The Coso Range of eastern

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

is located immediately south of

Owens Lake Owens Lake is a dry lake in the Owens Valley on the eastern side of the Sierra Nevada in Inyo County, California. It is about south of Lone Pine. Unlike most dry lakes in the Basin and Range Province that have been dry for thousands of years, ...

, east of the

Sierra Nevada The Sierra Nevada ( ) is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primari ...

, and west of the

Argus Range The Argus Range is a mountain range located primarily in Inyo County, California, southeast of the town of Darwin. The range forms the western boundary of Panamint Valley, and the northwestern boundary of Searles Valley. The Coso Range is loc ...

. The southern part of the range lies in the restricted

Naval Air Weapons Station China Lake Naval Air Weapons Station (NAWS) China Lake is a large military installation in California that supports the research, testing and evaluation programs of the United States Navy. It is part of Navy Region Southwest under Commander, Navy Instal ...

and the northern part of the range is designated as the Coso Range Wilderness. The mountains include Coso Peak, at above sea level, as well as Silver Peak and Silver Mountain, both more than in height. The range is underlain principally by

Mesozoic The Mesozoic Era is the Era (geology), era of Earth's Geologic time scale, geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceous Period (geology), Periods. It is characterized by the dominance of archosaurian r ...

granitic rocks that are partly veneered by upper

Cenozoic The Cenozoic Era ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterized by the dominance of mammals, insects, birds and angiosperms (flowering plants). It is the latest of three g ...

volcanic rocks of the

Coso Volcanic Field The Coso Volcanic Field is located in Inyo County, California, at the western edge of the Basin and Range geologic province and northern region of the Mojave Desert. The Fossil Falls are part of the Coso Field, created by the prehistoric Owen ...

. The volcanic units (in apparent decreasing age) include (1) widespread

basalt Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ...

ic flows, (2)

dacitic Dacite () is a volcanic rock formed by rapid solidification of lava that is high in silica and low in alkali metal oxides. It has a fine-grained (aphanitic) to porphyritic texture and is intermediate in composition between andesite and rhyolite. ...

flows and

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 co ...

, and (3)

rhyolitic Rhyolite ( ) is the most silica-rich of volcanic rocks. It is generally glassy or fine-grained (aphanitic) in texture, but may be porphyritic, containing larger mineral crystals ( phenocrysts) in an otherwise fine-grained groundmass. The miner ...

domes and flows and basaltic cones and flows. These volcanic rocks are encompassed by an oval-shaped zone of late Cenozoic ring faulting that measures about east to west and north to south and that defines a structural basin. Most of the Coso Range and a slice of the adjacent Sierra Nevada lie within this ring structure. The youngest volcanic rocks are

Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

and, with associated active

fumarole A fumarole (or fumerole) is a vent in the surface of the Earth or another rocky planet from which hot volcanic gases and vapors are emitted, without any accompanying liquids or solids. Fumaroles are characteristic of the late stages of volcani ...

s, occupy a north-trending structural and topographic ridge about near the center of the basin. The ring structure and associated volcanic rocks suggest a large underlying

magma chamber A magma chamber is a large pool of liquid rock beneath the surface of the Earth. The molten rock, or magma, in such a chamber is less dense than the surrounding country rock, which produces buoyant forces on the magma that tend to drive it u ...

that has periodically erupted

lava Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a Natural satellite, moon onto its surface. Lava may be erupted at a volcano or through a Fissure vent, fractu ...

to the surface during the past few million years.

Prehistory

Numerous rock art sites (the

Coso Rock Art District Coso Rock Art District is a rock art site containing over 100,000 Petroglyphs by Paleo-Indians and/or Native Americans. The district is located near the towns of China Lake and Ridgecrest, California. Big and Little Petroglyph Canyons we ...

) are found in the range, left by the ancient

Coso people The Timbisha ("rock paint", Timbisha language: Nümü Tümpisattsi) are a Native American tribe federally recognized as the Death Valley Timbisha Shoshone Band of California. They are known as the Timbisha Shoshone Tribe and are located in south ...

. The prehistoric Coso inhabitants exported volcanic glass (Coso obsidian) and this highly valued toolstone has been found as far distant as the

Channel Islands of California The Channel Islands () are an eight-island archipelago located within the Southern California Bight in the Pacific Ocean, off the coast of California. They define the Santa Barbara Channel between the islands and the California mainland. The ...

.Garfinkel 2007 Little Petroglyph Canyon and Renegade Canyon within the Range are open for guided tours through the

Maturango Museum Maturango Museum is located in Ridgecrest, California. The museum is best known for the guided tours of the Coso Rock Art District located on China Lake Naval Weapons Station. The museum offers exhibits and displays featuring both the natural ...

Ridgecrest, California Ridgecrest is a city in Kern County, California, United States, along U.S. Route 395 in California, U.S. Route 395 in the Indian Wells Valley in northeastern Kern County, adjacent to the Naval Air Weapons Station China Lake (NAWS, or China Lake) ...

Notes

References

* California Road and Recreation Atlas. 2005, pg. 87 * C. Michael Hogan. 2008. ''Morro Creek'', ed. by A. Burnha

* Alan P. Garfinkel, 2007, Archaeology and Rock Art of the Eastern Sierra and Great Basin Frontier, Maturango Museum, Ridgecrest,California. * {{Authority control Mountain ranges of the Mojave Desert Volcanoes of Inyo County, California Igneous petrology of California Mountain ranges of Inyo County, California Mesozoic magmatism Pliocene volcanism Pleistocene volcanism

Prehistory

See also

Notes

References