Complex volcano

A complex volcano, also called a compound volcano, is a volcano with more than one characteristic. They form because changes of their eruptive characteristics or the site 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 frequent eruptions, to make multiple summits and vents. Stratovolcanoes could also shape a large caldera that gets filled in by multiple little cinder cones, lava domes and craters may also develop on the caldera's rim.

Although a moderately unusual type of volcano, they are incredibly extensive 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 significant 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 shaped on a collection 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.