A complex volcano, also called a compound volcano or a volcanic complex, is a mixed
landform consisting of related
volcanic centers and their associated
lava flows
Lava is molten or partially molten rock ( magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land o ...
and
pyroclastic rock
Pyroclastic rocks (derived from the el, πῦρ, links=no, meaning fire; and , meaning broken) are clastic rocks composed of rock fragments produced and ejected by explosive volcanic eruptions. The individual rock fragments are known as pyroc ...
. They may form due to changes in
eruptive habit or in the location of the principal vent area on a particular volcano.
Stratovolcano
A stratovolcano, also known as a composite volcano, is a conical volcano built up by many layers (strata) of hardened lava and tephra. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile with a summit crater and p ...
es can also form a large
caldera
A caldera ( ) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcano eruption. When large volumes of magma are erupted over a short time, structural support for the rock above the magma chamber ...
that gets filled in by a lava dome, or else multiple small
cinder cone
A cinder cone (or scoria cone) is a steep conical hill
A conical hill (also cone or conical mountain) is a landform with a distinctly conical shape. It is usually isolated or rises above other surrounding foothills, and is often of volcanic ...
s,
lava dome
In volcanology, a lava dome is a circular mound-shaped protrusion resulting from the slow extrusion of viscous lava from a volcano. Dome-building eruptions are common, particularly in convergent plate boundary settings. Around 6% of eruption ...
s and
craters may develop on the caldera's rim.
Although a comparatively unusual type of volcano, they are widespread in the world and in geologic history.
Metamorphosed ash flow
tuff
Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is lithified into a solid rock. Rock that contains greater than 75% ash is considered tuff, while rock ...
s are widespread in the
Precambrian
The Precambrian (or Pre-Cambrian, sometimes abbreviated pꞒ, or Cryptozoic) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of th ...
rocks of northern
New Mexico
)
, population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano)
, seat = Santa Fe, New Mexico, Santa Fe
, LargestCity = Albuquerque, New Mexico, Albuquerque
, LargestMetro = Albuquerque metropolitan area, Tiguex
, Offi ...
, which indicates that caldera complexes have been important for much of Earth's history.
Yellowstone National Park
Yellowstone National Park is an American national park located in the western United States, largely in the northwest corner of Wyoming
Wyoming () is a state in the Mountain West subregion of the Western United States. It is border ...
is on three partly covered caldera complexes. The
Long Valley Caldera
Long Valley Caldera is a depression in eastern California that is adjacent to Mammoth Mountain. The valley is one of the Earth's largest calderas, measuring about long (east-west), wide (north-south), and up to deep.
Long Valley was formed 7 ...
in eastern
California
California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the ...
is also a complex volcano; the
San Juan Mountains
The San Juan Mountains is a high and rugged mountain range in the Rocky Mountains in southwestern Colorado and northwestern New Mexico. The area is highly mineralized (the Colorado Mineral Belt) and figured in the gold and silver mining industry ...
in southwestern
Colorado
Colorado (, other variants) is a state in the Mountain states, Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the wes ...
are formed on a group of
Neogene
The Neogene ( ), informally Upper Tertiary or Late Tertiary, is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago (Mya) to the beginning of the present Quaternary Period Mya. ...
-age caldera complexes, and most of the
Mesozoic
The Mesozoic Era ( ), also called the Age of Reptiles, the Age of Conifers, and colloquially as the Age of the Dinosaurs is the second-to-last era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Creta ...
and
Cenozoic
The Cenozoic ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterised by the dominance of mammals, birds and flowering plants, a cooling and drying climate, and the current configu ...
rocks of
Nevada
Nevada ( ; ) is a state in the Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. Nevada is the 7th-most extensive, ...
,
Idaho
Idaho ( ) is a state in the Pacific Northwest region of the Western United States. To the north, it shares a small portion of the Canada–United States border with the province of British Columbia. It borders the states of Montana and W ...
, and eastern California are also caldera complexes and their erupted ash flow tuffs. The
Bennett Lake Caldera
The Bennett Lake Volcanic Complex (BLVC) is a huge 50-million-year-old extinct caldera complex that spans across the British Columbia-Yukon border in Canada. It is located near the western end of the West Arm of Bennett Lake. The caldera complex ...
in
British Columbia
British Columbia (commonly abbreviated as BC) is the westernmost Provinces and territories of Canada, province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include ...
and the
Yukon Territory
Yukon (; ; formerly called Yukon Territory and also referred to as the Yukon) is the smallest and westernmost of Canada's three territories. It also is the second-least populated province or territory in Canada, with a population of 43,964 as ...
is another example of a Cenozoic (
Eocene
The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', " ...
) caldera complex.
Examples
*
Akita-Yake-Yama (Honshū, Japan)
*
Asacha (
Kamchatka Peninsula
The Kamchatka Peninsula (russian: полуостров Камчатка, Poluostrov Kamchatka, ) is a peninsula in the Russian Far East, with an area of about . The Pacific Ocean and the Sea of Okhotsk make up the peninsula's eastern and we ...
, Russia)
*
Asama (Honshū, Japan)
*
Kusatsu-Shirane
is a active stratovolcano in Kusatsu, Gunma, Japan. It is called Kusatsu Shirane to differentiate it from the Mount Nikkō-Shirane on the other side of Gunma Prefecture. The summit of Kusatsu-Shirane volcano, located immediately north of Asam ...
(Kusatsu, Gunma, Japan)
*
Banahaw (Luzon, Philippines)
*
Bennett Lake Caldera
The Bennett Lake Volcanic Complex (BLVC) is a huge 50-million-year-old extinct caldera complex that spans across the British Columbia-Yukon border in Canada. It is located near the western end of the West Arm of Bennett Lake. The caldera complex ...
(British Columbia/Yukon, Canada)
*
Cumbre Vieja (Canary Islands, Spain)
*
Mount Edziza volcanic complex (British Columbia, Canada)
*
Galeras (Colombia, South America)
*
Grozny Group
Grozny Group (also Grozny Volcano) is a complex volcano located in the central part of Iturup Island, Kuril Islands, controlled by Russia, and claimed by Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island countr ...
(Kuril Islands, Russia)
*
Hakone
is a town in Kanagawa Prefecture, Japan. , the town had a population of 11,293 and a population density of 122 persons per km². The total area of the town is . The town is a popular tourist destination due to its many hot springs and views of ...
(Japan)
*
Homa Mountain
Homa may refer to:
Places Ethiopia
* Homa (woreda), a district in Oromia Region, Ethiopia
Kenya
* Homa Bay, a town and a bay on the shore of Lake Victoria in Kenya
* Homa Mountain, a volcano near Homa Bay, Kenya
Iran
* Chal Homa, Ma ...
(Kenya)
*
Irazú Volcano (Costa Rica)
*
Ischia
Ischia ( , , ) is a volcanic island in the Tyrrhenian Sea. It lies at the northern end of the Gulf of Naples, about from Naples. It is the largest of the Phlegrean Islands. Roughly trapezoidal in shape, it measures approximately east to wes ...
(Italy)
*
Kelimutu (Flores, Indonesia)
*
Las Pilas
Las Pilas (or El Hoyo) is a complex volcano located in the western part of Nicaragua. Part of a 30-km-long volcanic massif, Las Pilas has a series of well-preserved flank vents surrounding a central cone. Las Pilas last erupted in the 1950s and be ...
(Nicaragua)
*
Long Valley Caldera
Long Valley Caldera is a depression in eastern California that is adjacent to Mammoth Mountain. The valley is one of the Earth's largest calderas, measuring about long (east-west), wide (north-south), and up to deep.
Long Valley was formed 7 ...
(California, United States)
*
McDonald Islands (Indian Ocean, Australia)
*
Mount Meager massif
The Mount Meager massif is a group of volcanic peaks in the of the Coast Mountains in southwestern British Columbia, Canada. Part of the Cascade Volcanic Arc of western North America, it is located north of Vancouver at the northern end of the ...
(British Columbia, Canada)
*
Morne Trois Pitons
Morne is an Old-French word for a small mountain. It may refer to:
* Morne a Chandelle, a village in the Sud-Est department of Haiti
* Morne-à-l'Eau, a commune in Guadeloupe
* Morne Bois-Pin, the fourth highest mountain in Haiti
* Morne la Vigie, ...
(Dominica)
*
Moutohora Island (New Zealand)
*
Mundua (New Britain, Papua New Guinea)
*
Pacaya (Guatemala)
*
Puyehue-Cordón Caulle (Chile)
*
Rincón de la Vieja Volcano (Costa Rica)
*
Silverthrone Caldera (British Columbia, Canada)
*
St. Andrew Strait
St. Andrew Strait is a volcano in Papua New Guinea that has had eruptions in historical times. The volcano is not linked to any tectonic plates, the volcano is also in an area of very few earthquakes, suggesting that St. Andrew Strait is an Intrapl ...
(Admiralty Islands, Papua New Guinea)
*
Taal Volcano, (Batangas, Philippines)
*
Mount Talinis, (Negros Oriental, Philippines)
*
Taupō Volcano, (Taupō, New Zealand)
*
Three Sisters (Oregon)
-->
, topo = USGS South Sister and North Sister
, type = Two stratovolcanoes (South, Middle) and one shield volcano (North)
, age = Quaternary
, volcanic_arc = Cascade Volcanic Arc
, last_eruption = 440 CE
, first_ascent =
, easiest_r ...
(Oregon, United States)
*
Te Tatua-a-Riukiuta (Auckland, New Zealand)
*
Tongariro, (New Zealand)
*
Vesuvius
Mount Vesuvius ( ; it, Vesuvio ; nap, 'O Vesuvio , also or ; la, Vesuvius , also , or ) is a somma- stratovolcano located on the Gulf of Naples in Campania, Italy, about east of Naples and a short distance from the shore. It is one of ...
, (Italy)
*
Valles Caldera (New Mexico, United States)
*
Yellowstone Caldera
The Yellowstone Caldera, sometimes referred to as the Yellowstone Supervolcano, is a volcanic caldera and supervolcano in Yellowstone National Park in the Western United States. The caldera and most of the park are located in the northwest corne ...
(Wyoming, United States)
*
Mount Mazama (Oregon, United States)
See also
*
References
{{DEFAULTSORT:Complex Volcano
Volcanic landforms