Complex volcano
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A complex volcano is a volcano with more then one feature. They form because changes of their eruptive characteristics or the location of multiple vents in an area. Stratovolcanoes may form complex volcanoes, because they may overlap another from explosive eruptions, lava flows, pyroclastic flows and by repeated eruptions, to make multiple summits and vents. Stratovolcanoes could also form a large caldera that gets filled in by multiple small cinder cones, lava domes and craters may also develop on the caldera's rim.
Although a comparatively unusual type of volcano, they are incredibly widespread in the world and in geologic history. Metamorphosed ash flow tuffs are widespread in the Precambrian rocks of northern New Mexico, which describes that caldera complexes have been important for much of the Earth's history. Yellowstone National Park is on three partly covered caldera complexes. The Long Valley Caldera in eastern California is also a complex volcano; the San Juan Mountains in southwestern Colorado are formed on a group of Tertiary-age caldera complexes, and most of the Mesozoic and Tertiary rock of Nevada, Idaho, and eastern California are also caldera complexes and their erupted ash flow tuffs. The Bennett Lake Caldera in British Columbia and the Yukon Territory is another example of a Tertiary-age caldera complex.
[edit] Examples
- Mount Edziza (British Columbia, Canada)
- Mount Meager (British Columbia, Canada)
- Mount Silverthrone (British Columbia, Canada)
- Bennett Lake Caldera (British Columbia/Yukon, Canada)
- North Sister Field (Oregon, United States)
- South Sister (Oregon, United States)
- Valles Caldera (New Mexico, United States)
- Yellowstone Caldera (Wyoming, United States)
- Long Valley Caldera (California, United States)
- Pacaya (Guatemala)
- Pilas, Las (Nicaragua)
- Trois Pitons, Morne (West Indies)
- Akita-Take-Yama (Honshū, Japan)
- Mount Asama (Honshū, Japan)
- Mundua (New Britain, Papua New Guinea)
- St. Andrew Strait (Admiralty Islands, Papua New Guinea)
- Asacha (Kamchatka Peninsula, Russia)
- Grozny Group (Kuril Islands, Russia)
- Mount Banahaw (Luzon, Philippines)
- Ischia (Italy)
- Homa Mountain (Eastern Africa, Kenya)
- Galeras (Colombia, South America)
- McDonald Islands (Indian Ocean, Australia)
- Suretamatal (Vanuatu)
- Three Kings (New Zealand)
- Whale Island (New Zealand)
- Kelimutu (Flores Island, Indonesia)