The Clear Lake Volcanic Field is a volcanic field

Volcanic field

A volcanic field is an area of the Earth's crust that is prone to localized volcanic activity. They usually contain 10 to 100 volcanoes, such as cinder cones and are usually in clusters. Lava flows may also occur...

 beside Clear Lake in California

California

California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

's northern Coast Ranges. The site of late-Pliocene

Pliocene

The Pliocene Epoch is the period in the geologic timescale that extends from 5.332 million to 2.588 million years before present. It is the second and youngest epoch of the Neogene Period in the Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch...

 to early Holocene

Holocene

The Holocene is a geological epoch which began at the end of the Pleistocene and continues to the present. The Holocene is part of the Quaternary period. Its name comes from the Greek words and , meaning "entirely recent"...

 activity, the volcanic field consists of lava dome

Lava dome

|250px|thumb|right|Image of the [[rhyolitic]] lava dome of [[Chaitén Volcano]] during its 2008–2009 eruption.In volcanology, a lava dome is a roughly circular mound-shaped protrusion resulting from the slow extrusion of viscous lava from a volcano...

s, cinder cone

Cinder cone

According to the , Cinder Cone is the proper name of 1 cinder cone in Canada and 7 cinder cones in the United States:In Canada: Cinder Cone In the United States:...

s, and maars with eruptive products varying from basalt

Basalt

Basalt is a common extrusive volcanic rock. It is usually grey to black and fine-grained due to rapid cooling of lava at the surface of a planet. It may be porphyritic containing larger crystals in a fine matrix, or vesicular, or frothy scoria. Unweathered basalt is black or grey...

 to rhyolite

Rhyolite

This page is about a volcanic rock. For the ghost town see Rhyolite, Nevada, and for the satellite system, see Rhyolite/Aquacade.Rhyolite is an igneous, volcanic rock, of felsic composition . It may have any texture from glassy to aphanitic to porphyritic...

. Cobb Mountain

Cobb Mountain

Cobb Mountain is the tallest mountain in the Mayacamas Mountains of California. Its 4720+ feet, main summit is located in Lake County, west of the town of Cobb...

 and Mount Konocti

Mount Konocti

Mount Konocti is a volcano in Lake County, California on the south shore of Clear Lake. At , it is the second highest peak in the Clear Lake Volcanic Field, which consists of numerous volcanic domes and cones ranging from 10,000 to 2.1 million years old....

 are the two highest peaks in the volcanic field, at 4724 feet (1,440 m) and 4285 feet (1,306 m) respectively.

The field's magma chamber also powers a geothermal field called The Geysers

The Geysers

The Geysers is a complex of 22 geothermal power plants, drawing steam from more than 350 wells, located in the Mayacamas Mountains north of San Francisco, California.The largest in the world, the Geysers has...

, which hosts the largest complex of geothermal power

Geothermal power

Geothermal energy is thermal energy generated and stored in the Earth. Thermal energy is the energy that determines the temperature of matter. Earth's geothermal energy originates from the original formation of the planet and from radioactive decay of minerals...

 plants in the world. These can generate approximately 2000 megawatts, enough to power two cities the size of San Francisco.

External links

• Clear Lake Volcanic Field, California, Cascades Volcano Observatory, United States Geological Service
• The Geysers, Calpine
  Calpine
  Calpine Corporation is a Fortune 500 power company founded in 1984 in San Jose, California.Calpine's headquarters were permanently moved from San Jose to Houston, Texas in 2009. The company's stock was traded on the New York Stock Exchange under the symbol CPN until it was delisted on December 5,...