island is older and less topographically rugged than the NE part of the island. It was tentatively listed as a young volcano in the Post-Miocene Volcanoes of the World catalog of the International Association of Volcanology and Chemistry of the Earth's Interior (1973), but the age of its latest eruption is not precisely known.

Isanotski Peaks
Rugged pinnacles form the summit of the deeply eroded Isanotski Peaks stratovolcano, locally known as Ragged Jack, at the center of a group of three volcanoes on eastern Unimak Island. Four poorly documented eruptions were noted in the 18th and 19th centuries. However, Miller et al. (1998) considered that some or all of these events could have been from neighboring Shishaldin, and that the extreme degree of erosional dissection makes recent eruptions unlikely.

Adagdak
Mount Adagdak, at the NE tip of Adak Island, lies across Andrew Lagoon from Mount Moffett volcano and ~15 km NNE of the town of Adak. It consists of a small stratovolcano capping an older shield volcano exposed on the southern side of the complex. An andesitic lava dome fills the summit crater. A late-stage basaltic lava dome was constructed on the SE flank, and a phreatic vent is located on the W flank of the shield volcano. The most recent eruptions are thought to be Holocene (Marsh, in Wood and Kienle 1990) or Pleistocene (Motyka et al. 1993, Nye et al. 1998). Three stages of volcanism were mapped by Bratten, the youngest of which was a lava dome dated at about 210,000 years (AVO, 2005-). The older Andrew Bay volcano, located north of Andrew Lagoon between Adagdak and Moffett volcanoes, is preserved only in erosional remnants. Andrew Bay Hot Springs lie along the coast west of Mount Adagdak.

Gilbert
Mount Gilbert is deeply eroded and an area of former solfataric activity appears to have been glaciated. Solfataric activity had ceased between 1942 and 1945 (Byers and Barth 1953).

Trader Mountain
Trader Mountain is a small dacitic stratocone-like feature with an extrusive dome; lava flows dip away from the center in all directions (Chris Nye, oral commun., 2007). Wilson and others (1995) alternatively described Trader Mountain as a hypabyssal dacite plug, and report a potassium-argon age of 0.98+/- 0.05 Ma (F.H. Wilson and Nora Shew, unpub. data, 1988).

Maly Payalpan
Maly Payalpan (Little Payalpan) is a small Quaternary shield-like volcano NE of Ichinsky. Andesitic lava domes of uncertain age are located to the south. It is of basaltic andesite to andesitic composition and was constructed on top of a late-Pliocene to early Pleistocene alkaline basaltic plateau. Basaltic cinder cones of late-Pleistocene to possible Holocene age are on the edifice. Early geological studies in the Sredinny Range (Ogorodov et al., 1972) assigned Holocene ages based on morphology, but later work noted that these volcanoes appear younger because they have less tephra cover than those in eastern Kamchatka. Researchers such as Ponomareva et al. (2007) do not consider this volcano to be Holocene.

Bolshoi Payalpan
The Quaternary shield-like Bolshoi Payalpan (Big Payalpan) volcano is north of Ichinsky in the southern Sredinny Range. It is of dominantly basaltic andesite to andesitic composition and overlain by a late-Pleistocene to possible Holocene age basaltic cinder cones. The Pleistocene Payalpan shield volcano is located immediately SW of Bolshoi Payalpan, and itself has several lava flows of possible Holocene age that descend its NW and SE flanks. Early geological studies in the Sredinny Range (Ogorodov et al., 1972) assigned Holocene ages based on morphology, but later work noted that these volcanoes appear younger because they have less tephra cover than those in eastern Kamchatka. Researchers such as Ponomareva et al. (2007) do not consider this volcano to be Holocene.

Plosky
The small Quaternary shield-like Plosky volcano south of the Bolshaya Kimitina River is SE of Ichinsky near the SE margin of the Sredinny Range. The summit consists of a small basaltic stratovolcano overtopping the lava shield. Early geological studies in the Sredinny Range (Ogorodov et al., 1972) assigned Holocene ages based on morphology, but later work noted that these volcanoes appear younger because they have less tephra cover than those in eastern Kamchatka. Researchers such as Ponomareva et al. (2007) do not consider this volcano to be Holocene.

Akhtang
The late Pleistocene Akhtang Massif is located between the Bolshaya Kimitina and Kozyrevka rivers SE of Ichinsky volcano in the southern Sredinny Range. This stratovolcano is at the NE end of line of smaller monogenetic cones extending about 16 km SE. Volynets et al. (2020) obtained K-Ar dates of about 250-310 ka from lava samples taken near the youngest cones at the SW end of the chain.

Kozyrevsky
Kozyrevsky is a small Quaternary basaltic to basaltic andesite shield-like volcano located east of the Bystraya River, ~40 km E of Ichinsky in the southern Sredinny Range. It is topped by a small stratovolcano and has a large cinder cone on the SW flank. Early geological studies in the Sredinny Range (Ogorodov et al., 1972) assigned Holocene ages based on morphology, but later work noted that these volcanoes appear younger because they have less tephra cover than those in eastern Kamchatka. Researchers such as Ponomareva et al. (2007) do not consider this volcano to be Holocene.

Romanovka
Romanovka is a small Quaternary stratovolcano immediately north of the Kozyrevka River in the southern Sredinny Range. A broad area of cinder cones and associated lava flows is present on both sides of the river and extends primarily to the east of the volcano to the SE margin of the Sredinny Range. Early geological studies in the Sredinny Range (Ogorodov et al., 1972) assigned Holocene ages based on morphology, but later work noted that these volcanoes appear younger because they have less tephra cover than those in eastern Kamchatka. Researchers such as Ponomareva et al. (2007) do not consider this volcano to be Holocene.

Uksichan
The large gently dipping shield-like Uksichan volcano covers 1,850 km2, and is the largest of the Sredinny Range with a 300 km3 volume. Several dacitic domes fill the 12-km-wide central caldera; the largest of these rises 900 m above the caldera floor to form the summit. Initial lava flows traveled up to 15-20 km, but later flows were thicker and more viscous. In contrast to the W and NW flanks, which consist exclusively of lava flows, the E and SE flanks contain substantial amounts of pyroclastic material. Cinder cones and small shields are located on the flanks. Early geological studies in the Sredinny Range (Ogorodov et al., 1972) assigned Holocene ages based on morphology, but later work noted that these volcanoes appear younger because they have less tephra cover than those in eastern Kamchatka. Researchers such as Ponomareva et al. (2007) do not consider this volcano to be Holocene.

Kulkev
Kulkev is a small Quaternary basaltic to basaltic andesite shield-like volcano in the southern Sredinny Range that is dwarfed by its massive neighbor immediately to the south, Uksichan.Early geological studies in the Sredinny Range (Ogorodov et al., 1972) assigned Holocene ages based on morphology, but later work noted that these volcanoes appear younger because they have less tephra cover than those in eastern Kamchatka. Researchers such as Ponomareva et al. (2007) do not consider this volcano to be Holocene.

Geodesistov
Geodesistov is a small basaltic to basaltic andesite shield-like volcano immediately WNW of the larger Anaun in the southern Sredinny Range. A small cone with a lava flow was constructed to the WSW, and a small lava field is to the south. Early geological studies in the Sredinny Range (Ogorodov et al., 1972) assigned Holocene ages based on morphology, but later work noted that these volcanoes appear younger because they have less tephra cover than those in eastern Kamchatka. Researchers such as Ponomareva et al. (2007) do not consider this volcano to be Holocene.

Anaun
Anaun is a Quaternary basaltic stratovolcano NE of Uksichan in the southern Sredinny Range. A chain of NE-SW-trending cinder cones extends to the SW, and another chain of numerous cinder cones displays the same orientation S and SE of the volcano. Early geological studies in the Sredinny Range (Ogorodov et al., 1972) assigned Holocene ages based on morphology, but later work noted that these volcanoes appear younger because they have less tephra cover than those in eastern Kamchatka. Researchers such as Ponomareva et al. (2007) do not consider this volcano to be Holocene.

Krainy
Krainy is a small Quaternary basaltic to basaltic andesite shield-like volcano NE of Anaun in the southern Sredinny Range. Cinder cones are found across the flanks and a lava flow is on the SW. Early geological studies in the Sredinny Range (Ogorodov et al., 1972) assigned Holocene ages based on morphology, but later work noted that these volcanoes appear younger because they have less tephra cover than those in eastern Kamchatka. Researchers such as Ponomareva et al. (2007) do not consider this volcano to be Holocene.

Kekurny
Kekurny is the northernmost of two overlapping small Quaternary basaltic to basaltic andesite shield-like volcanoes north of Anaun and west of Krainy volcanoes in the southern Sredinny Range. A chain of small cinder cones was constructed along a NE-SW-trending rift cutting across the volcano. The Bunanya shield immediately to the south has cinder cones on its NE flank. Early geological studies in the Sredinny Range (Ogorodov et al., 1972) assigned Holocene ages based on morphology, but later work noted that these volcanoes appear younger because they have less tephra cover than those in eastern Kamchatka. Researchers such as Ponomareva et al. (2007) do not consider this volcano to be Holocene.

Eggella
Eggella is a small basaltic to basaltic andesite shield-like volcano on the flank of the Pleistocene Chavycha shield, west of the axis of the southern Sredinny Range. A chain of small cones on the E flank trends NE-SW. Early geological studies in the Sredinny Range (Ogorodov et al., 1972) assigned Holocene ages based on morphology, but later work noted that these volcanoes appear younger because they have less tephra cover than those in eastern Kamchatka. Researchers such as Ponomareva et al. (2007) do not consider this volcano to be Holocene.

Verkhovoy
Verkhovoy, a small Quaternary basaltic to basaltic andesite shield-like volcano in the central Sredinny Range, is dwarfed by its massive neighbor to the NNE, Alney-Chashakondzha. Early geological studies in the Sredinny Range (Ogorodov et al., 1972) assigned Holocene ages based on morphology, but later work noted that these volcanoes appear younger because they have less tephra cover than those in eastern Kamchatka. Researchers such as Ponomareva et al. (2007) do not consider this volcano to be Holocene.

Cherny
Cherny is a small Quaternary stratovolcano immediately north of the massive Alney-Chashakondzha complex in the central Sredinny Range. An ENE-WSW-trending line of cinder cones was constructed on the western flank of Cherny, which is the southernmost of a cluster of small stratovolcanoes and shields trending NE from Alney-Chashakondzha. Early geological studies in the Sredinny Range (Ogorodov et al., 1972) assigned Holocene ages based on morphology, but later work noted that these volcanoes appear younger because they have less tephra cover than those in eastern Kamchatka. Researchers such as Pevzner (2006) and Ponomareva et al. (2007) do not consider this volcano to be Holocene.

Pogranychny
Pogranychny is the highest and easternmost of a group of three small Quaternary basaltic to basaltic andesite shield-like volcanoes in the central Sredinny Range about 20 km NE of teh Alney-Chashakondzha complex. A chain of cinder cones extends NNE-SSW across Vodorazdelny at the N to Centralny at the SW. Early geological studies in the Sredinny Range (Ogorodov et al., 1972) assigned Holocene ages based on morphology, but later work noted that these volcanoes appear younger because they have less tephra cover than those in eastern Kamchatka. Researchers such as Pevzner (2006) and Ponomareva et al. (2007) do not consider this volcano to be Holocene.

Zaozerny
A group of three small Quaternary basaltic to basaltic andesite shield-like volcanoes are present slightly east of the axis of the central Sredinny Range, about 30 km NE of Alney-Chashakondzha volcano and NNW of Lake Dvukhyurtochnoye. The highest and westernmost is Zaozerny, with Oleny to the SE and Kastriulya volcano to the NE. Early geological studies in the Sredinny Range (Ogorodov et al., 1972) assigned Holocene ages based on morphology, but later work noted that these volcanoes appear younger because they have less tephra cover than those in eastern Kamchatka. Researchers such as Pevzner (2006) and Ponomareva et al. (2007) do not consider this volcano to be Holocene.

Bliznets
Bliznets is a Quaternary basaltic stratovolcano on the crest of the central Sredinny Range SW of Kebeney volcano. Cinder cones were constructed on the E flank, and a group of cones and associated lava flows cover the northern side of the volcano. Early geological studies in the Sredinny Range (Ogorodov et al., 1972) assigned Holocene ages based on morphology, but later work noted that these volcanoes appear younger because they have less tephra cover than those in eastern Kamchatka. Researchers such as Pevzner (2006) and Ponomareva et al. (2007) do not consider this volcano to be Holocene.

Kebeney
Kebeney is a prominent Quaternary basaltic to basaltic andesite shield-like volcano in the central Sredinny Range. Two groups of NE-SW-trending cinder cones are on the SW and SE flanks, and other cinder cones are on the NE flank. Lavas surround the small eroded Kalgnitunup cone to the SW. Early geological studies in the Sredinny Range (Ogorodov et al., 1972) assigned Holocene ages based on morphology, but later work noted that these volcanoes appear younger because they have less tephra cover than those in eastern Kamchatka. Researchers such as Pevzner (2006) and Ponomareva et al. (2007) do not consider this volcano to be Holocene.

Fedotych
Fedotych, a small Quaternary basaltic to basaltic andesite shield-like volcano, is about 20 km E of the crest of the central Sredinny Range ENE of Kebeney volcano. Minor fissure-fed lava flows are located WNW. Early geological studies in the Sredinny Range (Ogorodov et al., 1972) assigned Holocene ages based on morphology, but later work noted that these volcanoes appear younger because they have less tephra cover than those in eastern Kamchatka. Researchers such as Pevzner (2006) and Ponomareva et al. (2007) do not consider this volcano to be Holocene.

Leutongey
The Quaternary Leutongey basaltic shield-like volcano is at the south end of a NE-SW-trending graben about 20 km W of the crest of the central Sredinny Range. A chain of cinder cones along the same trend cuts across the summit, and another larger cinder cone is on the S flank. The small basaltic Medveshiy stratovolcano is immediately to the SE. Early geological studies in the Sredinny Range (Ogorodov et al., 1972) assigned Holocene ages based on morphology, but later work noted that these volcanoes appear younger because they have less tephra cover than those in eastern Kamchatka. Researchers such as Pevzner (2006) and Ponomareva et al. (2007) do not consider this volcano to be Holocene.

Tuzovsky
Three small overlapping Quaternary basaltic to basaltic andesite shield-like volcanoes are located NE of Leutongey volcano, west of the crest of the central Sredinny Range. Tuzovsky, the SW-most edifice, is the highest; Tvitunup is the northernmost, and Sredny is NE of Tuzovsky. Early geological studies in the Sredinny Range (Ogorodov et al., 1972) assigned Holocene ages based on morphology, but later work noted that these volcanoes appear younger because they have less tephra cover than those in eastern Kamchatka. Researchers such as Pevzner (2006) and Ponomareva et al. (2007) do not consider this volcano to be Holocene.

Mezhdusopochny
Mezhdusopochny, a Quaternary basaltic shield-like volcano, lies at the NE end of a group of small shields in a NE-SW-trending graben extending west of the crest of the Sredinny Range north of Kebeny volcano. The volcano rises above the north shore of Lake Mezhdusopochny, and basaltic lava covers the graben floor to the south. Early geological studies in the Sredinny Range (Ogorodov et al., 1972) assigned Holocene ages based on morphology, but later work noted that these volcanoes appear younger because they have less tephra cover than those in eastern Kamchatka. Researchers such as Pevzner (2006) and Ponomareva et al. (2007) do not consider this volcano to be Holocene.

Shishel
Shishel is a glacier-capped Quaternary basaltic shield-like volcano along the crest of the central Sredinny Range. It is on the east side of a broad graben containing a NE-SW-trending chain of overlapping small shields ranging from Leutongey on the SW to Mezhdusopochny on the NE. Small cinder cones are located S and SW of Shishel, and a major lava field is located on its NE flank. Early geological studies in the Sredinny Range (Ogorodov et al., 1972) assigned Holocene ages based on morphology, but later work noted that these volcanoes appear younger because they have less tephra cover than those in eastern Kamchatka. Researchers such as Pevzner (2006) and Ponomareva et al. (2007) do not consider this volcano to be Holocene.

Alngey
Alngey, a small Quaternary stratovolcano, is immediately east of the large Pleistocene Tekletunup shield volcano, west of the crest of the northern Sredinny Range. It was constructed near the western margin of a large NE-SW-trending graben running along the axis of the Sredinny Range. Early geological studies in the Sredinny Range (Ogorodov et al., 1972) assigned Holocene ages based on morphology, but later work noted that these volcanoes appear younger because they have less tephra cover than those in eastern Kamchatka. Researchers such as Pevzner (2006) and Ponomareva et al. (2007) do not consider this volcano to be Holocene.

Uka
Uka, a small Quaternary basaltic shield-like volcano, was constructed near the eastern margin of a large NE-SW-trending graben along the axis of the northern Sredinny Range. It is immediately east of the crest of the Sredinny Range, opposite Alngey volcano on the western side of the graben. Early geological studies in the Sredinny Range (Ogorodov et al., 1972) assigned Holocene ages based on morphology, but later work noted that these volcanoes appear younger because they have less tephra cover than those in eastern Kamchatka. Researchers such as Pevzner (2006) and Ponomareva et al. (2007) do not consider this volcano to be Holocene.

Kaileney
Kaileney is a small Quaternary basaltic shield-like volcano near the eastern margin of a large NE-SW-trending graben running along the axis of the northern Sredinny Range. It is located NE of Uka, another shield volcano along the east side of the graben. A chain of E-W-trending cinder cones extends to the west from the summit. Early geological studies in the Sredinny Range (Ogorodov et al., 1972) assigned Holocene ages based on morphology, but later work noted that these volcanoes appear younger because they have less tephra cover than those in eastern Kamchatka. Researchers such as Pevzner (2006) and Ponomareva et al. (2007) do not consider this volcano to be Holocene.

Plosky
Plosky, a small Quaternary basaltic shield-like volcano about 20 km W of the crest of the Sredinny Range, is the westernmost volcano of the northern Sredinny Range. It is located immediately north of the large Pleistocene Tekletunup volcano. Early geological studies in the Sredinny Range (Ogorodov et al., 1972) assigned Holocene ages based on morphology, but later work noted that these volcanoes appear younger because they have less tephra cover than those in eastern Kamchatka. Researchers such as Pevzner (2006) and Ponomareva et al. (2007) do not consider this volcano to be Holocene.

Bely
The Quaternary basaltic Bely shield-like volcano in the northern Sredinny Range is topped by a small stratovolcano. The smaller Sergeeva and Keveneytunup shields are located to the south and east, respectively, and the late-Pleistocene Lagerny shield is to the SE. Keveneytunup is the highest of these volcanoes, slightly exceeding Bely. Early geological studies in the Sredinny Range (Ogorodov et al., 1972) assigned Holocene ages based on morphology, but later work noted that these volcanoes appear younger because they have less tephra cover than those in eastern Kamchatka. Researchers such as Pevzner (2006) and Ponomareva et al. (2007) do not consider this volcano to be Holocene.

Snezhniy
Snezhniy is a small Quaternary basaltic shield-like volcano that was constructed near the eastern margin of a large NE-SW-trending graben running along the axis of the northern Sredinny Range. The smaller shield volcano Grechishkina is just NW, on the saddle between Snezhniy and Keveney volcanoes. Early geological studies in the Sredinny Range (Ogorodov et al., 1972) assigned Holocene ages based on morphology, but later work noted that these volcanoes appear younger because they have less tephra cover than those in eastern Kamchatka. Researchers such as Pevzner (2006) and Ponomareva et al. (2007) do not consider this volcano to be Holocene.

Iktunup
The Quaternary basaltic to basaltic andesite shield-like Iktunup was constructed 5 km west of the lower, but larger shield of Tunipilyakum. The two volcanoes are located immediately NW and NE, respectively, of the Pleistocene Keveney volcano. Early geological studies in the Sredinny Range (Ogorodov et al., 1972) assigned Holocene ages based on morphology, but later work noted that these volcanoes appear younger because they have less tephra cover than those in eastern Kamchatka. Researchers such as Pevzner (2006) and Ponomareva et al. (2007) do not consider this volcano to be Holocene.

Snegovoy
Glacier-covered Snegovoy is a late-Quaternary shield-like volcano topped by a small basaltic cone. It was constructed about 10 km ENE of Ostry volcano, near the NE end of the Sredinny Range. Early geological studies in the Sredinny Range (Ogorodov et al., 1972) assigned Holocene ages based on morphology, but later work noted that these volcanoes appear younger because they have less tephra cover than those in eastern Kamchatka. Researchers such as Pevzner (2006) and Ponomareva et al. (2007) do not consider this volcano to be Holocene.

Iettunup
Iettunup and Lamutsky are small overlapping late-Quatenary basaltic to basaltic andesite shield-like volcanoes at the far NE end of the Sredinny Range. The summit of Iettunup is about 7 km NW of the summit cone of Lamutsky. Early geological studies in the Sredinny Range (Ogorodov et al., 1972) assigned Holocene ages based on morphology, but later work noted that these volcanoes appear younger because they have less tephra cover than those in eastern Kamchatka. Researchers such as Pevzner (2006) and Ponomareva et al. (2007) do not consider this volcano to be Holocene.

Voyampolsky
Voyampolsky and Kakhtana are two basaltic to basaltic andesite shield-like volcanoes that form the NW-most volcanoes of the Sredinny Range near the headwaters of the Kakhtana River. Early geological studies in the Sredinny Range (Ogorodov et al., 1972) assigned Holocene ages based on morphology, but later work noted that these volcanoes appear younger because they have less tephra cover than those in eastern Kamchatka. Researchers such as Pevzner (2006) and Ponomareva et al. (2007) do not consider this volcano to be Holocene.

Lyzyk
The small isolated Lyzyk volcano is probably of late-Pleistocene age (Erlich 1985, pers. comm.).

Uchkoren
Uchkoren is a small Pleistocene volcano (Erlich 1985, pers. comm.).

Tynua
Two Pleistocene Icelandic shield volcanoes (Ogorodov et al. 1972).

Etopan
Late-Pleistocene Icelandic-type shield volcano (Ogorodov et al. 1972).

Kimitina
Pleistocene basaltic stratovolcano (Ogorodov et al. 1972).

Central Kamchatka Arc at 55.5�N
Pleistocene (Erlich 1985, pers. comm.).

Ochchamo
Lower-Pleistocene shield volcano east of Ichinsky volcano (Erlich 1985, pers. comm.).

Bolshoy Kozyrevsky
Lower-Pleistocene shield volcano (Erlich 1985, pers. comm.).

Bolshaya Romanovka
Lower-Pleistocene shield volcano (Erlich 1985, pers. comm.).

Central Kamchatka Arc at 55.9�N
Group of three Pleistocene stratovolcanoes (Erlich, 1985 pers. comm.).

Bongabti
Early Pleistocene shield volcano (Ogorodov et al., 1972).

Nosichan
Late-Pleistocene Icelandic shield volcano (Ogorodov et al. 1972).

Buduli
Late Pleistocene shield volcano (Ogorodov et al., 1972).

Kopkan
Late Pleistocene shield volcano; the Krugelenky shield to the NE along the regional NE-SW trend is listed with Kapkan (Erlich 1985, pers. comm.).

Yanpat
Yanpat and Vetrovoy volcano to the north are late-Pleistocene Icelandic-type shield volcanoes (Ogorodov et al. 1972).

Chavycha
Chavycha and Olka volcano to the north are mid to late-Pleistocene Icelandic-type shield volcanoes (Ogorodov et al. 1972).

Malaya Ketepana
Malaya Ketepana is one of several large shield volcanoes along the western margin of the Sredinny Range. Smaller Icelandic-type shield volcanoes are located on the south flank and NE of Malaya Ketepana.

Bolshoy Ketepana
Bolshoy Ketepana is a large isolated early Pleistocene shield volcano on the west side of the Sredinny Range (Ogorodov et al. 1972).

Central Kamchatka Arc at 57.0�N
Pleistocene shield volcano (Erlich, 1985 pers. comm.).

Ovalny
Mid to late-Pleistocene shield volcano (Ogorodov et al. 1972).

Tigilsky
The lower to mid-Pleistocene Tigilsky shield volcano (Ogorodov et al. 1972) appears to have a 2-km-wide crater just SE of the summit. An area on the W flank was previously listed as an Unnamed Holocene basaltic shield volcano. The morphology as observed in satellite imagery suggests that the "shield" is simply an erosional feature along a volcanic ridge of the larger edifice.

Perevalovyi
Mid-Pleistocene shield volcano with a summit caldera (Ogorodov et al. 1972).

Maly Alney
The mid to late-Pleistocene basaltic stratovolcanoes of Maly Alney and Polovinny are located SE of Alney volcano (Ogorodov et al. 1972).

Maly Chekchebonay
Mid-Pleistocene shield volcano with Hawaiian-type summit caldera (Ogorodov et al. 1972; Erlich 1986).

Bolshoy Chekchebonay
Lower-Pleistocene shield volcano with Hawaiian-type summit caldera (Ogorodov et al. 1972).

Kireunsky
Late-Pleistocene Icelandic-type shield volcano (Ogorodov et al. 1972).

Dvukhyurtochny
Late-Pleistocene Icelandic-type shield volcano (Ogorodov et al. 1972).

Group of mid-Pleistocene extrusive lava domes (Erlich, 1985 pers. comm.).

Kalgauch
Late-Pleistocene basaltic stratovolcano (Ogorodov et al. 1972).

Kunkhilok
Late-Pleistocene basaltic stratovolcano east of the Sredinny Range crest (Ogorodov et al. 1972).

Shlen
Shlen is a large mid-Pleistocene shield volcano west of the main Sredinny Range (Ogorodov et al. 1972).

Pirozhnikova
Late-Pleistocene basaltic stratovolcano (Ogorodov et al. 1972).

Kamenisty
Late-Pleistocene basaltic stratovolcano (Ogorodov et al. 1972).

Tekletunup
Tekletunup is a large eroded Pliocene to lower-Pleistocene shield volcano (Ogorodov et al. 1972).

Ulvaney
Late Pleistocene shield volcano (Ogorodov et al., 1972).

Mutny
Late Pleistocene shield volcano (Ogorodov et al., 1972).

Khuvkhoitun
The late-Pleistocene complex stratovolcano Khuvkhoitun forms the highest peak of the northern Sredinny Range. Two small late-Pleistocene shield volcanoes are located immediately to the NE (Ogorodov et al. 1972).

Keveney
Keveney is a late-Pleistocene Icelandic-type shield volcano (Ogorodov et al. 1972).

Langtutkin
Langtutkin is a late-Pleistocene Icelandic-type shield volcano east of the crest of the Sredinny Range (Ogorodov et al. 1972).

Schmidt
Schmidt volcano is a large mid- to late-Pleistocene eroded shield-like volcano located N of Kronotsky volcano and SW of Gamchen (Lutchitsky, 1974). A dike complex is prominent along a NE-trending fault zone. Andreev et al. (1988) reported that following the cessation of Pleistocene activity, regional basaltic volcanism produced some monogenetic cinder cones on the E and NE flanks during the Holocene. However, Ponomareva et al. (2007) did not include this volcano as a Holocene center.

Aak
Aak, Arik, and Pinachevsky are Pleistocene volcanoes along a ridge trending NW from Koryaksky volcano. Abnormal shallow earthquakes occurred in August 1966 (Gorel'chik, 1969).

Kupol
Kupol is a Pleistocene basaltic andesite stratovolcano (Luchitsky 1974).

Kitkhoysky
Two Pleistocene shield-like volcanoes are located NW of Kupol and SW of Vershkinsky volcanoes (Erlich 1985, pers. comm.). Satellite imagery in Google Earth appears to show a 6-km-diameter caldera open to the N with a later cone or dome complex on the eastern side.

Vershinsky

Zhupanovskiye Vostriyaky
Large Pleistocene stratovolcano north of Zhupanova River

Ditmara
Ditmara is a broad, low stratovolcano SE of Akademia Nauk caldera.

Krainy

Razlaty

Skalistiy

Unana
Unana stratovolcano is of Pleistocene age; hot springs on the volcano are related to tectonic faults (Erlich 1985, pers. comm.).

Adamozhets
Satellite imagery shows a 2-km cone with an open crater that appears to be a volcanic feature about 9 km SE of the original location provided by Erlich (1985, pers. comm.), who identified this as a Pleistocene volcano. It is about 35 km NW of the Uzon caldera.

Bogachensky
Pleistocene shield-like volcano north of Kolkhozhny volcano (Erlich 1985, pers. comm.).

Piip
Pleistocene shield-like volcano (Erlich 1985, pers. comm.).

Konechnaya
Mid to upper Pleistocene shield-like volcano (Luchitsky 1974).

Konradi
Vlasov (1967) notes postglacial activity of Konradi; later work indicates it is of Pleistocene age (Erlich 1985, pers. comm.).

Tumrok
Mid to upper Pleistocene shield-like volcano (Luchitsky 1974).

Iult
Iult (also spelled Iul't) is a large stratovolcano located north of Konradi volcano and NNW of the Gamchen volcanic complex. Lava domes on the lower northern and southern flanks were assigned a Holocene age by Luchitsky (1974), but Andreev et al. (1988) mapped them as late Pleistocene.

Sokol
Mid to upper Pleistocene stratovolcano north of Konradi volcano (Luchitsky 1974).

Zarechny
Zarechny is a low, forested volcano constructed in the lake-filled lowlands between Kliuchevskoi and Shiveluch volcanoes, and immediately S of Kharchinsky volcano. The 760-m-high edifice contains two nested calderas, both breached widely to the SE. The larger 4.5 x 3.7 km wide caldera is filled by an uneroded cone truncated by a 3.2 x 1.8 km wide caldera. Both horseshoe-shaped calderas resemble those produced by edifice failure, but deposits related to their origin are buried beneath younger Holocene deposits in the Kamchatka River valley. Zarechny was at one point considered to be of Holocene age (Erlich, 1986), but more recent tephrochronology has shown that the older edifice precedes formation of 23,000-24,000 year old glacial moraines, and that the younger inner edifice ceased activity during the late Pleistocene (Volynets et al., 1999).

Kharchinsky
Kharchinsky is a Pleistocene volcano immediately north of Zarechny volcano (Luchitsky, 1974) in the lowlands north of the Kamchatka River. The magnesian basaltic volcano rises 1400 m above the surrounding plains. It was constructed during the late Pleistocene and predates glacial moraines dated at 23,000-24,000 years ago. Faulting and edifice failures have deeply affected the edifice, and debris-avalanche fans are found at its base.

Eastern Kamchatka Arc at 56.5�N
A group of basaltic cinder cones is located north of Kharchinsky volcano in the lowlands SW of Sheveluch volcano. The cones and lava flows cover a broad area north of Kharchinsky and form a peninsula extending into Lake Kharchinsky. They are part of the arcuate Kharchinsky regional zone of more than 100 cinder cones, lava cones, tuyas, and explosion craters that extends across both Kharchinsky and Zarechny volcanoes and were formed during a later volcanic cycle unrelated to Kharchinsky (Erlich, 1985 pers. comm.). The cones were initially considered to be late-Pleistocene to Holocene (Luchitsky, 1974), but later tephrochronological studies showed them to be late Pleistocene (Volynets et al., 1999).

Lauchachan
Small late Pleistocene basaltic shield volcano SW of Ichinsky volcano (Ogorodov et al., 1972).

Prodolny
Prodolny and Lauchan are adjacent Pleistocene shield volcanoes SW of Ichinsky volcano (Erlich 1985, pers. comm.).

Kobalan
Pleistocene basaltic stratovolcano, SW of Ichinsky volcano (Ogorodov et al. 1972).

Shikaribetsu Group
Shikaribetsu consists of a group of andesitic-to-dacitic lava domes west and south of Lake Shikaribetsu in central Hokkaido. The youngest domes were constructed along a ENE-WSW line south of the lake. The largest dome, Higashi-Nupukaushinupuri, was built at the SW, breached end of a horseshoe-shaped crater. Two or more large debris-avalanche deposits extend to the south. Although the Japan Association of Quaternary Research (1987) mapped the youngest domes as Holocene, and Nakano et al. (2001-) indicated that the age of the latest eruptions was less than 20,000 years, Hayakawa (2009, pers. comm.) stated that there was no evidence of Holocene eruptions.

Tomuraushi Volcanic Group
The andesitic-to-dacitic Tomuraushi) volcano group located between Tokachi and Daisetsu volcanoes consists of a half dozen stratovolcanoes and lava domes that were active about 1.1-0.1 million years ago (Nakano et al., 2001-).

Chubetsu
Chubetsu volcano (Chubetsu-dake or Tyubetu-dake), an andesitic stratovolcano SE of Daisetsu volcano, was active about 1-0.8 million years ago (Nakano et al., 2001-).

Tokachi-Eboshi
The Tokachi-Eboshi volcano group consists of several lava domes and volcanic necks that were active about 1.8-0.7 million years ago (Nakano et al., 2001-).

Niseikaushuppe
The basaltic Niseikaushuppe-dake stratovolcano was active about 1.1 million years ago (Nakano et al., 2001-).

Tengu-Hirayama
The Tengu-Hirayama volcano group consists of the andesitic-to-dacitic Tengu and Hira-yama volcanoes. They were active about 1.3-1.0 million years ago (Nakano et al., 2001-). Ariake-yama and Hirami-yama form the high points of Tengu and Hira-yama volcanoes, respectively. The northern part of this area contains the 1.6-1.3 million year Kitamitoge volcanic rocks.

Shiitokoro
Shiitokoro-yama, an andesitic-to-dacitic lava dome and lava flow, was active about 1.4 million years ago (Nakano et al., 2001-).

Kumaneshiri
Kumaneshiri volcano consists of two andesitic-to-dacitic stratovolcanoes, Nishi-Kumaneshiri-dake and Kumaneshiri-dake, that were active about 1.3 million years ago (Nakano et al., 2001-).

Tokachi-Mitsumata
Tokachi-Mitsumata, a rhyolitic caldera that was the source of the Muka and Meto pyroclastic flows, was active about 0.6-0.3 million years ago (Nakano et al., 2001-). Ishii et al. (2008) listed dates of around 1 million years ago for formation of the Tokachi-Mitsumata caldera.

Birao
The Birao volcano group consists of Birao-yama and Sattomonai andesitic-to-rhyolitic stratovolcanoes. Birao was active about 500,000-300,000 years ago and Sattomonai volcano about 100,000 years ago (Nakano et al, 2001-).

Samakkenupuri
Samakkenupuri volcano consists of the andesitic Samakkenupuri-yama and Shibetsu-dake stratovolcanoes that were active about 1.1-0.8 million years ago (Nakano et al., 2001-).

Musa
The andesitic-to-dacitic Musa-dake volcano was active about 0.9-0.5 million years ago (Nakano et al., 2001-).

Shari
The andesitic-to-dacitic Shari-dake volcano was active about 0.3-0.25 million years ago (Nakano et al., 2001-).

Unabetsu
The basaltic-to-andesitic Unabetsu-dake stratovolcano was active about 0.9-0.5 million years ago (Nakano et al., 2001-).

Onnebetsu
Onnebetsu volcano was active about 0.4-0.2 million years ago and Chinishibetsu volcano about 0.2-0.1 million years ago (Nakano et al., 2001-).

Shiretoko
Shiretoko volcano, the NE-most in Hokkaido, was active about 0.6-0.2 million years ago (Nakano et al., 2001-). The andesitic Shiretoko-dake volcano lies at the tip of the Shiretoko Peninsula.

Moekeshiwan [Lvinaya Past]
The rim of the 7 x 9 km Moekeshiwan [Lvinaya Past] caldera on southern Iturup Island drops to 50 m below sea level on the NW side. Lvinaya Past, meaning Lion's Jaw, derives from a rock formation resembling a sleeping lion. The caldera is breached on the NW, where a shallow 5-km-wide passage opens to the Sea of Okhotsk. The caldera floor is about 550 m below sea level and lies almost 1 km below the caldera rim. Radiocarbon dating places caldera formation in the late Pleistocene, around about 12,300 years ago (see Smirnov et al., 2025), which deposited thick dacitic pumice deposits that form the 50-60 m high Yuzhny (Southern) isthmus. No post-caldera features or activity have been reported. This volcano is not included in the list of active volcanoes by the Japan Meteorological Agency (2013).

Kuril Arc at 45.0�N
Designated as "Volcano 8.10" in a catalog of submarine Kuril Arc volcanic centers (Avdeiko, 1992), this seamount is located ~22 km NNW of the Iturup Island peninsula with Etorofu-Atosanupuri stratovolcano. Although Gushchenko (1979) listed a submarine eruption in 1967 based on an oral communication from Gushkov, the description is more consistent with hydrothermal activity and dredging of nearby volcanic material. Blokh et al. (2021) summarized findings from 1982-1989 R/V Vulcanologist cruises, describing a large edifice with a flat summit area (~1.8 km diameter) and a peak at ~120 m depth; sounds detected during a September 1987 cruise were interpreted as "gas-hydrothermal" activity. The flat top of the edifice suggested a pre-Holocene age to Blokh et al. (2021), which they linked to erosion in the late Pleistocene that resulted in a sedimentary layer on the lower slopes.

Rucharu [Golets-Tornyi Group]
Rucharu, with the small cones of Golets and Tornyi, is SW of Moyorodake (Medvezhia) volcano at one of the narrowest parts of Iturup Island, and formed during the late Pleistocene or early Holocene. A small lava flow from the Tornyi cone reportedly occupies a broad glacial cirque. The andesitic-dacitic Golets cone, constructed above the eroded remnants of the Pleistocene Parusnaya Mountain volcano, produced lava flows that reached the coast. Those features are on the NE side of the Vetrovoi Isthmus (or Ruchuru) Caldera, a 6-7 km wide feature formed during a Pleistocene submarine eruption; a 1-km-wide explosion crater with a small cone (Klumba) is on its western margin (Gorshkov 1970).

Chirippusan [Chirip]
Chirippusan (also simply Chirip) volcano is on the Chirip Peninsula, which extends N into the Sea of Okhotsk from central Iturup Island. The summits of two overlapping stratovolcanoes are ~4.5 km apart along a volcanic ridge, with Kitachirippusan on the north and Minamichirippu (also called Bogdan Khmelnitskii) on the south. Lava flows from both edifices are truncated by a 4-km-wide depression on the west side of the peninsula. Basaltic rocks dominate at both over basaltic andesite and andesitic products. Kitachirippusan has a shallow summit crater, partially filled by a small lake, that has fed lava flows down all sides; cones are located on the N flank. Lava flows from Minamichirippusan reach the coast on both the east and west. Eruptions or possible activity has been listed in various catalogs and references for 1843, 1857, 1860, and 1879 CE. However, no original sources, deposits, or descriptions have been identified. No clear evidence for Holocene eruptive activity is known. Satellite imagery shows a scarp open to the W that extends 1.5 km between the main summits, where largely unvegetated areas extend 1 km into the valley. The exposed areas have a yellow color, suggesting fumarolic activity and possible avalanche collapses of the ridge.

Rakkibetsudake [Demon]
Rakkibetsudake [Demon], along with the Pleistocene Kamui volcano, forms the northern peninsula of the NW end of Iturup Island. Gorshkov (1970) wrote that the large cone was built in the Holocene, with lavas that "flooded U-shaped valleys of the second glaciation" and late activity was "an eastward-directed explosion" followed by "subsequent erosion [that] cut a large canyon through from the caldera to the shore of Vries Strait." No subsequent work is known that supports this directed-blast interpretation of the existing partially filled scarp open to the ENE, or that describes any Holocene eruptions. Unlike Moyorodake volcano on the peninsula to the S, this volcanic complex is not included in the list of active volcanoes by the Japan Meteorological Agency (2013). It is listed as late Pleistocene by Nakano et al. (2001-).

Rudakov
The small Rudakov stratovolcano is on the NW side of the Tokotan Isthmus on the Sea of Okhotsk coast of central Urup Island. The basaltic andesite cone has a 500-m-diameter summit crater containing a 300-m-diameter lake. The age was considered to be late Pleistocene or early Holocene by Gorshkov (1970), but no later research is known that describes or dates eruption deposits.

Tri Sestry
The Tri Sestry ("Three Sisters") volcanic complex is located in the center of Urup Island, in the south-central Kuril Islands. Erosion of this andesitic massif has cut deep ravines on the flanks and produced multiple peaks around a river valley open to the NNE. The southern range of those peaks is known as Petr Shmidt Ridge. A summit lava dome was considered by Gorshkov (1970) to have been active during either the late Pleistocene or early Holocene; hot springs were reported along the coast to the NW. No later research is known that describes or dates eruption deposits.

Arkhangelsky
The Arkhangelsky volcanic massif, designated as "Volcano 6.12" in a catalog of submarine Kuril Arc volcanic centers (Avdeiko, 1992), is located in the Bussol Strait between Simushir and Urup Islands, E of Chirpoi. In their review of research on this volcano, Blokh et al. (2019) describes it as follows: "The size of the massif at the base is 39 x 22 km, and the flat top measuring 4 x 21 km is located at a depth of ~50?600 m." They also note that the edifice slopes are steep and uneven, with large landslide blocks at the SSE base. Based mainly on the flat eroded top, Blokh et al. (2019) stated that the massif, composed of basalts and basaltic andesites, "most likely formed no later than the late Pleistocene" when it was subject to a long period of erosion near sea level and then underwent subsidence.

Urbich Caldera
The 6-km-wide Urbich caldera (also known as Urumombetsu), formed during a Pleistocene interglacial period and hosts a freshwater lake. No activity has occurred during the Holocene (Gorshkov, 1970). Urbich partially overlies the Rokko caldera.

Tsirk
The 6-km-wide Tsirk caldera formed during the Pleistocene. The caldera floor contains a hot lake (Gorshkov 1970).

Antipin

Gora Desantnaya

Brontona Island
Pleistocene according to Gorshkov (1970) map.

Ikanmikot

Kuntomintar
Kuntomintar is a Pleistocene andesitic stratovolcano at the southern end of Shiashkotan Island in the central Kuriles. A central cone fills a 4-4.5 km caldera, whose rim is visible on the NE side. A second caldera on the west side is breached to the west. An Ainu village that reportedly was destroyed by an eruption in 1872 was later found to be located near Sinarka volcano (Gorshkov, 1970). The only known postglacial activity is continuous solfataric activity that originates near the east wall of the inner caldera and a nearby hot sulfur spring.

Shestakov
Shestakov is an eroded volcanic complex in the north-central part of Onekotan Island, south of the Nemo Peak caldera system. Gorshkov (1970) notes that this "massif was formed in preglacial times and then underwent glacial abrasion and postglacial erosion to such a degree that at present it is extremely difficult to restore its original form." No age information is known for the Shestakov volcanics, but it was not included in Gorshkov (1958, CAVW) or the IAVCEI Post-Miocene Volcanoes of the World (1973-80).

Avos' Rocks

Makanru Island
Mapped as Pleistocene (Gorshkov 1970).

Mashkovtsev
The small basaltic Mashkovtsev stratovolcano forms a peninsula on the Sea of Okhotsk near the southern tip of the Kamchatka Peninsula. It was considered Holocene by Masurenkov (1980), and there is a postglacial summit cone (Sviatlovsky 1959). Two basaltic cones are located to the north. This was not included by Ponomareva et al. (2007) in their review of Holocene volcanoes in Kamchatka.

Kell
Kell volcano is a small stratovolcano considered to be Holocene by Masurenkov (1980), located within the Prizrak caldera immediately north of Zheltovsky volcano. This remote volcanic complex consists of three partially nested 3-5 km wide calderas containing lava domes and several small stratovolcanoes, the largest of which is Kell. This was not included by Ponomareva et al. (2007) in their review of Holocene volcanoes in Kamchatka.

Belenkaya
Belenkaya is a small basaltic volcano considered to be Holocene by Masurenkov (1980) that lies SW of Ksudach and NW of Kell. The conical stratovolcano rises 700 m above a topographic low in the center of the southern Kamchatka Peninsula. This was not included by Ponomareva et al. (2007) in their review of Holocene volcanoes in Kamchatka.

Piratkovsky
Piratkovsky, identified by Masurenkov (1980) as a mid-Pleistocene to Holocene stratovolcano with a small caldera, is NE of Khodutka volcano. It partially overlaps Pleistocene volcanoes to the NW and lies at the eastern margin of the Quaternary volcanic chain of southern Kamchatka. This was not included by Ponomareva et al. (2007) in their review of Holocene volcanoes in Kamchatka.

Ostanets
The Ostanets shield volcano, considered to be Holocene by Masurenkov (1980), is located south of the Pleistocene Savan volcano surrounded by a large group of late-Pleistocene to Holocene cinder cones. Small pyroclastic cone groups also occur north and east of Igolki volcano, ~30 km SW of Savan. This was not included by Ponomareva et al. (2007) in their review of Holocene volcanoes in Kamchatka.

Otdelniy
The Otdelniy shield volcano, considered early Holocene by Masurenkov (1980), lies east of the Savan River, across from the Pleistocene Savan volcano. It, along with adjacent shield volcanoes and a large group of late-Pleistocene to Holocene basaltic pyroclastic cones, is about halfway between Khodutka and Opala volcanoes. Three groups of late-Pleistocene to Holocene pyroclastic cones and associated lava fields are also located along a roughly 20-km-wide area between the Opala and Savan rivers, SE, S, and SW of Opala. This was not included by Ponomareva et al. (2007) in their review of Holocene volcanoes in Kamchatka.

Golaya
Golaya is a small basaltic stratovolcano of Pleistocene-to-Holocene age (Masurenkov, 1980) south of Asacha volcano. It is elongated in a N-S direction and overlooks small shield volcanoes and cinder cones related to regional basaltic volcanism near the headwaters of the Asacha River. This was not included by Ponomareva et al. (2007) in their review of Holocene volcanoes in Kamchatka.

Karymshina
The large 15 x 25 km early Pleistocene Karymshina caldera is located SW of Petropavlovsk-Kamchatskiy and N of Gorely volcano. It produced about 800 km3 of rhyolitic ignimbrite about 1.78 million years ago, followed by rhyolitic post-caldera extrusive material (Bindeman et al, 2019). There are about a dozen extrusive domes surrounding the structure. Reported K-Ar dates from the domes are in the 2.2-0.5 Ma range. The Bolshe-Banny geothermal field is at the NW edge of the caldera area.

Vysokii
Vysokii and an unnamed volcano to the north are Pliocene stratovolcanoes with Pleistocene lava domes on or near their flanks (Masurenkov 1980).

Tumanniy
Tumanniy is a Pliocene-Pleistocene shield-like volcano with flank lava domes (Masurenkov 1980).

Ded i Baba
Ded i Baba (Ded and Baba) is an early Pleistocene shield-like volcano SW of Koshelev volcano; an unnamed mid-Pleistocene volcano with a small caldera breached to the east lies between these two volcanoes (Masurenkov 1980).

Tretya Rechka
Tretya Rechka is an early Pleistocene shield-like volcano with a small caldera open to the SE (Masurenkov 1980).

Kuzheten
Mid-Pleistocene shield-like volcano (Masurenkov 1980).

Kuzanek
Pliocene to lower Pleistocene shield-like volcano (Masurenkov 1980).

Igolki
Igolki and Bol'shiye Igolki are two lower to mid-Pleistocene shield-like volcanoes (Masurenkov 1980).

Skalistiy
Pliocene to lower Pleistocene shield-like volcano (Masurenkov 1980).

Perevalny
Perevalny is a small upper-Pleistocene shield volcano NNE of Khodutka volcano; an unnamed Pleistocene stratovolcano is located immediately NE of Perevalny (Masurenkov 1980).

Krugliy
Upper Pleistocene shield volcano (Masurenkov 1980).

Savan
Savan is a Pliocene to lower Pleistocene shield volcano (Masurenkov 1980).

Malaya Ipelka
Malaya Ipelka is an isolated mid to late-Pleistocene volcanic massif rising above the SW coastal lowlands north of the Opala River (Masurenkov 1980).

Kamen
Late-Pleistocene conical basaltic volcano (Masurenkov 1980).

Ploskiy
The conical early Pleistocene basaltic Ploskiy volcano is located west of Asacha volcano and north of a large group of late Pleistocene to Holocene pyroclastic cones (Masurenkov, 1980).

Vostochnaya Khodutka
Two lower to mid-Pleistocene shield-like volcanoes (Masurenkov 1980).

Zheltiy
Small conical late Pleistocene basaltic volcano (Masurenkov, 1980).

Tolmachev
Tolmacheva and Utes are conical basaltic volcanoes of late-Pleistocene age (Masurenkov 1980).

Udochka
Udochka is a mid-Pleistocene shield-like volcano SW of Opala (Masurenkov 1980).

Bolshaya Ipelka
Bolshaya Ipelka is a massive eroded lower Pleistocene shield-like volcano that covers a 32 x 42 km area west of the main volcanic zone of southern Kamchatka. A Holocene cinder cone on the SE flank is listed separately in this compilation.

Kirigamine
Kirigamine is a small shield volcano and lava dome (Wada-Toge) that lies west of Kita-Yatsugatake volcano and NW of Yatsugatake volcano. Kirigamine was active about 1.3-0.75 million years ago (Oikawa and Nishiki, 2005).

Utsukushigahara
Utsukushigahara, NE of Yatstuga-take, was active about 1.6-1.2 million years ago (Nakano et al., 2001-).

Kurofuji
The Kurofuji (Black Fuji) lava-dome complex and Kanaga-take and Kayaga-take stratovolcanoes active from about 1 million to 0.4 or 0.2 million years ago lie in Chichibu-Tama National Park north of the city of Kofu (Nakano et al., 2001-).

Yatsugatake
The older Yatsugatake volcano was active about 1 million years ago and the younger was active about 0.2 million years ago (Nakano et al., 2001). This complex of N-S-trending stratovolcanoes extends for about 10 km and is also known as Minami Yatsugatake ("Southern Eight Peaks") (Matsuhisa and Kurasawa, 1983). Both ends of the complex produced volcanic dry avalanche deposits (sector collapses of a volcanic cone), ranging from 0.27 to 9.0 km3 in volume(Tadahide, 1983). The volcanic rocks of the northern end generally consist of hornblende and pyroxene dacites, whereas those at the southern end are composed of olivine and pyroxene andesites. The volcanic products also contain xenoliths derived from a diverse assortment of basement rocks (Matsuhisa and Kurasawa, 1983). Extensive geochemical data is available from Matsuhisa and Kurasawa (1983).

Kamitakara
Kamitakara (or Takara) volcano was the source of deposits forming the Kamitakara pyroclastic flow plateau. The dacitic-to-rhyolitic deposits were erupted about 0.75 or 0.70 million years ago (Nakano et al., 2001-). Ono et al. (1981) listed a Potassium-Argon date of about 600,000 years.

Shirouma-Oike
The andesitic and dacitic Shirouma-Oike volcanic complex consists of the Norikura-dake stratovolcano and the Kazafuki-dake lava dome. An older volcano was active 0.8-0.5 million years ago and younger volcano was active since 0.2 million years ago (Nakano et al., 2001-).

Madarao
Madarao-yama is an andesitic-to-dacitic stratovolcano and lava domes that were active about 0.7-0.55 million years ago (Nakano et al., 2001).

Kurohime
Kurohime is a stratovolcano and associated lava domes south of Myoko volcano that were active from about 250,000 to 50,000 years ago (Nakano et al., 2001-).

Iizuna
Iizuna stratovolcano south of Kurohime volcano was active about 0.34-0.15 million years ago (Nakano et al., 2001-).

Motodori
The andesitic Motodori-yama lava dome was active about 0.2 million years ago (Nakano et al., 2001-).

Minakami
Minakami-yama lava dome was active about 0.3 million years ago (Nakano et al., 2001-) and is a post-caldera dome of Matsushiro volcano.

Eboshi
The Eboshi volcano group immediately west of Asama volcano includes a group of andesitic-to-dacitic stratovolcanoes and lava domes that were active about 0.97-0.35 million years ago (Takahashi and Miyake, 2004; Takahashi, 2004).

Hanamagari
The andesitic Hanamagari-yama and neighboring Asamakakushi-yama stratovolcanoes immediately east of Asama volcano were active about 1.1-0.7 million years ago (Nakano et al., 2001-).

Azumayasan
Azumayasan is an andesitic stratovolcano and lava dome that was active about 0.9-0.3 million years ago (Nakano et al., 2001-). A plinian eruption took place about 0.3 million years ago.

Omeshidake
The andesitic Omeshidake stratovolcano west of Kusatsu-Shirane volcano was active about 1.1 million years ago (Nakano et al., 2001-).

Takayashiro
Takayashiro-yama is an andesitic stratovolcano that was active about 0.3-0.2 million years ago (Nakano et al., 2001-).

Sekita
Volcano type: Stratovolcano?
The andesitic Sekita volcano was active about 1.7-1.1 million years ago (Nakano et al., 2001-).

Kenashi
Kenashi-yama is an andesitic stratovolcano active about 1.6-1.0 million years ago (Nakano et al., 2001-).

Torikabuto
The andesitic Torikabuto-yama stratovolcano was active about 0.9-0.7 million years ago (Nakano et al., 2001-).

Naeba
The andesitic Naeba-san stratovolcano and caldera was active about 0.8-0.2 Ma (Nakano et al., 2001-).

Iiji
The andesitic Iiji-san stratovolcano was active about 0.3-0.2 million years ago (Nakano et al., 2001-). The Iiji Moka Pumice was erupted about 0.22-0.23 million years ago.

Masugata
The andesitic Masugata-yama pyroclastic cone and lava flow was active about 1.1 million years ago (Nakano et al., 2001-).

Komochi-Onoko
The Komochi-Onoko volcano group NW of Maebashi City consists of the andesitic Komochi-yama stratovolcano and lava dome on the east and andesitic Onoko-yama stratovolcano on the west. Komochi-yama was active from about 0.9-0.2 million years and Onoko-yama from about 1.3-1.2 million years (Nakano et al., 2001-).

Kinunuma-Nenakusa
The dacitic Kinunuma volcano produced a lava flow and pyroclastic flow about 0.24 or 0.20 million years ago. The Kinunuma-Kurodahara tephra consists of pumice fall deposits (~5 km3) and mostly-welded pyroclastic flow deposits (less than 1 km3), erupted at 0.20-0.24 Ma. Andesitic and dacitic lava domes of the Nenakusa-yama volcano to the SE were active about 0.3 million years ago.

Sukai-Kesemaru
The basaltic-to-dacitic Sukai stratovolcano was active about 1.6-0.9 million years ago (Nakano et al., 2001-). Koshin-zan volcano is part of the Sukai edifice, and activity of the roughly 1-million-year-old Kesemaru-yama volcano to the south overlapped with activity at Sukai-san volcano.

Numanokami
The andesitic Numanokami-yama stratovolcano was active about 1.1 million years ago (Nakano et al., 2001-).

Hotaka
The andesitic-to-dacitic Hotaka-yama volcano (also known as Joshu-Hotaka) was active about 1.2-1 million years ago (Nakano et al., 2001-).

Ayame-daira
The Ayame-daira stratovolcano south of Ozegahara in Nikko National Park was active about 1.6 million years ago (Nakano et al., 2001-). Nikura-yama volcano lies to the SE.

Nyoho-Akanagi
Nyoho and Akanagi volcano consists of a basaltic-to-dacitic stratovolcano and lava dome active about 0.5-0.4 million years ago (Nakano et al., 2001-).

Sunagohara
The rhyolitic Sunagohara caldera and lava dome, east of Numazawa caldera, was active about 0.29-0.22 million years ago (Nakano et al., 2001-). The Sunagohara-Kubota tephra is made up of pumice fall deposits (ca. 4 km3 in volume) and pyroclastic flow deposits (more than 2 km3 in volume), erupted from Sunagohara caldera at about 0.22Ma.

Nekoma
The andesitic Nekoma volcano, immediately W of Bandai, was active about 1-0.8 million years ago (Nakano et al., 2001-). The caldera is about 3 km in diameter and contains a lake on the western side.

Futamata
Futamata-yama is a late Pleistocene (about 140,000 or 90,000 years old) stratovolcano and lava dome (Nakano et al., 2001-). A thick lava flow extends to the NW. It is located within the Quaternary Tonohetsuri caldera (Yamamoto, 1995; 2007). The oval-shaped Narioka caldera cuts the western rim of Tonohetsuri caldera and the western rim of the older Ono caldera. These large calderas were formed during eruption of the Kumado, Ashino, and Nishigo pyroclastic flows about 1.4, 1.2, and 1.0 million years ago, respectively.

Aizu Nunobiki
Aizu Nunobiki-yama is an andesitic-to-dacitic stratovolcano that was active about 1.4 million years ago (Nakano et al., 2001-).

Asakusa
Asakusa-dake is an andesitic-to-dacitic stratovolcano active about 1.7-1.5 million years ago (Nakano et al., 2001-).

Sumon
Sumon volcano is an andesitic stratovolcano active about 2.4-1.7 million years ago (Nakano et al., 2001-). The main part of the edifice of Sumon-dake was constructed during the early Quaternary.

Aoso
Aoso volcano is an andesitic-to-dacitic stratovolcano at the SE end of the Zao massif. Aoso-yama was active about 0.4-0.3 million years ago (Nakano et al., 2001-). Aoso was constructed within a Pleistocene caldera.

Mukaimachi
Mukaimachi is a dacitic and andesitic caldera with a post-caldera lava dome. Post-caldera activity at Mukaimachi took place about 0.8-0.6 million years ago Nakano et al., 2001-).

Shirataka
Shirataka is an andesitic-to-dacitic stratovolcano NW of the Zao volcanic massif. Shiratakayama was active about 0.9-0.7 million years ago. Growth of a stratovolcano was followed by emplacement of a pyroclastic flow and growth of lava domes. Late-stage collapse produced a large debris avalanche and formed a 4-km-wide breached crater.

Ganto-Kamuro
Ganto and Kamuro volcanoes form the Kita-Zao (North Zao) volcano group. They were active about 0.4-0.3 million years ago (Nakano et al., 2001-).

Adachi
Adachi is a dacitic pyroclastic cone that was the source of the Adachi-Medeshima pumice deposit about 80,000 years ago (Nakano et al., 2001-).

Daito
Daito volcano is an andesitic stratovolcano NNE of the Zao volcanic massif. Daito-dake was active about 1 million years ago (Nakano et al., 2001-).

Funagata
The Funagata volcanic complex consists of two basaltic-to-andesitic stratovolcanoes NW of Sendai City. Funagata-yama was active about 0.9-0.5 million years ago and Izumiga-take volcano about 1.5-1.1 million years ago (Nakano et al., 2001-).

Gassan
Gassan is a massive andesitic-to-dacitic stratovolcano south of Chokai volcano that was active about 900,000-300,000 years ago (Nakano et al., 2001-). It was constructed with a large Pleistocene caldera.

Onikobe
Onikobe caldera, located SW of Kurikoma volcano, is one of the few calderas in Japan with evidence of ring fractures and a resurgent dome. The Takahinata lava dome was last active about 350,000 years ago according to a fission-track date. Onikobe was active until about 0.2 million years ago (Nakano et al., 2001-). Geysers were said to be discovered about 1700 years ago at Onikobe, and geysers and hot springs are present today within the caldera.

Takamatsu
Takamatsu volcano (Takamatsu-dake) is a dacitic stratovolcano active about 0.3 million years ago (Nakano et al., 2001-). Takamatsu was constructed within a Pliocene caldera.

Kobinai
Kobanai volcano (Kobinai-yama) is an andesitic-to-dacitic stratovolcano active about 1-0.6 million years ago (Nakano et al., 2001-).

Yakeishi
Yakeishi volcano (Yakeishi-dake) is an andesitic stratovolcano that was active about 1-0.2 million years ago (Nakano et al., 2001-).

Tazawa
Volcano type: Caldera(?)
Tazawa was considered to be a late-Pleistocene caldera (Japan Assoc. Quat. Res. 1987), however Nakano et al. (2001-) noted that it is uncertain whether the depression was formed by volcanic activity. The elevation listed is that of the surface of Tazawa lake.

Kayo
Early or mid-Pleistocene (Japan Assoc. Quat. Res., 1987).

Nyuto-Takakura
The Nyuto-Takakura volcano group consists of Nyuto-san, Takakura-yama, Hiragakura-yama, Marumori, Sankagu-yama, Sasamori-yama, Yumori-yama volcanoes. The basaltic-to-dacitic volcano group was active about 0.6-0.1 million years ago (Nakano et al., 2001-).

Tamagawa
The dacitic and rhyolitic Tamagawa caldera was the source of the Tamagawa Ignimbrite associated with formation of a pre-Yaka-yama caldera. The caldera was active about 2 million and 1 million years ago (Nakano et al., 2001-).

Nanashigure
Nanashigure volcano is a Pleistocene pyroclastic-flow plateau and lava dome. Nanashigure-yama was active about 1.1-0.9 million years ago (Nakano et al., 2001-).

Daira-Komagatake
Daira-Komagatake is an andesitic stratovolcano active about 0.2 million years ago (Nakano et al., 2001-).

Tashiro
Tashiro-dake is an andesitic stratovolcano and lava dome that is younger than about 0.6 million years (Nakano et al., 2001-).

Moriyoshi
Moriyoshi-zan is a basaltic-to-dacitic stratovolcano and lava dome that was active about 1.1-0.7 million years ago (Nakano et al., 2001-).

Kanpu
The small Kanpu stratovolcano lies on the Oga Peninsula along the western coast of Honshu NW of Akita City. It was at one time considered to be Holocene, but later work has shown it to be late Pleistocene. Accounts of radiocarbon dates of about 2,700 years BP for a pumice eruption followed by a pyroclastic flow (Hasenaka et al., 1992) have been revised, and the report on the 1810 "eruption" submitted to the Shognate was created by the people of the Akita Clan in Edo (present Tokyo) in order to receive reimbursement for damaged crops. Nakano et al. (2001-) list the age of Kanpu as less than 30,000 years, and Kudo and Hoshizumi (2006-) listed no Holocene eruptions. Kanpu produced mostly andesites (Notsu, 1983).

Okiura
The 15-km-wide Okiura caldera was formed by the eruption of the Aoni Tuff about 1.5 million years ago. Post-caldera volcanoes comprise several lava domes including Kenashi-yama.

Mutsu-Hiuchidake
Mutsu-Hiuchidake, on the Shimokita Peninsula, is the northernmost volcano on the island of Honshu. The andesitic-dacitic stratovolcano is Pleistocene in age, with dated activity during an interval ranging from about 700,000 to 50,000 years ago, although fumarolic activity continues.

Esan Maruyama
Esan Maruyama, an andesitic stratovolcano lying NW of E-san volcano, was active about 0.2 million years ago (Nakano et al., 2001-).

Yokotsu
Most of Yokotsu-dake volcano formed during the Pliocene, but Nakitsura-yama on the east side was probably constructed during the late Quaternary (Nakano et al., 2001-).

Oshima-Kojima
Oshima-Kojima, also known as Matsumae-Kojima, is an andesitic stratovolcano whose summit forms a small island off the SW tip of Hokkaido (Nakano et al., 2001-).

Oshima Maruyama
Oshima Maruyama, a Pleistocene stratovolcano and lava dome near the SW tip of Hokkaido, was active from about 2.5-1.5 million years ago.

Hakodateyama
Hakodateyama, a low dacitic stratovolcano, rises above the city of Hakodate in SW Hokkaido.

Zenikame
A 2-km-wide shallow submarine caldera just off the SW tip of Hokkaido, SE of Hakodate City reaches to within 30 m of the ocean surface. It was the source of the Zenikame-Menagawa (Z-M) tephra about 33,000-45,000 years ago.

Nigorikawa
The Mori geothermal field is located in the late-Pleistocene Nigorikawa caldera in SW Hokkaido. The small 3-km-wide caldera along the shores of Uchiura Bay WNW of Komagatake volcano, was formed during a major explosive eruption about 12,000 years ago. The caldera-forming eruption included the emplacement of pyroclastic-fall and -surge deposits and pyroclastic-flow deposits that extend north and west to the Pacific coast. The flat-bottomed caldera floor is intersected by roads and houses of the town of Nigorigawa, and a river of the same name drains the caldera to the NE through a notch in the caldera rim.

Okushiri-Katsumayama
Okushiri-Katsumayama volcano lies at the northern end of Okushiri Island off the SW coast of Hokkaido and consists of three centers, Horonaigawa caldera, Katsumayama and Nishi-Katsumayama. They were active about 0.7-0.2 million years ago (Kano et al., 2006).

Kariba
Kariba-yama, an andesitic stratovolcano along the SW coast of Hokkaido, was active about 0.8-0.25 million years ago (Nakano et al., 2001-).

Washibetsu
Washibetsu-dake volcano, an andesitic stratovolcano SE of Usu volcano, was active about 0.5 million years ago (Nakano et al., 2001-).

Akaigawa
Akaigawa, a late-Pliocene double caldera containing several somma volcanoes, was active about 1.7-1.3 million years ago (Nakano et al., 2001-).

Shiribetsu
Shiribetsu volcano, located immediately SE of Yotei volcano in southwestern Hokkaido, is a small, 1107-m-high andesitic stratovolcano that contains a 1.5-km-wide crater breached widely to the west. It was created by a massive debris avalanche that removed the summit and swept more than 7 km to the west, forming a hummocky deposit at the SE foot of Yotei volcano. Shiribetsu volcano was mapped as Holocene in age (Japan Association of Quaternary Research, 1987), however Nakano et al. (2001-) list its age as several hundred thousand years.

Orofure-Raiba
The Orofure-Raibe volcano group consists of Orofure-yama and Raibe-dake andesitic stratovolcanoes lying immediately west of Kuttara volcano. They were active about 0.6 million years ago (Nakano et al., 2001-).

Horohoro-Tokushumbetsu
The andesitic Horohoro-yama and Tokushumbetsu volcanoes were active about 0.7 or 0.6 million years ago (Nakano et al., 2001-).

Raiden
The Raiden-yama volcano complex along the SW coast of Hokkaido consists of Raiden-yama, Iwanai-dake and Mekunnai-dake volcanoes and was active about 1.4-0.8 million years ago (Nakano et al., 2001-).

Soranuma
Soranuma, a small andesitic shield volcano and lava flow, was active about 0.8 million years ago (Nakano et al., 2001-).

Sapporo
Sapporo volcano (Sapporo-dake), a small andesitic shield volcano and lava flow, was active about 0.8 million years ago (Nakano et al., 2001-).

Dorobu
The Dorobu caldera, 13 x 6 km in diameter, is located within the southern part of NE Honshu about 10 km W of Takaharayama volcano. Miura and Tamai (1998) note that many other volcanoes formed during the late Miocene-Pliocene are within a 40 x 40 km area known as the Minami-Aizu geothermal field, including Okukinu, Kawaji, Yunishigawa, Tokusa, Yaso, Sannotoge, and Furumachi. Based on K-Ar ages, Dorobu is thought to have been active from the early Pliocene into the Pleistocene (5.59-1.79 Ma).

Nanzaki
Nanzaki (also known as Ikenohara) is a basaltic pyroclastic cone at the southern tip of the Izu Peninsula dated at about 450,000 or 400,000 years (Nakano et al., 2001-).

Jaishi
Jaishiyama is a small andesitic shield volcano with a lava flow dated at about 1.4-1.3 million years (Nakano et al., 2001-).

Tanaba
Tanaba-yama is an andesitic stratovolcano dated at about 1.5-1.2 million years (Nakano et al., 2001-).

Daruma
Daruma-yama is an andesitic stratovolcano dated at about 0.8-0.5 million years (Nakano et al., 2001-). Ida volcano and the underlying Osezaki volcano lie to the north at the NW tip of the Izu Peninsula.

Tenshi
Tenshi is an andesitic and dacitic stratovolcano dated at about 1.7-1.4 million years (Nakano et al., 2001-).

Usami
Usami is a basaltic-to-andesitic stratovolcano north of the Izu-Toba volcano group dated at about 0.9 to 0.4 million years (Nakano et al., 2001-).

Taga
Taga is an basaltic-to-andesitic stratovolcano SW of Atami City dated at about 0.7-0.3 million years (Nakano et al., 2001-).

Yugawara
Yugawara is an andesitic and basaltic stratovolcano south of Hakone volcano dated at about 0.4-0.2 million years (Nakano et al., 2001-).

Ashitaka
Ashitaka-yama is a large basaltic-to-dacitic stratovolcano and lava dome SE of Fuji that was active from about 0.4-0.1 million years ago (Nakano et al., 2001-).

Udonejima
Udonejima, though technically part of the Izu Volcanic Arc, is actually considered to be situated just behind the true volcanic front, along a line of volcanoes that is oblique to the Izu Trench. The volcanic rocks of this lineament are characterized by high-alumina basalts, calc-alkaline basalts, andesites, and rhyolites (Onuma et al., 1983). The andesites are rich in pyroxene, and the rhyolites often contain hypersthene, hornblende, and biotite (Onuma et al., 1983).

Inambajima

Onoharajima
Onoharajima is considered to be situated behind the true front of the Izu Volcanic Arc, along a line of volcanoes that is oblique to the Izu Trench. The volcanic rocks of this lineament are characterized by high-alumina basalts, calc-alkaline basalts, andesites, and rhyolites (Onuma et al., 1983). Onoharajima is dominated by andesites of calc-alkaline composition (Onuma et al., 1983).

Mikura Seamount

Nichiyo Seamount
Nichiyo, one of the Shichiyo Seamounts, named for the seven days of the week ("Sunday"), lies south of Sofugan volcano. No hydrothermal activity or other unrest has been noted here, but it is assumed to be at least Pleistocene.

Getsuyo Seamount
Getsuyo, one of the Shichiyo Seamounts, named for the seven days of the week ("Monday"), lies south of Sofugan volcano. No hydrothermal activity or other unrest has been noted here, but it is assumed to be at least Pleistocene.

Kayo Seamount
Kayo, one of the Shichiyo Seamounts, named for the seven days of the week ("Tuesday"), lies south of Sofugan volcano. No hydrothermal activity or other unrest has been noted here, but it is assumed to be at least Pleistocene.

Kinyo Seamount
Kinyo, one of the Shichiyo Seamounts, named for the seven days of the week ("Friday"), lies south of Sofugan volcano. No hydrothermal activity or other unrest has been noted here, but it is assumed to be at least Pleistocene.

Tracey Seamount
The conical Tracey Seamount, ~50 km W of the northern end of Guam, had pumice dredged from the summit (Corwin, 1971).

Kasuga 3
Kasuga 3 is the southern-most of three volcanoes forming the Kasuga seamount chain, which trends SSW from the volcanic front of the Izu-Marianas arc. Embley et al. (2004) found no evidence of continuing hydrothermal activity.

Eifuku
Seamount N of Daikoku in the northern Marianas Arc.

Syoyo Ridge
Submarine volcanic ridge with eight peaks or seamounts along the East Mariana Ridge between Nikko and Fukujin. Unknown eruptive history.

South Daikoku
Seamount about 50 km SE of Daikoku. Unknown eruptive history.

Chamorro
Volcano type:
Seamount about 35 km NW of Farallon de Pajaros. Unknown eruptive history.

Cheref
Seamount about 30 km SSE of Asuncion Island. Eruption history is unknown.

Poyo
Seamount about 50 km SSE of Asuncion Island. Eruption history is unknown.

Southwest Pagan
Submarine volcanic edifice ~25 km SW of Pagan Island.

West Guguan
Submarine volcanic edifice ~28 km WSW of Guguan Island.

Northwest Zealandia
Submarine volcanic edifice ~18 km NW of Zealandia Bank.

West Zealandia
Submarine volcanic edifice ~14 km W of Zealandia Bank.

West Sarigan
Submarine volcanic edifice ~15 km WNW of Sarigan Island.

West Diamante
Submarine volcanic edifice ~50 km SSW of Anatahan Island.

West Saipan
Submarine volcanic edifice ~30 km NW of Saipan Island with a summit crater ~1.5 km in diameter.

West Tinian
Submarine volcanic edifice ~15 km WNW of Tinian Island.

West Rota
Submarine volcanic edifice ~35 km NW of Rota Island with an elongate 5 x 10 km summit caldera.

Northwest Guam
Submarine volcanic edifice ~55 km WSW of Rota and ~45 km NW of Guam islands.

Sone
A basaltic scoria cone lies along the W coast of the northern peninsula of Nakadori-jima of the Goto Islands off the western coast of Kyushu (Nakano et al., 2001-). It is described in the GSJ database (2015) as an isolated monogenetic volcano distinct from the Ojikajima volcano group to the N, with the most recent activity in the middle Pleistocene (0.19 Ma). It is designated as a natural monument, Sone volcano "red fired cliff" after the a cliff face along the bay to the SW from the summit. The villages of Sonego and Sone lie on the NW flank of the cone.

Ojikajima
Ojikajima is a field of monogenetic cinder cones located about 200 km behind the active volcanic front (Sudo et al., 1998). Ojikajima itself is a shield volcano forming a relatively flat island about 36 km2 in area, containing a variety of small peaks and pyroclastic cones ranging from 50 to 110 m high (Sudo et al., 1998; Nakano et al., 2001). The products of this volcanic group, considered to be cogenetic, are predominantly scoria deposits and lava flows (Sudo et al., 1998). The scatter of small islands surrounding Ojikajima are considered part of the Ojikajima Volcanic Group as well (Sudo et al., 1998). The 1.3-1.1 Ma Ukujima stratovolcano occupies an island to the north (Nakan et al., 2001; Sudo et al.,1998). Based on K-Ar ages (Nakano et al., 2001; Sudo et al., 1998) and the local geology, the eruptive history is divided into four stages: 1 (1.1-0.85 Ma): the most voluminous eruptive phase, with activity concentrated at the center of the field; 2 (0.85-0.7 Ma): after a possible volcanic hiatus between 0.95 and 0.76 Ma, activity resumes in the center of the field; 3 (0.7-0.56 Ma): volcanic activity expands to the adjacent eastern and western islands; 4 (0.56-0.3 Ma): volcanic activity continues but at a lower intensity (Sudo et al., 1998). Volcanism in this field is likely a result of a mantle diapir (Sudo et al., 1998).

Taradake
Taradake is a stratovolcano and lava dome NW of Unzen volcano that was active mostly between 1.3 and 0.4 million years ago (Nakano et al., 2001). Mainly basalt was erupted from about 4.6 to 1 Ma. At this point, a stratovolcano formed, erupting calc-alkaline andesites and dacites. Basaltic volcanism resumed at around 0.8 Ma, and from 0.6 to 0.4 Ma was mostly andesitic lavas (Higo and Mashima, 2004).

Kinpo
The Kinpo stratovolcano and lava dome were active from about 1.4 to 0.18 million years ago (Toshida et al., 2006). In total it is about 150 km2 in area and comprised of four main cones and some lava domes (Yanagi et al., 1988). Deposits mainly consist of andesitic lava flows and pyroclastics, the latter of which are more heavily dissected (Yanagi et al., 1988).

Yabakei
The largely buried Yabakei caldera (also known as the Shishimuta caldera), a member of the Hohi Volcanic Zone, was the source of two major Pleistocene explosive eruptions producing the dacitic Yabakei (0.1 Ma) and Imaichi (0.9 Ma) pyroclastic flows (Hayashida et al., 1996; Kamata, 1989). The Yabakei pyroclastics take the form of densely welded tuffs, originally more than 110 km3 in total volume, and crop out over an area of about 480 km2 (Kamata, 1989). The 8-km-diameter funnel-shaped caldera is filled with breccia and shows no evidence of resurgent volcanic activity after these two caldera eruptions. However, post-caldera monogenetic activity appears to have continued for about 600,000 years after the caldera activity (Kamata, 1989).

Haneyama
Haneyama and Kameishiyama are rhyolitic and dacitic volcanoes dated between 0.6 and 0.5 million years (Nakano et al., 2005).

Hohi
The Hohi volcanic group was Potassium-Argon age dated at about 600,000 - 400,000 years (Nakano et al., 2001-).

Futago
The Futago volcano group consists of several lava domes and a lava plateau with ages of 1.5-1.1 million years forming a peninsula NE of Beppu City (Nakano et al., 2001-).

Himeshima Volcanic Group
The Himeshima volcano group north of the northern coast of Kyushu consists of lava domes and pyroclastic cones active from 350,000 to 20,000 years ago (Nakano et al., 2001-).

Kurose
Volcano type: Volcanic remnant
Small basaltic islets forming a volcanic neck rise only 8 m above sea level north of Genkaijima off the NW coast of Kyushu and are dated at about 1.13 +/- 0.12 million years (Nakano et al., 2001; Yokochi et al., 2005). Kurose is actually a small reef, formed from a highly eroded lava flow and columnar basalts (Yokochi et al., 2005). It is known for its ultramafic xenoliths, rich in olivine and pyroxene, which have been extensively studied geochemically for insight into the origin of these back-arc magmas (Senda et al., 2007).

Iki Volcanic Group
A group of pyroclastic cones on Iki Island NW of Kyushu was active from the Pliocene to about 600,000 years ago (Nakano et al., 2001). However, volcanic activity here began around 15 Ma as the back-arc basin began to open, producing mostly basaltic lavas (Kimura et al., 2005). The Iki volcanic group is part of a Quaternary alkaline province in northwestern Kyushu; the volcanic compositions range from basaltic to rhyolitic (Aoki and Oji, 1966).

Oki-Dogo
Dogo, one of the Oki islands, is located north of the SW Honshu city of Matsue off the west coast of Japan. Some of the alkaline basalts on the island contain abundant mantle xenoliths. No unambiguous volcanic features are visible, though Tomita (1969) described a shield volcano and cinder cone. Reportedly the Daimanji-san lava flow overlies alluvial gravel containing an ancient water-jar, and the name Takuhi-yama ("Burning Mountain") may record a tradition of an eruption. The Misaki Basalt Group of lava flows form a small flat peninsula on the SW side of the island where the airport is located. Uto et al. (1994) identified the Misaki basalts as the youngest on the island, with a K-Ar date of about 550,000 years.

Washiba-Kumonotaira
The Washiba-Kumonotaira volcano group consists of a cluster of small shield volcanoes with possible lava domes in a remote area in Chubu Sangaku National Park in the heart of the Northern Japan Alps. Iwagokekodani, an older Kumonotaira volcano was active from about 1-0.9 million years (Ma). The younger Kumonotaira volcano was active about 300-100 ka. Washiba-ike volcano is younger than 120 ka (Nakano et al., 2001-). Hayakawa (2009 pers. comm.) indicated that the Washiba-ike explosion crater was formed in an area that post-dates the latest Pleistocene glaciation, and produced a tephra layer consisting of accretionary lapilli and fresh volcanic bombs. However, the Japan Meteorological Agency (2013) did not include it in their national catalogue of Holocene volcanoes.

Mutsurejima
A lava flow dated at about 1.2 million years forms Mutsurejima island just off the SW tip of Honshu (Nakano et al., 2001-). Kifune volcano (1.6 or 1.3 million years old), 7 km E, consists of basaltic scoria cones and lava flows.

Shikuma
Shikuma volcano consists of Shikumaga-take (dated at about 450,000 years ago) and Dake-yama lava domes (Nakano et al., 2001-).

Tokuyama-Mitake
Tokuyama-Mitake is a lava dome in SW Honshu dated at about 0.43 million years (Nakano et al., 2001-). It is also known as Mitake-yama or Kinpo-san.

Sengoku
The Sengoku volcano group consists of a group of four mid-Pleistocene lava domes active from about 0.5 to 0.36 million years ago (Nakano et al., 2001-).

Chojagahara
Chojagahara is a 1.7 million year old pyroclastic cone and lava flow (Nakano et al., 2001-).

Aonoyama
The Aonoyama volcano group consists of about 10 lava domes from about 1.3 to 0.15 million years in age (Nakano et al., 2001-). The volcanic products have a narrow chemical composition similar to that of Daisen and consist of biotite and hornblende andesites that often contain granulitic inclusions (Matsuhisa and Kurasawa, 1983).

Oetakayama
Oetakeyama consists of a group of lava domes active from about 1.8 to 0.8 million years ago (Nakano et al., 2001-). Kano and Takarada (2007) noted late-Pliocene to early Pleistocene activity, including at the early Pleistocene Senyama pyroclastic cone north of the Oetakayama (O'e-Takayama). The latest activity noted was K-Ar dated at about 1.8-1.6 million years.

Yokote
The Yokote volcano group was active between about 2.3 and 0.9 million years and consists of 10 monogenetic volcanoes (Nakano et al., 2001-).

Noro
The Noro basaltic lava flow was erupted about 1.1 million years ago from a monogenetic volcano (Nakano et al., 2001-).

Daikonjima
A scoria cone and lava flow at Daikonjima was erupted about 250,000 or 200,000 years ago (Nakano et al., 2001-).

Tsuruta
The Tsuruta volcano group consists of a group of scoria cones about 1.2 million years in age aligned NW-SE, including the Takatsuka-yama cone (Nakano et al., 2001-).

Daisen
Daisen volcano, along the northern coast of SW Honshu, has been the source of large explosive eruptions during the late Pleistocene. The last dated major eruption took place about 17,000-18,000 years before present, but at least one large tephra deposit is younger (Machida and Arai, 1992). Although included in a list of volcanoes with eruptions in the past 2,000 years (Hayakawa, 1994a), that list includes some youthful volcanoes that are not Holocene, and the latest eruption of Daisen occurred during the late Pleistocene (Hayakawa 1996, pers. comm.). The volcanic products mostly consist of biotite and hornblende andesites (Matsuhisa and Kurasawa, 1983).

Ogino-Sen
The Ogino-Sen volcano group in eastern Tottori Prefecture consists of 20 monogenetic volcanoes from 1.2 to 0.4 million years in age (Nakano et al., 2001-). The adjacent Mikata volcano group in western Hyogo Prefecture consists of 8 monogenetic volcanoes from 1.7 to 0.22 million years in age.

Kannabe
The Kannabe volcano group is the westernmost and youngest of a cluster of monogenetic volcanoes that are part of the Kita-Tajima volcano group in Hyogo Prefecture, along with Mesaka, Kamisano, and Gembudo volcanoes. A radiocarbon age of 19,000 years before present was obtained from the small shield volcano of Kannabe-yama (Ono et al., 1981), and Nakano et al (2001-) listed an age of 20,000 or 10,000 years. Mesaka volcano was dated at 130,000 years, Kamisano volcano at 230,000 years, and Gembudo (Genbudo) at about 1.6 million years (Nakano et al., 2001-). Other more isolated volcanoes of the Kita-Tajima volcano group, such as the Ogino-Sen and Mikata volcano groups and Takara-yama, are listed separately in this compilation.

Takara
Takara-yama (also known as Takura-yama) is a small shield volcano topped by a pyroclastic cone and was active about 0.4 or 0.3 million years ago (Nakano et al., 2001-). It is the SE-most volcano of the Kita-Tajima volcano group in SW Honshu.

Ueno
Ueno volcano is a small basaltic-to-andesitic shield volcano and lava flow that was active about 1.6 or 1.5 million years ago (Nakano et al., 2001-). Ono et al. (1981) listed a Potassium-Argon date of <110,000 thousand years ago.

Yuga-mine
Yuga-mine is a rhyolitic lava dome SW of On-take volcano that was active about 0.1 million years ago (Nakano et al., 2001-).

Eboshi-Washigatake
Eboshi and Washigatake are early Pleistocene andesitic stratovolcanoes active about 1.6-1.1 million years ago (Nakano et al., 2001-).

Bishamondake
Bishamondake is an andesitic stratovolcano active about 0.4-0.25 million years ago (Nakano et al., 2001-).

Dainichigatake
Dainichigatake is an andesitic-to-dacitic stratovolcano that was active about 1.1-0.9 million years ago (Nakano et al., 2001-).

Ryohaku Maruyama
Ryohaku Maruyama (named to distinguish from Maruyama volcano in Hokkaido) is an andesitic stratovolcano active about 0.4-0.3 million years ago (Nakano et al., 2001-).

Gankyoji
Gankyoji-yama is a Pliocene-Pleistocene andesitic stratovolcano active until about 1.3 million years ago (Nakano et al., 2001-).

Kyogatake
The Kyogatake volcano group consists of andesitic stratovolcanoes active about 1.4-0.7 million years ago (Nakano et al., 2001-).

Dainichiyama
Dainichiyama is an early Pleistocene andesitic stratovolcano west of Haku-san volcano (Ono et al., 1981). This volcano was not listed by Nakano et al. (2001-).

Tomuro
The Tomuro lava-dome complex contains four domes that were active from about 0.4-0.3 million years (Nakano et al., 2001-).

Kaminoroka
Kaminoroka volcano produced andesitic and dacitic lava flows about 0.4-0.2 million years ago (Nakano et al., 2001-).

Hodakadake
Hodakadake, the highest of a rugged group of peaks in the scenic Northern Alps National Park, lies within the Hodaka Graben, the source of two major explosive eruptions about 1.75 million years ago. The eruption of the caldera-forming Nyukawa Pyroclastic Flow Deposit about 1.76 million years ago (Kimura and Nagahashi, 2007) was followed by the Ebisutoge-Fukuda Tephra, with an estimated volume of 380-490 km3 (Kataoka et al., 2001).

Momisawadake
Momisawadake volcano in the Northern Japan Alps was the source of a dacitic-rhyolitic pyroclastic-flow plateau. The complex includes the Sueindani vent and the Okuhida pyroclastic-flow deposit and was active sometime between about 0.65 and 0.3 million years ago (Nakano et al., 2001-).

Tsaolingshan
Taiwan
Tsaolingshan volcano was active during the late Pleistocene (Wang et al., 1999).

Chilung Group
The Chilung volcano group (also spelled Keelung) is of Pleistocene age (Ho, 1988; Wang et al., 1999).

Pengchiahsu
Pengchiahsu is one of five small Pleistocene volcanic islands NE of Taiwan. The summit of the andesitic island (also known as Agincourt) reaches only 129 m above sea level. The age of volcanism is considered to be Pleistocene, but it was reported to display fumarolic activity (Volcanological Society of Japan, 1971). However, there are no more recent reports of fumaroles or other indications of ongoing unrest as of 2015, and the Central Geological Survey makes no mention of them, though it does for other locations.

Huapinghsu
The island of Huapinghsu is thought to be of Pleistocene age (Ho, 1988).

Mienhuayu
Meinhuayu was active from about 0.5 to less than 0.1 million years ago (Wang et al., 1999).

Kogajajima
The small volcanic island of Kogajajima (Little Gaja Island), about 20 km WNW of Nakanoshima, has andesitic lava domes that were considered to be of late-Pleistocene to Holocene age (Nakano et al., 2001-), and a K-Ar date of 28 +/- 6 ka was reported by Matsumoto et al. (2006). Hydrothermal alteration along with several fumaroles and hot springs were noted during fieldwork in 2005 and 2006 by Nakano and Geshi (2008).

Kobi-sho
Kobi-sho stratovolcano breaches the surface of the East China Sea to form a small 1-km-wide island. A few craters are present, but thin basalt flows make up the majority of the island. These basalts are typically porphyritic, characterized by phenocrysts of plagioclase (dominant), olivine, and clinopyroxene (Shinjo, 1998). It was probably active less than a few tens of thousand years ago, but is generally less than 0.2 million years old (Nakano et al., 2001; Shinjo, 1998).

Gajajima
The andesitic Gajajima stratovolcano lies east of the main Ryukyu arc, 30 km WNW of Nakanoshima. The age of the volcano is mid-Pleistocene (Nakano et al., 2001-, mistranslated in the English version as late-Pleistocene to Holocene). Kogajajima (Little Gaja Island) lies 8 km ESE.

Tokara Hirase
Takara Hirase is a group of small islets along a NE-SW trend NE of Kuchino-shima. The highest islet reaches 27 m above sea level above a 600-m-high submarine rise. The rocks are altered but were considered of probable Quaternary age (Nakano et al., 2001-).

Kuroshima
Kuroshima is a basaltic-andesitic stratovolcano characterized by an abundance of monogenetic cinder cones (Joshima et al., 1978; Shinjo et al., 2000). Located in a back-arc region of the Ryuku arc, it has been K-Ar dated at 1.03 +/- 0.13 million years (Ono et al. 1981; Shinjo et al., 2000).

Satsuma Maruyama
The Satsuma Maruyama andesitic lava dome was dated at about 0.5 Ma (Nakano et al., 2001-).

Imuta
Early Pleistocene lava domes (Ono et al., 1981).

Hokusatsu
Hokusatsu erupted expansive plateau lavas ranging from 100-200 m in thickness (Hosono et al., 2003). Lava compositions mostly range from basaltic to andesitic. While silicic deposits were produced throughout Hokusatsu's eruptive history, they mostly dominate the youngest products. Hokusatsu lavas are Plio-Pleistocene in age, ranging from 0.35 to 3.4 Ma (Nakano et al., 2001; Hosono et al., 2008). They are calc-alkaline in composition (Hosono et al., 2008). The Hokusatsu volcanic region is also noted for its silver and gold deposits and is therefore of economic importance to Japan (Hosono et al., 2008).

Sendai
Fission track age dated at 1 million years ago (Ono et al., 1981).

Kakuto
Kakuto is a large figure-eight shaped caldera north of Kirishima that consists of the overlapping Kakuto and Kobayashi calderas, formed about 0.4-0.5 and 0.3 Ma, respectively (Nakano et al., 2001-). Major explosive eruptions have occurred around 110,000, 65,000 and 12,000 years ago (Newhall and Dzurisin, 1988).

Malindig
The forested Malindig, also known as Marlanga, is located at the southern tip of Marinduque Island, west of the Bondoc Peninsula on Luzon Island. Sharp-topped peaks form the summit of this andesitic stratovolcano. The age of the most recent eruptions is not known, but hot springs are located at its western foot.

Mariveles
The low Mariveles stratovolcano lies at the southern end of the Bataan Peninsula, on the west side of Manila Bay. This massive, dominantly andesitic, volcano includes a 4-km-wide caldera that drains to the north. Flank cones are located to the NNE (Mount Samat) and E (Mount Limay). Although one source (NRC, 1979) noted an eruption dated at 4,000 years before present, no details were available about the sample or method. Other age determinations (EBASCO, 1977) of lava flow samples ranged from about 3.5 million to 190,000 years old.

Natib
The massive, dominantly andesitic, Mount Natib stratovolcano, at the northern end of the Bataan Peninsula, is truncated by a 6 x 7 km caldera. The latest dated (by fission track) eruptive products are 69,000 +/- 27,000 years old (Ebasco Services, 1977), but sampling was not of sufficient detail to determine the date of the most recent eruptions. Although Ruaya and Panem (1991) listed a "Young Volcanics" unit in a late Pleistocene to Holocene stratigraphic group, they noted that the latest eruption was estimated at 90-100,000 years ago. Five thermal areas are present in the summit region.

Arayat
The forested Arayat volcano is one of the few topographic features that rise above the flat Central Plain of Luzon Island, NE of the city of Angeles. A large breached crater on the WNW side is the apparent source of a major debris-avalanche deposit that forms hummocky terrain beyond the W and NW flanks. The volcano has been listed as active during the past 2,000 years (IAVCEI, 1973), perhaps referring to its thermal activity; weak steaming occurs at the NW side of the summit. The only dated rocks are 530,000 and 650,000 year old basalts that predated the collapse and formation of an andesitic dome known as White Rock in the collapse amphitheater. No eruptions have been recorded or observed.

Amorong Group
Mount Amorong is the only one of a cluster of small trachyandesitic lava domes and diatremes at the northern end of the Luzon Central Plain, along the Eastern Bataan volcanic lineament, that displays solfataric activity (Wolfe, 1982, pers. comm.). A date of about 1.14 million years (K-Ar) was obtained. Yumul et al. (1999) collectively called Amorong, Mount Balungao, and Mount Cuyapo the Paniqui Plugs, and noted that nearby Mount Bangcay was a tuff cone.

Santo Tomas
Santo Tomas is a stratovolcano with numerous volcanic vents and fissures (Philippines Commission of Volcanology, 1981). There was a report of an eruption or "displacement" in the region on 4 January 1641, described as an outburst of water accompanied by an earthquake. That is also the date of the major eruption of Parker volcano in southern Mindanao that impacted much of the Philippines. The Asin Hot Springs are about 12 km NNW of the summit, but their connection to the volcano is unknown.

Laguna Caldera
The elliptical 12 x 24 km Laguna Caldera SE of Manila forms the middle of the three large basins of Laguna de Bay, the largest lake on Luzon Island. Pre-caldera Pleistocene volcanism formed basaltic to basaltic-andesitic volcanoes, including Mount Sembrano on the Jalajala peninsula E of the current caldera. That peninsula is the E rim of the caldera, and hosts the Jalajala solfataric field on the S flank of Mount Sembrano. Elongated Talim Island forms the SW rim of the caldera. The caldera may have formed during at least two major explosive eruptions about 1 million and 27,000-29,000 years ago.

Dagit-Dagitan
Dagit-Dagitan is an andesitic volcano forming the small Verde Island between Luzon and Mindoro Islands. The most recent activity on Verde Island is probably late Pleistocene in age (Wolfe and Self, 1983) and formed a small tuff cone. No hot springs are present, although wells are hot and argillic alteration is taking place (Wolfe 1982, pers. comm.).

Panay
Mount Panay is a low andesitic stratovolcano on the Calumpang Peninsula west of the Batangas Bay, south of Lake Taal. Panay was mapped as Pleistocene in age by the Philippine Bureau of Mines (Wolf and Self, 1983), but displays strong solfataric activity. Batangas Bay lies at the intersection of two major regional trends, the Bataan Lineament and the Palawan-Macolod Lineament, and may represent a submarine caldera.

Malepunyo
Malepunyo is an andesitic stratovolcano located east of Taal volcano. K-Ar dates ranging from 3.0 to 0.58 million years were obtained.

Anilao Hill
Anilao Hill is a basaltic scoria cone east of Taal volcano and SW of Malepunyo volcano. A K-Ar date of about 0.87 millions years was obtained from Anilao Hill.

Cariliao
Cariliao volcano, also known as Mt. Talamitan, is an andesitic stratovolcano located NW of Taal volcano. A K-Ar date of about 1.34 million years was obtained from Cariliao.

Corregidor
Corregidor is a largely submarine caldera with a post-caldera dacitic lava dome located on the Bataan lineament at the mouth of Manila Bay. Corregidor Island forms the northern part of the caldera, and Caraballo Island lies on the SE part of the caldera rim. A radiometric date of 1.0 +/- 0.09 million years was obtained from Corregidor.

Matarem
Radiometric dates for Matarem (Mafarem) volcano at the SW end of Bataan Island range from about 6 to 1.71 million years (Richards et al., 1986).

Balintang
The Balintang Islands are a group of seven small rocky islands in the middle of the Balintang Channel north of Luzon. The largest island is about 1,600 m long by 500 m wide, and reaches over 100 m above sea level. They are the summit of a large submarine edifice slightly smaller than the volcanic edifice under Babuyan Claro, 50 km SSW.

Diogo

Mabudis-Siayan
Submarine volcanic edifice with the islands of Mabudis, Maysanga, and Siayan representing the exposed summit area.

Y'Ami-North
Submarine volcanic edifice with the islands of Y'Ami and North representing the exposed summit area.

Hsiaolanyu

Lutao

Paco-Maniayao
Located at the NE tip of Mindanao, the Paco-Maniayao volcanic complex is truncated by two nested calderas, 2.5 and 5 km in diameter. The basaltic-dacitic volcano is located east of the N-S-trending Philippine Fault that cuts across eastern Mindanao. Andesitic lava domes rim a breached crater, and the youngest dated rock is an overlying basaltic lava flow dated at about 90,000 yrs +/- 40,000 years BP. Legends record a major caldera collapse eruption (Wolfe 1982, pers. comm.). The age of the last eruption is not known, although the volcano currently displays fumarolic activity. Geological mapping by Omac and Fermin (2012; see Africa et al., 2015) indicated that the youngest volcanics were late Pleistocene.

Mahagnao
The forested Mahagnao volcano in central Leyte Island is also known as Kasiboi or Casiboi. The andesitic volcano contains a steep-walled forested summit crater open to the south. Thermal areas with fumaroles and mud pots occur on the flanks. Two lakes, Malagsom and Danao, are located on the S flank. The former is a crater lake that is acidic and green in color, and the latter is a freshwater lake with an irregular shoreline and hot springs on its southern side. No source or confirmation is known for the possible 1895 eruption listed by the Commission on Volcanology (1981).

Nelangaapan
This volcanic edifice was mapped at the SE tip of Panaon Island; a K-Ar date of 1.61 +/- 0.08 million years was obtained from a sample.

Ilihan
Ilihan is Quaternary volcano with a lava flow dated at about 1.24 million years lies in SE Leyte Island, north of Cabal�an volcano (Sajona et al., 1997). Another undated Quaternary volcano was mapped immediately to the north of Silago.

Cancajanag
Cancajanag is a lava dome complex on Leyte Island, north of Mahagnao volcano on the lower NW flank of Lobi. The age of its most recent eruptions is not known, but it was classified as potentially active by PHIVOLCS.

Alto
The massive compound Alto volcano at the northern end of Leyte Island has K-Ar dates of 0.43-0.38 million years and contains the Tongonan geothermal field.

Maripipi
Maripipi is a small island volcano located NW of Biliran Island. The age of its most recent eruptions is not known, but PHIVOLCS classified it as potentially active.

Pocdol Mountains
The triangular-shaped Pocdol Mountains volcanic range, also known as the Bacon-Manito complex, covers an area of about 225 km2 between Saragon Bay and Albay Gulf in southern Luzon, SE of Mayon volcano. Volcanic cones in the western part of the complex are dissected, but those in the eastern part are morphologically youthful. Several Pleistocene K-Ar dates have been obtained from the volcanic complex. The age of its latest eruptions is not known, but a fumarole field that contains a geyser is located near the summit of the compound, dominantly andesitic volcanic complex.

Masaraga
Masaraga is a sharp-topped, forested andesitic-to-rhyolitic stratovolcano ~11 km NW of Mayon volcano. Thick lava flows occur on the flanks. It was classified as Holocene by IAVCEI (1973), and K-Ar dates of zero age were obtained. However, as of 2025 it was not listed by PHIVOLCS as active (Holocene).

Gate Mountains
The andesitic-to-rhyolitic Gate Mountains at the southern tip of Luzon Island have K-Ar dates ranging from 2.16 to 0.8 million years.

Sangay
K-Ar dates of about 0.556 to 0.387 million years were obtained from Sangay volcano, which lies NE of Iriga volcano and NW of Malinao volcano.

Cone-Culasi
The Cone-Culasi volcanic field covers an area of about 270 km2 to the W of San Miguel Bay and SE of Labo volcano. K-Ar dates of about 1.21-0.83 Ma have been obtained from this andesitic-to-dacitic volcanic field.

Labo
Mount Labo is a compound volcano at the NW end of the Bicol Peninsula in SE Luzon, SW of the city of Daet. The forested 1544-m-high andesitic stratovolcano is surrounded by numerous andesitic-to-dacitic satellitic lava domes. Mid-Pleistocene eruptions beginning about 580,000 years ago formed lava domes on the northern side of the complex. The present edifice was formed beginning about 270,000 years ago, and flank lava dome emplacement took place from about 200,000 to about 40,000 years ago. The latest activity from Mt. Labo produced pyroclastic flows from the summit cone about 27,000 years ago. Thermal activity in the form of hot and warm springs continues, and Mount Labo has been the object of an extensive geothermal exploration program.

Malinao
Forested Malinao stratovolcano, NNW of Mayon, contains a large summit crater that is breached to the east. This Quaternary volcano, also known as Buhi or Takit, was active from about 500,000 to 60,000 years ago (Nielson et al., 1996), but the E flank is the site of Luzon's largest solfataras and hot springs, some of which deposit siliceous sinter. A minor explosion from the Naglabong thermal area that ejected blocks in 1980 was probably due to water drawdown during development of the Tiwi geothermal field (Newhall 1994, pers. comm.).

Hingatungan
Undated Quaternary volcano mapped as Quaternary immediately N of Silago (Sajona et al., 1997).

Lobi
Mapped as Quaternary by Sajona et al. (1997). Listed as inactive by PHIVOLCS.

Pacdahauan
Volcanic features mapped as Quaternary by Sajona et al. (1997) on the Leyte Island peninsula south of Biliran Island.

Tawau Hills
Malaysia
Negros-Sulu Volcanic Arc
The Tawau Hills is a large Miocene to late-Pleistocene volcanic field on the Semporna Peninsula of NE Borneo, in the Malaysian province of Sabah, across Port Cowie bay from the Indonesian province of Kalimantan. Tahir et al. (2010) noted that the larger mountains resulted from Pleistocene dacite eruptions on top of older andesites; late Pleistocene olivine basalt lavas originated from multiple small cones (eg. Tiger Hill, Bombalai Hill, and Quoin Hill). Two young lava flows from Bombalai extend almost to the coastal plain; they were considered younger than a lava flow radiocarbon dated at about 27,000 years before present (Kirk, 1968), but later workers make no mention of Holocene activity. The lavas from the Tawau area are geochemically distinct from those erupted from fissures at Mostyn (Macpherson et al., 2010), also on the Semporna Peninsula about 30 km NE.

Mostyn
Malaysia
Volcano type: Fissure vent(s) ?
Late Quaternary lavas (Kirk 1968).

Jolo
Numerous pyroclastic cones and craters are present on the 60-km-wide Jolo Island at the SW end of the Philippines archipelago. Jolo lies in the Sulu archipelago, ~150 km SW of the tip of the Zamboanga Peninsula on SW Mindanao Island. Youthful-looking Tumatangus cone forms the high point of the island. Bud Dajo (or Buddajo) is a basaltic cinder cone that reaches above 600 m elevation; other nearby cones are Matanding, Guimba, and Sungal. Hot springs have been reported at craters on Cagayan Sulu, and solfataras at Siit Lake. Reported activity in 1641 CE was actually ashfall from Melebingoy eruption on Mindanao. Two large earthquakes (M 7.4-7.5) on 20-21 September 1897 caused a significant tsunami and later speculation of a possible submarine eruption, but there were no direct observations or later evidence of volcanism.

Imbing
Mount Imbing is one of the highest of a group of volcanoes at the southern end of the SE-most peninsula of the Zamboanga Peninsula. A K-Ar date of 0.82 million years from a sample on the western coast of this peninsula (Sajona et al., 1994, 1997).

Kaladis
K-Ar dates of about 1.08 and 1.21 million years were obtained from a lava flow from Mt. Kaladis on the Zamboanga Peninsula (Sajona et al., 1994, 1997).

Cuernos de Negros
Cuernos de Negros (also known as Magaso) is a large stratovolcano complex at the SE tip of Negros Island. The eastern side of the complex consists of two stratovolcanoes and a lava dome; two crater lakes up to 1.5 km in diameter are present. The lower western part of the complex contains four volcanic centers. The small summit crater of Magaso, the highest peak of the complex, rises above the city of Dumaguete and contains fumaroles; two sulfuric springs are found on the ESE flank, with hot springs on the NE flank. The youngest radiocarbon date obtained was 14,000 years BP from a dacitic breccia, and a younger andesitic unit is present. An increase in fumarolic activity took place after a major tectonic earthquake in 1902. The Palinpinon geothermal field is located south of the Okoy River on the N flank.

Mandalagan
The deeply dissected, dominantly andesitic-to-dacitic Mandalagan volcanic complex on northern Negros Island contains a vigorous solfataric area at a highly altered domed structure. The complex consists of seven volcanic centers, including at least five craters up to 2 km in diameter. One solfataric area emits a high-temperature (106�C) plume to 30 m height with a roaring noise. The age of the most recent eruptive activity, which produced a thin basaltic lava flow, is not known.

Silay
Silay, the northernmost volcano on Negros Island, lies 28 km E of Silay City. The compound basaltic andesite stratovolcano contains a partially breached, 3.5-km-wide caldera. Though listed as Holocene by IAVCEI (1973), the age of its most recent eruptions is not known. The Malisbog solfatara field displays fumarolic activity and extensive sulfur deposits.

Balut
Balut volcano, also known as Sanguil, forms a small island in the Sarangani Island group south of the Batulaki Peninsula of southern Mindanao. Hot springs and thermally altered ground are located on the W and SW flanks. Reports in Mindanao of a major eruption in 1641 CE from an unknown volcano to the south, which caused darkness over much of Mindanao, were originally attributed to Balut; later work indicated that the source was Melebingoy, ~80 km NW of Balut on southern Mindanao.

Apo
Apo volcano but its geologic history is poorly known. Apo, which means master or grandfather, is the highest peak in the Philippines, located SW of the coastal city of Davao. The andesitic-to-dacitic volcano has a flat-topped summit with three peaks and a 500-m-wide crater containing a small lake. A line of solfataras rises from a fissure on the SE side that extends ~1 km downslope. No reported eruptions are known, but it is one of several volcanoes to which the major 1641 CE eruption from Melebingoy volcano was incorrectly attributed.

Latukan
The poorly known Latukan volcano is in NW Mindanao SE of Lake Lanao just SW of Ragang volcano. The Makaturing volcano in the Butig Mountains is to the W. Though listed as an active volcano in the Catalog of Active Volcanoes of the World (Neumann van Padang, 1953), the age of its most recent eruptions is not known and PHIVOLCS lists it as an "inactive" volcano.

Kalatungan
Kalatungan, also known as Catatungan, is a dominantly basaltic edifice that forms a broad east-west trending volcanic ridge in central Mindanao east of Lake Lanao. It was listed as "potentially active" (with possible Holocene activity) by the Philippine Institute of Volcanology and Seismology (2004-), but no dated eruptions are known.

Malindang
The Quaternary Malindang volcano is located at the southern end of an eroded massif (Ampiro volcano is at the northern end), W of Iligan Bay in N-central Mindanao. Legends record a large eruption from the dominantly basaltic-to-andesitic volcano in the past, although no confirmed eruptions have been documented (Salise et al., 1991). Reports of increased activity in 1991 at the time of tectonic earthquakes prompted widespread evacuations, and although an eruption did not occur, a previously unknown geothermal area was discovered.

Balatukan
Balatukan (also known as Balingoan or Balatocan) is a massive compound stratovolcano that rises above the SW shore of Gingoog Bay in north-central Mindanao, opposite Camiguin Island. Lava flows on its flanks have Pleistocene ages. Although the volcano currently displays fumarolic activity, it is extensively eroded and the age of its latest eruption is not known.

Blit
Mt. Blit, a poorly known volcanic complex in south-central Mindanao, south of Cotabato City, has two main summits. The youngest dated rocks of the basaltic-to-dacitic volcano, also known as Blik, are about 760,000 years old.

Quezon
Low basaltic to andesitic lava domes at Quezon, north of the Cotabato Basin and east of Illana Bay, were dated at about 115,000 yrs BP.

Kitabud
A lava flow from the Kitabud Mountains, south of Ragang volcano, was dated at about 460,000 years BP.

Ampiro
Ampiro lies north of Malindang volcano in NW Mindanao. It was classified as "active" by Sajona et al. (1994), although it appears on the "inactive" list of PHIVOLCS (2004-). Samples from the flanks of the volcano were dated at between about 700,000 and 290,000 years BP.

Tondano Caldera
Tondano is an approximately 20 x 30 km Quaternary caldera in north Sulawesi containing post-caldera pyroclastic cones, obsidian flows, and thermal areas. Lake Tondano lies against the well-defined eastern caldera rim. Active andesitic-to-basaltic stratovolcanoes lie astride the poorly defined southern and northern rims of the caldera. The age of the latest eruptions within the caldera is not known, although thermal areas occur at Batu Kolok and Sarangson, and at the Tampusu cinder cone and Lahendong maar.

Kawio Barat
The conical Kawio Barat submarine volcano sits just W of the Sangihe volcanic arc between Sulawesi Island in Indonesia and Mindanao Island in the Philippines. Satellite imagery showed submarine vents generating visible hydrothermal activity on the W side of the arc. A detailed survey was conducted in June 2010.

Lipang

Napo Taroare

Kawalusu

North Kawio
The North Kawio volcano is a large primarily submarine edifice with multiple peaks, including the islands of Marore (Maru), Kawio, and Kamboreng.

Biaro

Tahulandang
Cone within a caldera breached to the north.

Tamata
Largest of the three volcanic cones of central Siau Island just S of Karangetang. No age dates are known, but the distinct edifice with much less erosion relative to cones to the S suggests a Quaternary age.

Makalehi
Back-arc island volcano W of the main Sangihe volcanic front, km W of Karangetang. The island is a 1.5-km-diameter caldera, breached to the SW, but with a 500-m-diameter post-caldera dome on the SW side of the caldera and a crater lake in the NE. The submarine edifice appears to be ~20 km in diameter. Identified as Quaternary by Hanyu et al. (2012).

Kalama
The heavily eroded Kalama Island, just N of Mahengatang/Banua Wuhu and S of Sangihe Island, is the emergent summit of a larger submarine edifice. Hanyu et al, (2012) identified it as being part of the Quaternary volcanic front.

Tigalalu
Gunung Tigalalu is located at the northern end of Kayoa Island, which straddles the equator and is the southernmost of a chain of volcanic islands off the western coast of Halmahera Island. This N-S-trending volcanic ridge at the north end of the island is partially flanked by coral limestones. Although it was mapped as Holocene (Apandi and Sudana, 1980), no eruptions have been reported or dated. Little work has been published about this island, but it is generally not considered part of the active Holocene arc.

Amasing
Bukit Amasing (Amasing Hill) is the largest and NW-most of a group of three small andesitic volcanoes along a NW-SE line on central Bacan Island, west of the southern tip of Halmahera. Two smaller volcanoes, Cakasuanggi and Dua Saudara, were constructed to the SE, north of the Sibela Mountains metamorphic complex. These mountains separate the Amasing group from another group of three andesitic volcanic features on SE Bacan Island. Although mapped as Holocene by Yasin (1980), work by Malaihollo (1993) found that the most recent volcanic material was Pleistocene.

Bibinoi
Bukit Bibinoi (Bibinoi Hill) is the largest and SE-most of a group of three andesitic volcanoes located along a NW-SE line on the SE part of Bacan Island, west of the southern tip of Halmahera. The smaller Songa and Lansa volcanoes straddle a narrow isthmus separating the SE-most peninsula from the Sibela Mountains metamorphic complex. The group lies along the same trend as the Amasing volcano group, located to the NW on the other side of the Sibela Mountains. Although mapped as Holocene by Yasin (1980), work by Malaihollo (1993) found that the most recent volcanic material was Pleistocene.

Hamiding
Hamidang volcano is mapped as Quaternary (Supriatna 1980). Based on the morphology of the area, it appears to consist of approximately a dozen small cones.

Telaga
The NE part of Tidore Island off the west coast of Halmahera contains an eroded volcanic edifice with the 2.1 � 2.2 km Telaga caldera (also called Sabale). The date of the caldera-forming eruption is unknown, but Faral et al. (2022) suggested that it occurred between 22,000 and 17,500 cal. years BP, when an eruption produced thick (4-10 m) pumiceous dilute pyroclastic density currents within the caldera and north of the edifice, removing 1.20 � 0.28 km3 of material (based on modeling of the previous cone). The caldera floor is occupied by a lake and a volcanic dome. Maitara Island is another volcanic edifice on the W flank just offshore.

Mamuya
Small stratovolcano outside the Dukono complex, 10 km NE of the summit along the coast. Previously an island, a lava flow during a major eruption of Dukono in 1550 CE filled in the strait, connecting Mamuya to Halmahera.

Baluan
The circular, 5.5-km-wide island of Baluan in the Admiralty Islands is formed by a Pleistocene stratovolcano with a large summit crater and several flank vents. Some of these might be of Holocene age (Johnson, 1990 pers. comm.). In contrast to its neighboring islands to the north, Baluan has erupted basaltic rather than rhyolitic rocks. Sabroma, the elliptical summit crater, has a maximum width of about 1 km. The arcuate rim of the Batapona pyroclastic cone is prominent at the north edge of the island. Several small islands consisting of cone remnants are located within a kilometer of the north coast. Warm springs occur along the coast. An unsubstantiated description of a submarine eruption near the island in 1931 has been assigned to the Tuluman volcano of the St. Andrew Strait complex, located 9 km NNE of Baluan..

Mundua
A cluster of basaltic volcanoes forms the Mundua island group in the Witu Islands of Papua New Guinea. The largest volcanic center is formed by the W tip of the 7-km-wide, linear Mundua Island and the arcuate Wingoru Island immediately to the W. The crater of this volcano is flooded by the sea through narrow channels on the N and S sides; remnants of crater walls form Wingoru island and are exposed at the W tip of Mundua island. Five small cones occupy the central and eastern sides of Mundua, two of these have well-preserved craters Johnson and Blake (1972). No eruptions have been recorded or dated.

Garove
Garove is the largest of the Witu Islands, which lie north of New Britain. The low, 12-km-wide elongated island contains a 5-km-wide crater open to the sea through a narrow breach on the southern side of the island, forming Johann Albrecht Harbor. The steep crater walls rise 100-150 m above the sea. Cones are present along the NE and SW coasts. Based on preserved lava flow structures on a NW coast headland Johnson and Blake (1972) suggested that they could be as young as a few hundred years, but no sources for the flows were identified using aerial photos. Fisher (1957) noted four thermal areas and a solfatara on the island. There are no recorded or dated eruptions.

Unea
A 6-km-wide caldera rim forms the margin of Unea Island, which contains three post-caldera domes. The volcano is largely of Pleistocene age, although Holocene activity cannot be ruled out (Johnson 1990, pers. comm.).

Narage
The small forested island of Narage is the northernmost of the Witu (or Vitu) Islands, which lie north of western New Britain. Narage is the summit of a Pleistocene stratovolcano that displays strong thermal activity, and was included in the Catalog of Active Volcanoes of the World (Fisher, 1957) based on its geothermal activity. Boiling springs and a geyser are found along the SE and SW coasts; in 1863 a geyser 45 m high was observed at a sandbank 8 km offshore. A fringing reef, prominent on satellite imagery, encircles the island at a distance of 200 m to 400 m and encloses a narrow lagoon.

Boisa
The 1.4 x 1.7 km Boisa (or Aris) Island consists of a basaltic-andesitic cone with a summit crater open to the north whose rim extends to the island's east coast. The crater of the basaltic older cone is filled by two steep-sided andesitic lava domes. A third lava dome, separated from the eastern cone by a low saddle, forms a peninsula on the western side of the island. Although Gust and Johnson (1981) suggest that the last eruption "may have been quite recent" based on the visible island morphology, there is no thermal activity and no reports of activity or dated eruptions.

Vokeo
The westernmost volcano of the Quaternary Bismarck volcanic arc, Vokeo is a dissected, forest-covered volcano with a central basin. It is the only Bismarck arc volcano surrounded by a raised coral reef. Two thermal areas are present on the north coast (Johnson et al. 1972).

Viai
The 4.5-km-long arcuate island of Viai (or Wei) is a remnant of a larger volcano. One thermal area is present on the N coast (Johnson et al., 1972).

Crown Island
The deeply dissected 3-km-wide Crown Island is covered by rain forest. There is no known thermal activity or recorded eruptions. Young tephras on the island probably originate from Long Island (Johnson et al., 1972). Possible submarine debris-avalanche deposits lie both north and south of the island (Silver et al., 2009).

Bagabag
The 7 x 8 km Bagabag island is truncated by a 3 x 5 km crater that is breached by the sea on the SE side. A shallow ridge marks the submerged portion of the crater rim. An offshore reef rings the island (Johnson et al. 1972).

Tolokiwa
The circular 8-km-wide island of Tolokiwa contains a summit crater breached to the NE that is largely filled by a later cone. The volcano is of Quaternary age (Johnson et al. 1972). The largest documented submarine debris-avalanche deposit mapped in the Bismarck Arc lies north of Tolokiwa (Silver et al., 2009).

Tangi
The dissected Tangi stratovolcano, occupying the southern end of New Britain's Cape Gloucester Peninsula, contains a breached summit crater and a single flank cone on the SW flank. The degree of erosional dissection suggests activity ceased during the Pleistocene (Johnson et al. 1971).

Lotomgan Group
A group of small Quaternary andesitic and rhyolitic volcanoes are located south of Bola volcano (Lowder and Carmichael 1970).

Bangum
Bangum is a Pleistocene stratovolcano dissected to much the same stage as the Garbuna volcanoes (Johnson and Blake 1972; Johnson 1990, pers. comm.). IAVCEI lists a thermal area, but gives a coordinate that appears to be at the west foot of Welcker volcano. Johnson and Blake note no thermal areas on Bangum.

Oto Group
The Oto volcanic group consists of five stratovolcanoes and a caldera of early to late Pleistocene age. The oldest volcanoes, Ko and Husa, are about 800-900,000 years old, and the steep-sided Oto, Mululus and Mateleloch volcanoes range from about 190,000 to less that 70,000 years old (Blake and McDougall 1973, Johnson and Blake 1972). The 4-km-wide Busui caldera of probable Pleistocene age is formed in a broad, low-angle cone of dominantly pyroclastic material. The names of Oto, Mululus and Mateloch peaks on published maps differ from that used by local inhabitants and in the geological literature.

Likuruanga
Likuruanga is a dissected, low stratovolcano with a large crater breached to the north. In September 2006, a boy died of carbon dioxide asphyxiation in a hole at Bakada village on the volcano's N flank.

Koil
Koil is a small island near the NW end of the Schouten Islands in the Bismarck volcanic arc between Vokeo and Vaia.

Eastern New Guinea Volcanic Province

Doma Peaks
Eastern New Guinea Volcanic Province
The Doma Peaks, at the western end of a volcanic chain in the highlands of Papua New Guinea, are dominated by two westward-facing escarpments of probable landslide origin. Satellite cones and lava domes occur on the NE and S flanks of the dominantly andesitic volcano. There is no evidence for magmatic eruptions within the last few hundred or possibly few thousand years (Mackenzie and Johnson, 1984). A reported eruption within the past few hundred years was actually from Long Island, and an older lahar mentioned by Blong (1979) was not accompanied by any significant tephra production (Blong, 1982).

Crater Mountain
Eastern New Guinea Volcanic Province
Crater Mountain, an arcuate chain of peaks, is extensively eroded to the point that its volcanic origin is almost unrecognizable. However, steep-sided valleys to the N and E are floored by lava flows and other young volcanic features. The easternmost Agotu Valley contains several small craters, cinder cones, and maars of late-Pleistocene or Holocene age (Mackenzie and Johnson, 1984). Several small cones, lava domes, and associated lava flows N and NW of the Erun Anticline may, in part, be Holocene in age.

Yelia
Mount Yelia, first recognized as a volcano in 1963, contains a group of andesitic lava domes in the summit area and NW flank. Marble Peak is an older volcanic center immediately to the south. The largest dome in the summit crater is perforated by at least 11 craters. Two large steep-sided, flat-topped lava domes occupy the NNE flank, and two smaller domes are located to the west. The last significant eruption occurred about 18,000 years ago, and no direct evidence for Holocene eruptions has been observed. Weak solfataric activity is present and there was an unverified report from local inhabitants of an eruption during the early 1940's. Weak fumarolic activity continues in the summit crater.

Kerewa
Mt. Kerewa is a deeply dissected Pleistocene andesitic stratovolcano south of Doma Peaks. A group of small cones, craters and domes is located to the west, and Mt. Ne is situated immediately to the NE (Mackenzie and Johnson 1984).

Sisa
Mt. Sisa is a deeply dissected Pleistocene stratovolcano with a large U-shaped depression open to the SW that may have originated by slope failure (Johnson 1987).

Bosavi
Mt. Bosavi is a truncated Pleistocene basaltic to andesitic stratovolcano with a 5-km-wide erosion caldera enlarged by the Turama River through a narrow breach on the SE. A group of cones, craters and maars are scattered over the plains to the SW of Bosavi (Mackenzie and Johnson, 1984).

Darai Hills
A group of Pleistocene cones and craters are scattered over a limestone karst plateau SE of Mt. Bosavi (Mackenzie and Johnson 1984).

Biwau Hills
The Pleistocene Mt. Biwau consists of two coalescing cones surrounded by lavas and probable lahar deposits. The northern cone is capped by a spine-like peak and a dome-like protuberance 1.5 km to the east. A small cinder cone lies 17 km to the west (Mackenzie and Johnson 1984).

Sugarloaf
The Pleistocene Sugarloaf Volcanic Field is composed of a group of coalescing lava domes, with several small cinder cones, explosion craters, and maars (Mackenzie and Johnson, 1984).

Hagen
The heavily eroded Mount Hagen massif is comprised of three coalescing stratovolcanoes with NW-facing escarpments that may resulted from slope failure (Johnson, 1987). Mackenzie and Johnson (1984) obtained Potassium-Argon dates of 420,000 and 220,000 years ago.

Giluwe
Mount Giluwe is the only shield volcano in the New Guinea Highlands. The 30-km-wide basaltic-andesitic volcano has numerous cinder cones and lava domes; the upper slopes are heavily dissected by glaciers. The latest volcanism may post-date the younger glaciation that lasted until about 23,000 before present (Blake and Loffler, 1971).

Ialibu
The Pleistocene Ialibu stratovolcano is morphologically complex, with deeply eroded gorges and a major fault zone that cuts the entire edifice. In contrast to many other Highlands volcanoes, the most mafic basaltic rocks are topographically higher than andesitic rocks (Mackenzie and Johnson, 1984).

Murray
The Pleistocene Mt. Murray stratovolcano straddles WNW-trending limestone ridges and contains a 6-km-wide crater breached to the south that may have originated from slope failure (Johnson, 1987). Two cones are situated on the NE and SE flanks.

Suaru
Suaru is a conical Pleistocene stratovolcano with three satellitic cones on the east flank. The volcano is extensively modified by seven narrow valleys that radiate from the dissected summit region (Mackenzie and Johnson 1984).

Karimui
The Pleistocene Karimui volcano is composed of 3-5 closely spaced eruptive centers extensively modified by a complex 17-20 km wide erosion caldera (Mackenzie and Johnson, 1984).

Duau
The Pleistocene Mt. Duau is dominated by a 10-km-wide breached escarpment that may result from slope failure (Johnson, 1987). A slide block that includes the summit crater is located at the head of the escarpment.

Favenc
The Pleistocene Mt. Favenc has a SW-facing escarpment similar to that of neighboring Duau that may originate from slope failure, although the structural relationships are less clear than on Duau (Johnson, 1987).

Aird Hills
The Aird Hills are a group of Pleistocene andesitic and dacitic lava domes that rise above the Kikori River delta (Mackenzie and Johnson 1984).

Trafalgar
Mount Trafalgar is a deeply dissected stratovolcano of Pleistocene age (Smith and Davies, 1976).

New Ireland Volcanic Province

Lihir
New Ireland Volcanic Province
The Lihir Group of islands N of New Ireland is a Pliocene-to-Pleistocene volcanic complex that is the exposed part of a submarine edifice ~12 km in diameter. Five stratovolcanoes form the large island of Aniolam (or Lihir): Huniho (NW), Wurtol (S central), Luise (E central), Londolovit (N), and Kinami (SE). Luise consists of an elliptical 5.5-km-wide edifice collapse scarp breached by the sea on the NE side that formed about 400,000 years ago. The flanks are only moderately dissected, and the steep scarp wall rises to 700 m above sea level. A central lava plug is strongly hydrothermally altered and displays extensive thermal activity along its margins. Thermal activity includes boiling hot springs, mud pools, and sulfur-encrusted low-temperature fumaroles. Open pit mining of the Ladolam hydrothermal deposit, hosted in the collapse scarp adjacent to the harbor, began in 1997. The Kinami volcano, which is also now a collapse feature, is thought to be the youngest on the island, but no eruption dates are known.

Feni
New Ireland Volcanic Province
The Feni island group, consisting of Ambitle and Babase islands, is located NE of New Ireland. The islands are the emergent summit of a large submarine, dominantly Pliocene-to-Pleistocene, volcanic edifice characterized by a variety of alkalic rocks types. Ambitle is covered by trachytic volcanics, including a possible 3-km-diameter central crater with lava domes K-Ar dated by Licence at al. (1987) to 490,000-680,000 years. Licence et al. (1987) also mapped an 800-m-diameter maar on the E side of the domes that they described as a phreato-magmatic event which produced a 5-30 m thick trachyte tuff-breccia deposit 14C dated at 2,300 +/- 100 years (no details about the sample). Distinct crater features are not clearly identifiable among the highly irregular eroded landscape visible in satellite images (as of 2025), though topographic renderings reveal features consistent with the geological mapping. Several thermal areas, consisting of hot and boiling springs, mud pools, and low-temperature fumaroles, are across the central part of the island. Shallow-water hydrothermal venting also occurs in a coral reef environment just off the western coast. Babase Island, immediately NE of Ambitle, is composed of a low eroded 2.5-km-diameter crater and a lava dome connected by a narrow isthmus.

Tabar
Tabar Island, the southernmost of the Tabar island group, consists of two partially coalescing Pleistocene volcanoes connected by a low isthmus. The younger, southern cone contains a 3-5 km wide depression breached to the SE.

Tanga
The Tanga Island Group of Malendok, Lif and Tefa are the visible summit of a mostly submerged volcanic edifice. In the center of the caldera, the small islands of Bitlik and Bitbok mark remnants of early Pleistocene post-caldera lava domes, the volcano's latest activity.

Tore
Features in the Emperor Range on NW Bougainville Island about 10 km N and NNW of Balbi volcano have been described as an andesitic volcano and a related 6 x 9 km caldera named Tore. This location may be the source of two Pleistocene ignimbrites that form a broad fan that extends the coastline to the west. The S and SW sides of the supposed caldera rim are covered by lava flows that extend up to 14 km from a large lava cone. The summit consists of an erosional pyramidal peak and a forested satellitic ash cone 3 km to the NW. Blake and Miezitis (1967) noted that freshly preserved features of the post-caldera ash cone and lava cone indicate a Recent age. These features as described are not apparent in satellite imagery (2022) of the area.

Emperor Range
The Emperor Range in northern Bougainville Island is a group of strongly eroded volcanic centers of Pleistocene age. A poorly preserved caldera 5-6 km in diameter is filled by a lava dome complex. The Kunua complex immediately to the west contains a 3.5 x 4.5 km caldera that produced ignimbrites dated about 0.2 million years ago that reached the western coast.

Numa Numa
The broad, densely forested Numa Numa stratovolcano contains an erosion caldera more than 3 km wide with a lava dome immediately to the south. Extensive erosion suggests a Pleistocene age (Blake and Miezitis (1967).

Bakanovi
Bakanovi is the deeply eroded crescentic remnant of an andesitic stratovolcano about 15 km east of Bagana volcano. Its poor state of preservation suggests a Pleistocene or even Pliocene age (Blake and Miezitis, 1967).

Gallego
The Pliocene-to-Quaternary Gallego volcanics, comprising a group of steeply dissected cones, cover a large area of NW Guadalcanal Island (Hackman, 1980). Mount Roundhead is a small, but well-preserved volcano. Local traditions mention an eruption, but this could refer to activity from Savo, a volcanic island ~15 km offshore to the NE (1991 pers. comm. from Coleman to R W Johnson). The International Association of Volcanology and Chemistry of the Earth's Interior (1973) considered andesitic Mount Esperance, a peak adjacent to Roundhead on the coast N of the main volcanic highland, to have been active during the past 2,000 years. However, there are no obviously recent volcanic features across the complex.

Nonda
Nonda volcano, on Vella Lavella Island in the Solomon Islands, is a lava dome located within an eroded crater open to the NE. No eruptions have been reported, although inhabitants reported "smoke" and explosive activity in the vicinity of andesitic Nonda Hill at the time of a major earthquake in 1959 (Taylor, 1976). The island was mapped as several coalescing Pliocene to possibly Pleistocene volcanic centers (Solomon Islands Geological Survey, 1982), and was included in the Catalog of Active Volcanoes of the World (Fisher, 1957) based on its geothermal activity. The Paraso thermal area displays solfataras, hot springs, and boiling mud pots.

Kolombangara
Kolombangara is a Pleistocene stratovolcano with young scoria cones on the western and NE flanks. No Holocene rocks have been mapped (Solomon Is Geol Surv, 1982). Thermal areas are also present (Grover, 1955).

Rendova
Rendova Island consists of a Pliocene to Pleistocene basaltic volcano on the north and uplifted submarine lavas to the south.

Mbareke
The Pliocene to Pleistocene Mbareke volcanic center consists of a core of basaltic andesite to andesite lavas and breccias overlain by a thick pile of olivine basalt lavas. An andesitic plug lies on the southern rim of the dissected summit crater.

Vangunu
The Pliocene to Pleistocene Vangunu volcano has two deeply eroded central craters breached on their southern sides.

Nggatokae
Nggatokae consists of a well-formed volcanic cone of Pliocene to Pleistocene age with a breached central crater and a subsidiary scoria cone on the northern flank<.

Mere Lava
The small 5-km-diameter island of Mere Lava (also known as Star Peak) in the southern Banks Islands has a well-preserved summit crater containing a small cinder cone. Eruptive products are olivine basalt lavas and related tephra, and nine small craters are aligned down and across the NE flank above a small coastal plain extending into the ocean (Mallick and Ash, 1975). Although Mallick and Ash (1975) considered the volcano to be "very young", they noted that there were no records or legends of activity. Although some writers claim that the Spanish explorer Queiros reported the volcano to be "smoking" in 1606, a reading of the Markham (1904) translation seems to describe human, not volcanic, activity.

Northeast Shepherd Islands
This group of small islands (Ewose, Buninga, and Tongariki) SE of Tongoa Island have no obvious volcanic features. Although it has been suggested that they lie on the rim of a caldera (Crawford et al. 1988, Macfarlane et al. 1988), no evidence for such a feature was found by Eissen et al. (1991). Buninga and Tongariki appear to be the exposed parts of a submarine edifice that extends towards Emae island, 15 km SW. Pyroclastic rocks intruded by dikes are exposed on Ewose, whereas Buninga is largely composed of tilted lava flows. Tongariki consists of basalts with dacitic pumiceous tuffs in low-lying areas.

Aneityum
Aneityum Island, also known as Anatom or Anetchom, is a 17-km-wide oval-shaped island SE of Tanna Island and is the southernmost of the Vanuatu Islands chain. Aneityum consists of two coalescing, dominantly basaltic Pleistocene volcanoes. Both the NW side of Inrerow Atamwan volcano and the SE side of Nanawarez volcano are truncated by large erosional cirques. Volcanic activity ceased during the late Pleistocene to Holocene (Carney and Macfarlane, 1979).

Ureparapara
The 8-km-wide Ureparapara Island is topped by a 5-km-wide erosional caldera that is open to the sea on the NE. Sapper (1917) states that Ureparapara must have still been active in 1872, but the latest activity occurred during the Pleistocene (Ash et al., 1980).

Mota
The 5-km-wide Mota Island is comprised of the eroded vent-filling intrusive of a Pleistocene volcano that rises above a wide raised Holocene platform of reef limestones.

Merig
A andesite plug dated 1.1 million years ago surrounded by basaltic and andesitic breccia is all that remains above sea level on the tiny island of Merig (Macfarlane et al. 1988).

Paama Island
Williams & Warden (1964) report an eruption of Paama in 1897 (p 54) but Warden (1967) reports extensive erosion has destroyed the original volcanoes on Paama and classifies them as older than the Pliocene-early Pleistocene volcanoes of Emae.

Northwest Shepherd Islands
The Northwest Shepherd Islands group includes three volcanic cones on Emae Island (Pahunga, Talimasa, and Tipikal), Makura Island (~8 km SE of Emae), and the large submarine edifice under them. Williams and Warden (1964) report historical activity on Emae and some ashfall, which could have originated from a different volcano (Eissen et al. 1991). Warden (1967) reported strongly eroded summit craters and deep dissection of surficial deposits, and suggested that the Emae volcanoes may have become extinct in the Pliocene or early Pleistocene. Crawford et al. (1988) place Emae on the rim of a large caldera that extends to Mataso Island, more than 15 km S. Macfarlane et al. (1988) place two smaller uncertain calderas at this location; Eissen et al. (1991) did not find evidence for a caldera. Makura is largely composed of tilted lava flows.

Southern Shepherd Islands
There are two main edifices that comprise the Southern Shepherd Islands volcano group. Mataso Island is a volcanic remnant and the only surface expression of a large submarine edifice. A submarine volcano with a central crater, ~15 km ESE of Mataso and distinct from that edifice, was discovered during a 1984 survey (Crawford et al., 1988).

Northern Efate
Largely submarine basaltic eruptions during the Pleistocene from 1.5 to 0.9 million years ago constructed composite volcanoes on northern �fat� Island (Macfarlane et al., 1988).

William
The Pleistocene William stratovolcano of dominates the northern end of Erromango Island. Headward erosion by streams has excavated a 5-6 km diameter erosional basin which is partially filled by a basaltic lava plug (Colley and Ash, 1971).

Pumpan
The eroded Pleistocene basaltic Pumpan volcano occupies the center of Erromango Island. Rocks are dominantly pyroclastics overlain by widespread thick lava flows (Colley and Ash, 1971).

Melkum
The eroded Pleistocene Mt. Melkum stratovolcano occupies the west-central part of Erromango Island, along with several other small stratovolcanoes.

East Tanna
Volcanic rocks forming much of the northern part of Tanna island originated from the Pleistocene East Tanna volcano, now largely collapsed below sea level on the eastern side of the island (Robin et al., 1993). Lavas and pyroclastics along the east coast of the island have a westward dip. The Green Hill volcanics at the northern end of the island (Carney and Macfarlane, 1979) can be considered a subordinate center to East Tanna.

Pomare
The Pomare stratovolcano (also known as Tavani Kutali or Nikalo) on Epi Island is immediately W and outside of the suggested submarine East Epi caldera. Epi Island is largely volcanic, with Mount Allombei on the west, Pomare on the east, and Tavani Ruro forming the SE peninsula. There are three subsidiary cones to the east.

Tavani Ruro
The broad late-Pleistocene or Holocene Tavani Ruro volcano forms the SE peninsula of Epi Island, NW of Kuwae caldera.

Tongoa
Volcano type:
The volcanic island of Tongoa in Vanuatu is just south of Epi Island and the Kuwae caldera. The 4.5-km-diameter island includes multiple eroded volcanic cones, the most prominent being Tavani Hurata.

Vanuatu Arc at 18.2�S
Submarine volcanic cone approximately halfway between Erromango and Efate islands in Vanuatu.

Volsmar
The submarine Volsmar volcanic field lies near the southern end of the Vanuatu (or New Hebrides) Volcanic Arc, ~150 km SSE of Aneityum Island and about 60 km SSE of the Gemini-Oscostar cones. Bathymetric mapping has identified a large stratovolcano at the N end named Mariposa, and a slightly smaller volcano, Abeja, about 5 km SW; additional small cones extend 10-12 km further S.

Koro
Fiji
The 8 x 18 km Koro Island, located between Fiji's Viti Levu and Vanua Levu Islands, is part of the volcanic Lomaiviti Islands. A chain of basaltic cinder cones of late Pleistocene or possibly Holocene age extends NNE-SSW along the crest of the island (Coulson, 1976). The youngest lava flows erupted from those cones on the central plateau, where they form a flat undissected lava field. Young lava flows also reached the sea from one vent location on the W coast. In a study of peridotite xenoliths from Koro, Barrett (2021, and included references) noted that they were hosted by the most recent localized alkali basalt volcanism, and that surface volcanism had been dated between 2.6 and 1.0 Ma by K-Ar.

Nairai
Nairai is composed of five basaltic volcanic centers of Pliocene age; the well-preserved Pleistocene cinder cone Rairainiika is located on the NW coast.

Waikama
Waikama volcano comprises much of the northern end of Ngau Island and appears to have been active well into the Pleistocene (Coulson 1976).

Lau Ridge Volcanic Arc

Mago
Lau Ridge Volcanic Arc
A K-Ar date of about 0.3 million years was obtained from a basaltic rock from Mago Island on the Lau Ridge (Cole et al., 1990). Three scoria cones and short lava flows, some of which contain peridotite xenoliths, are located on the island.

Katafaga
Lau Ridge Volcanic Arc
Basaltic rocks from Katafaga Island on the Lau Ridge were K-Ar dated at about 1.6 million years (Cole et al., 1990).

Kabara
Basaltic rocks from Kabara Island on the Lau Ridge were K-Ar dated at about 1.0 million years (Cole et al., 1990).

East Mata
East Mata is a submarine volcano in the northeastern Lau Basin at the northern end of the Tofua arc, about 200 km SW of Samoa and north of the historically active Curacoa submarine volcano. It was discovered during a November 2008 NOAA Vents Program expedition.

Northern Matas
The Northern Matas volcanic ridges (Taha, Ua, Tolu, Fa, Nima, Ono, Fitu) are 900-1,300 m tall and variably elongate in ENE and E directions (Anderson et al., 2021).

Niua Volcanic Complex
The Niua Volcanic Complex is a roughly rectangular area at the N end of the Tofua Arc, up to 25 km long and 13 km wide, that rises to depths of ~2,000 m above the seafloor; it is characterized by an irregular morphology, with smaller volcanic features that occur on the periphery of the larger edifices, and lava flows (Anderson et al., 2021).

Ata Volcanic Complex
Volcanic features associated with 'Ata Island.

Toku
The island of Toku, about 20 km SE of Fonualei, is the emergent summit of a large submarine volcano. No eruptions have been recorded, but it is at the north end of the active Tofua Arc, making at least Pleistocene activity likely.

Bathymetry appears to show a large cone-like structure with a 5-km-diameter caldera located midway between Lateiki (25 km NNE) and Kao (25 km SSW). Although no reports of volcanism are known from this feature, it is directly along the active Tofua Volcanic Arc, and has likely erupted within the Pleistocene.

Feinga Seamount
The bathymetry of this seamount shows a 4-km-diameter caldera open to the N, in which a dome appears to have grown. The edifice is located along the trend of the Tofua volcanic arc, about 43 km SSW of Tofua and 32 km NE of Fonuafo'ou (Falcon Island). Although no reports of volcanism are known from this location, it has likely erupted within the Pleistocene.

Informally designated as "Volcano 3" (R/V Sonne 167 survey).

Informally designated as "Volcano 4" (R/V Sonne 167 survey).

Informally designated as "Volcano 5a" (R/V Sonne 167 survey).

Informally designated as "Volcano 5b" (R/V Sonne 167 survey).

Informally designated as "Volcano 6e" (R/V Sonne 167 survey).

Informally designated as "Volcano 7" (R/V Sonne 167 survey).

Informally designated as "Volcano 8" (R/V Sonne 167 survey), and also known as Pelorus reef.

Niuatoputapu

Seamount in the area between Niuatoputatu and Fonualei. Informally designated as "Volcano L" (R/V Southern Surveyor SS11/2004).

Seamount in the area between Niuatoputatu and Fonualei. Informally designated as "Volcano K" (R/V Southern Surveyor SS11/2004).

Seamount in the area between Niuatoputatu and Fonualei. Informally designated as "Volcano J North" (R/V Southern Surveyor SS11/2004).

Seamount in the area between Niuatoputatu and Fonualei. Informally designated as "Volcano J South" (R/V Southern Surveyor SS11/2004).

Seamount in the area between Niuatoputatu and Fonualei. Informally designated as "Volcano I" (R/V Southern Surveyor SS11/2004).

Seamount in the area between Niuatoputatu and Fonualei. Informally designated as "Volcano H" (R/V Southern Surveyor SS11/2004).

Submarine cone seen in satellite bathymetry along the volcanic arc ~20 km SW of Tofua. No reports of eruptions are known.

Hinetapeka

Volcano OP

Putoto
Seamount in the northern Kermadec arc, about 160 km N of Raoul Island.

Volcano Q

Gamble

Rakahore

Hinepuia

Kermadec Arc at 23.6�S

Kermadec Arc at 23.9�S

Informally designated as "Volcano 18 N" (R/V Sonne 167 survey).

Informally designated as "Volcano 18 S" (R/V Sonne 167 survey). Caldera is about 6 km in diameter.

Informally designated as "Volcano 20" (R/V Sonne 167 survey), or "Volcano V".

Informally designated as "Volcano 21" (R/V Sonne 167 survey), or "Volcano U".

Sonne

Ngatoroirangi

Kuiwai

Haungaroa

Oliver-Speight

Cole

Rumble II East

Thompson

Silent II West

Silent II East

Yokosuka

Rapuhia

Giljanes

Kibblewhite

Reporoa
The 10 x 15 km Reporoa caldera, occupying the Reporoa-Broadlands basin, lies near the W margin of the Taupo volcanic zone SSW of the Okataina volcanic center. The caldera formed about 230,000 years ago during the eruption of the voluminous ~100 km3 Kaingaroa Ignimbrite. Large slump scarps cut the N caldera rim; the S rim is buried by sediments. The Deer Hill rhyolitic lava dome was erupted after the caldera's S rim collapse; two other rhyolitic domes, Kairuru and Pukekahu, were emplaced within the caldera along a possible ring fault. The active Reporoa hydrothermal field lies within the caldera, and the Waiotapu and Broadlands (Ohaki) hydrothermal fields lie N and S of the poorly defined caldera margin. Eruptions within the caldera have not occurred since the late Pleistocene, but large hydrothermal explosions occurred at the Waiotapu thermal area immediately to the N at the time of the Kaharoa eruption of neighboring Tarawera volcano about 770 years ago.

Maroa
The 16 x 25 km area defined as the Maroa Volcanic Centre formed sometime after 230,000 years ago (230 ka) in the NE corner of the 30 x 40 km Whakamaru caldera, which is the largest of the Taupo Volcanic Zone. The Whakamaru caldera partially overlaps with the Taupo caldera on the south and was formed during the eruption of the Whakamaru Group ignimbrites between about 340 and 330 ka. The Maroa area was subsequently filled by at least 70 rhyolitic lava domes or flows, mostly erupted along a SW-NE trend. Lesser amounts of basalt were also erupted. The latest dated magmatic eruption took place about 14 ka, when the rhyolitic Puketarata tuff ring and lava domes were formed (Brooker et al., 1993). The Orakeikorako, Ngatamariki, Rotokaua, and Wairakei hydrothermal areas are located within or adjacent to the Whakamaru caldera. Large hydrothermal eruptions have occurred at the Orakeikorako thermal area during the Holocene, the latest immediately prior to the Taupo eruption about 1,800 years ago.

Moutohora Island
Moutohora (Whale) Island forms the summit of a largely submerged Pleistocene dacitic-andesitic complex volcano that lies 11 km offshore from Whakatane in the Bay of Plenty. The 2.5-km-long island includes a central dome complex flanked, by East Dome and Pa Hill lava dome, which forms the NW tip of the island. Acid hot springs, steaming ground, and fumaroles are present on the island. The central cone and east dome are both older than the roughly 42,000 before present (BP) Rotoehu Tephra, and Pa Hill dome is overlain by the 9,000 years BP Rotoma Ash, but may be considerably older. It was included in the Catalog of Active Volcanoes of the World (Nairn and Cole, 1975) based on its thermal activity.

Rotorua
The 22-km-wide Rotorua caldera is the NW-most caldera of the Taupo volcanic zone. It is the only single-event caldera in the Taupo Volcanic Zone and was formed about 220,000 years ago following eruption of the more than 340 km3 rhyolitic Mamaku Ignimbrite. Although caldera collapse occurred in a single event, the process was complex and involved multiple collapse blocks. The major city of Rotorua lies at the south end of the lake that fills much of the caldera. Post-collapse eruptive activity, which ceased during the Pleistocene, was restricted to lava dome extrusion without major explosive activity. The youngest activity consisted of the eruption of three lava domes less than 25,000 years ago. The major thermal areas of Takeke, Tikitere, Lake Rotokawa, and Rotorua-Whakarewarewa are located within the caldera or outside its rim, and the city of Rotorua lies within and adjacent to active geothermal fields.

Rungapapa Knoll
Rungapapa Knoll, a seamount in the Bay of Plenty 17 km WSW of White Island, has an internal heat source (Latter 1985, pers. comm.). No eruptions are known.

Kapenga
The Kapenga volcanic center was active from sometime between 890 to 710 thousand years ago (ka) and again from about 280 to 270 ka and contains two collapse structures and rhyolitic lava domes (Wilson et al. 1984, Houghton et al. 1995). The NE center, previously considered part of the Okataina center, contains numerous pre-50 ka rhyolitic domes and was the source of the ca. 65 ka Earthquake Flat Breccia. No eruptive activity is known from the Holocene.

Mangakino
The Pleistocene Mangakino volcanic center has been the source of large-volume rhyolite ignimbrites erupted between 1.6 and 0.9 million years ago (Ma) (Wilson et al., 1984; Houghton et al., 1995). Two principal periods of activity occurred, from 1.6 to 1.53 Ma and 1.21 to 0.9 Ma (Wilson et al., 1995a). One of the largest ignimbrite eruptions of the Taupo volcanic zone took place at 1.21 Ma from Mangakino. The Titiraupenga and Pureora andesitic lava domes lie just to the south of the inferred caldera margin.

Northern Tongariro Group
A group of Pleistocene andesitic stratovolcanoes lies between Lakes Rotoaira and Taupo and to the west, forming the northern end of the Tongariro volcanic center. The Rotopounamu graben, trending SW from Lake Taupo, cuts Pihanga volcano, and is these of several young cones and craters less than 20,000 years old (Cole et al. 1986).

Maungatautari
The Pleistocene Maungatautari stratovolcano is an andesitic-dacitic composite cone about 35 km SE of Hamilton on the North Island of New Zealand. Robertson (1983) reported a single K-Ar age of 1.8 � 0.10 Ma, which Prentice et al. (2020) noted makes it contemporaneous with subduction-related volcanism of the nearby Alexandra Volcanics and the early Taupo Volcanic Zone.

Tauranga Volcanic Centre
The late Pliocene to early Pleistocene Tauranga Volcanic Centre is located in the western Bay of Plenty region near the city of Tauranga, northwest of the Taupo Volcanic Zone. As defined by Pittari et al. (2021), this volcanic region comprises an eroded andesitic stratovolcano (Otawa Formation), approximately 17 rhyolite-rhyodacite lava dome complexes (Minden Rhyolite Subgroup), two ignimbrites (Waiteariki and Papamoa formations), and the small Matakana Formation basalt lava flow. Previous researchers had placed the more southern Kaimai-Kakahu-Te Weraiti dome complex and the Waiteariki Formation into a distinct Kaimai Volcanic Centre, but Pittari et al. (2021) found that they were not spatially distinct from other domes in the area.

Puhipuhi-Whangarei
The Puhipuhi-Whangarei volcanic fields include Quaternary basaltic scoria cones and lava flows. These fields are south of Kaikohe-Bay of Islands volcanic field in the central part of the Northland Peninsula, within the Northland Intraplate Province. In addition to the younger dominantly basaltic rocks, Miocene dacitic lava domes and rhyolitic breccias are also present at Whangarei. Quaternary volcanics form a group of large cones SE of Whangarei, a NE-aligned group of scoria cones north of the city, and a group of lava flows east of the city along a major fault. Though basalts were mapped by Kear and Thompson (1964) as Holocene, later work by Smith et al. (1993) provided a range of Pleistocene K-Ar dates, including about 1 Ma for the Mirowhakitiki lavas, 260 +/- 120 ka for flows near Whangarei, and 310 +/- 150 ka for the Hurupaki cone.

Kaikohe-Bay of Islands
The Kaikohe-Bay of Islands volcanic field, at the upper end of the Northland Peninsula, contains 30 eruptive centers consisting primarily of basaltic scoria cones, lava flows, and small shield volcanoes, along with minor rhyolitic lava flows and domes. Volcanism in the field has progressively shifted to the SE, with the younger Taheke Basalts being aligned along a NE trend at the S end of the field. The most recent eruptions produced basaltic lava flows at Tauanui around 50,000 years ago and Te Puke around 80,000 years ago (Coote et al., 2018; Smith et al., 1993). Work that suggested possible activity from Te Puke around 1,500 years ago (e.g. Kear, 1961) was not corroborated by any subsequent research. The Ngawha Springs geothermal area lies within the area of the volcanic field.

Karioi
The eroded Pliocene-early Pleistocene Karioi stratovolcano lies along the Tasman Sea and is the westernmost volcano of the Alexandra Volcanic Group. Potassium-Argon (K-Ar) dates range from 2.92-2.16 Ma, but scoria cones, tuff rings, and basaltic lava flows primarily on the northern and eastern flanks are in part younger than the youngest K-Ar date of 1.8 Ma (Briggs, 1983).

Pirongia
Pirongia is an eroded Pliocene-early Pleistocene stratovolcano in the Alexandra Volcanic Group about 27 km SW of Hamilton and 18 km W of Te Awamutu in the Waikato region of North Island, New Zealand. Potassium-Argon dates of 2.25 and 2.06 Ma have been obtained, but flank cones are younger (Briggs, 1983).

Kakepuku
Volcano type: Lava cone(s)
The Kakepuku cone, near the SE end of the Alexandra Volcanic Group, is about 30 km S of the city of Hamilton in the Waikato region of North Island, New Zealand. The related Pliocene-early Pleistocene Pirongia stratovolcano is about 15 km NW, and the smaller Te Kawa cone is 4 km SE.

Kaitake
Kaitake, an eroded, heavily vegetated Pleistocene volcano, is the NW-most stratovolcano of the Taranaki volcanic region.

Pouakai
Pouakai volcano, NW of Taranaki, is an eroded Pleistocene stratovolcano surrounded by a ring plain of lahar deposits dating from about 0.25 million years ago (Neall et al., 1986). The relationship of German Hill cone, 10 km NE of Pouakai, is not clear.

South Auckland
The South Auckland (Pukekohe) volcanic field consists of basaltic shield volcanoes, scoria cones, and tuff cones and rings from 1.56-0.51 million years ago (Smith, in Johnson et al. 1989). The Ngatutura scoria cone group across the Waikato River is of late Pliocene to early Pleistocene age.

Mokohinau Islands
The Mokohinau Islands are the surface expression of a largely submarine rhyolitic plateau and are a part of the Hauraki volcanic region offshore from the Northland Peninsula. Burgess Island contains basaltic to rhyolitic rocks. Fanal Island consists of a rhyolitic lava dome with an obsidian cap that is fission-track dated at 500,000 years ago (Skinner, 1986). Houghton (1994 pers. comm.) considers this date to be suspect.

Little Barrier
Little Barrier Island, part of the Hauraki volcanic region, is a Pliocene to Pleistocene dacitic to rhyodacitic stratovolcano, with its latest stage of activity taking place from 1.6-1.2 million years ago (Lindsay et al., 1999).

South Coromandel Peninsula
The southern Coromandel Peninsula contains three areas where Pleistocene basalts outcrop: Table Mountain west of Tairua Harbour, an area NW of Whangamata, and a larger area between Te Aroha and Athenree (Latter 1985, pers. comm.). Houghton (1994, pers. comm.) notes that age data for many of the Coromandel localities is suspect, and that it is possible that all of the Coromandel arc volcanoes are Miocene-Pliocene in age.

Te Kawa
The small (1.3 km diameter) crater-dominated Te Kawa cone and low Tokanui cone are located about 30 km S of the city of Hamilton in the Waikato region of North Island, New Zealand. They are the SE-most features of the Alexandra Volcanic Group, which includes an alignment of late Pliocene-early Pleistocene edifices, including the larger Kakepuku and Pirongia volcanoes, ending with Karioi more than 50 km NW on the Tasman Sea coast.

Macquarie Ridge Volcanic Province

Hautere
Macquarie Ridge Volcanic Province
Hautere (Solander Island) is the 1.5-km-wide emergent surface of an andesitic stratovolcano lying 40 km S of the tip of South Island, NW of Steward Island. A Potassium-Argon date of about 1 million years ago was obtained by C J D Adams (Reay, 1986). Ar-Ar dates as young as about 400-150 ka were obtained by Mortimer et al. (2008).

Campbell Plateau Volcanic Province

Antipodes Island
Campbell Plateau Volcanic Province
The isolated, uninhabited Antipodes Islands are located in the south Pacific, 770 km SE of New Zealand. Volcanism has been dominantly pyroclastic, and the presence of well-preserved scoria cones suggests a Holocene age (LeMasurier and Thomson, 1990). The most recent eruptions occurred on the cone forming Mount Galloway and Mount Waterhouse at the center of 4-km-wide main island. Marine erosion has exposed sections through tuff cones at Perpendicular Head and Albatross Point at the NE and SE tips of the island, respectively. Radiometric dates indicated basalts that are younger than 1 million years (250-500 ka with high uncertainty W of Reef Point), and Cullen (1969) also speculated that volcanism may have begun in the Tertiary and persisted "almost to the present day."

Pacific-Antarctic Ridge at 50.5�S
A basalt dredge sample Ar-Ar dated by Koppers et al. (2004) was 1.110 +/- 0.055 Ma. This seamount is about 90 km NW of Lonsdale Seamount and 400 km N of the Hollister Ridge 1991 acoustic signal location. It is near the extreme eastern end of the Louisville Seamount Chain where it intersects the Pacific-Antarctic Ridge, near where some models locate the Louisville hotspot (Vlastelic and Dosso, 2005).

Juan Fernandez Hotspot Volcano Group

Robinson Crusoe
Juan Fernandez Hotspot Volcano Group
The main part of Robinson Crusoe (Mas a Tierra) Island, in the central part of the Juan Fernandez Island group, is composed of four overlapping shield volcanoes with calderas breached to the NE. The SW part of the basaltic island consists of smaller altered cones. Potassium-Argon dates for the island range from 5.8 to 3.8 million years ago (Steussy et al., 1984) and the island is more dissected than Alexander Selkirk (Mas a Fuera) Island to the west. An eruption at El Yunque was reported in 1743, but is considered uncertain (Catalog of Active Volcanoes of the World). Reports exist of a submarine eruption about 1.5 km north of the island in 1835 that produced an explosion and flames that lit up the island, primarily from the Governor, but the story varied over the years and no evidence was ever located (see CAVW for summary).

Seamount JF6
Juan Fernandez Hotspot Volcano Group
Volcano type: Lava dome?
A submarine eruption reported in 1839 from a seamount (identified as JF6 by Yanez et al., 2009) at the eastern end of the Juan Fernandez island chain is considered highly suspect (Catalog of Active Volcanoes of the World). Although an ephemeral island was reportedly formed, the seamount has a depth of more than 600 m and lies at the eastern end of an island chain that is progressively younger to the west.

Alexander Selkirk
The dome-shaped island of Alexander Selkirk (Masafuera) is the emergent summit of a Pleistocene shield volcano. A Potassium-Argon date of 1.01 million years ago (Steissy et al., 1984) is the youngest obtained for the Juan Fernandez islands (Stuessy et al., 1984).

San Felix Hotspot Volcano Group

San Felix
San Felix Hotspot Volcano Group
San F�lix Island, 800 km W of the Chilean coast, consists largely of a low, cliff-bounded lava platform separating two tuff cones. The Islota Gonz�les cone to the SW is separated from the main island by a shallow submerged platform. Cerro Amarillo at the western end forms the high point of the island and is the source of fresh-looking hawaiite lava flows that reached the sea and formed the low lava platform at the SW tip of the island. A ship captain reported a dull red glow at the summit in 1923. Willis and Washington (1924) considered the youthful lava flows to predate discovery of the island in the 16th century, but not be more than a few centuries old. However, Ar-Ar dating by Haase et al. (2000) determined an age of 421 +/- 18 ka, and considered the advanced erosion of the island as indicative of several hundred thousands of years of inactivity.

Salas y Gomez
Salas y G�mez Ridge Volcano Group
Volcano type: Shield?
A small volcanic islet, 400 x 700 m wide, forms the summit of a large seamount. No volcanic vents have been identified, but rocks from the islet are Potassium-Argon dated at 1.94-1.31 million years ago (Clark and Dymond, 1977). Both Rapa Nui (Easter Island) and Salas y G�mez are east of the East Pacific Rise.

Pitcairn
Pitcairn Hotspot Volcano Group
Located at the SE end of the Duke of Gloucester-Gabbier Islands chain, Pitcairn is a small island remnant of a shield volcano with a dissected caldera. Potassium-Argon dates range from 0.95-0.45 million years ago (Duncan et al. 1974).

Marquesas Hotspot Volcanic Group

Hiva Oa
Marquesas Hotspot Volcanic Group
The Marquesas Islands show an age progression with the youngest volcanoes occurring at the SE end of the chain. Hiva Oa, a large shield volcano with a caldera truncated on the south side, is the NW-most volcano of the chain with some Pleistocene activity. Potassium-Argon dates range from 2.48-1.58 million years ago (Duncan and Mcdougall 1974). Radiometric ages for Tahuata Island, immediately south of Hiva Oa, are Pliocene.

Fatu Hiva
Marquesas Hotspot Volcanic Group
Fatu Hiva is the SE-most and youngest of the Marquesas Islands. Potassium-Argon dates for the island, a shield volcano with a large summit caldera truncated on the west, range from 1.39-1.30 million years ago (Duncan and Mcdougall, 1974).

Moorea
Like several other central Pacific island chains, the Society Islands are progressively younger to the SE. Moorea, the NW-most of the Society Islands with Pleistocene volcanism, is a dissected shield volcano whose caldera is open to the north and surrounded by sharp-topped peaks. Potassium-Argon dates for the island range from 1.64-1.49 million years ago (Duncan and Mcdougall 1976).

Tahiti-Nui
Tahiti-Nui is the larger of two coalescing shield volcanoes forming the island of Tahiti. Much of the original volcano is intact; the central caldera is drained to the north by the Papenoo River. Potassium-Argon dates range from 1.23-0.48 million years ago (Duncan and Mcdougall, 1976).

Tahiti-Iti
The smaller and younger of two coalescing shield volcanoes on Tahiti, Tahiti-Iti (Taiarapu) is connected to Tahiti-Nui by a narrow isthmus. Potassium-Argon ages range from 0.48-0.38 million years ago (Duncan and Mcdougall 1976).

Aitutaki
Austral-Cook Hotspot Volcano Group
Volcanic rocks of Aitutaki Atoll in the Cook Islands are Potassium-Argon dated 0.77-0.66 million years ago (Duncan and Mcdougall 1976).

Rarotonga
Potassium-Argon dates from the Rarotonga shield volcano in the Cook Islands range from 1.8-1.2 million years ago (Duncan and Mcdougall 1976).

Rurutu
Rurutu is an eroded shield volcano in the Austral (Tubuai) Islands capped by later Pleistocene lava flows that reached the sea through gaps in the fringing coral reef. The younger volcanics are Potassium-Argon dated from 1.85-1.05 million years ago (Duncan and McDougall, 1976).

Tisa
Seamount about 45 km W of Tutuila Island. Koppers et al. (2011) reported an Ar-Ar date of 2.18 � 0.03 Ma.

Northeast Bank
Northeast Bank is a seamount about 45 km NW of Ofu-Olosega. Koppers et al. (2011) reported Ar-Ar dates of less than 1 Ma. The informal cruise designation of "Muli" has been present in the scientific literature since 1999, but should not be used as a common name.

Soso
The Soso seamount is about 65 km NE of Tutuila Island. Koppers et al. (2011) reported Ar-Ar dates of 1.35-1.43 Ma.

Tamai
The Tama'i seamount is about 65 km NNW of Tutuila Island. Koppers et al. (2011) reported Ar-Ar ages between 1.87 and 2.07 Ma.

Tulaga
The Tulaga seamount is about 60 km ESE of Tutuila Island in the Samoan Islands. Koppers et al. (2011) report that Ar-Ar ages from samples dredged on the S flank are 0.79-1.07 Ma.

Malutut
The Malutut seamount is the high point near the end of a submarine volcanic ridge that extends more than 40 km ESE from Tutuila Island in the Samoan Islands. Koppers et al. (2011) report that Ar-Ar ages from samples dredged on the SW flank are 1.04-1.48 Ma.

Vitiaz Lineament Volcanic Province

Wallis Islands
Vitiaz Lineament Volcanic Province
The Wallis Islands consist of one relatively large island, 7 x 14 km Uvea Island, and 22 smaller islands and islets that are surrounded by a barrier reef. The low forested islands, formed of flat-lying basaltic lava flows cut by explosion craters, are capped by tuff cones and cinder cones. Numerous small shields (lava cones) and tuff cones were considered by Stearns (1945) on morphological grounds to be of Pleistocene to "Recent" age. Although Price et al. (1991) noted that rocks of Pleistocene or Holocene age were present, K-Ar ages of dated samples range from 500,000 to 80,000 years old. The origins and tectonic setting of this volcanic feature are uncertain, but researchers agree that this was not a product the Samoan hotspot.

East Central Australia Volcanic Provinces

Bundaberg-Boyne Province
East Central Australia Volcanic Provinces
The Hummock (1.1-0.9 million years ago) (Ma), Berrembea, and Barambah (0.6 Ma) basalts from the Bundaberg, Gin Gin and Gayndah areas, respectively, are of Pleistocene age. The northern Boyne area has also had Pleistocene volcanism (Robertson, Sutherland, and Hollis, in Johnson et al., 1989).

Maer Volcanic Province
Northeastern Australia Volcanic Province
Eight small islands in the NE part of the Torres Straits form the northernmost east-Australian Cenozoic volcanic field. The Quaternary pyroclastic cones have been dated between 3 and 1 million years ago (Stephenson, in Johnson et al., 1989).

Piebald Volcanic Province
The Piebald volcanic province consists of eroded small shield volcanoes and pyroclastic cones dated between 1.6 and 1.2 million years ago (Stephenson, in Johnson et al., 1989).

Mclean Volcanic Province
The McLean Volcanic Province consists of Tertiary volcanoes, undated younger scoria cones, and valley-floor lava fields that are probably less than 1 million years old (Stephenson, in Johnson et al., 1989).

Atherton Basalt Province
The Atherton Basalt Province covers an area of 1,800 km2 and contains 52 eruptive centers, including small lava shields, cinder cones, maars, and one diatreme. The maars, the only ones in Northern Queensland, range in age from 200,000 to 10,000 years before present (Stephenson, in Johnson et al., 1989).

Fox
Mount Fox is a pyroclastic cone distinct from the large volcanic provinces of NE Australia. Young basanite lava flows dated 1.5 million years ago descend the coastal scarp into the Stone River valley (Stephenson, in Johnson et al., 1989).

Chudleigh Volcanic Province
Straddling the Great Divide, the Chudleigh volcanic province contains 46 vents and covers an area of 2,000 km2. Several lava shields and numerous pyroclastic cones are present; the youngest dated rocks are 250 ka. Two lava flows traveled 100 km from their source (Stephenson, in Johnson et al. 1989).

Nulla Volcanic Province
The Nulla volcanic province consists of 46 vents and associated lava flows covering an area of 7,500 km2. The youngest volcano, Toomba, is only 13,000 years old, and produced a massive 120 km long lava flow. Three other lava flows exceed 100 km length (Stephenson and Griffin, 1976).

Sturgeon Volcanic Province
Wide lava plains of the Sturgeon volcanic field cover 7500 km2. The youngest lava flow is dated at 0.92 Ma and traveled 120 km from its source at Twins crater (Stephenson, in Johnson et al. 1989).

Utara Wetar
The island of Gunungapi, or Utara Wetar (North Wetar) is located in the Banda Sea ~100 km N of Wetar Island. The small circular island reaches less than 300 m above the ocean surface but is the summit of a massive stratovolcano that rises 5,000 m above the seafloor. There are three notable landslide scarps, the largest of which forms a prominent embayment on the NE coast, and the others overlapping on the W and SW flanks. Andesite sampled from the island was K-Ar dated by Honthaas et al. (1998) at 420,000 +/- 100,000 years. Observations from 1512 CE of a possible lava flow have been attributed to this island, along with gas-and-steam emissions in 1699 CE. However, in an analysis of documents related to the route taken by Portuguese ships commanded by Abreu in 1512, Sollewijn Gelpke (1995) determined that this was not the erupting volcano described; a drawing of the event showed Sangeang Api.

Seulawah Agam
Seulawah Agam, near the NW tip of Sumatra, is an extensively forested volcano with a small summit crater. It was constructed within the large Pleistocene Lam Teuba caldera, which also contains a smaller 6 x 8 caldera. The van Heutsz crater is an active fumarolic area on the NNE flank extending about 200 m downslope around 700 m elevation; it does not have the appearance of a volcanic crater. Additional geothermal areas are noted by Marwan et al. (2021). Sapper (1927) and Neumann van Padang (1951 CAVW) listed an explosive eruption in the early 16th century, and the CAVW also listed an eruption from the van Heutsz crater in 1839. However, Rock et al. (1982) found no evidence for historical eruptions. The Volcanological Survey of Indonesia also noted that although no reported eruptions have occurred from the main cone, the NNE-flank activity may have only been hydrothermal.

Toba
The 35 x 100 km Toba volcano, the Earth's largest Quaternary caldera, was formed during four major Pleistocene ignimbrite-producing eruptions beginning at 1.2 million years ago. The latest of these produced the Young Toba Tuff (YTT) about 74,000 years ago from vents at the NW and SE ends of present-day Lake Toba. The YTT represents the largest known Quaternary eruption, ejecting about 3,800 km3 (dense rock equivalent) of ash that covered ~40 million km2 to a depth greater than 5 mm, plus another 1,500 km3 of pyroclastic density current (PDC) deposits (Costa et al., 2014). Resurgent doming formed the massive Samosir Island and Uluan Peninsula structural blocks after the YTT eruption. Additional post-YTT eruptions include emplacement of a series of lava domes, growth of the solfatarically active Pusukbukit volcano on the south margin of the caldera, and formation of Tandukbenua volcano at the NW-most rim of the caldera. Lack of vegetation suggests that Tandukbenua may be only a few hundred years old (Chesner and Rose, 1991), but no radiometric dating has been done.

Imun
Imun is a single small dacitic and/or rhyolitic cone south of Lake Toba with a youthful, undissected morphology. It is surrounded by and sits over Toba tuffs, and is considered to be of late-Pleistocene/Holocene age (Aldiss et al., 1983; Ryberg et al., 2016). Nukman and Moeck (2013, reproduced in Niasari, 2015) mapped it as Pleistocene. Imun lies along the Sumatra Fault, and magmatic processes in this region appear to be related to activity on this fault (Muksin et al., 2013).

Lubuk Raya
Lubuk Raya is an andesitic stratovolcano of latest Pleistocene to possibly Holocene age with a broad crater breached to the S and a prominent lava dome at the southern foot. (Aspden et al., 1982).

Sibualbuali
Sibualbuali is an eroded Pleistocene stratovolcano with two solfatara fields on the eastern flank. Rhyolitic-dacitic lava domes erupted from fissure vents along the Toru-Asik fault to the S are late Pleistocene or possibly Holocene in age, and are considered part of the Sibualbuali volcanic center (Aspden et al., 1982).

Sarik-Gajah
The Sarik center consists of two young andesitic/basaltic cones with vegetated, but uneroded surfaces. The andesitic-dacitic Gajah center, about 6 km SW, consists of a single cone with a rubbly lava flow. Both centers were considered to be Quaternary (Rock et al., 1983).

Kunyit
Kunyit volcano lies about 10 km S of Lake Kerinci, well to the N of its location listed in Neumann van Padang (1951). The summit of the dacitic volcano contains two craters open to the S, the uppermost of which has a small crater lake. The age of the latest eruptive activity is not known, but there do not appear to be any recent volcanic features. Fumarolic activity occurs at the youngest crater on the N side of the summit area. Social media reports from hikers confirmed hot springs and sulfur odors along the trail in 2013. Silitonga et al. (2015) mapped the most recent volcanic unit as late Pleistocene while researching the area as a geothermal energy prospect.

Bukit Hulu Lais
Bukit Hulu Lais is an eroded volcanic complex towards the NW end of a volcanic ridge ~30 km long offset ~7 km SW of the Great Sumatra Fault. A large NE-facing scarp SE of the summit hosts abundant thermal activity; the SW high point is Belirang Beriti and the SE high point is Beriti Besar. The area was mapped by Budiardjo et al. (2001) as the Pleistocene 907 ka Hululais Andesite. The crater and a large area to the north are part of a major geothermal development area.

Bukit Daun
Located in a sparsely populated region of Sumatra, Bukit Daun is part of a volcanic complex with multiple peaks at the SE end of a volcanic ridge ~30 km long. The complex is truncated by what might be a 3-km-wide caldera. Its 600-m-wide summit crater contains a lake; a smaller crater lake is found at Tologo Kecil on the SSW flank. No eruptions are known, although active fumaroles are present on the SSW peak.

Besar
The Gunung Besar stratovolcano in SE Sumatra was characterized by Neumann van Padang (1951) as a solfatara field (Marga Bajur or Bayur) on the NW and N foot of the edifice. The crater was noted as having an "unimportant" sulfur deposit in its crater and vapor exhalation. The remaining edifice consists of about 50% of a crater rim completely open to the E, with three small domes or cones, the largest of which contains a small pond in a summit crater. The geothermal area was described by Neumann van Padang (1951) as including four small solfatara fields: Gemurah Badas (8 x 10 m with hot springs and sulfur gas exhalation), Gemurah Bubur (large basin of boiling water formed between 1930-40), Gemurah Keningan (boiling mud springs, very active 1938-40), and Gemurah Ilahan (2 km upstream of Badas with geyser-like mud springs and dead trees). A "phreatic steam eruption" in April 1940 was noted from Gemurah Ilahan. Hochstein and Sudarman (1993) considered the Marga Bayur geothermal system to be associated with a degassing magma reservoir because "radiometric dating of the youngest tuff deposits (unpublished data, Pertamina files) showed that [the volcano had been] active during the last 30 kyr." This geothermal prospect has been studied but not yet developed.

Sekincau Belirang
Sekincau volcano was constructed near the southern rim of the small NW-SE-trending double Belirang and Balak calderas, 2 and 2.5 km wide, respectively. The 300-m-wide crater of Sekincau is open to the south. The age of the latest eruptive activity is not known, although fumarolic activity occurs on the caldera floor and on the E and SE outer flanks of Balak caldera.

Ulubelu
Ulubelu is an elliptical, 4-km-long, volcano-tectonic depression in SE Sumatra. The age of its latest eruptions is not known, although solfataric areas, mud volcanoes, and hot springs occur at several locations. Thermal areas are aligned NE of and parallel to the Great Sumatran Fault.

Rajabasa
Rajabasa is a prominent isolated volcano along the Sunda Strait at the SE-most tip of Sumatra. The eroded edifice is ~7.5 km diameter overall, with the Balerang summit towards the SE and the slightly higher Rajabasa to the NW with a crater ~600 m in diameter. Fumarolic activity occurs on the foot and flanks of the edifice; increased activity was reported in April 1863 and May 1892. Bronto et al. (2012) described Quaternary lavas (andesite-basalt), breccias, and tuff. Hasibuan et al. (2020) reported that the youngest eruptive material, an andesite from the Rajabasa cone, was K-Ar dated at 0.120 +/- 0.04 Ma.

Pulau Weh
Pulau Weh island off the NW tip of Sumatra has been interpreted as the remains of a partially collapsed older center breached to the NW and filled by the sea. Pulau Weh was included in the Catalog of Active Volcanoes of the World (Neumann van Padang 1951) based on its geothermal activity. Volcanism was assumed to be of Pleistocene age (Bennett et al., 1981), but fumaroles and hot springs are found a NW-E-trending line along the summit of the island and near the western shore of Lhok Perialakot bay on the northern side of the island.

Seulawah Inong
Seulawah Inong is mapped as a Quaternary volcano (Bennett et al. 1981).

Olim
The Olim volcanics are Pleistocene porphyritic andesitic volcaniclastics erupted from fissure vents (Bennett et al., 1981, Keats et al., 1981).

Teu Minas
Teu Minas is a small eroded Pleistocene andesitic stratovolcano with local thin basalt lava flows (Keats et al. 1981). Porphyritic andesite is also present at the volcanic center (Rock et al., 1982).

Geureugoh
The Geureugoh volcanics are mapped as andesitic pyroclastic breccias originating from fissure vents (Keats et al. 1981).

Gunung Tudeuk
Gunung Tudeuk is a recently extinct Pleistocene andesitic to dacitic lava dome (Keats et al. 1981, Cameron et al. 1983).

Nama Salah
Nama Salah is mapped as pumiceous andesites and dacites of Pleistocene age (Cameron et al. 1983). Lahars from Nama Salah blocked drainages, forming lake Laut Tawar.

Gunung Telago
Gunung Telago is mapped as a complex double volcanic center of Pleistocene age (in part Pliocene) by Cameron et al. (1983).

Gunung Sembuang
Volcano type: Explosion crater
Gunung Sembuang is an andesitic Pleistocene explosion crater with a lava flow (Cameron et al. 1983).

Geureudong
Geureudong is a massive, 30-km-wide complex that rises above schists and granitic rocks and is one of the largest volcanic complexes in NW Sumatra. The 2885-m-high Bur ni Geureudong is Pleistocene in age, but hot springs are found on its northern and southern flanks. The Pupandji pyroclastic cone was constructed on its SE flank, adjacent to two maars with diameters of 300 and 60 m.

Kembar
The Gayolesten fumarole field is located on the flanks of the Pleistocene Gunung Kembar volcano. The Kembar complex, located at the junction of two fault systems, is an andesitic shield volcano capped by a complex of craters and cones (Cameron et al. 1982). Gayolesten was included in the Catalog of Active Volcanoes of the World (Neumann van Padang 1951) based on its geothermal activity. Active fumaroles and hot springs are present at several locations.

Bekulap
Volcano type: Lava dome(s) ?
The Bekulap volcanic center consists of three possible lava domes and an explosion crater of Pleistocene age (Cameron et al. 1982). The Palpalan and Sumilir volcanoes of IAVCEI (1973) near this location are mapped (Paipalan and Semilir) as sedimentary rocks by Cameron et al. (1982).

Takur-Takur
Takur-Takur (Takor) is a dissected volcano composed of plagioclase-hornblende-phyric dacite and mapped as Pliocene to Pleistocene in age (Rock et al., 1983; Cameron et al. 1982).

Bukit Tenaroh
Bukit Tenaroh is mapped as Pliocene to Pleistocene (Cameron et al. 1982).

Simbolon
Simbolon is a Pleistocene volcano with a large summit caldera and several flank lava plugs (Cameron et al. 1982).

Martimbang
Martimbang is an andesitic volcano of Pleistocene age (Aspden et al. 1982).

Melintang
Melintang (also known as Malintang or Gunung Sago) is a andesitic to basaltic volcano of Quaternary age with a crater breached to the SE (Silotonga and Kastowo 1975).

Maninjau
Maninjau caldera is the largest silicic volcanic center in the Padang area of central Sumatra. The elongated caldera, filled by a lake, was formed during three Pleistocene eruptive episodes. K-Ar dating on the andesites and tuffs surrounding the caldera yielded ages of 0.83 +/- 0.42 Ma for older pre-caldera andesites (Barber et al., 2005). The youngest rhyolitic ashflow deposit was dated at about 0.28 +/- 0.12 million years (Leo et al., 1980; Barber et al., 2005).

Bukit Telor
Bukit Telor, also known as Bukit Ibul, is a basaltic cone located along the northern coast of Sumatra, more than 200 km behind the axis of Quaternary volcanism. It is only about 38 m high, but the total outcrop of the basalts is as much 4 km2 in area (Barber et al., 2005). The K-Ar age of these basalts is about 1.25 +/- 0.19 million years. As with Sukadana and because of its back-arc location, Bukit Telor basalts are quite texturally and compositionally different from the arc volcanics. Lherzolite mantle xenoliths are common, and the lavas typically range from quartz-tholeiite to mildly alkaline in composition (Barber et al., 2005).

Tujuh
Tujuh is a Quaternary volcano with a caldera partially filled by Lake Gunung Tujuh. A post-caldera composite cone, breached to the NW, fills the NW part of the caldera, giving the caldera lake a half-moon shape.

Runcing
Gunung Runcing was identified by Rosidi et al. (1976) as an early Quaternary volcano. The exact age is unknown, and it appears heavily eroded with about half of a remnant edifice rim on the west side.

Raja-Sabanda
Gunung Raja (or Raya) appears to be a remnant stratovolcano with a large caldera open towards the entire SE side that may originally have been about 3 km in diameter. The Bukit Sabanda cone lies about 2 km NE of the caldera. Although eroded, the volcanic features are still evident. Mapping related to geothermal exploration of the adjacent Kunyit volcano identified a "Raja volcanic unit" as Middle Pleistocene, but did not include this volcano in the mapped area that was published (Silitonga et al., 2015).

Hulunilo
The Hulunilo stratovolcano, about 5 km E of Sumbing volcano, has a caldera about 1.5 km in diameter that is breached to the W. Morphologically it appears no more eroded than other Quaternary edifices in central Sumatra, though the age of it's most recent eruption is unknown.

Tungkat
The small Bukit Tungkat about 10 km E of the Masurai complex exhibits an extensively eroded appearance, but is still a recognizable volcanic cone. Pleistocene activity is possible , although no ages are known.

Masurai
Gunung Masurai is a large volcanic complex with a remnant half-caldera and a chain of two summit crater lakes and a cone extending SW beyond the former caldera rim. Its youthful constructional phase suggests a late Pleistocene age (Sieh and Natawidjaja, 2000). The Masurai volcanic cluster is associated with the Sungai Penuh pull-apart basin, a feature of the Sumatra strike-slip fault, which becomes wider towards the volcanic cluster (Muraoka et al., 2010).

Isau-Isau
Isau-Isau is of Quaternary age, and though it was a predominantly andesitic volcano, it is part of the Pasoemah Highland ignimbrite complex (van Bemmelen 1949b; Westerveld, 1952). The edifice is mostly surrounded by andesites, dacites, and basalts from Isau-Isau and the surrounding stratovolcanos (Westerveld, 1952).

Bukit Nanti
Bukit Nanti is a young Quaternary volcano (van Bemmelen 1949b).

Raja
Raja volcano, located north of Ranau Lake, was mapped as a morphologically youthful volcano of likely late Pleistocene age (Sieh and Natawidjaja, 2000).

Pesagi
Pesagi volcano, a collapsed caldera SE of Ranau Lake, was mapped as a morphologically youthful volcano of likely late Pleistocene age (Sieh and Natawidjaja, 2000; Widarto et al., 2016). However, Wahib (1998) suggests that it erupted in the Holocene, and is in part responsible for young volcanic breccias, tuffs, and andesites in the region. The slopes are quite dissected in spots and approach angles as steep as 70� near the summit (Wahib, 1998). These inherently unstable slopes collapsed in the wake of the 1993 Liwa earthquake, leading to destructive landslides.

Tanggamus
Gunung Tanggamus is of Quaternary age (van Bemmelen 1949b). Its products, which mostly consist of lavas, breccias, and tuffs of predominantly dacitic and andesitic composition, dominate the geology of the western part of the Lampung Province in southern Sumatra (Zulkarnain, 2011). Older Tanggamus products close to the main cone are generally pyroclastic breccias, consisting of porphyritic andesite and lapilli tuff. The younger products that make up the relatively undissected cone are of intermediate composition, and those deposits in the proximal zone surrounding the cone and in more distal regions are pyroclastic and laharic breccias and ignimbrites (Husein et al., 2015). The ignimbrites appear to be younger than the pyroclastic breccias (Husein et al., 2015). The lavas on Tanggamus are vesicular and porphyritic, and at about 1.4 million years old, are younger than the pyroclastic breccias and ignimbrites. The laharic breccias, consisting of porphyritic andesite and pumice, yielded an age of 1.5 Ma; however, field observations indicate that these units may be younger (Husein et al., 2015).

Sukadana Basalts
The low Sukadana Plateau, 30 x 11 km wide, is a volcanic expression of the Sukadana Basalts of Pleistocene age (Barber et al., 2005). The plateau itself covers an area of approximately 1000 km2 and contains fissure-fed lava flows 2-3 m thick issued from NW-SE trending fissures (Barber et al., 2005; van Bemmelen 1949b). The basaltic region may be over 200 m thick in areas, localized around eruptive centers, but no deposits greater than 10 m have been observed. Some columnar jointing is present. K-Ar dating gave ages ranging from 0.44 Ma to 1.15 Ma for the oldest samples (Soeria-Atmadja et al., 1985 in Barber et al., 2005), but more recent ages measured from more well-preserved flows and spatter cones are around 0.01 to 0.8 million years. Sukadana is technically part of the back-arc region of the Sumatra Volcanic Arc Segment, evidenced by notable textural and compositional differences from the arc volcanics, as well as a similarity to the back-arc Bukit Telor basalts (Barber et al., 2005).

Malabar
The broad, forested, Gunung Malabar stratovolcano is located immediately south of the city of Bandung in western Java. While it was previously thought to be of possible Holocene age (Bronto 1995, pers. comm.), K-Ar dates of 0.23 Ma were reported by Bogie and Mackenzie (1997). Additionally, Malabar material was overlain by other Pleistocene deposits from the Wayang-Windu domes a few kilometers south. A geothermal energy project is present on the S flank closest to Wayang-Windu, but no active geothermal features have been reported.

Wayang-Windu
Wayang-Windu, the site of a geothermal prospect, is a series of andesitic lava domes about 30 km S of Bandung and immediately S of Malabar volcano. Both Gunung Wayang and Gunung Windu have fumarolic areas. The age of the latest eruptive activity is not known, but Bogie and MacKenzie (1997) reported K-Ar dates of 0.49 Ma (G. Wayang), 0.19 Ma (G. Bedil), and 0.10 Ma (G. Windu).

Kendang
Gunung Kendang is located ~9 km N of Papandayan volcano at the N end of a volcanic massif, and is associated with Darajang geothermal reservoir on the E flank and along the Kendang fault, which extends NE to the Kawah Kamojang geothermal field. There are four fumarole fields, the most prominent of which is Kawah Manuk, located in a broad 2.75-km-wide depression; thermal activity consists of fumaroles with sulfur sublimation, mud pots, and hot water pools with occasional mild water ejections. The latest eruptions produced the Kiamis rhyolitic lava dome and obsidian lava flows, 2 km NE of Darajat, characterized as "Recent" by Whittome and Salveson (1990). Mapping of the Darajat area and stratigraphic interpretations by Intani et al. (2021) found Plio-Pleistocene Kendang volcanics, Rakutak pyroclastics, and Gagak volcanics, followed by Pleistocene Kamasan volcanics, dacite domes, and Kiamis volcanics; no Holocene deposits were noted.

Gunung Putri
Gunung Putri is a peak in an area of eroded Quaternary volcanoes about 10 km WSW of Galunggung.

Telomoyo
The Telomoyo cone was constructed over the southern flank of the eroded Pleistocene Soropati volcano, about 3 km from the approximate center of that older edifice. A similar eroded cone or lava dome, Gunung Andong, is 4 km SW. Both of these features are also on the NW flank of Merbabu, with Telomoyo ~11 km from the summit, and appear to be partially buried by deposits from that volcano. These volcanoes are along a NNW-SSE line of volcanoes extending from Ungaran in the north to Merapi in the south. Although van Bemmelen (1941) suggested that part of this complex was Holocene, no eruptions have been identified or dated.

Ungaran
Gunung Ungaran, S of the northern Java coastal city of Semarang, lies at the northern end of four volcanoes extending NNW from Merapi. According to van Bemmelen (1941), the edifice was formed in three stages, with the youngest constructed S of three large remnant structural blocks of the second edifice during the late Pleistocene and Holocene. A group of pyroclastic cones was also constructed along the margins of the older edifice. However, there have been no deposits dated or eruptions reported from this deeply eroded volcano. There have been many geothermal studies, and there are active fumarole fields are located on the flanks. One such study, by Muchni and Suryantini (2025), noted that an uncited geological map indicated a measured age of less than 600,000 years for the youngest dome (Kemalon); other domes were dated at 620 +/- 500 ka (Mergi and Kemalon), and 680 +/- 500 ka (Munding). Kohno et al. (2006, cited in Setyawan et al., 2009), placed the formation of the "Young Ungaran" volcano around 300 ka.

Muria
The Muria (also spelled Muriah) stratovolcano forms much of the broad Muria Peninsula along the northern coast of central Java, well N of the main volcanic chain. This edifice is flanked to the N by Genuk, an eroded dome complex near the coast. It is largely Pleistocene in age, with a deeply eroded central edifice and flanks. The most recent eruptive activity produced three maars on the SE and NE flanks, and a lava flow from a SE-flank vent that entered one of the maars. Conflicting late-Pleistocene to Holocene dates for these maars leave uncertainties about their ages; McBirney et al. (2003) noted that their youthful morphology in surrounding eroded terrain suggested Holocene activity. Radiocarbon dating by McBirney et al., (2003) of a paleosol underlying E-flank maar deposits gave 2,110 � 360 BP from Gunung Bambang and 6,230 � 360 BP from Gunung Rowo, but they were considered unreliable because of possible contamination with young organic material.

Wilis
Gunung Wilis is a volcanic massif ~30 km long surrounded by low-elevation plains on all but its southern side. The complex includes multiple valleys and eroded peaks, but no cones or craters suggestive of recent activity. It was formed during three episodes dating to the early Pleistocene, with the final magmatic episode during the Holocene (van Bemmelen, 1949, summarizing Tissot van Patot, 1926, and Duyfyes, 1938). Mapping, aerial photo analysis, and radiometric dating by Hartono (1994) found no clear support for Holocene activity, with the most recent ages from sampled material being over 500 ka. No confirmed eruptions are known; one listing of an eruption in 1641 CE was likely confused with a major eruption of nearby Kelud that same year. Fumaroles and mud pots occur near Lake Ngebel on the lower W flank.

Malang Plain
A group of nine "small eruption" centers were mapped by van Bemelen (1937) as "subrecent or recent" within an area almost 40 km N-S on the Malang alluvial plain, west of Semeru and the Tengger Caldera. Some of these may be related to Tengger activity, but others have no clear connection to any specific eruption center and are situated on a distinct N-S zone of tectonic weakness. No other studies are known, and van Bemmelen (1937) provided no further descriptions that would indicate Holocene activity. Two of the locations appear to be eroded cones with craters, while others are small hills with no distinguishing volcanic features.

Lurus
The small Lurus volcanic complex along the northern coast of eastern Java, north of the Iyang-Argapura massif, produced leucite-bearing rocks followed by later eruptions of andesitic and trachytic composition. This little known complex was mapped as subrecent-to-recent age by van Bemmelen (1949b). Ringgit, 30 km E also along the N coast of Java, was dated at 1.2-0.5 Ma.

Gede
Gede volcano on the NW tip of Java is of Quaternary age and is located about 280 km from the trench (van Bemmelen 1949b). The Gede Salak volcanic complex consists of pyroclastic flows on its western flanks and lava flows on its eastern flanks (Kurniawan et al., 2011). Mt. Gede is also surrounded by Plio-Quaternary tuffs (Banten Tuffs) ranging from 0.07 to 0.1 Ma in age (Pramumijoyo and Sebrier, 1991). Kurniawan et al. (2011) suggest that these Tuffs came from the calderas of the nearby Rawa Dano volcanic complex but gravity anomalies in the region suggest that neither Gede nor its nearby volcanoes could have been responsible for these ignimbrites and instead suggest a pre-existing caldera in the Sunda Straight was responsible (Nishimura et al., 1986).

Cibugis
Volcanoes in this portion of Java are Quaternary in age (van Bemmelen 1949b).

Kendeng
Kendeng is a stratovolcano of Pleistocene age characterized by andesites and andesitic breccias (Bronto, 1995, pers. comm.; Tun et al., 2014). These deposits cover older andesites and lapilli tuffs; unlike other volcanic deposits in western Java, they are not greatly affected by hydrothermal alteration (Tun et al., 2014).

Endut
Endut volcano ceased activity in the late Pleistocene (van Bemmelen, 1949b). The size of Gunung Endut suggests that it was a stratovolcano that underwent a summit crater breach and sector collapse, which may have been aided by hydrothermal processes (Bogie et al., 2010). Endut is a volcanic edifice that makes up a series of volcanoes framing the Gunung Salak Geothermal Field (Keetley et al., 2003). It is a largely andesitic volcano (Bogie et al., 2010).

Halimun
Activity at the NW-most of two adjacent volcanoes named Halimun ceased in the late Pleistocene (van Bemmelen, 1949b).

Halimun-Talaga
Activity at the SE-most of two adjacent volcanoes named Halimun ceased in the late Pleistocene (van Bemmelen 1949b). Halimun and Talaga are the two main peaks about 2.5 km apart along a ridge.

Sanggabuana
Volcanic activity at Sanggabuana, a stratovolcano in northwest Java, began in the late Tertiary, but continued into the Quaternary (Bronto 1995, pers. comm.; Soeria-Atmadja, 1998). K-Ar dating on a sample from an andesite lava outcrop yielded an age of about 5.35 Ma (Soeria-Atmadja et al., 1998). Products consist of lava flows alternating with pyroclastic and laharic breccias. There are also several andesitic plugs (Soeria-Atmadja et al., 1998). Sanggabuana is also associated with the Jatiluhur-Sanggabuana-Gunung Subang mineral belt (Soeria-Atmadja et al., 1998).

Kancana
Active in older Quaternary but extinct in Holocene (IAVCEI).

Tilu
Tilu volcano is of Pleistocene age (van Bemmelen 1949b).

Kancana
Kancana is a Quaternary stratovolcano (Bronto 1995, pers. comm.).

Mandalagiri
Volcanoes in this portion of Java are Quaternary in age (van Bemmelen, 1949b).

Cikuray
Cikuray, a prominent stratovolcano SW of Garut, is of Quaternary age (van Bemmelen 1949b). Products mainly consist of lava flows of basaltic andesite, with some pyroclastic flow and lahar deposits (Abdurrachman and Yamamoto, 2012). Cikuray, along with Papandayan, are located within the Triangular Volcanic Complex of West Java, a group of Pliocene to Quaternary volcanoes (Abdurrachman et al., 2015; Abdurrachman and Yamamoto, 2012).

Sedakeling
Sedakeling is a stratovolcano of Quaternary age (Bronto 1995, pers. comm.).

Mandalawangi
Mandalawangi is stratovolcano of Quaternary age (Bronto 1995, pers. comm.).

Kaledong
The Quaternary Kaledong lava dome is about 5 km E of Gunung Mandalawangi.

Canlancang
Calancang, at the NNE end of a group of volcanoes extending SSW to Papandayan, is of Quaternary age (van Bemmelen 1949b).

Cakrabuana
Cakrabuana is a Pleistocene stratovolcano (van Bemmelen 1949b).

Sawal
Sawal is a stratovolcano of Quaternary age (Katili and Sudradjat 1984a), with a large crater breached to the south.

Lasem
Lasem was active in the middle late Pleistocene (IAVCEI). Deposits have been dated to 1.6-1.1 Ma, and it appears to be the oldest and least potassic Quaternary volcano in the back-arc region of central Java (Leterrier et al., 1990). Products mostly consist of pyroclastic flow deposits, small lava flows, and dome extrusions. Composition is dominantly potassic calc-alkaline andesites, but there are also some basaltic andesites and dacites (Leterrier et al., 1990).

Selokaki
Selokaki is a Quaternary stratovolcano (Bronto 1995, pers. comm.).

Argowayang
Argowayang is a Quaternary stratovolcano (Bronto 1995, pers. comm.).

Ringgit
Ringgit volcano in eastern Java is of Plio-Pleistocene age, dated to about 1.2-0.5 Ma (van Bemmelen 1941; Leterrier et al., 1990). Eruptions mentioned by Von Wolff (1929) in 1586, 1593, and 1597 are attributed to Raung. Ringgit's products generally consist of leucite basanites and tephras (Leterrier et al., 1990).

Poco Leok
Poco Leok in western Flores Island consists of a heavily dissected edifice with a central 3-km-wide central caldera-like depression of uncertain origin. No pyroclastic-flow deposits are associated with the volcano, which is poorly known geologically (Casadevall, 1989, pers. comm.). There is andesite lava within the crater area, which Mahon and others (1992) attributed to the volcanic group immediately north. Volcanism is of Quaternary age (van Bemmelen, 1949), and four fumarole fields are located at elevations of 825-1,200 m within the depression. The Ulumbu geothermal field is located on its flank at 650 m elevation and includes hot springs, fumaroles, mud pots, and steaming ground.

Ilimuda
The heavily Ilimuda volcano is located 6.5 km N of Lewotobi Lakilaki volcano opposite Konga Bay in eastern Flores Island. The morphology suggests a 1-km-wide, 450-m-deep crescentic crater open to the SE. Satellitic cones, including the Ilibotong lava dome, are located on the lower SE and NE flanks. No eruptions are known, but a fumarole was reported inside the NE crater rim.

Lereboleng
A large volcanic massif extending ~12 km near the E end of Flores Island includes at least five major peaks: Tenawahang, Lereboleng, Kihak, Lekung, and Padung (SW to NE). Without obvious distinct edifices, the entire group is included here as a single complex. Distinctly older edifices are located S and NE of this massif, which is shown as Quaternary on a geological map in Widodo et al. (2005). A "Leroboleng" entry by Neumann van Padang (1951, CAVW citing Kemmerling, 1929, and Stehn, 1940) noted 29 small craters aligned on six fissures, with lava flows originating from Gelimun crater. Neumann van Padang (1951) also listed three eruptions during 1873-1881 that formed small craters within the larger Burak crater, which based on the included Stehn (1940) map corresponds to the Subdit Geothermal area described by Widodo et al. (2005) to the SE below the Kihak peak; these were likely hydrothermal explosions. Pilot reports of eruption plumes during June-July 2003 were not seen in satellite imagery, reported by news media, or confirmed by observatory staff; an official hazard map (Taufiqurrohman, 2010) stated that the volcano had not been active for 117 years. Reports of the 2003 events were likely mis-assigned, and have been moved to Lewotobi (20 km SW), for which there was a confirmed eruption during May-September 2003. A possible volcanic plume in an Aqua/MODIS image on 7 September 2013 was attributed by NASA to Lereboleng, but the origin of the cloud is not clear. Satellite imagery as of May 2025 shows no recently active craters in the area, or any MODVOLC thermal alerts.

Merbuk
Merbuk is mapped as a Quaternary volcano (Purbo-Hadiwidjojo 1971).

Patas
Patas is mapped as a Quaternary volcano (Purbo-Hadiwidjojo 1971).

Seraja
Seraja volcano at the eastern tip of Bali, is mapped as Quaternary (Purbo-Hadiwidjojo 1971).

Punikan
Punikan is a young volcanic cone, part of the Quaternary volcanic arc (van Bemmelen 1949b).

Ramu-Labumbu
This heavily eroded volcano has two peaks, Doro Ramu and Doro Labumbu, and is located about 30 km SE of Tambora. It was mapped by Garvin (2002, shown in Khant et al., 2013) as early Pleistocene.

Doro Lambuwu
Doro Lambuwu (or Lambuwa) is a broad Quaternary volcanic zone west of Bima Bay with a caldera open to the NE (Ratman and Yasin 1978). IAVCEI (1973) lists a Doro Oromboha volcano in this area. The area, about 30 km across, was mapped by Garvin (2002, shown in Khant et al., 2013) as early Pleistocene. The Garvin (2002) map also identified volcanic features named Doro Matua and Doro Pokah, but clearly identifying specific peaks in this heavily eroded region is difficult.

Doro Maria
Doro Maria is a large eroded stratovolcano at the NE end of Sumbawa Island of Quaternary age (Ratman and Yasin 1978). It was mapped by Garvin (2002, shown in Khant et al., 2013) as early Pleistocene, and includes the peaks named Doro Kuta and Doro Kota.

Doro Saboke
Doro Saboke, at the SE tip of Sumbawa Island, is a Quaternary volcano (Ratman and Yasin 1978). the area was mapped by Garvin (2002, shown in Khant et al., 2013) as Pliocene into early Pleistocene.

Gilibanta
The small island of Gilibanta was reported by a pilot to be destroyed by a volcanic eruption in 1957, but the report has not been confirmed by scientific sources and is considered doubtful (Hantke, 1962). Ratman and Yasin (1978) map the island as a Quaternary volcano with a caldera open to the north forming Ouingke Bay.

Doro Otota
Doro Otota at the southern end of Komodo Island, is a Quaternary volcano (Ratman and Yasin 1978).

Doro Ora
Doro Ora volcano forming the southern end of Rinja Island is of Quaternary age (Ratman and Yasin 1978). Nuso Kode within a bay at the southern end of the island is also of Quaternary age.

Beliling
Gunung Beliling is a Quaternary volcano (Ratman and Yasin 1978).

Uruk Simacak
Converted from subfeature of Singkut caldera. Mapped as part of the Pliocene-Pleistocene QTvk unit (see Harahap, 2011; Aldiss et al., 1983; Cameron et al., 1982).

Barus
Converted from subfeature of Singkut caldera. Mapped as part of the late Pleistocene Qvbr unit of andesitic lavas and pyroclastics (see Harahap, 2011; Aldiss et al., 1983; Cameron et al., 1982).

Sangenges
Sangenges (also known as Puncak Ngenges) was mapped as Pleistocene to early Holocene by Garvin (2002, shown in Khant et al., 2013). Edifices immediately NE (Sesset) and SE (Batu Lanteh) are interpreted as Miocene-Pliocene features. This volcanic group forms the northern part of western Sumbawa, in the West Nusa Tenggara province of Indonesia. The 7-km-diameter caldera is open to the NNW.

Tarowa
A geological map by Garvin (2002, shown in Khant et al., 2013) identifies this Tarowa as late Pliocene-early Pleistocene. This volcano is in the center of Sumbawa and includes an eroded caldera about 3.5 x 5 km, open to the SSW.

Pesawaran-Ratai
Named for the two high points on the crater rim, the Pesawaran-Ratai edifice was probably a typical stratovolcanic cone that appears to have collapsed to the north, where the crater has breached. The volcano and surrounding area has been mapped as Quaternary on Indonesian geological maps (Mangga 1994, Suharno et al., 2015). Hot springs and geysers are present on the S flank (Suharno et al., 2015).

Bukit Lumut
Located in south-central Sumatra overlooking the Semalako Plain, Bukit Lumut has a 2.1-km-diameter crater open to the north. It was mapped by Budiardjo et al. (2001) as the Pleistocene 0.893 Ma Lumut Andesite. Two small hills within that unit, one of which is name Bukit Pabus, consist of the slightly older Pabus Tuff (0.895 Ma). The Hululais volcano and geothermal are lies immediately to the SE.

Bukit Tiga
Located in south-central Sumatra SSE of the Semalako Plain, Bukit Tiga has a 1.3-km-diameter crater open to the SW. It was mapped by Budiardjo et al. (2001) as the Pleistocene 0.984 Ma Tiga Andesite. The Hululais volcano and geothermal are lies immediately to the N.

Haruman
The Quaternary Haruman lava dome is about 8 km ESE of Gunung Mandalawangi.

Pandan
Small eroded Pleistocene cone in eastern Java about 40 km N of Wilis volcano and 10 km S of the main Kendeng Fault. As noted in a review by Alawiyah et al. (2022), there are several hot springs in the area, with a geothermal system hosted in a tuffaceous sandstone; the source of seismicity in the area is unclear.

Narcondam
India
Andaman Volcanic Province
The 2.5 x 4 km island of Narcondam is located in the Andaman Sea about 130 km E of North Andaman Island. The island is densely vegetated, bounded by cliffs on the southern side, and capped by three peaks on the main cone. The island's name means "pit of hell," though the name could have been mistakenly transferred from the active Barren Island volcano, 140 km SSW. Volcanism at the andesitic volcano was considered to have continued into the Holocene by Krishnan (1957), but the last eruption is unknown. A review by Bandopadhyay (2017) found no documented Holocene activity.

Leizhou Bandao
The Leizhou Bandao volcanic field is an area of extensive Quaternary lava flows and basaltic cones on the Leizhou (Liuchow) Peninsula in SE China, across the Qiongzhou strait N of Hainan Island. The field is the northern portion of the Qionglei volcano group (also known as the Leiqiong volcanic field), a 7300 km2 basaltic-to-basanitic plateau that covers the southern Leizhou (Liuchow) Peninsula and extends across a broad area of northern Hainan. Volcanism on the peninsula was controlled by E-W extension related to the opening of the South China Sea Basin. Yingfengling and Tianyang are Pleistocene stratovolcanoes that contain large amounts of mantle xenoliths. Many cones are found in the southern portion of the peninsula, and another similar area lies at the northern end, W of Zhanjiang City. No Holocene features have been identified in either of the volcanic areas on the Leizhou Peninsula.

Toroeng Prong
Vietnam
Toroeng Prong is in west-central Vietnam SW of the coastal city of Quang Ngai. Whitford-Stark (1987, pers. comm.) indicated that this was a small well-preserved basaltic volcano with a crater lake and three vents, possibly of Holocene age. However, no distinct volcanic features are observable in this area or reported elsewhere, so this may refer to a small basaltic plateau between Quang Ngai and the Pleiku-Bantour basalts to the SW.

Haut Dong Nai
Haut Dong Nai volcanic field, also known as the Djiring Plateau volcanic field, is an extensive lava field in south-central Vietnam NE of Ho Chi Minh city (Saigon). The 70 x 150 km area contains both extensively eroded and well-preserved features, with the younger landforms located to the east. Haut Dong Nai was considered to be late-Pleistocene or possibly Holocene in age (Whitford-Stark, 1987, pers. comm.).

Bas Dong Nai
The Bas Dong Nai volcanic field, also known as the Xuan Loc Plateau volcanic field, is located in SE Vietnam, east of Ho Chi Minh city (Saigon).

Lower Chindwin
Burma (Myanmar)
The Lower Chindwin area contains seven or eight late-Pliocene and Pleistocene explosion craters. A lake-filled crater located at Songyuang is surrounded by olivine basaltic lava flows and pyroclastic material. This region along the lower Chindwin River also contains rhyolitic, dacitic, and andesitic rocks. Although some workers have made statements about the presence of Holocene or "sub-Recent" basalts, there is no clear morphological or dating evidence of such activity.

Singu Plateau
Burma (Myanmar)
The Singu Plateau volcanic field, also known as Letha Taung, is a basaltic trachyandesite lava plateau in north-central Burma, N of the city of Mandalay. The lava flows originated from fissure vents and cover an area of about 62 km2. Though some previous catalogues indicated a Holocene age, Bertrand et al. (1998) provided 40K-40Ar ages of 0.25-0.31 Ma from five of the youngest flows at the southern border of the plateau.

Gaojianshi
Late-Cenozoic Gaojianshi volcanoes are located in the Xisha Islands (Wei et al. 1988).

Weizhoudao
Circular, shield-like 4 x 5 km island with a 1 km explosion crater on the south side, of Pleistocene (?) age (Whitford-Stark, 1987). Part of Qionglei Volcano Group.

Nghia Dan Volcanic Plateau
This volcanic area is described by Hoang et al. (2015) as follows: "The Nghia Dan volcanic plateau comprises a number of monogenetic volcanoes, forming a lava cover with thickness ranging from several meters to more than 200 m. The volcanoes include Nui Tien (Nghia Son village), Nui Hang (Nghia Lam), Doi Tro and Doi Troc (Nghia My) and Nui Ro (Xuan Binh). The basalts are both massive and porous, but porous lava type is dominant. The massive type sometimes occurs as 4-to-5 sided columnar lavas (KeLui, Nghia Lam)." This area was listed on the IAVCEI Post-Miocene data sheets, which indicated two adjacent areas with basaltic cones in this general location, one with three and the other with four volcanoes. A geological map (Fromagel, 1971) showed six small areas of basalt outcrops, and satellite imagery shows no cones. Hoang et al. (2015) further noted that there was an "Ar-Ar age of 5.9 Ma (C.T. Chi et al., 1998) for a sample collected in the Nghia My village area; and another was dated to 4.2 Ma (Lee et al., 1998)."

Vinkh-Linkh

Ban Chay Plateau
Cambodia-Vietnam
This small basalt plateau immediately NE of the Boleo Volcanic Field was described by Whitford-Stark (1987, citing Lacombe, 1969) as having lavas that appear to have flowed radially away from a vent in the S-central portion of the field. Piilonen et al. (2018) place this small basalt plateau mainly within Cambodia north of the Seasan River.

Pleiku-Bantour Volcanic Field
Volcano type: Cone(s)
Extensive volcanic area with a number of edifices, most of which are poorly preserved. IAVCEI (1973) and Whitford-Stark (1987) list it as Pleistocene.

Darlac Volcanic Field
Volcano type: Cone(s)
Darlac is the southern extension of the Pleiku-Bantour Volcanic Field.

Bas Song Be
Basaltic field 25 km in diameter (Whitford-Stark 1987).

Pailin
Cambodia
Lavas dated at 1.99 +/- 0.19 million years ago (Whitford-Stark 1987).

Cham
Cambodia

Chup
Cambodia
Lower Pleistocene aged basalts (Whitford-Stark 1987).

Snoul
Lower Pleistocene aged basalts (Whitford-Stark 1987).

Haut Song Be

Bokeo Volcanic Plateau
Activity continued during mid & recent Quaternary (Whitford-Stark, 1987).

Bolaven Plateau
Laos
Basalt dated at 1.10 +/- 0.9 million years ago (Whitford-Stark 1987).

Buriram
Thailand
Basalt flow from a central vent Potassium-Argon dated 0.92 +/- 0.30 million years ago.

Chanthaburi
Thailand
Potassium-Argon age date of 0.44 million years ago for Khao Phloi Waen cone. Basalt E of Chanthaburi fission track dated at 2.57 million years ago (Whitford-Stark).

Lampang
Thailand
Flows overlie gravel deposits containing pebble tools. Fission track and K-Ar dating yield Pleistocene ages of 0.64 to 0.95 million years ago (Whitford-Stark 1987).

Ban Chiang Khian
Dissected lava flows dated 1.62 +/- 1.25 million years ago (Whitford-Stark).

Ban Hui Sai
Alkali olivine basalts form dike-like bodies in the Mekong River and a Potassium-Argon age of 1.74 +/- 0.12 million years ago has been obtained from a subcircular outcrop of basanite (Whitford-Stark 1987).

Kuantan Basalt
Malaysia
Basaltic lava flows crop out over an area of 150 km2 near the coast of the South China Sea at Pantai Batu Hitam and Beserah. Bignell and Snelling (1977) obtained a K-Ar age of 1.6 +/- 0.2 Ma.

Medaw Island
Plateau of basalt probably of late Tertiary to sub-Recent age (Whitford-Stark 1987).

Thaton
Rhyolites and rhyolitic tuffs of late Pliocene to Pleistocene age are found at Thaton (Whitford-Stark 1987).

Namyong
Pliocene to Pleistocene basalts to rhyolites erupted from fissure vents (Whitford-Stark 1987).

Henglianghu-Dongyuehu Volcanic Field
Northern Tibetan Plateau Volcanic Province
A volcanic zone spanning ~350 km E-W in NE Tibet was identified by Tong et al. (1988) as having multiple Cenozoic volcanoes. Five locations were named on the small-scale map (Yongbocuo, Bamaoqiongzhong, Kushuihuan-Beishan, Heiguotou, and Yuyiehu). Although only Bamaoqiongzhong is mentioned in later research, this may be due to unknown synonyms or other language translations. However, within this area of the Northern Qiangtang Terrane between the Jinsha Suture to the N and the Longmu Co-Shuanghu Suture to the S, maps compiled by Wang et al. (2008) and Qi et al. (2023) did identify numerous volcanic areas, with a wide range of dates back to 46 Ma. The Bamaoqiongzong volcanic area, ~180 km W and exposed over ~100 km2, contains peralkaline phonolitic and foiditic rocks; although previous described as having a preserved edifice and a lava flow that overlies Quaternary lake deposits (Whitford-Stark, 1987), is further described and mapped as 28-30 Ma by Qi et al. (2023). Two areas were identified in Wang et al. (2026) and Qi et al. (2023) as early Pleistocene: adakitic rhyolites in the Henglianghu area, N of Duogecuoren Lake, was shown as being 3.2-2.5 Ma; non-adakitic felsic lavas in the Dongyue Lake 2.3 Ma area, immediately S of Duogecuoren Lake, had a reported 2.3 Ma age.

Heishibeihu
Listed as an unnamed Quaternary volcano by IAVCEI (1973), it was included in a summary list of northern Tibetan volcanic locations by Guo et al. (2006) under the name Heishibeihu with a cited 14C date of 670,000 years. A small shield feature is present, with a large lava field. Located ~115 km ESE of the Ashikule Volcanic Field, SE of the Altyn Tagh fault in the Songpan-Ganzi Terrane, the lava field covers 355 km2 (Guo et al., 2006).

Ulagh Muztagh
An unnamed basaltic volcano was listed in this general area by IAVCEI (1973). Although mislocated ~100 km E (1� of longitude), this entry may have been referencing the small mountain ridge of Ulagh Muztagh, ~30 km long and largely snow-covered. It was mapped as 11-4.0 Ma rhyolites in Wang et al. (2016, see citations).

Bukendaban
Rhyolites dated to 1.5 Ma are mapped at the western end of the mostly snow-covered Bukendaban mountains (Wang et al., 2016) NE of Taiyang Lake in Tibet, just S of the Anyimaqen-Kunlun-Muztagh suture zone in the Songpan-Ganzi block. A feature ~75 km SE along the fault zone, described as the Kekexili caldera, was once thought to have been observed in eruption on a satellite photo in 1973; it was later determined to be a meteorological event (Kidd, 1990 pers. comm.).

Weixueshan
Volcano type: Cone(s)
A group of small rhyolite cones, along the Anyimaqen-Kunlun-Muztagh suture zone between the Songpan-Ganzi and Central Kunlun blocks immediately N of a small 15-km-long mountain range, are mapped as "<1.0 Ma?" (Wang et al., 2016). A sample from this are was collected and analyzed by Jolivet et al. (2003), where the cones are described as follows: "At the eastern end of the basin, the South Kunlun Fault is connected to the main Kunlun Fault by a SW-NE trending normal fault exposed at the edge of a large calc-alkaline granite [Roger et al., 2003], the Wei Xue Shan pluton.... The northern end of this normal fault is connected to a push-up structure through what appears to be an 'open crack' filled with rhyolitic volcanic cones.... The rhyolite is a very clear, fresh, pale pink to white rock mostly composed of millimeter-size quartz grains."

Laohukou
Shoshonitic cones 1-3 km in diameter, mostly covered by Quaternary sediments, are present in the Jingyu basin just NE of Jingyu Lake and SW of the Anyimaqen-Kunlun-Muztagh suture zone (Jolivet et al., 2003). Apatite fission track dating by Jolivet et al. (2003) gave 0.5 +/- 0.2 Ma, which were considered to correspond to crystallisation ages.

Jindingshan
A small cone with a lava field covering ~65 km2 was identified in Wang et al. (2016) as non-adakitic trachyandesites in the 1.08-0.3 Ma age range. It is in the Central Kunlun Block, ~30 km N of the Anyimaqen-Kunlun-Muztagh suture zone with the Songpan-Ganzi block to the S.

Dariganga Volcanic Field
Mongolia
The Dariganga volcanic field, located in SE Mongolia near the China border, consists of more than 200 lava and cinder cones erupted from NE-trending parallel fissures. The cones range in height from 25 to 300 m, and vary from partially eroded to completely preserved. Compositionally they are more Na-rich than the K-rich rocks of northern and central Mongolia, and consist of basaltic, trachybasaltic, and foiditic rocks. The southern part of the volcanic field, which may be contiguous with the Dolon Nor volcanic field across the border in China, is rich in ultramafic xenoliths. Yarmolyuk et al. (2024) identified four stages of activity, from the middle Miocene to Pleistocene. Rasskazov et al. (2024) reported that the youngest K-Ar date in their study, 1.6 +/- 0.1 Ma, was from a sample of the Undur-Khuret cone in the southern part of the field.

Longhai
Longhai is a late-Cenozoic volcano (Tong et al. 1988) at the south end of the Zhemin Volcano Group of Chen (1986).

Jianghui Group
The Jianghui Volcano Group consists of remnants of about 20 basaltic hills. Comparatively well-preserved craters exist along the eastern shore of Nushanhu and the western shore of Chaohu. The basalt is of early Quaternary age (Chen 1986; Whitford-Stark 1987, pers. comm.).

Nushan
Truncated cone of Pliocene-lower Pleistocene age (IAVCEI).

Yichuan
Late-Cenozoic volcano (Tong et al. 1988).

Tangy'n
Late-Cenozoic volcano; name appears as "Tangy n" in Tong et al. (1988).

Huixian
Late-Cenozoic volcano (Tong et al. 1988).

Heibei Plain
Late-Cenozoic volcano (Tong et al. 1988).

Datong-Fengzen
The Datong-Fengzhen volcano group, also known as Ta-T'ung or Fanjiatun, is located at the intersection of two regional fault zones. The volcanic field contains about 80 volcanic vents, including cinder cones and small lava domes. The central Datong group contains 12 cones. An historical eruption reported during the 5th century (Chen 1986) has been shown to have originated from spontaneous combustion of a Jurassic coal seam (Zhang 1989, pers. comm.). The 13 youngest cones of the volcanic field have been Potassium-Argon dated at 0.34-0.37 million years.

Chifeng

Dalainuoer
Tapponnier and Molnar (1977) documented from satellite images a large volcanic field with fresh features suggesting possible Holocene eruptions. Hang (1989, pers. comm.) indicates that extensive dating by Yang indicates the youngest eruptions were of late Pleistocene age.

Nuomin
The Nuomin volcanic field, identified as Shatu in Ogara (1969) and Whiford-Stark (1987), is dominated by monogenetic cones and lava flows that cover about 600 km2 (Zhao and others, 2014). K-Ar dating by Fan and others (2012, cited in Zhao and others, 2014) indicated eruptions between 2.3 and 0.13 Ma. The most recent activity was at the Sifang Mountain, which is the southernmost cone of the group and contains a small lake in the summit crater.

Jianshan
Jianshan volcano (at the Jianshan Farm) is located NW of the Wudalianchi volcanic field. Zhao and others (2014) reported that this isolated monogenetic cinder cone was K?Ar dated at 0.12 � 0.02 Ma.

Erkeshan
Two adjacent volcanic cones are located just NE of the city of Kedong in the Heilongjiang Province of far northeastern of China. The larger eastern cone is about 700 m in diameter, and the smaller western one is 600 m. A third circular feature about 200 m in diameter forms a very low (12 m high) hill about 1 km NW of the western cone. Zhao and others (2014) reported a date of 0.43 +/- 0.01 Ma for the north cone, and noted that Liu and others (2001) had dated the east cone at 0.563 +/- 0.133 Ma.

Dunhua
Dunhua was described by Whitford-Stark (1987) as being composed of flows of two or three different ages.

Yitong Group

Fanjiatung Group

Kuandian

Ch'uga-ryong
North Korea-South Korea
An area of extensive basaltic lava flows occupies a graben, the NNE-SSW-trending Ch'uga-ryong rift, that cuts diagonally across the border between North and South Korea. As summarized by Whitford-Stark (1987), Tomita (1969) noted that a 40-km-long lava flow originated from the low Ap-san shield volcano, which has a 200-m-wide summit crater and more than 20 satellitic cones, and another voluminous late-Pleistocene lava flow is 60 km long. Tomita (1967) stated that there has been no Holocene volcanism on the Korean Peninsula. Alkaline basaltic lava flows at the SW portion of the rift were erupted over Precambrian sediments and igneous rocks, and were estimated by Lee (1981) to have been produced by up to 11 eruptions in the late Pleistocene or early Holocene. There are no recorded eruptions or dated deposits confirming Holocene activity. The location of this shield volcano and area of lava flows is not well documented, but a map reproduced in Koh et al. (2022) identifies multiple areas of late Pleistocene extrusive rocks in the central part of the peninsula.

Kilchu-Myongch'on
North Korea

Koksan-Singye
North Korea
Lava flows located between the cities of Koksan and Singye were listed as probably active in last 2,000 years by IAVCEI (1973). However, Whitford-Stark (1987) lists it as Pleistocene and Tomita (1967) states there has been no Holocene volcanism on the Korean Peninsula. As summarized by Whitford-Stark (1987): "According to Tomita (1969), this area contains one of the largest lava flows in eastern Asia, being some 45 km from north to south and 20 km from east to west. The flow parallels the Ch'uga-ryong flow to the east, running in a northeast-southwest direction. The lava is of late Pleistocene age and may be associated with a shield volcano." These flows are shown on a map reproduced in Koh et al. (2022) that identifies multiple areas of late Pleistocene extrusive rocks in the central part of the peninsula.

Vitim Volcanic Field
Volcanism in the Vitim Volcanic Field dates back to the Miocene and covers an area of about 4,500 km2 east of the northern part of Lake Baikal. The most voluminous activity took place from the Miocene to Pleistocene. Most of the volcanic centers are located in the NW part of the field (Johnson et al., 2005). Mantle xenoliths are found in several locations. Ivanov et al. (2015) mapped it as Pleistocene and reported ages between 0.5 and 1.2 Ma.

Tunkin Depression
The Tunkin Depression volcanic field (also known as the Tunka Depression) covers a broad area immediately west of the SW tip of Lake Baikal. The Khobok group of basaltic cinder cones near the village of Tunka, one of five groups of cinder cones characterized by some sources as late-Pleistocene to Holocene in age, has the largest concentration of vents. Drill cores show that the upper 500 m of the basin is filled with Quaternary tuffs and a dozen lava flows; subsidence continues, partially burying volcanic features. Other cinder cones of probable Pleistocene age are located to the SE in the Khamar-Dayan Range. The youngest cinder cones and lava flows are in the NE part of the Tunkin Depression. A regional review by Ivanov et al. (2015) mapped volcanism in this area as Pleistocene.

East Tuva Volcanic Field
The large East Tuva volcanic field is located WNW of the SW tip of Lake Baikal and N of the Mongolian border. The gently sloping Azas Plateau, also known as the East Tuva Plateau, the Northeast Tuva Plateau, or the Khamsara-Biykhem Plateau, covers an area of about 2,000 km2. Its glacially dissected surface is cut by broad valleys and contains several table-like mountains composed of hyaloclastites and lava flows, and has numerous small scoria cones. The Shivit-Tayga stratovolcano is one of the most prominent features of the plateau and is capped by two craters that once contained lava lakes. Derbi-Tayga is glacially eroded shield volcano. The surface of the Ulug-Arginsky cinder cone, initially considered to be Holocene, has large granitic erratics and was given a late Pleistocene age by Hasenaka et al. (1999). Some valley filling basaltic flows are not glacially eroded; lava flows near the Bii-Hem River may be of Holocene age. Ivanov et al. (2015) identified only Pliocene and/or Pleistocene volcanoes as part of this field.

Dgida Basin
The Dgida Basin volcanic field, also known as the Dzhida Basin, is located south of the SW tip of Lake Baikal, near the border with Mongolia. One of a series of approximately E-W-trending depressions, the basin contains Quaternary lava flows and cinder cones ranging from 55 to 240 m in height. At least two stages of volcanism are present, the first of which includes lava flows overlying the 20 m terrace of the Dgida, Darkhintuy, and Khammey rivers. Lava flows in the Darkhintuy valley are overlain by gravels, which are in turn are overlain by lava flows from the Bartoy valley. Earlier Pleistocene-to-Holocene estimates of the age of the volcanism (summarized in Whitford Stark, 1987) were modified by age-dating by Rasskazov et al. (1996), who indicated that the final stage of activity took place during the early to mid-Pleistocene.

Khanuy Gol Volcanic Field
The Khanuy Gol (also spelled Hanui or Hanuy Gol) Volcanic Field is also known as the Chanuj Gol or Bulgan volcanic field. It consists of a group of 10 olivine-basaltic lava and cinder cones in west-central Mongolia about 150 km WNW of the capital city of Ulaanbaatar. The field covers a 3,500 km2 plain along the Khanuy River and in drainages to the east. Basalts along the Orkhan Gol (Orkhan River) to the east were dated at 6.4 to 1.5 million years (Whitford-Stark, 1987). The Togo (or Togoo) group of cones, ~50 km E of Khanuy and N of the settlement of Bulgan, are rich in ilmenite megacrysts and altered peridotite xenoliths; two main cones are ~7 km apart N-S. The volcanic field was considered by IAVCEI (1973) to be late Pleistocene to Holocene, though no precise age dates are available. Ivanov et al. (2015) mapped the volcanic features in this area NE of the Taryat volcanic field as Pliocene and/or Quaternary, but not Holocene.

Northern Russia Volcanic Province

Anjuisky
Northern Russia Volcanic Province
The Anjuisky (Anyuy) volcano group consists of fissure vents and small pyroclastic cones, the largest of which is 120-m high and is capped by a 300-m-wide crater. The initial fissure eruptions produced trachybasaltic lava flows 15-17 km long that covered an area of 100 km2. The most recent eruptions were considered by the Catalog of Active Volcanoes of the World (Vlodavetz and Piip, 1959) to have occurred between about 1300 and 1700 CE from Aniusk (Monni) cone, based on morphological evidence. Later work (Ignatiev, 1994) showed that Monni was partially destroyed by glaciers and phreatic explosions produced by glacial meltwater flowing into the vent. Lava flows from Maly Anyuy volcano flowed onto glacial ice, and explosions induced by glacial meltwater destroyed the cone. The Monni lava flows dammed up drainages, forming lakes. During an early Holocene period of warming, large creeks overflowed from these lakes and deposited fluvial materials. The cone and lava flow are located between the Maly Anyuy and Bolshoy Anyuy rivers, about 75 km SSE of the community of Keperveyem.

Balagan-Tas
Northern Russia Volcanic Province
Balagan-Tas is a cinder cone constructed along a fault on the SW flank of the Momskiy Mountains in the NE part of Russia's Sakha Republic. A poorly preserved crater fed subalkaline basaltic lava flows that covered an area of 4-5 km2. A Potassium-Argon date of 300,000 years was obtained (Prokopiev, 2007 pers. comm.).

Sigurd
Norway
Volcano type: Explosion crater
Semevskii (1965) considered a Holocene age to be a reasonable probability for all the young volcanoes on Spitsbetgen, but more detailed glacial and volcanic stratigraphy indicates that Sigurdfjell is an eroded diatreme of similar age to Sverrefjell,which is considered to be between 100,000 and 250,000 years old (Skjelkvale et al., 1989).

Halvdan
Volcano type: Explosion crater
A Holocene age was considered reasonably probable for all the young volcanoes of Spitsbergen by Semevskii (1965), but more detailed glacial and volcanic stratigraphy indicates that Halvdan is an eroded diatreme probably older than Sverrefjell, which is thought to be between 100,000 and 250,000 year old (Skjelkvale et al., 1989).

Sverrefjell
Early investigators considered Sverre to be of postglacial age based on its location in a glacially carved valley. Semevskii (1965) assigned an age between 6,500 and 4,000 years before present (BP) marine terraces. A more detailed study of glacial and volcanic stratigraphy suggests an age between 100,000 and 250,000 BP (Skjelkvale et al., 1989).

Grensdalur
The small Grensdalur volcanic system (also known as the Hveragerdi system) lies at the eastern end of the Reykjanes Peninsula, SE of the Hengill volcanic system and south of the Hr�mundartindur volcanic system. Grensdalur is the oldest of the three volcanic systems in the Hengill area and was last active during the Pleistocene. The Hveragerdi geothermal area contains high- and low-temperature geothermal features that include fumaroles, hot springs and pools, mud pots, and geysers, and provide heat to the town of Hveragerdi.

Lyngdalsheidi
Interglacial shield volcano (Thorarinsson 1960).

Geysir
The Geysir volcanic system in the Haukadalur valley of SW Iceland consists of an eroded basaltic central volcano and rhyolitic lava domes of Pleistocene age. Geysers around the world are named for the Geysir geothermal field, which lies SE of the rhyolitic Laugarfjall lava dome and is one of the most frequently visited geological sites in Iceland. No eruptions are known from the Geysir volcanic system during the Holocene.

Hlodufell
Volcano type: Tuya
Hl�dufell is a Pleistocene table mountain located ENE of Skjaldbreidur shield volcano.

Thorisjokull
Thorisj�kull is a large glacier-covered shield volcano SW of Langj�kull volcano.

Ok
The large Ok shield volcano is topped by a small glacial icecap and lies west of the SW tip of Langj�kull and NW of Thorisj�kull volcano.

Er�ksjokull
Volcano type: Tuya
Er�ksj�kull is a large Pleistocene table mountain located north of Prestahnukur volcano and SW of Langj�kull volcano.

Hrutfell
Volcano type: Tuya
Hr�tfell is a Pleistocene ice-capped table mountain east of Langj�kull.

Blafell
Bl�fell is a Pleistocene table mountain located SW of Kerlingarfj�ll volcano.

Hreppar
Two elongated NE-SW-trending Pleistocene hyaloclastite ridges extend from Kerlingarfj�ll volcano in the Hreppar area.

Strutur
Str�tur is a Pleistocene table mountain located north of Myrdalsj�kull.

Tungnaarfjoll
An elongated, NW-SE-trending hyaolocasltic ridge of Pleistocene age lies in the Tungna�rfj�ll area between the Veidiv�tn and Laki fissure systems.

Kistufell
Kistufell is a Pleistocene table mountain lying NNE of Bardabunga at the margin of Dyngjuj�kull.

Valdalda
Interglacial (Krafft 1974).

Herdubreid
The renowned flat-topped Icelandic table mountain Herdubreid, located NE of Askja volcano, was active until the late Pleistocene.

Sellandafjall
Sellandafjall is a Pleistocene table mountain that lies south of Lake Myvatn, WSW of Fremrinamar volcano.

Blafjall
Bl�fjall is a Pleistocene table mountain SE of Lake Myvatn and west of Fremrinamar volcano.

Burfell
Burfell is a Pleistocene table mountain north of Fremrinamar volcano.

Fjallgardar Ridge
The elongated Fjallfadar Ridge is a Pleistocene hyaloclastite ridge that lies on the Pleistocene ice divide east of Fremrinamar volcano.

Gaesafjoll
The Gaesafj�ll table mountain of Pleistocene age lies between Krafla and Theistareykhabunga volcanoes.

Lambafjoll
The Pleistocene Lambafj�ll fissure vents lie west of Theistareykjarbunga volcano.

Trindade Hotspot Volcano Group

Trindade
Brazil
Trindade Hotspot Volcano Group
The small island of Trindade lies more than halfway between Brazil and the Mid-Atlantic Ridge at the eastern end of the Vit�ria-Trindade Ridge, an E-W-trending chain of submarine volcanoes and guyots extending about 1,100 km from the continental shelf off the Brazilian coast. It is a dissected volcanic island with numerous phonolitic lava domes and steep-sided volcanic plugs. The youngest volcanism, at Vulcao de Paredao on the SE tip of the island, constructed a pyroclastic cone with lava flows (Almeida, 1961). Remnants of the crater of the cinder cone are still preserved. Lava flows traveled from the cone to the N, where they form an irregular shoreline and offshore islands. Smaller centers of the latest volcanic stage are found in the Morro Vermelho area in the south-central part of the island.

Martin Vaz
Brazil
Trindade Hotspot Volcano Group
The Martin Vaz archipelago lies 48 km east of Trindade Island, about 1750 km west of the Mid-Atantic Ridge. A larger islet, Martin Vaz, is adjacent to three smaller ones. K-Ar ages of about 1.5 Ma and less than 0.73 Ma were obtained.

Gough Island
Gough Island, also known as Diego Alvarez, lies about 340 km SE of the Tristan da Cunha island group. The shield volcano was active from about 2.5 to 0.13 million years ago.

Inaccessible Island
Inaccessible Island, located about 40 km SW of Tristan da Cunha, was Potassium-Argon age dated at 6 +/- 1.5 million years ago (Baker et al., 1964), but more recent dates of about 1 million have been obtained (Cliff et al., 1991). The island is the remnant of a stratovolcano centered about 2 km SW.

Sao Tome
Sao Tome and Principe
Sao Tome is a roughly conical island in the Gulf of Guinea that rises from a depth of 3,000 m below sea level. The S and W parts of the island are more dissected, and dramatic phonolitic and trachytic spines rise vertically out of the rain forest. Most of the lavas erupted over the last million years are basaltic in composition. Argon isotope dating reported by Barfod and Fitton (2014) showed that the most recent activity was 0.036 +/- 0.004 Ma, following frequent eruptions over much of the Pleistocene.

Gran Caldera de Luba
Equatorial Guinea
Gran Caldera de Luba is a basaltic shield volcano with a broad summit caldera that forms the SW peninsula of Bioko Island in the Gulf of Guinea. Although classified as having been active during the last 2,000 years by IAVCEI (1973), there are no known dated deposits or reported eruptions.

Pico Biao
Equatorial Guinea
Pico Bia� is a basaltic shield volcano on the SE side of Bioko Island in the Gulf of Guinea. The summit contains a small lake-filled crater. Although classified as having been active during the last 2,000 years by IAVCEI (1973), there are no known dated deposits or reported eruptions.

Manengouba
The Manengouba volcanic complex is located across the Tombel Graben from Mount Cameroon. Growth of the initial Manengouba shield volcano during the early Pleistocene was followed by growth of the Eboga stratovolcano. The subsequent Elengoum extrusive complex consists of trachytic pyroclastic flows and trachyandesitic to trachytic lava domes, and magma withdrawal associated with these eruptions was linked to formation of the 4-km-wide Eboga caldera. Renewed eruptions within the caldera and on its flanks produced about one hundred pyroclastic cones and three maars during the latest stage of activity at Manengouba that were dated between about 0.45 and 0.11 Ma.

Ngaoundere Plateau
The Ngaoundere volcanic field is located within a larger late-Miocene region of plateau basalts, plug domes and a single large basanitic-to-trachytic stratovolcano, Nganha. Quaternary volcanism is situated east of Ngaoundere and Wakwa, and consists of scoria cones and lava flows, maars, and tuff cones. A single Potassium-Argon date of 0.9 million years ago has been obtained from a lava flow east of Wakwa, although some volcanoes are possibly of Holocene age (Vincent 1992, pers. comm.). The most recent eruptive activity originated from a chain of cinder cones aligned in a WNW-ESE direction.

Biu Plateau
Nigeria
The Biu Plateau in NE Nigeria is composed of basaltic lava flows. A large number of recent cinder cones with well-defined craters are aligned in a NNW-SSE direction over a distance of 50 km. The cinder cones and lava flows often contain abundant peridotite xenoliths. Work in this area has been inconsistent and infrequent. Age dates (K-Ar) were reported by Lar and others (2013; citing Baudin, 1991) as being in the 5-1.4 Ma range. Fitton and Dunlop (1985) presented K-Ar ages of 5.20 +/- 0.33 Ma for a basalt 24 km S of the town of Biu near the base of the plateau, and 0.84 +/- 0.09 Ma for a basanite on the north end of the plateau; neither roadside sample was clearly identified with a specific cone. Obaje (2009) describes the chronology of the Biu Plateau as "well controlled by radiometric dating" with plateau basalts in the 7-5 Ma range and Quaternary basalts less than 1 Ma; no citations are provided. A pollen record from Lake Tila (Salzmann, 2000) spanned the entire Holocene; however, adjacent graph scales showing age (in ka BP) and core depth terminating at 840 cm have apparently been misunderstood, resulting in Salzmann being cited in some places as indicating volcanism 840,000 years ago.

Jos Plateau
Nigeria
Volcanic features on the Jos Plateau include domes, single vents, and clusters of 3-4 cones aligned mainly NW-SE (Lar et al., 2013). Preliminary K-Ar dating of volcanic features reported by Lar et al. (2013) showed an age range of 2.5-1.34 Ma.

Kumba Volcanic Field
Volcanic field SW of Tombel Graben and NNE of Mount Cameroon (within rectangular area of 4�48'15"N, 9�30'E and 4�24'15"N, 9�5'E). This area is known for the maar lakes Barombe Mbo, Barombi Koto, and Mboandong.

Haruj
Libya
The extensive Plio-Pleistocene Haruj volcanic field covers a broad 45,000 km2 area in central Libya with very well-preserved basaltic scoria cones, lava flows, and explosion craters (Liegeois et al., 2005). The youngest lava flows of the Haruj field (also known as Al-Haruj al Aswad or Djebel Haroudj) were considered by Klitzsch (1968) to be Holocene in age and are located at the northern side of the field, but K-Ar ages generally range from 6 to 0.4 Ma (Liegeois et al., 2005). The field contains about 150 volcanoes, 30 of which are small shield volcanoes with heights between 100 and 400 m. The volcanics are located along the SE extension of the Hon graben system of late Cretaceous to Tertiary age, near the intersection of the Paleozoic southern Haruj uplift and the western edge of the Mesozoic Tibesti-Sirte uplift.

Waw an Namous
Libya
The isolated Waw an Namous (also spelled Wau-en-Namus or Uaw en Namus) lies in the Sahara desert of south-central Libya, south of the Haruj volcanic field. A 4-km-wide, 100-m-deep caldera contains the Waw an Namous post-caldera scoria cone. An apron of dark basaltic tephra extends 10-20 km around the caldera in stark contrast to the light-colored desert sand prominent in satellite views. Three small salt lakes of variable color contribute to the name of the volcano, which means "Oasis of Mosquitoes." The youthful appearance of the central cone has suggested it may be as young as a few thousand years, although the arid climate may mask its actual age. Yellow sulfur deposits are found in the 150-m-wide crater. Other basaltic lava flows occur several tens of kilometers NW of the volcano.

Gharyan Volcanic Field
Libya
The Gharyan volcanic field is about 3000 km2 in area, but its volcanic structures and products, which include a lava plateau, phonolite domes, and younger small volcanic centers, are relatively thin, at only 350 km3 in volume (Liegeois et al., 2005). Potassium-Argon ages of the youngest volcanics range from 1-12 Ma (Almond, 1974; Liegeois et al., 2005). These volcanic centers are generally basanitic and contain abundant lherzolitic xenoliths (Liegeois et al., 2005).

Tarso Emi Chi
Tarso Emi Chi forms a SSW-NNE trending massif capped by Quaternary basalts (Geze et al. 1959).

Tarso Ahon
Tarso Ahon forms an elongated ridge 100 km long running NNW from Emi Koussi that is capped by Quaternary basalts from well-preserved vents (Geze et al., 1959).

Tin Taralle Volcanic Field
Niger
The Tin Taralle volcanic field was erupted through Precambrian basement rocks of the Tuareg shield in the southern A�r region of Niger. The latest dated rocks are of Pleistocene age (Liegeois et al., 2005).

In Teria Volcanic Field
Volcano type: Tuff ring(s)
The In Teria volcanic field, which covers an area of about 100 km2, consists of about 20 explosion craters that produced tuff rings and xenolith-rich porphyritic melilititic rocks (Liegeois et al., 2005). Lava blocks and lapilli are found within the tuffs, which may be phreatomagmatic in origin (Dautria et al., 1992). The fresh-looking morphology of some tuff rings suggests a Quaternary age (Dautria et al., 1992), and Liegeois et al. (2005) suggested that it may be Holocene, but were uncertain.

Senegalo-Mauritania Basin Volcanic Province

Cap-Vert
Senegal
Senegalo-Mauritania Basin Volcanic Province
Volcanism on the Cap-Vert Peninsula took place in five episodes from the Oligocene to the Pleistocene, ending about 600,000 years ago. The volcanic field covers an area of about 100 km2 on the peninsula hosting the capital city of Dakar.

Sao Vicente
Cabo Verde
The 15 x 25 km island of Sao Vicente contains mafic lavas covering prominent peninsulas on the eastern and NE sides (Mitchell-Thome, 1976). The largest indentation on this island with an irregular shoreline is formed by a caldera on the NW coast that is breached by the sea and forms the setting for the port of Mindelo, the island's largest village. No Holocene material has been dated, and as of 2015 scientists in Cape Verde consider it's last activity to have been in the Pleistocene.

Santo Antao
The 20 x 40 km dominantly volcanic island of Santo Antao is the NW-most of the Cape Verde Islands. Volcanic activity dates back to the Pliocene and continued into the late Pleistocene. A large 7-km-wide E-facing depression, Cha de Morte, was thought at one point to be a caldera, but was later interpreted as an erosional feature. Much of the island is covered by phonolitic pumice deposits of the Cao Grande Pumice, erupted about 200,000 years ago. The youngest eruptive products are lava flows that originated from vents at Cha de Lagoa in the central part of the island, just south of the NE-SW axial ridge. The lava flows cover an area of 40 km2 and reached the SE coast just SW of the coastal village of Porto Novo. These flows were initially considered by Mitchell-Thome (1976) to be Holocene in age based on morphological evidence, but later 40Ar/39Ar dating by Plesner et al. (2003) for these lava flows produced an age of 90,000 +/- 30,000 years.

Sao Nicolau
Sao Nicolau, located the eastern end of an E-W-trending chain of islands in the NW Cape Verde islands, was constructed in four stages dating back to the Pliocene. The last two stages took place during the Pleistocene, and the youngest stage produced scoria cones and lava flows about 50,000 years ago.

Northwestern Africa Volcanic Province

Oulmes Volcanic Field
Morocco
Northwestern Africa Volcanic Province
The alkaline Olm�s volcanic field covers an area of 20 x 70 km in the Middle Atlas Range of Morocco. The volcanic field was active during the Pliocene and Pleistocene, with K-Ar dates of 0.9-0.31 million years (Liegeois et al., 2005).

Azrou Volcanic Field
Morocco
Northwestern Africa Volcanic Province
The Azrou volcanic field in the Middle Atlas Range of Morocco covers an area of about 1500 km2.

Rekkame Volcanic Field
Morocco
Volcano type: Explosion crater(s)
The youngest rocks of the Rekkame Volcanic Field were K-Ar dated at 1.4 million years (Liegeois et al., 2005).

Oujda Volcanic Field
Includes more than 20 older Quaternary volcanoes (IAVCEI).

Mrit-Ment Volcanic Field

Berguent Volcanic Field

Chott Tigri Volcanic Field

Nemours-Nedroma
An age of 2.1 million years was obtained from this part of the Oranie Volcanic Field, a 2000 km2 field located along the Mediterranean coast of NW Algeria (Coulon et al., 2002; Liegeois et al., 2005). It is not known if younger rocks are present in this part of the field. Maury et al. (2000) gives ages of 0.8 to 3.9 Ma for the whole Oranie Volcanic Field. The volcanic products associated with this field are generally alkaline basalts; mantle xenoliths are also present within the volcanics (Maury et al., 2000; Liegeois et al., 2005).

Tafna Beni Saf
Alkaline volcanism continued into the Pleistocene in the Tafna Beni Saf (2.7-1.4 Ma) and A�n Temouchent (1.28-0.82 Ma) areas along the Mediterranean Sea coast of NW Algeria (Coulon et al., 2002). This volcano is a member of the Neogene-Pleistocene Oranie Volcanic Field, which covers an area of about 2000 km2 and has a total volume of about 200 km3. The volcanic products generally consist of alkaline basalts, and mantle xenoliths are also present (Doblas et al., 2007; Maury et al., 2000; Liegeois et al., 2005).

Cofrentes
Mapped by Lopez-Ruiz et al. (2002) as part of the Pliocene-to-Pleistocene Gulf of Valencia volcanic province located west of Valencia, Spain.

Islas Columbretes
A group of islands in the Gulf of Valencia was mapped by Lopez-Ruiz et al. (2002) as Quaternary in age. The three largest islands are Illa Grossa, Illa Ferrera , and Illa Foradada.

Logudoro
Plio-Pleistocene volcanic rocks ranging from 3.2 to 0.11 million years old are located in the Logudoro area of NW Sardinia (Beccaluva et al., 1977; Petteruti Lieberknecht et al., 2003; Peccerillo, 2005). Lustrino et al. (2007) gives an age of 2.4 to 0.1 Ma. These volcanics are generally of mafic composition, formed from monogenetic cinder and spatter cones, as well as lava flows (Peccerillo, 2005). Minor pyroclastics are also present. All together, the products cover about 500 km2 (Peccerillo, 2005).

Corvo
The 4 x 6 km island of Corvo is located at the NW end of the Azores archipelago, west of the Mid-Atlantic Ridge. A 2-km-wide caldera on the NW side of the island is the most prominent feature. The caldera floor contains several small cinder cones and two shallow lakes. Scoria cones south of the caldera fed lava flows that underlie the village of Corvo at the southern end of the island; that activity has been dated at 80,000 years ago, the most recent known eruption.

South Harghita Mountains
Romania
Central European Volcanic Province
The Ciomadul lava-dome complex is the youngest volcanic center of the Carpathian-Pannonian region. Located at the SE end of the Calimani-Harghita Range, it consists of a dacitic dome complex formed about 500-700 ka. The dome complex is cut by twin craters, Mohos and St. Anna. The latest eruption, from St. Anna, produced subplinian airfall and pyroclastic-surge deposits that have been variously dated between about 10.7 and 42 ka. Pecskay et al. (2006) noted ages of 1.0-0.03 Ma. A number of samples from other South Harghita locations (Porcuhu, Cucu, Kapus, Pilisca, Balvanyos, Haramul Mare, and Koves Peak) had Quaternary dates.

Persani Mountains
Romania
The Persani Mountains, an area that includes Pliocene-to-Pleistocene alkali basalts, are located south of the Calimani-Harghita Mountains in east-central Romania (Poka 1988). Bleheau et al. (1973) and Boccaletti et al. (1973) had also noted Pleistocene basalts in the area. Panaiotu et al. (2004) identified a number of volcanic features across a 22 x 8 km zone, finding that there were pulses of activity during 1.5-1.2 and 0.67-0.52 Ma.

Apuseni Mountains
Romania
There are a number of locations south of the Apuseni Mountains in west-central Romania with deposits dated in the Quaternary. The Beritia lava dome (IAVCEI 1973) is located in an area of numerous alkali basalt vents of Pliocene-to-Pleistocene age (Bleahu et al. 1973, Poka 1988). Uroiu Hill, 15 km SE of Beritia, was dated by Pecskay (1995) at 1.6 +/- 0.1 Ma.

Lucaret Basalts
The Lucaret basalt plateau, located near Timisoara in west-central Romania about 35 km ENE of Timisoara, is thought to be early Pleistocene (Savu et al. 1994, Poka 1988). Bleahu et al. (1973) also noted Pleistocene basalts SE of Timisoara.

Bakony-Balaton Highland
Hungary
The Bakony-Balaton Highland Volcanic Field is a large area of monogenetic Pliocene-to-Pleistocene basaltic shield volcanoes and cinder cones located around Lake Balaton in western Hungary (Bleahu et al., 1973; Poka, 1988). The age of volcanism, as summarized by Kereszturi and Nemeth (2011), extended from about 7.94 to 2.29 Ma.

Little Hungarian Plain
Hungary
The Little Hungarian Plain Volcanic Field (also called the Kemenesalja Hills) area in western Hungary contains a group of Pliocene-to-Pleistocene cones (Bleahu et al. 1973, Poka 1988). Martin et al. (2003) described it, and the Bakony-Balaton Highland field to the south, as an eroded phreatomagmatic field with remnants of nested maar complexes, multiple vent systems, and individual tuff rings.

Nograd-Southern Slovakia
Hungary-Slovakia
The basaltic Nogr�d-Southern Slovakia volcanic field in north-central Hungary and southern Slovakia contains cones of Pliocene-to-Pleistocene age (Boccaletti et al., 1973; Poka, 1988). The area is part of a larger volcanic field that straddles the Hungary-Czechoslovakia border. It is variously referred to as Northern Hungary-Southern Slovakia, or the Filakovo-Salgotarjan volcanics. Dating by Balogh et al. (1981 in Pecskay et al., 2006) gave dates of 0.4-2.2 Ma.

Central Slovakia
Slovakia
The Central Slovakia volcanic field consists of small basaltic shield volcanoes and cinder cones of Pliocene-to-Pleistocene age (Bleahu et al. 1973, IAVCEI 1973, Poka 1988). The SW part of the field is dominated by the Stiavnica stratovolcano, which is comprised of a large 18 x 22 km caldera, an extensive intrusive complex, and a resurgent horst with late-stage rhyolite. Based on stratigraphy (late Riss glacial stage), the Putikov vrsok cone of Stiavnica erupted about 130-140 ka (Simon and Halouzka, 1996). K-Ar dates from that scoria cone by Cherbyshev et al. (2013) were 390-460 ka, with the distal end of related lava flows slightly later.

Bruntal Volcanic Field
Czechia
The Bruntal Volcanic Field in Moravia, west of Ostrava, contains many cinder cones and lava flows of Pliocene-to-Pleistocene age (IAVCEI 1973). Cajz et al. (2012) K-Ar dated lava from the Venusina volcano at 0.83 +/- 0.12 Ma.

Cheb Basin
Czechia
An area of NW Bohemia near the border with Germany, known as the Czech Auvergne, contains small basaltic volcanoes of Miocene-to-Pleistocene age and world-renowned hot springs (Ager, 1980). Two cinder cones and a maar are found in the Cheb Basin area of the western Eger RIft; the Cheb Basin is an area of carbon dioxide dominated surface degassing in mofettes and mineral springs and active seismicity.

East Eifel Volcanic Field
Germany
Activity at the East Eifel volcanic field began about 0.65-0.45 Ma with the formation of scoria cones, lava flows, and tephra deposits. The Reiden complex at the western end produced a series of scoria cones, lava flows, and lava domes from 0.45 to 0.35 Ma. Activity resumed around 0.215 Ma, continuing until 0.115 Ma, with the formation of scoria cones, maars and lava flows. The latest eruption, at the Laacher See maar, took place about 12,900 years ago (40Ar/39Ar) and produced about 20 km3 of tephra (Schmincke et al., 2002).

Rodderberg
Germany
Rodderberg, in the Rodderberg Volcanic Complex (RVC), is a late Pleistocene cinder cone on the west side of the Rhine River. The complex itself consists of a circular depression with a diameter of about 600 m, a feature that is interpreted to be the remnant of a maar crater (Paulick et al., 2009). This field most likely represents a distal feature of the East Eifel Volcanic Field. The eruption of Rodderberg occurred in two phases. The first was phreatomagmatic, producing xenolith-rich, poorly sorted deposits. The second phase was dominated by Strombolian activity, resulting in xenolith-poor, thick and well-sorted coarse scoria deposits (Paulick et al., 2009). Geochemistry reveals the rocks erupted from the RVC to be leucitic nephelinite. The total erupted volume of material from the RVC eruption is estimated to be about 1.0x10^-2 km3 of magma and 2-3x10^-2 km3 of tephra - a rough order of magnitude estimate. The RVC deposits were previously dated at 26,000-27,000 years before present (IAVCEI 1973), but more recent thermoluminescence data placed the eruption at around 300 ka, during a glacial period in central Europe (Paulick et al., 2009).

Vulsini
The Vulsini volcanic complex in central Italy covers about 2,200 km2 at the northern end of the Roman Magmatic Province. Following lava extrusion and explosive eruptions that constructed the main complex, the 16 km lake-filled Bolsena caldera on the east and the 8 x 11 km Latera caldera on the west were formed during major Pleistocene eruptions at about 0.3 and 0.16 million years ago, respectively. Five major Plinian fall deposits were erupted from vents at or near Latera caldera during the late Pleistocene. The latest major eruption formed unwelded pumice flows and welded airfall tuffs of the Pitigliano Formation, associated with collapse of the Vepe caldera about 166,000 years ago at the NW end of Latera caldera. Post-caldera volcanism produced scoria cones and lava flows from vents within and to the west of Latera caldera. Remnants of ash cones in Lake Bolsena may have given rise to a legend of a pre-historical fire-god, Volta. Stothers and Rampino (1983) cited Obsequens, writing about four centuries later and likely drawing from Livy, that "a flame shot up near Volsinii" in 104 BCE; direct translations did not specify the volcano: "In the Vulsinian territory a flame was seen to rise from the earth and touch the sky."

Amiata
Amiata is a lava dome complex located about 20 km NW of Lago di Bolsena in the southern Tuscany region of Italy. The trachydacitic domes and associated lava flows were erupted along regional ENE-WSW-trending faults. The largest of the domes is Monte Amiata (La Vetta), a compound lava dome with a trachytic lava flow that extends to the E. A massive viscous trachydacitic lava flow, 5 km long and 4 km wide, is part of the basal complex and extends from beneath the southern base of the Corno de Bellaria dome. Radiometric dates indicate a major eruptive episode about 300,000 years ago. No eruptive activity has occurred during the Holocene, but thermal activity, including cinnabar mineralization, continues at a producing geothermal field near the town of Bagnore, at the SW end of the dome complex.

Radicofani
Volcano type: Volcanic remnant
Radicofani, a part of the Tuscan Magmatic Province located within the Sierra-Radicofani Graben, is a relatively small monogenetic volcano now represented by a volcanic neck (Peccerillo, 2005; Conticello et al., 2011). Although the original edifice was a cinder cone, it is highly dissected, leaving only lava flow remnants and scoria deposits east of Monte Amiata (Peccerillo, 2005; Conticello et al., 2011). Columnar jointing is present in the middle and lower portions of the neck, and large lava blocks and bombs are scattered about within several kilometers (Conticello et al., 2011). The lavas are generally basaltic-andesitic to shoshonitic in composition (Conticello et al., 2011). The lavas of the upper and lower parts of the neck have been dated to about 1.3 Ma and 1.08-1.22 Ma, respectively (Conticello et al., 2011; Peccerillo, 2005).

Torre Alfina
Volcano type: Volcanic remnant
Torre Alfina is a monogenetic volcano consisting of two volcanic necks and a lava flow several hundred meters long located SE of Monte Amiata (Peccerillo, 2005). Both blocky lava flows and smoother flows formed from lower viscosity lava crop out within a few kilometers of the volcano, and lapilli and scoria deposits surround the vent. Some lava tubes are also present in the eastern part of the lava field near the Paglia River canyon (Conticelli, 1998). These lavas are potassic alkaline olivine-latites and have been dated at 0.9-0.82 Ma (Conticelli, 1998; Peccerillo, 2005). Torre Alfina rocks contain a large number of crustal and mantle xenoliths (Conticello et al., 1998).

San Venanzo
The San Venanzo complex consists of the San Venanzo maar and the Pian di Celle tuff ring, both part of the Umbria-Latium ultra-alkaline district. The tuff ring is also associated with two spatter cones and a scoria cone. This complex of vents lies within the Tiber Valley Graben, where magmatism is believed to be a result of extension that began during the Pliocene (Stoppa, 1996). Early on, the eruption was explosive, producing pyroclastic flows and dry lapilli surges covering an area of about 0.15 km2; later eruptive behavior was dominated by lava flows. Block collapse and debris flows led to the formation of the steep inner crater walls. The tuffs of both San Venanzo and Pian di Celle are calcitic to carbonatitic in composition, and have been dated at about 265 +/- 3 ka (Stoppa, 1996; Stoppa and Sforna, 1995).

Acquasparta
Acquasparta is characterized by monogenetic centers aligned N-S along a 10 km line. It's pyroclastic flow, fall, and surge deposits form a small plateau and are likely of phreatomagmatic origin. Ar/Ar dating of these products has produced an age of about 390 ka (Peccerillo, 2005).

Polino
Volcano type: Explosion crater(s)
Polino is made up of two small diatremes surrounded by layered tuffs and filled with breccia and carbonate-rich locks and lapilli (Pecerillo, 2005). It is classified as a carbonatite, the products of which consist of two facies: tuffisite and large carbonatite bombs. Both crustal and mantle lithics are also present within the welded tuff (Rosatelli et al., 2010). These deposits were Ar/Ar dated at about 246 ka (Peccerillo, 2005).

Cupaello
Cupaello is responsible for a 750-m-long lava flow that covers layers of pyroclastic material, including ash, breccias, lapilli, and scoria. These products were channelized and accumulated downslope of the volcanic edifice (Stoppa and Cundari, 1995). These pyroclastics are carbonatitic in composition, and yielded an Ar/Ar age of 639 ka (Peccerillo, 2005). However, Stoppa and Cundari (1995) list a date of about 491 +/- 3 ka. Structures within the pyroclastic layers indicate that the tuff could still deform plastically when covered by the lava, suggesting that both the explosive and effusive phases were part of the same eruption (Stoppa and Cundari, 1995).

Oricola-Carsoli
Oricola-Carsoli, about 40 km SW of L'Aquila, is part of the Intra-Appenine Magmatic Province. Its monogenetic pyroclastic cones are composed of altered breccias, tuff, along with surge and fall deposits. They are possibly hydrovolcanic in origin. These deposits were K-Ar dated at about 530 ka (Peccerillo, 2005).

Vico-Cimino Complex
The Vico volcano is classified as part of the Roman Magmatic Province; however, the Cimino volcano that Vico partially overlies technically belongs to the Tuscan Magmatic Province, based on geochemical affinity (Peccerillo, 2005). The Monte Cimino trachytic lava dome complex was active from 1.35-0.94 Ma (Peccerillo, 2005). The PT Ignimbrite was erupted about 1.3 million years ago. The adjacent Vico central volcano and caldera was active during three periods from 0.4 to 0.15 Ma (Sollevanti, 1983; Peccerillo, 2005). Period 1 was dominated by pyroclastics and minor lava flows. Period 2 involved the emplacement of intermediate to felsic lavas that constructed the main cone. The post-caldera activity of Period 3 produced mafic lavas, scoria, and phreatomagmatic products. Vico also has a few post-caldera monogenetic centers, the largest of which is the Monte Venere cone inside the caldera (Peccerillo, 2005). Four ignimbrite-producing eruptions related to caldera formation took place from about 0.25-0.144 million years ago.

Sabatini Complex
The Sabatini Volcanic Complex has no clearly delineated volcanic structure, but is a distribution of volcanic vents (Conticelli et al., 1997). The Sacrofano center in the eastern part of the complex and the Bacciano center in the west were active from 0.5 to 0.09 Ma (De Rita et al., 1983). Other smaller volcanic systems are Morlupo, Vigna di Valle, Trevignano, and Baccano (Conticelli et al., 1997). The Sacrofano and Bacciano centers dominate the five phases of the complex's eruptive history. The first two phases involved intense explosive activity at Sacrofano and Molupa (0.6-0.4 Ma), resulting in tuffs, ashes, and pyroclastic flows during the pre-Sacrofano Caldera stage. During the third phase, hydro-magmatic eruptions formed the Sacrofano Caldera and minor lava flows occurred in the post-caldera stage. In the western sector, a stratovolcano and the Bracciano Caldera developed, along with fissure eruptions that produced flood lavas greater than 100 km3, air-fall tuffs, and surge deposits. Activity at small eruptive vents on the rims of the collapsed Bracciano and Sacrofano Calderas dominated the fourth phase, resulting in pyroclastics at Bracciano along with cinder cones and lava flows at Sacrofano. Hydro-magmatic activity localized between the two calderas, which produced tuff rings, cones, and maars, dominated the final phase (Conticelli et al., 1997).

Monti Ernici
The Monti Ernici volcanic field, also known as the Mid Latin Valley volcanic field, is a monogenetic center about 70 km SE of Rome. It consists of about 20 cinder cones, tuff cones, and associated lava flows and pyroclastic-flow deposits. The field was active from about 0.7 to 0.1 Ma (Peccerillo, 2005). Geochemically, the Ernici-Roccamonfina Province exhibits characteristics of both the Roman and Campanian Magmatic Provinces.

Roccamonfina
Roccamonfina is a large Pleistocene stratovolcano with numerous post-caldera cones within the summit caldera and on the flanks. The eruptive history consists of three main phases. The first stage built the main cone via lava flows and pyroclastics. The second stage is defined by large explosive eruptions, tuff deposits, and caldera collapse. The third stage formed the lava flows, domes, and scoria cones that exist on the volcanic edifice today. A report of a historical eruption in 269 BCE ("a flame shot up and burned for three days near Cales" (Stothers and Rampino, 1983)) is considered uncertain by Scandone and Principe (1986), who noted that the youngest products have been dated at 0.30 million years. Later work (Rouchon et al., 2008) dated summit caldera lava domes at 170-150,000 years ago. Peccerillo (2005) gives an age range of 0.58-0.1 Ma for Roccamonfina activity.

Monte Vulture
The isolated Monte Vulture is a stratovolcano with a summit caldera and a few cones that erupted lavas and pyroclastics covering 150 km2. Petrologically and geochemically distinct, it is classified as its own magmatic province: the Lucanian Magmatic Province, in the Apulian Region (Peccerillo, 2005). The most recent volcanic activity formed two intra-caldera maars and involved explosive eruptions of carbonate-rich tuff, with the Lago Piccolo di Monticchio maar dated at 0.141 Ma (Peccerillo, 2005; Villa and Buettner, 2009). Capaldi et al. (1985) reported the youngest dated products from Vulture as 0.42 million years old. Peccerillo (2005) give an age range of 0.8-0.13 Ma for Vulture volcanics.

Ventotene
Ventotene is a trachybasaltic to phonolitic stratovolcano with associated lava flows, domes, and pyroclastics (IAVCEI, 1973; Peccerillo, 2005). The mafic lava flows are cut by a caldera rim and overlain by pyroclastics. The nearby Santo Stefano island is an associated lava dome, also covered by pyroclastics. The pyroclastics are the products of both magmatic and hydrovolcanic processes, and contain lava lithic fragments and xenoliths (Peccerillio, 2005). Scandone (pers. comm.) gives 0.3 Ma as the youngest age for the Ventotene volcanics, but Peccerillo (2005) gives an age range of 0.8 to less than 0.13 Ma.

Pontine Islands
The Pontine Islands are Plio-Pleistocene in age, ranging from 4.2-1.0 Ma (Scandone, 1987, pers. comm.; Peccerillo, 2005). The islands are mostly formed of Pliocene rhyolites and Pleistocene trachytes and alkaline rhyolites. Volcanic products also consist of obsidian lava flows, domes, dykes, breccias, and hydromagmatic products. The rhyolitic volcanism on Ponza occurred between 4.2 and 3.0 Ma, followed by trachytic activity at about 1.0 Ma. The eruptive activity on Palmarola took place around 1.6 Ma (Peccerillo, 2005).

Gaeta Bay Volcanic Field
The Gaeta Bay Volcanic Field consists of a group of eight buried submarine volcanoes of early to mid-Pleistocene age (Torrente and Milia, 2013). This volcanism is generally characterized by thick lava flows and volcaniclastic deposits. The entire volcanic field is up to 1,500 m thick. Volcanic activity in the Gaeta Bay and surrounding regions was largely fault bounded, where extension and subsidence controlled the emplacement and displacement of most of the volcanic centers (Torrente and Milia, 2013). These volcanic centers developed between 400,000 and 100,000 years ago. The extension and volcanism responsible for the volcanic field migrated eastward with time, towards the Campi Flegrei (Torrente and Milia, 2013).

Salina
Salina is made up of calc-alkaline basaltic to andesitic stratovolcanoes (Rivi, Capo, and Corvo), which are overlain by two andesitic cones (Monte Felci and Monte Porri), the latter of which erupted about 67 ka (Peccerillo, 2005). Monte Porri also underwent intense explosive activity, producing a series of tuffs that have been identified on nearby islands; these eruptions also produced lahars and pyroclastic surges (Guest et al., 2003). The final eruptive activity produced basaltic-dacitic-andesitic lava flows and a rhyolitic explosion crater (Pollara) (Peccerillo, 2005; Guest et al., 2003). Pollara Crater erupted about 13,000 years before present; the rest of the island is mid-late Pleistocene, 430,000-500,000 years old (Keller, 1974; Peccerillo, 2005; Guest et al., 2003).

Filicudi
Filicudi was formed from the coalescence of eruptive centers that developed as part of a NW-SE elongated volcanic complex (Peccerillo, 2005; Guest et al., 2003). It's volcanic structures include basaltic to andesitic composite cones and dacitic domes, lava flows, and pyroclastics (Peccerillo, 2005). The Filicudi rocks also often contain igneous and metamorphic xenoliths (Peccerillo, 2005). Potassium-Argon dates of 0.170 and 0.166 million years were obtained by Capaldi et al. (1985), but Peccerillo (2005) gives a general age range of 440-40 ka. Tephrochronology indicates that the youngest eruptions occurred less than 35,000 years ago (Keller, 1989, pers. comm.). The Eruptive history is generally broken into four phases. The first (1.02 Ma) consisted of pyroclastic eruptions followed by lava flows. The second (390 ka) produced lava flows. The third is responsible for the construction of Fossa Felci, the main volcanic edifice on the island, and the production of basaltic andesitic lavas and pyroclastics. The fourth (40 ka) involved explosive activity from Fossa Felci, creating pumiceous pyroclastics (Guest et al., 2003).

Alicudi
Alicudi, in the Aeolian Island Arc, is a basaltic to andesitic stratovolcano containing a summit caldera, domes, and lava flows that formed over the course of three main stages in its eruptive history (Peccerillo, 2005). The first two stages involved basaltic to basaltic-andesitic lava flows and minor scoria and ash deposits, both followed by a summit collapse, the second of which formed the Dirittusu caldera (Peccerillo, 2005; Guest et al., 2003). Pyroclastic activity increased towards the end of the second stage (Guest et al., 2003). The third stage was dominated by andesite lava flows and the formation of domes within the summit crater and on the southeastern cone flank (Peccerillo, 2005). The youngest K-Ar date from Alicudi is 0.027-0.028 Ma, and the oldest, obtained from the lowest exposed rocks, is about 60-90 ka (Capaldi et al., 1985; Peccerillo, 2005; Guest et al., 2003).

Ustica
Ustica, the subaerial expression of a large submerged volcanic complex about 30 km wide, is formed mostly of lava flows, with minor hydrovolcanic products. Initial activity produced mostly pillow lavas, hyaloclastites, and breccias, having begun underwater. This was followed by effusive and hydromagmatic explosive activity, from two main volcanic centers: Monte Guardia dei Turchi (500 ka) and Monte Costa del Fallo (Peccerillo, 2005; Guest et al., 2003). These eruptions produced lavas, domes, basaltic scoria, pumice, and lapilli (Guest et al., 2003). This predominantly mafic activity was followed by a trachytic explosion and dome emplacement at about 424 ka (Peccerillo, 2005; Guest et al., 2003). One of the youngest eruptions on the island was a Surtseyan eruption, which produced extensive tuff deposits and formed the Falconiera pyroclastic cone (Guest et al., 2003). The volcanics on the island are middle Pleistocene, about 750-130 ka (Romano & Sturiale, 1971; Peccerillo, 2005; Guest et al., 2003).

Iblei
Volcano type: Shield?
Iblei consists of mostly submarine volcanics with some subaerial deposits; however, there is no clear volcanic edifice (Scandone, 1987, pers. comm.). The volcanic features consist mostly of monogenetic cones, maars, and lava flows of basaltic to andesitic composition; the older Pliocene submarine products are pillow lavas and hyaloclastites (Peccerillo, 2005). The youngest volcanic products are K-Ar dated at 1.7 Ma, but volcanism is believed to have taken place from 4.9 to 1.5 Ma (Capaldi et al., 1985; Peccerillo, 2005).

Linosa
Linosa Island, in the Straight of Sicily graben system midway between Sicily and Tunisia, is the subaerial exposure of a large submarine volcano. The island contains several monogenetic hydrovolcanic eruptive centers, both effusive and Strombolian, as well cinder cones and lava flows dated to 1.06-0.53 Ma (Peccerillo, 2005). During this time, there were three main episodes of volcanism. The first phase developed hydromagmatic scoria cones and tuff rings of mafic composition. The second phase involved both effusive and explosive hydromagmatic activity, producing scoria and lava flows. The third phase produced basaltic lava flows, scoria deposits, and some hydromagmatic deposits, during which time the largest cones on the island formed (Peccerillo, 2005). Within each eruptive phase, hydromagmatic activity decreased with time, as lava flows helped reduce the islands erodability and limited the contact between craters and seawater (Guest et al., 2003).

Yali
Yali, a small crescent-shaped island between the N coast of Nisyros and the SW coast of Kos islands, consists of rhyolitic obsidian domes and pumice deposits. It lies within the inferred location of the large submarine caldera associated with the eruption of the voluminous Kos Plateau Tuff, about 160,000 years ago, which produced extensive ignimbrites that cover much of the western half of Kos island and which produced a caldera of uncertain dimensions but one that could extend from Kefalos Bay on the SW side of Kos to Nisyros. Yali is oriented NNE-SSW and contains two distinct segments connected by a narrow isthmus formed of modern reef sediments. The SW part of the island consists primarily of a layered pumice-fall unit about 200 m thick; the NE part contains rhyolitic obsidian lava flows of similar thickness. Pumice deposits overlie soils containing pottery and Neolithic obsidian artifacts (Keller, 1982), but radiometric tephra dates are all older than 30,000 years.

Aegina
Aegina is part of the Saronic Gulf Volcanic Group, in the Hellenic Volcanic Arc. The complex consists of domes and lava flows erupted from effusive monogenetic centers with low eruption rates (0.4 km3/m.y. at Aegina) (D'Alessandro et al., 2008). Activity took place between 4.7 and 2.0 Ma, during the first part of which mostly basaltic-andesitic to rhyodacitic rocks were produced. The remaining 1 million years of activity produced basaltic-andesitic rocks (D'Alessandro et al., 2008; Francalanci et al., 2007). Volcanism ended in the late Pleistocene, but a low-temperature geothermal field presently exists (Keller, 1971; Francalanci et al., 2007).

Poros
Poros consists of a small Pliocene to Pleistocene lava volcano erupted from fissures (IAVCEI, Keller 1982).

Antiparos
Antiparos Island, positioned within the back-arc region of the South Aegean Volcanic Arc, contains a group of rhyolitic lava domes and pyroclastic cones with associated lava flows that are of Miocene to early Quaternary age (Pe-Piper and Piper, 2007; IAVCEI; Keller, 1982; Clapsopoulos, 1998). The domes are surrounded by tuffs containing obsidian particles and pumice, which are believed to be the result of subaqueous pyroclastic flows. The volcanic products are distributed over a total area of about 4.5 km2 (Clapsopoulos, 1998). K-Ar dates listed in Fytikas et al. (1984) range from 5.4 to 4.0 Ma.

Kos
The island of Kos is dominantly non-volcanic but contains Miocene to Pleistocene volcanic centers. The Kamari caldera is of mid-Pleistocene age and contains the 1.0-0.55 million year old, post-caldera Zini lava dome. The formation of a large caldera deposited the widespread Kos Plateau Tuff (erupted about 160,000 years ago), which covers much of the western half of Kos and originated from a source between Kos and Nisyros islands. The caldera dimensions are uncertain, but may extend as much as 20 km from Kefalos Bay in SW Kos Island to Nisyros Island. Remnants of the pre-eruption stratovolcano are preserved on the islets of Pachia and Pyrgousa and as submarine volcanic rocks on Nisyros. Kos was included in the Catalog of Active Volcanoes of the World (Georgalas, 1962) based on its geothermal activity. Several solfatara fields are present, including Vromotopos at Kefalos Isthmus on the western side of the island and a group of thermal areas at the eastern side of Kos. Thermal activity consists of weak hydrogen sulfide emission, sulfur deposits, and two hot springs along the SE coast.

Psathoura
Psathoura Island, in the northern Aegean Sea Sporades Archipelago, has outcrops of small overlapping lava flows (Koutsovitis et al., 2015), dated by Fytikas et al. (1984) as 0.7 Ma. Other volcanism in the central and northern Aegean islands and the Western Thrace area of mainland Greece is of Oligocene to Pliocene age, with Quaternary volcanism being restricted to the southern Aegean arc (Fytikas et al., 1984). The volcanism is controlled by faulting along the North Aegean Trough, a westward extension of the North Anatolian Fault (Pe-Piper and Piper, 2007; Koutsovitis et al., 2015).

Volos-Atalanti
The Volos-Atalanti (also known as Volos-Evia) area contains a number of small monogenetic Pliocene to Pleistocene lava flows, cones, and domes. The largest lava outcropping, which originated from the Migoula cone, is about 0.2 km3 in volume and 6-7 km long (Innocenti et al., 2010). The volcanic products are generally basaltic trachyandesitic (Innocenti et al., 2010). The lava flows at Porphyrion and Microthivai date to about 1.6-1.3 Ma. The Toumbanos Hills lava dome, near Achilleion, dates to about 3.4-2.7 Ma. In the Atalanti channel, the cones and lava flows of the Likhades Islands date to about 0.5 Ma, as does a lava flow at Kammena Vourla on the Greek coast (Innocenti et al., 2010). K-Ar dates from Fytikas et al. (1984) range from 3.0-0.5 Ma. Volos-Evia is believed to lie on the westward extension of the North Anatolian Fault, rather than the Hellenic Arc (Innocenti et al., 2010).

Karapinar Monogenetic Field
The Karapinar Monogenetic Field is the SW-most area of Quaternary volcanism in Central Anatolia, SW of the Karacadag volcano. As defined by Uslusar et al. (2021), the field contains 17 scoria cones (basaltic), one lava dome (andesitic), four maars (basaltic), and three undifferentiated features. They note that a NE-SW alignment of maars and adjacent scoria cones almost parallel to the Ecemis fault. The maars evolved from hyaloclastite tuff rings to maars to cinder cones, reflecting varying lake water levels during eruptions. Meke Dagi, at the southern extent of the field, is one of the largest cinder cones in Central Anatolia. Ar-Ar radiometric ages from scoria cones were 160-500 ka (from Reid et al., 2017, reported by Uslusar et al., 2021).

Derinkuyu Volcanic Complex
The Derinkuyu Volcanic Complex in central Anatolia lies between the Hasan Dagi and Nevsehir-Acig�l complexes. As defined by Uslular et al. (2021), this system includes the buried Tertiary Derinkuyu caldera and the Quaternary Sahinkalesi and G�ll�dag dome complexes, along with 30 lava domes (andesitic to rhyolitic), 28 scoria cones (basaltic), one maar (basaltic), and three undifferentiated features. Some of the cones were considered by Keller (1980, pers. comm.) to be Holocene in age due to their freshly preserved features, but Uslular et al. (2021) reported a youngest age of 90 ka for a lava dome (U-Pb). Fission track ages on obsidians ranged from 1.33 to 0.84 million years old (Bigazzi et al., 1995). Hydrothermal alteration and hot springs are present in the Sahin Kalesi resurgent dome complex west of G�ll� Dag and on the southern flank of the Erdas Dag massif to the north.

Nevsehir-Acigol Volcanic Complex
The Nevsehir-Acig�l Volcanic Complex is located in the Cappadocia region of central Turkey largely in the area between the towns of Acig�l and Nevsehir. A hypothesized 7 x 8 km late-Pleistocene caldera (Acig�l, or Kocadag) is part of a partially buried larger caldera and contains a group of maars, lava domes, basaltic lava flows, and pyroclastic cones. As defined by Uslusar et al. (2021), this complex includes 24 lava domes (andesitic to rhyolitic), 10 scoria cones (basaltic to andesitic), six maars (basaltic trachyandesitic and rhyolitic), two tuff rings (basaltic), and another 28 undifferentiated features; the youngest dome and maar ages are about 20 ka (U-Th/He). Three groups of obsidian lava flows have been dated; pre-collapse flows between about 190,000 and 180,000 years before present (BP), 75,000 years BP lava domes (such as Taskesik Tepe on the east), and lava domes on the west about 20,000 to 15,000 years old. Thirteen tephra layers deposited between about 11,000 and 4,300 years ago were found in sediment cores in the late Pleistocene Eski Acig�l maar (Kuzucuoglu et al., 1998), but their source is uncertain. An ash layer near the Kocatepe dome was reported by Pasquare (1968) to overlie artifacts of Roman-Cappadocian age, but no detailed work is known.

Golcuk
Thick ignimbrite deposits are associated with formation of the G�lc�k caldera, which was partially destroyed by a phreatoplinian eruption. The caldera was partially filled by lava domes and flows and then modified by maar formation during the last phase, which concluded with eruption of lava domes within the lake-filled maar. The volcano was initially thought to be Pliocene in age, but Platevoet et al. (2008) showed that much of the volcano's activity took place during the Pleistocene, and the latest eruption from lava domes was about 24,000 years ago.

Ceyhan-Osmaniye
The Ceyhan-Osmaniye volcanic field, as summarized by Gursoy et al. (2003), includes basaltic eruptions from about 20 vents (Yurtmen et al., 2000) dated between 0.61 +/- 0.10 and 2.25 +/- 0.78 Ma (Arger et al., 2000). Outcrops and volcanic units along the Karatas Osmaniye Fault Zone NE of the Gulf of Iskenderum are described by a variety of names by different workers. Lava flows along the NW shoreline are identified by Gursoy et al. (2000) as the Botas Volcanics, while those just inland to the NE towards the city of Toprakkale are the Osmaniye Volcanics. The Osmaniye lava flows include a number of preserved vent locations, including the Delihalil Tepe tephra cone.

Egrikuyu Monogenetic Field
The Egrikuyu Monogenetic Field is located in Central Anatolia S of Hasandag volcano and NE of the Karacadag edifice. As summarized by Uslular et al. (2021), the clustering of vents in this 28 x 38 km area follows a generally NE-SW in the west and mostly N-S to NW-SE in the east. Scoria cone alignments may indicate buried faults. There are a few basaltic maars in the region. Usulular et al. (2021) identified 110 scoria cones (basaltic), one lava dome (andesitic), four maars (basaltic), and three undifferentiated features within this field.

Suphan Dagi
S�phan Dagi is a basaltic-to-rhyolitic stratovolcano located immediately north of Lake Van with a glacial icecap on the summit. Andesitic-dacitic lava flows alternated with fluid basaltic flows, followed by construction of a large lava dome over the central vent. The flanks have numerous lava domes and pyroclastic cones erupted along radial and circumferential fissures, particularly on the N, S, and E sides. Voluminous basaltic lava flows traveled as far as 30 km from the summit. Although Yilmaz et al. (1998) reported that there had been a basaltic eruption about 10,000 years ago, Ozdemir and Gulec (2013) made no mention of any activity that recent; based on previous K-Ar studies and new Ar-Ar dating work, they found an activity range of 760,000-60,000 years ago. Dacitic and rhyolitic domes in the summit crater followed all lava flows and pyroclastic deposits from the main cone, with one dated at 64 +/- 14 ka. The 1.5-km-wide, low-rimmed Aygir G�l� maar was formed on the lower S flank, and represents the most recent activity (undated), characterized by a phreatomagmatic eruption and related deposits.

Girekol
Girekol Tepe, a Pleistocene-to-Holocene, calc-alkaline to alkaline shield volcano, is located directly north of the NE arm of Lake Van and NE of the city of Ercis in eastern Anatolia (Yilmaz, 1990). Work by Lebedev at al. (2009) found no volcanic products younger than 0.36 +/- 0.06 Ma associated with Girekol.

Etrusk
As described by Oyan et al. (2010), the Pliocene Etr�sk volcano is one of the major volcanic centers of eastern Anatolia, just NE of Lake Van. There is a ~5-km-wide open caldera near the center of the volcano, with the Pleistocene Karniyak scoria cone about 11 km away on the SW flank near the lake. K-Ar age determinations by Oyan et al. (2010) indicate that the main volcanic edifice was formed between 4.3 and 3.9 Ma, ending with caldera collapse. Between ~1 and 0.43 Ma, basalts erupted from the SW flank, predominantly from a ~N-S extending fissure, as well as from Karniyarik hill and a maar-shaped volcanic center (D�zgeyik�ukuru). Lebedev et al. (2009) noted that the youngest dated trachybasalt from Karniyarek was 360 +/- 6 ka.

Arpacay
Arpacay is a Pliocene to mid-Pleistocene calc-alkaline to alkaline volcanic center (Yilmaz 1990).

Kisir Dagi
Kisirdagi is a heavily eroded Miocene to Pleistocene volcanic center of calc-alkaline to alkaline composition (Yilmaz, 1990).

Keli Highland
Georgia
This large volcanic plateau contains 35 small cones and extrusions, mostly andesite-dacite edifices (Lebedev, 2014 pers comm).

Akhuryan Valley
This group of six andesitic-dacitic cinder cones of lower to middle Pleistocene age was unnamed by IAVCEI (1973). Neill et al. (2013) sampled the Sepasar, Eznasar, and Kaputkogh cones in the "Cone Series" of the Akhuryan Valley. U-Pb dating of volcanic ash from a nearby archeological site gave an age of 1.8 Ma (Presnyakov et al., 2012).

Shamiram Plateau
A group of 13 cinder and lava cones and domes of Pliocene to mid-Pleistocene age are located in the Aragatz upland (IAVCEI 1973).

Southeast Syunik Upland
Armenia-Azerbaijan
This area of the large Syunik Volcanic Upland was originally listed in IAVCEI (1973) as a group of 11 cinder cones, lava cones, and lava domes of Pliocene to mid-Pleistocene age in the Syunik Upland. Meliksetian (2013) included a geological map and described the entire upland as extending 70 km NW-SE by 35 km wide, with 163 volcanic features, mostly lava cones, cinder cones, and some rhyolitic domes. The portion of the upland NW of the Plio-Pleistocene Tskhouk stratovolcano, including Holocene pyroclastic cones and lava flows, is identified as the Tskhouk-Karckar volcano group. This catalog entry includes Pleistocene monogenetic cones and lava flows SW and SE of Tskhouk towards the Plio-Pleistocene Ishkhanasar stratovolcano, along with additional cones inside the crater and S of Ishkhanasar.

Sahand
Iran
Sahand volcano (Kuh-e-Sahand) is located in NW Iran, about 60 km E of Lake Urmia and 40 km SSE of the city of Tabriz. Numerous lava domes are present on the lower flanks. Pleistocene Potassium-Argon dates from 1.2-0.8 million years ago have been obtained (Innocenti et al., 1982), though Karakhanian et al. (2002) stated that eruptions continued into the Holocene. In their review of research on Sahand, Ghalamghash et al. (2019) concluded that the most recent activity was less than 173 ka, but not Holocene.

Sabalan
Iran
Sabalan volcano (Kuhha-ye-Sabalan) lies in NW Iran, about 90 km W of the Caspian Sea and west of the city of Ardabil. The andesitic volcano is the highest point in NW Iran. Seven glaciers descend from the summit, and rock glaciers are also present. Potassium-Argon dates ranged from 5.6 to 1.4 million years ago (Innocenti et al., 1982), though Karakhanian et al. (2002) indicated that activity continued into the Holocene. In their research review, Ghalamghash et al. (2019) concluded that the most recent activity was less than 149 ka, but not Holocene.

Kuh-e Ayyub Ansar
Two volcanic centers near Takab noted by Boccaletti (1976-77) may be the same features identified in IAVCEI (1973) to the SE of Sahand volcano, though located about a degree of latitude further south. The northern-most feature, Kuh-e Ayyub Ansar, appears to be a dome (about 3 x 5 km) in satellite imagery. A second hill about 20 km ESE may be a resistant outcrop of a lava flow, a situation seen in other parts of Iran.

Bijar Volcanic Field
The Bijar volcanic field of a cluster of Miocene dacitic and rhyolitic lava domes along with a group of Pleistocene (K-Ar dates 1.3-0.5 Ma) alkaline cinder/spatter cones and two rhyolitic lava domes (Boccaletti et al., 1976-77).

Dzau
The Dzau (Java) volcanic center produced fissure eruptions of andesitic lavas between 200 and 100 ka (Chernyshev et al, 2002).

Saray
Saray is a heavily eroded late Miocene-Quaternary volcano about 75 km WNW of Sahand. The small edifice forms Islami Island in Lake Urmia in NW Iran.

Central Asia Volcanic Province

Qal'eh Hasan Ali
Central Asia Volcanic Province
The Qal'eh Hasan Ali volcanic field in SE Iran contains 14 maars of late Quaternary age, which were erupted through desert alluvium, granodioritic rocks, and Eocene volcanics in an area several hundred kilometers away from the closest Quaternary volcanoes. The maars, which produced tephritic pyroclastic deposits, have diameters ranging from 150 to 1200 m. The largest, known as Great Crater, is 1.2 km wide and 200-300 m deep. Ar-Ar dating of phlogopite in volcanic bomb samples from Great Crater gave ages of 112-119 ka (Pang and others, 2015).

Bazman
Central Asia Volcanic Province
Bazman is a dominantly andesitic stratovolcano in SE Iran with a 500-m-wide summit crater. Satellitic lava cones have been the source of olivine basalt lava flows, and a steep cone on the N flank produced a lava flow that traveled to the N before diverging to the NW and NE. Only minor fumarolic activity has been reported. The youngest dates obtained by Ghalamghash et al. (2019), using Uranium-series (238U-230Th) disequilibrium in zircons for dacitic to andesitic lava near the summit, obtained a date for an eruption phase about 41,000 years before present.

Nader
Quaternary basaltic lava flows have issued from vents within the Nader Mountains between Taftan (65 km NE) and Bazman (65 km SSW) volcanoes in SE Iran (Catalog of Active Volcanoes of the World). These flows, including some cones and craters, were erupted amongst a group of rugged Cretaceous limestone peaks. Little research has been done on these deposits, but dating of material from Bazman and Taftan showed no Holocene eruptions.

Taftan
Taftan is a strongly eroded andesitic stratovolcano with two prominent summits. The volcano was constructed along the Makran-Chagai Arc in SE Iran. The higher SE summit cone has been the source of lava flows, as well as of highly active, sulfur-encrusted fumaroles. In January 1902 the volcano was reported to be smoking heavily for several days, with occasional strong night-time glow. A lava flow was reported in 1993, but may have been a mistaken observation of a molten sulfur flow. Despite these reports there is no clear evidence for Holocene activity. The youngest date obtained by Pang et al. (2014), using U-Pb on a zircon, was about 800 ka. Biabangard and Moradian (2008) obtained K-Ar dates around 700 ka.

Dacht-i-Navar Group
Afghanistan
The Dacht-i-Navar volcanic field is a group of 15 trachyandesitic lava domes along the southern margin of Dacht-i-Navar in west-central Afghanistan, SW of Kabul. The age of the volcanoes is not known precisely; they were tentatively considered to be of Pleistocene age (Lapparent et al., 1965) and were listed as Recent by Bordet (IAVCEI, 1973).

Vakak Group
Afghanistan
The Vakak Group (also spelled Wakak) consists of 18 dacitic and trachytic volcanoes located WSW of Kabul. It is the northernmost of a group of small volcanic fields in the Ghanzi region and consists of endogenous lava domes, one of which occupies an old caldera. The age of the volcanoes is not known precisely; they were tentatively considered to be of Pleistocene age (Lapparent et al., 1965) and were listed as Recent by Bordet (International Association of Volcanology and Chemistry of the Earth's Interior, 1973).

Gandom Beryan
Previously identified as an unnamed area with two small Quaternary centers (IAVCEI, 1973), this location corresponds to the lava plateau (480 km2) on the edge of the Dasht-e Lut (Lut desert) of Iran named Gandom Beryan (meaning "Scorched Wheat" in Persian). Also known as Gandom-e Beryan or Rig-e Soukhteh, it is located 80 km N of Shahdad city. Some small cinder cones are present, but the source of the extensive basalt flows is not certain. Ar-Ar dating (Walker et al., 2009) of basalt from three locations in the lava field ranged from about 2.15 to 2.80 Ma.

Dehaj-Meduk
Dehaj-Meduk is a Quaternary andesitic volcano group with perfectly preserved volcanic cones (Catalog of Active Volcanoes of the World, Jung et al. 1976).

Shahsavaran
A group of small perfectly preserved Quaternary lava cones covering an area of 60 x 120 km west of Bazman volcano have produced viscous basaltic lava flows (Catalog of Active Volcanoes of the World, Girod and Conrad 1975).

Sultan
Pakistan
Pleistocene volcano on the eastern side of the Makran-Chagai Arc in western Pakistan.

Zardolou Group
Afghanistan
Six or seven Quaternary lava domes (IAVCEI 1973).

Loman Volcano Group
Four Quaternary lava domes (IAVCEI 1973).

East Neh
Walker et al. (2009) dated basalts along the East Neh fault at 1.45-1.75, 1.69-1.79, and 4.71-4.91 Ma. Volcanic deposits are strung out along perhaps 50 km on either side of the fault.

Kaukab
Syria
Kaukab is a basaltic cone about 1 km in diameter with a large breached and eroded crater; additional smaller cones are located 2 km N and 500 m S. It was described as Holocene by Malki (in IAVCEI, 1973), but very little work has been done in this area, and no definitive age has been determined. Lease and Abdel-Rahman (2008) include this as part of the Plio-Quaternary Euphrates Volcanic Field, noting that "piles of lava flows at the Kaukab locality are about 10 m thick at the centre, diminishing to 3 m in thickness at the edge of the plateau."

Tigris Lava Flows
Syria
This location was included in IAVCEI (1973) as "mid-Pleistocene." Abdel-Rahman and Lease (2012) identify the area as the Tigris lava flows (basaltic lava flows, with minor pyroclastic flows). They note that it, along with lava flows in the Ardel-Sheikh area, is part of the Tigris Volcanic Field (~1,750 km2).

Feidat el-Mieza
Syria
This location was included in IAVCEI (1973) as a group of 11 volcanoes last active in the "mid-upper Pleistocene." Lease and Abdel-Rahman (2008) identify the area as Feidat el-Mieza (680 km2 with lava flows and minor pyroclastic flows). They note that it is part of the Plio-Quaternary Euphrates Volcanic Field.

Himmat el-Jazira
This location was included in IAVCEI (1973) as a group of seven volcanoes last active in the "mid-upper Pleistocene." Lease and Abdel-Rahman (2008) identify the area as including Ein Abou-Jema (~30 km2 of mafic?ultramafic lava flows) and Himmat el-Jazira (400 km2 with lava flows and minor pyroclastic flows). They note that it is part of the Plio-Quaternary Euphrates Volcanic Field.

Jabal al Qiranah
Jordan
Jabal al Qiranah lies in central Jordan, about halfway in between the city of Ma'an in southern Jordan and the Dead Sea. Basaltic lava from Jabal al Qiranah overlies middle Pleistocene fluviatile gravels, which yielded many Acheulian implements (Bender, 1975).

Karasu Rift
The Quaternary basalts of the Karasu Rift form a belt covering an area 94 km long and 12-25 km wide (as revealed by boreholes) between Fevzipasa and north of Revhanli in the northern section of the rift (Rojay et al., 2001). Located near the far NE corner of the Mediterranean Sea, some of the lava field extends into Syria. One especially dark fresh-looking area of lava flows just east of the city of Hassa covers an area of about 140 km2 over a N-S distance of 20 km, and includes the low K���kak Tepesi crater. Those flows almost surrounded the older lavas of B�y�kak Tepe. K-Ar dating by Rojay et al. (2001) on new samples showed five periods of volcanism between 1.6 and 0.05 Ma.

Harrat Hutaymah
Harrat Hutaymah is a Quaternary alkali basalt volcanic field that is rich in tuff cones and ultramafic xenoliths (Thornber, 1990). It lies NE of the trend of the main lava fields of Saudi Arabia and is one of the smaller fields. One K-Ar date of 1.80 +/- 0.05 was obtained from a lava flow cut by a tuff ring.

Harrat ar Rahah-'Uwayrid
Harrat ar Rahah-'Uwayrid is the northernmost of a series of Quaternary volcanic fields paralleling the Red Sea coast of Saudi Arabia, south of the city of Tabuk. The olivine basaltic field extends NW-SE about 240 km overall, and contains numerous scoria cones, tuff cones, and associated lava fields. The northern segments comprise Harrat ar Rahah, with an erosional divide where the field narrows to about 1 km at Matar. Lava flows are more numerous in the southern segment, where they rise above the Cambrian sandstone plain; on the S and SW sides the sandstones and basaltic lava fields are dissected, and lava flows traveled mainly NE. The Harrat 'Uwayrid area is south of another erosional divide, within which the Hala-'l-Bedr cone is located. Some analysis places an eruption around 640 CE at either or both of the Hala-'l-Bedr or Hala-'l-'Ischia cones within the field, including Bedouin legends of fire and stones erupting and killing herdsmen with their cattle and sheep. However, others place this event in the Harrat Rahat immediately south of Medina where young lava flows are present.

Jibal al Haylah
This isolated cone about 20 km E of late lava flows from the Harrat al Birk field was dated as Pleistocene (0.18-0.25 Ma) by Coleman et al. (1983). However, Brown et al. (1989) noted that those samples were from a basal flow, so the youthful-looking cone could be much more recent.

Jabal Baqarah
This isolated cone surrounded by lava flows about 18 km NE of the southern part of the Harrat al Birk field was considered to be similar in age to Jibal Haylah (54 km N), dated as Pleistocene by Coleman et al. (1983).

Borawli
This dome complex, one of several in Ethiopia named Borawli, consists of a group of rhyolitic lava domes on the floor of the southern Kali plain, NE of the town of Aisa Aita. A 1631 eruption (sometimes listed as 1627) attributed possibly to Amado dome (United Nations, 1973) was considered more likely to be from Dama Ali (Gouin, 1979). The southernmost lava flow dates from the Pleistocene, as K-Ar dated by Lahitte et al. (2003) around 0.49 Ma.

Oyma
Oyma is a complex stratovolcano with rhyolitic lava flows, domes, and pyroclastics, followed by formation of a 5-km-wide, 450-m-deep caldera. Oyma was age dated at around 0.5 million years ago (CNR-CNRS, 1973).

Didolli
Included in Dubbi line of volcanoes which decrease in age northward (Mohr et al. 1976). Didolli is next volcano south of Omya which is dated at 0.5 million years ago (CNR-CNRS 1973).

Katahelu
Included in Dubbi line of volcanoes which decrease in age northward (Mohr et al. 1976). Katahelu is approx. 40 km S of Oyma which is dated at 0.5 million years ago (CNR-CNRS, 1973).

Ali Mela
Ali Mela Ale is included in Dubbi line of volcanoes which decrease in age northward (Mohr et al. 1976). Alimelali is next volcano SE of Oyma, which is dated at 0.5 million years ago (CNR-CNRS 1973).

Dawa Ale-Quarry
The Dada Ale silicic stratovolcano and caldera and the Quarry lava dome lie on opposite sides of the Dadar graben. These rhyolitic volcanoes, with Potassium-Argon dates of 0.62 and 0.65 million years, respectively, were originally formed as a single volcanic structure that was dismantled by formation of the axial depression of the Dadar graben (Lahitte et al., 2003b).

Badi
A potassium-argon date of 0.29 million years was obtained from the silicic Badi volcano, located east of Dabbayra volcano (Lahitte et al., 2003b).

Gad Elu
Gad Elu is a 20-km-wide silicic stratovolcano with minor lava domes around the main cone and late-stage obsidian lava flows. Potassium-argon dates range from 1.46 to 0.38 million years (Lahitte et al., 2003a, 2003b).

Ela
The Ela silicic central volcano along the southern end of the Dadar graben was constructed by rhyolitic and trachytic lavas capped by minor basaltic volcanism. The silicic stage was dated at about 0.52 million years (Lahitte et al., 2003a, 2003b).

Asgura
The silicic Asgura volcanic center lies SW of the central Manda Hararo complex and was Potassium-Argon dated at about 1.27 million years (Lahitte et al., 2003b).

Finini
The Finini silicic volcanic center lies NE of Kurub volcano and was potassium-argon dated at about 1.32 million years (Lahitte et al., 2003b).

Dalaha'ale
The silicic Dalaha'ale volcano is cut by a large caldera open to the NE, which has been referred to as Dalaha'ale and Asa Ale. Silicic activity here and at the adjacent Data Gabalti volcano was dated at about 1.52 to 0.95 million years and followed by fissural basaltic lavas from about 1.0 to 0.33 million years (Lahitte et al., 2003a).

Data Gabalti
The silicic Data Gabalti is located SW of the Manda-Inikar volcanic complex and ESE of Dalaha'ale volcano. Silicic activity at these two volcanoes was dated at about 1.52 to 0.95 million years and followed by fissural basaltic lavas from about 1.0 to 0.33 million years (Lahitte et al., 2003a).

Egersuwa
The Egersuwa silicic lava dome complex north of the NW end of the Manda Inakir has K-Ar dates ranging from 0.391 to 0.221 million years (Lahitte et al., 2003b).

Undurer
Lahitte et al. (2003b) noted that "Despite poor constraints on timing of emplacement, Undurer and Babb-Olou volcanoes seem to have been more or less contemporaneous, erupting about 2 Myr ago...."

Babba'Olou
Djibouti
Lahitte et al. (2003b) noted that "Despite poor constraints on timing of emplacement, Undurer and Babba'Olou volcanoes seem to have been more or less contemporaneous, erupting about 2 Myr ago...."

Mabda
The Mabda complex, also called Dubbi Alto, is composed of rhyolitic lava domes (Wiart and Oppenheimer, 2005). The north flank has been partially covered by lava flows from Dubbi volcano, but it's relationship to that edifice is unknown. Although the age is also unknown, it's location between two Holocene volcanoes makes a Pleistocene age likely. In addition, there are fresher-looking cones and lava flows 9-12 km down the SSE flank (also possibly related to Dubbi) and a 32 km2 lava field 20 km SE (also possibly associated with Nabro).

Hobitcha Caldera
The Hobitcha Caldera, N of Lake Abaya, is a large Pleistocene caldera. The southern side of the caldera consists of a large ridge of trachytic lavas.

Chericha
Chericha is a rhyolitic stratovolcano located on the Wonji fault belt NE of Lake Abaya. Rift zone volcanoes are thought to be Pleistocene-to-Holocene in age; Chericha has been mapped as Pleistocene. Similar rhyolitic and trachytic lava flows are mapped 10 km SW at Donga volcano and up to 20 km SE. The Holocene fissure basalts to the W (Mohr and Wood 1976, WoldeGabriel 1987, pers. comm.), may be related to the Northern Lake Abaya volcanic field.

Tosa Sucha
A group of eroded cinder cones and craters are present in the Tosa Sucha area on the NW shore of Lake Chamo, or as islands in the lake, in the southern Ethiopian Rift. Ebinger et al. (1993) noted that lava flows were erupted along NNE-trending fissures between Lake Chamo and Lake Abaya to the north. The ridge of volcanic rocks between the lakes is called the "Bridge of God," or Tosa Sucha; in the local Dorze language Tosa means "God" and Sucha means "stone" (Williams, 2016). The ridge includes the Pleistocene Bobem trachybasalts (dated at 0.68 +/- 0.03 Ma) and the Nech Sar olivine basalts (dated at 0.77-1.34 Ma) (Ebinger et al., 1993).

Zikwala
Zikwala (Zuquala) is an isolated volcano west of the main Ethiopian Rift constructed of thick alkali-trachytic lava flows (Di Paola, 1972). Potassium-Argon dates of 1.29 and 0.85 million years ago have been obtained (WoldeGabriel 1987, pers. comm.).

Ch'Ilalo
One of the largest volcanoes of the central Ethiopian Rift, Ch'Ilalo lies east of the main rift and contains a 6-km-wide summit caldera. Akali-trachytic lava flows occupy the caldera floor and a small basaltic flow is found on the NE rim (Di Paola 1972). A Potassium-Argon date of 1.76 million years ago has been obtained (WoldeGabriel 1987, pers. comm.).

Gademota Caldera
Potassium-Argon date 1.27 million years ago (WoldeGabriel 1987, pers. comm.).

Duguna
Pleistocene in age (WoldeGabriel 1987, pers. comm.).

Boku
Boku is a Pleistocene volcano that had a caldera-forming eruption around 830,000 years ago (Fontijn et al., 2018).

Western Ethiopia Plateau Volcanic Province

Tepi
Western Ethiopia Plateau Volcanic Province
The densely forested Tepi basaltic shield volcano is at the northern end of the Turkana rift, ~300 km W of the center of the main Ethiopian rift, and was constructed along a zone of ENE-trending faults that extend in line with the Gulf of Aden. It is capped by prominent cinder cones and small craters, and there are associated hot springs. Three satellitic centers are located along an E-W line north of the main shield. Lava flows have traveled down pre-existing valleys. Davidson (1983) considered it to be of probable Holocene age, but no eruption dates are known.

Dilo-Dukana Volcanic Field
Ethiopia-Kenya
The Dilo-Dukana Volcanic Field in northern Kenya about 150 km E of Lake Turkana extends NE across the border into southern Ethiopia and covers about 1,000 km2. Franceschini et al. (2020) provides an excellent review of this field, from which most of this summary is taken. Using satellite images they recognized 52 volcanic vents (mainly cinder cones), with 26 still well-preserved (mainly maars and some cones). The most prominent feature in the southern part of the field is the 1.8-km-wide Gof Dukana maar. Both cones and maars are often found in clusters or alignments, suggesting several fissures; the largest flows covered almost 17 km2. Age dates (40Ar/39Ar) of four samples analyzed by Corti et al. (2019) ranged between 0.3 and 0.13 Ma.

Chew Bahir
In the Chew Bahir basin along the Ethiopia-Kenya border cones of basaltic ejecta surrounded by very recent sediments. The volcanics are mapped as Quaternary (Davidson, 1983).

Kilimanjaro
Massive Kilimanjaro consists of three overlapping edifices along a NW-SE trend, mostly constructed during the Pleistocene, with an ice-capped summit that reaches 5,200 m above the surrounding plains. Kibo is the central stratovolcano, which has a broad elongated profile and a 2 x 3 km summit caldera. Activity at the older Shira cone, which forms the broad WNW shoulder of the complex, began during the Pliocene. The extensively dissected Pleistocene Mawenzi forms a prominent, sharp-topped peak on the ESE flank, dominated by a densely packed radial dike swarm. More than 250 cones occupy a rift zone to the NW and SE. Fumarolic activity is present within a group of nested summit craters. Widespread statements that the "most recent activity was about 200 years ago," sometimes referencing the central "ash pit" formation, are of unknown origin with no supporting evidence in geological or anthropological literature. Nonnotte et al. (2008) K-Ar dated caldera-rim group lavas in the 170-274 ka range, and placed the most recent volcanism (formation of both the present summit crater, Inner Crater group lavas, and flank cones) around 150-200 ka. Martin-Jones et al. (2020) attributed two mafic tephra deposits in Lake Chala to Kilimanjaro that were dated to about 248 and 134 ka.

Porr
Mohr and Wood (1976) map a Pliocene-Quaternary volcano in this location. Ochieng' et al. (1988) and Wilkinson (1988) map widely spaced Tertiary basaltic flows not associated with prominent volcanic centers. Smith (1991 pers. comm.) notes that the youthful features of the small volcanic cone Porr may indicate a Quaternary age.

Kulal
The elongated N-S trending Kulal shield volcano east of the south end of Lake Turkana is mostly Pliocene in age, with cinder cones of probable Pleistocene age (Ochieng' et al., 1988).

Asie
The Hawaiian-type Asie shield volcano is the youngest and NE-most of a group of en echelon shields east of Lake Turkana. Asie was constructed during the Pliocene and Pleistocene; late-stage activity formed a series of cones and maars, with the last eruptions occurring about 0.42 million years ago on the NW flank. (Charsley 1987a).

Huri Hills
The 90 x 110 km Pliocene to Pleistocene Huri Hills shield volcano is capped by cinder cones along a NNE-SSW trend. Some relatively uneroded cones in this arid region are over 1 million years old (Charsley, 1987).

Bogoria
The late-Pleistocene Hannington formation consists of a broad shield volcano west of Lake Bogoria that has been cut by spectacular grid faults along the west margin of the Gregory Rift. Geysers on the west margin of Lake Bogoria may be of tectonic origin.

Kilombe Caldera
Pliocene-Pleistocene (Williams 1970).

Ol Doinyo Nyokie
Volcano type: Tuff cone
The late-Pleistocene Ol Doinyo Nyokie ignimbrite complex formed as a result of ash-flow fissure eruptions and ash flows erupted from a central vent, forming a dome-shaped tuff cone (Baker, 1975).

Gelai
Pleistocene shield volcano (Keller 1989, pers. comm.).

Ketumbeine
Activity at Ketumbeine volcano continued into the Pleistocene (Dawson, 1992).

Kerimasi
The carbonatitic volcano Kerimasi sits astride a major fault scarp of the eastern Gregory Rift and erupted during the last major episode of faulting 0.6-0.4 million years ago (Hay 1983).

Embagai
Included in a list of Quaternary volcanoes (Latter, 1975b).

Loolmalasin
A lava flow, possibly from Loolmalasin, was K-Ar dated at about 1.19 million years (Dawson, 1992).

Olmoti
Included in a list of Quaternary volcanoes (Latter, 1975b); no additional information. Ages derived from both K-Ar and 40Ar/39Ar on lavas and ignimbrites presumably from Olmoti yielded ages of 1.10-1.85 Ma (McHenry et al., 2008).

Sadiman
Dawson (1992) considered the age of Sadiman volcano to be uncertain, with one source considering it to be Pleistocene and another obtaining a K-Ar age of 4.5 Ma. Clasts of Sadiman lavas are found in sediments dated to 1.7-2.0 million years.

Ngorongoro

Sultan Hamud-Simba
The early Pleistocene Sultan Hamud-Simba volcanic cones and lava flows represent the beginning of volcanism that continued to the SE in the Chyulu Hills (Saggerson, 1963).

Burko
A K-Ar date of 0.97 +/- 0.03 million years was obtained from Burko volcano (Dawson, 1992).

Kwaraha

Hanang
Described as one of Pleistocene-Recent centers in the area, but not specifically described as Recent (Williams 1971).

Lenderut
Mapped as Pleistocene (Guth and Wood, 2014).

Shombole
Mapped as Pleistocene (Guth and Wood, 2014).

Katwe-Kikorongo Volcanic Field
Uganda
The Katwe-Kikorongo Volcanic Field extends from the NE shore of Lake Edward to the W shore of Lake George, south of the Ruwenzori Range. The field covers an area of about 180 km2 and contains a group of about 80 foiditic tuff cones and maars, some of which are filled by lakes. Lake Katwe is a shallow 3-km-long body of water that occupies two of three intersecting craters immediately NE of Lake Edward. Local stories suggest observations of volcanism in and around this area. However, Pitcavage et al. (2021) dated one sample from this field at about 87 ka (40Ar/39Ar).

Bunyaruguru Volcanic Field
The Bunyaruguru Volcanic Field (also known as Kichwambe) straddles the equator along the E side of the Western Rift Valley, south of Lake George. It contains more than 130 maars, 27 of which contain lakes. Friable calcareous volcanic tuffs are interbedded with Quaternary sediments. Only a few foiditic lava flows have been found. Although Reece (1955) suggested that there had been recent volcanic activity, no eruptions have been recorded, and Pitcavage et al. (2021) reported an 40Ar/39Ar date of about 188 ka on one sample.

Katunga
Katunga, an isolated tuff cone with associated lava flows located E of Lake Edward, is the southernmost feature of a N-S-trending chain of high-potassium foiditic volcanic fields in the Western Rift Valley of Uganda. It is the type locality of the rock type katungite, an olivine-melilitite. The undissected tuff cone was erupted through metamorphic basement rocks. Its rim and flanks are covered with ejected schists, and it contains a freshwater lake in its summit crater. Two lava flows traveled to the NE from vents on the N and NE flanks. The age of the cone is uncertain, but it is contemporaneous with tuff cones in the Bunyaruguru area to the north.

Visoke
DR Congo-Rwanda
Visoke is the NE edifice of a cluster of three large stratovolcanoes at the southern end of the Virunga Range on the border of the Democratic Republic of Congo and Rwanda. The trachyandesitic stratovolcano contains a 450-m-wide lake in its summit crater.

Muhavura
Uganda-Rwanda
Muhavura (or Muhabura) volcano, at the NE end of the Virunga Range, is a stratovolcano with a 40-m-wide lake in its summit crater. The smaller Mgahinga volcano is about 3.5 km E across a broad saddle. The two volcanoes have produced basanitic-to-trachyandesitic lavas.

Bufumbira Volcanic Field
The Bufumbira Volcanic Field in SW Uganda consists of a group of about 40 cinder cones over an area of about 320 km2 extending 20 km N of the large stratovolcanoes of the NE portion of the Virunga Mountains. The rocks are noted for their unusual ultrapotassic chemistry, including silica undersaturated and vesicular basalts (Barifaijo et al., 2010). The cinder cones occur in clusters, were erupted along lineaments, and are typically breached on one side by lava flows. The youngest 40Ar/39Ar dated samples reported by Pitcavage et al. (2021) were about 21 ka.

Tshibinda Volcanic Field
The Tshibinda Volcanic Field is described by Pouclet et al. (2016) as consisting of numerous well-preserved scoria cones and lava flows at the border of the Tshibinda step. The elongate SSW-NNE field is 33 km long, extending from Tshibinda to Leymera. Mapping revealed sixty cones, 50-150 m high, with most of them being a source of lava flows, primarily down the fault scarp and spreading towards the eastern lowlands. Previous work dated the activity from 1.9 to 1.6 Ma (Bellon and Pouclet, 1980).

Mikeno
The eroded Pliocene to Pleistocene Mikeno volcano is located west of the crest of the Virunga Mountains. Potassium-Argon dates of 0.5 million years ago have been obtained for its latest stage of activity (Krafft 1990).

Sabinyo
Uganda-Rwanda
Extensive erosion has carved five peaks into the summit of the Pliocene to Pleistocene Sabinyo volcano. Potassium-Argon dates of 0.14 and 0.09 million years ago have been obtained from lava flows.

Gahinga
Uganda-Rwanda
The Gahinga (or Mgahinga) stratovolcano is in the NE part of the Virunga Range, ~3.5 km E of Muhavura volcano across a broad saddle. The two volcanoes have produced basanitic-to-trachyandesitic lavas.

Central Virunga Volcanic Field
DR Congo-Rwanda
Unofficially designated the Central Virunga Volcanic Field for this catalog, this volcanic ridge with many small cones extends ~12 km NE-SW along the Dr Congo-Rwanda border area between the Visoke and Sabinyo edifices. As noted by Pitcavage et al. (2021), this is the third of three cinder cone fields in the Virunga area that "have produced primitive alkaline mafic lavas: (1) the Bufumbira volcanic field..., (2) Karisimbi primitive K-basanites (PKBs; Rogers et al., 1992) and (3) cinder cones located between Sabinyo and Visoke (Rogers et al., 1998)."

Southern Virunga Volcanic Field
Rwanda
Unofficially designated as the Southern Virunga Volcanic Field for this catalog, this describes numerous cones within ~80 km2 on the lava plains of Rwanda SW of Karisimba volcano. As noted by Pitcavage et al. (2021), this is the second of three cinder cone fields in the Virunga area that "have produced primitive alkaline mafic lavas: (1) the Bufumbira volcanic field..., (2) Karisimbi primitive K-basanites (PKBs; Rogers et al., 1992) and (3) cinder cones located between Sabinyo and Visoke (Rogers et al., 1998)."

Usangu Scarp Basalt
A small basaltic tephra cone on the edge of the Usangu escarpment, overlooking the Usangu basin north of the Poroto Mountains, was considered by Ebinger et al. (1989) to be of probable Holocene age, based on lack of vegetative cover. A lava flow traveled westward away from the rift valley along the back-tilted flank of the rift. The exact location of this feature is uncertain and is not obvious at the mapped location using satellite imagery. More recent papers do not reference this location or provide age dates for the sample taken by Ebinger et al. (1989). Fontijn et al. (2012) considered the volcanic centers in the adjacent SW Usangu Basin area to be unrelated to the late Cenozoic stage of volcanism in the Rungwe Volcanic Province.

SW Usangu Basin
A group of late-Pleistocene to Holocene phonolitic lava domes is located at the SW end of the Usangu Basin, NE of the Poroto Mountains. Vents of the SW Usangu Basin volcanic field are located along NNE-trending normal faults (Ebinger et al., 1989). However, Fontijn et al. (2012) considered the volcanic centers in this area, forming a phonolite dome field, to not be part of the late Cenozoic stage of volcanism in the Rungwe Volcanic Province; the most recent dated sample was 0.57 Ma.

Izumbwe-Mpoli
Two melanephelinite cones about 1.5 km apart, Izumbwe and Mpoli, are located ~18 km WNW of Ngozi caldera and just NW of Izumbwe village (Harkin, 1960). Basal lava flow trachyte units in the Songwe Basin were dated at 0.55 Ma (Ebinger et al., 1989). The youngest units in this area do not have age dates, but are covered with tephra from recent Rungwe and Ngozi eruptions.

Katete
This largely eroded Pleistocene volcano NE of Rungwe has never been studied systematically (Fontijn et al., 2012). A phonolite/trachyte sample from Katete was K-Ar dated by Ebinger et al. (1989) at 2.35 +/- 0.04 Ma.

Tukuyu
The Tukuyu shield volcano is thought to be made up of basaltic lavas, though Fontijn et al. (2012) also note that it has never been systematically studied. The town of Tukuyu is built upon this volcano. Dating by Ebinger et al. (1989) using K-Ar and by Ivanov et al. (1999) identified three lava ages between 2.12 +/- 0.04 and 1.34 +/- 0.02 Ma.

Tanzania Craton Volcanic Province

Igwisi Hills
Tanzania Craton Volcanic Province
Three kimberlitic volcanoes of late Pleistocene or Holocene age are located in the Igwisi Hills, WNW of the city of Tabora in NW Tanzania. They were erupted along a NE-SW-trending rift through a Precambrian granitic gneiss basement and are located on the W side of the Tanzanian Craton far from volcanoes near the Gregory Rift. Two pyroclastic cones with well-preserved craters are present, with a central cone and crater adjacent to the NE crater that contains a solidified lava lake. The NE crater is the largest feature, at 370 m in diameter, and has been breached on the ENE side; this was the source of a lava flow about 1 km long and wide. The SW crater is also breached on the ENE side, with a smaller lava flow on the E flank. Cosmogenic 3He exposure dating of olivine in the lavas has a large uncertainty range, which Brown et al. (2012) variously describes as late Pleistocene/Holocene or "near Holocene" in their text.

Ambre
Madagascar
The Massif d'Ambre volcanic field near the northern tip of Madagascar consists of Miocene volcanics capped by more recent cones. The earliest volcanism produced a large basaltic massif and minor pyroclastic flows. The rocks span a wide geochemical spectrum, including basaltic, andesitic, rhyolitic, trachytic, phonolitic, and foiditic compositions. Some features were mapped as Recent by Besairie (1973) based on morphology. Other relatively younger cones are located at the S end of the massif, where Rusquet et al. (2024) indicated an age range of 2-0.8 Ma, and a tabulation of radiometric dates by Cucciniello et al. (2016) listed the youngest as 830 +/- 20 ka (citing Emerick and Duncan, 1982 and 1983).

Nosy Be
Madagascar
Nosy Be, an island off the NW coast of Madagascar, contains basaltic lava flows that originated from cinder cones. A predominance of low-silica foiditic rocks overlie Mesozoic limestones and other sedimentary rocks. Initial eruptions of lava flows from the W side of the massif was followed by the construction of numerous cinder cones on the W plain. The volcanics were mapped as Recent by Besairie (1973). However, the youngest radiometric ages compiled by Cucciniello et al. (2016) were from Tucker et al. (2008), who reported an age of 900 � 26 ka for a basanite (40Ar-39Ar), and Bardintzeff et al. (2010), who reported a K-Ar age for a basanite of 550 � 40 ka.

Moheli
Union of the Comoros
The Pliocene-to-Pleistocene Moheli Island, also known as Mwali, was constructed by eruptions along a NW-SE rift zone. A renewal of activity during the late Pleistocene produced lava flows and cinder cones (Strong, 1972; Krafft, 1983). Ages reported by Rusquet et al. (2024) were in the 1.04-1.27 Ma range.

Anjouan
The triangular-shaped Anjouan Island is the dissected remnant of a large shield volcano. Formation of the N'Tingui shield volcano was followed by Pleistocene fissure eruptions in three directions. A long interval of erosion was followed by the eruption of lava flows that filled deep valleys and flooded coastal areas. Ages reported by Rusquet et al. (2024) were in the 0.94-0.95 Ma range.

Jumelles-Mwezi Volcanic Field
The submarine Jumelles Ridge and Mwezi province are lineaments of monogenic seamounts and domes approximately 60 km NE of Mayotte in the Comoros Islands. Rusquet at al. (2024) concluded that the Jumelles and Mwezi features represent a continuous zone of volcanic seamounts aligned along a N130-N135�E trend, with intermittent mafic activity from before 1.4 Ma until about 0.2 Ma. They also noted decreasing ages from the Jumelles ridges to Mwezi, less-evolved compositions of Mwezi magmas, decreasing height of edifices from the SE to the NW, and a change from polygenic to monogenic features, all suggesting that the Mwezi field is a propagation of the Jumelles volcano-tectonic structures toward the NW.

Central Madagascar Volcanic Province

Itasy Volcanic Field
Madagascar
Central Madagascar Volcanic Province
The Itasy Volcanic Field in central Madagascar contains a diverse assemblage of volcanic landforms, including scoria cones, lava domes, and maars. Activity began in the Pliocene, when eruptions produced trachytic lava domes and basanitic lava flows. Later activity produced trachytic lava flows and Vulcanian eruptions. A trachytic maar is located near Saovinandriana, and several other small crater lakes are present. Minor seismicity and thermal activity is present in the form of hot springs. Radiocarbon dates reported in 1970, 1973, and 1993 lack stratigraphic, location, and eruption source details. Rasoazanamparany (2021) conducted new sampling form lava flows and scoria cones across the volcanic field, resulting in 40Ar/39Ar ages from about 31 to 104 ka. While Holocene maars created by phreatic or phreatomagmatic explosions are possible, there is no clear evidence for such activity.

Vakinankaratra
Central Madagascar Volcanic Province
The Quaternary Vakinankaratra volcanic field is at the SW end of the larger Neogene Ankaratra volcanic field. Melluso et al. (2016) noted that there were extensive lava flow fields, domes, Strombolian scoria cones, tuff rings and maars. Rufer et al. (2014) used K-feldspar infrared-stimulated luminescence (IRSL) dating, finding ages of 32 � 3 and 19 � 2 from phreatomagmatic deposits near Lake Tritrivakely; they reported other dates in the 40-126 ka range.

Piton des Neiges
Reunion Hotspot Volcano Group
The massive Piton des Neiges shield volcano occupies the NW side of Reunion Island. The volcano emerged from the sea about 2.1 million years ago, beginning construction of a basaltic subaerial shield. Three large erosional cirques surround the central summit peak, and large submarine debris-avalanche deposits are found offshore. Deniel et al. (1992) reported a Th-U age of 12,000 +/- 3,000 BP for a trachytic pyroclastic density current deposit on the W flank, but noted that it trachytic intrusions in the cirque walls had not been dated, and 14C data on charcoal in air-fall deposits gave dates in the 28-35,000 BP range.

Mauritius
The island of Mauritius, located along the Reunion hot spot track NE of Reunion Island, is a massive shield volcano that was active from 7.8 million years to about 30,000 years ago.

Rodriguez Fracture Zone Volcano Group

Rodriguez Island
Mauritius
Rodriguez Fracture Zone Volcano Group
Rodriguez Island lies along the Rodriguez Fracture Zone about 650 km east of Mauritius Island. The 6.5 x 18 km island consists of a basaltic shield volcano of probably Plio-Pleistocene age. K-Ar ages of 1.54 and 1.32 million years were obtained from lava flows (Upton et al., 1967).

Eastern Antarctica Volcanic Province

Gaussberg
Eastern Antarctica Volcanic Province
Gaussgberg is an ice-free conical mountain composed primarily of subglacial eruptive products. No vent has been located and its present morphology is thought to result from glacial and subaerial erosion of a once-larger mountain that was formed about 55,000 years ago (LeMasurier and Thomson 1990).