Coso Range
Encyclopedia
The Coso Range of eastern California
is located immediately south of Owens Lake
(dry), east of the Sierra Nevada Mountains, and west of the Argus Range
. The southern part of the range lies in the restricted Naval Air Weapons Station China Lake
. The mountains include Coso Peak, at 8160 feet (2,487 m)above sea level, as well as Silver Peak and Silver Mountain, both more than 7400 ft (2,255.5 m) in height.
The range is underlain principally by Mesozoic
granitic rocks that are partly veneered by upper Cenozoic
volcanic rocks of the Coso Volcanic Field
. The volcanic units (in apparent decreasing age) include (1) widespread basalt
ic flows, (2) dacitic flows and tuff
, and (3) rhyolitic
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 24 miles (40 km) east to west and 45 km 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
and, with associated active fumarole
s, occupy a north-trending structural and topographic ridge about 18 km by 10 km near the center of the basin. The ring structure and associated volcanic rocks suggest a large underlying magma chamber
that has periodically erupted lava
to the surface during the past few million years.
) are found in the range, left by the ancient Coso People
. The prehistoric Coso inhabitants exported volcanic glass (Coso obsidian) and this highly valued toolstone has been found as far distant as the Channel Islands, California.. Little Petroglyph Canyon and Renegade Canyon within the Range are open for guided tours through the Maturango Museum in Ridgecrest, 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...
is located immediately south of Owens Lake
Owens Lake
Owens Lake is a mostly dry lake in the Owens Valley on the eastern side of the Sierra Nevada in Inyo County, California. It is located about south of Lone Pine, California...
(dry), east of the Sierra Nevada Mountains, and west of the Argus Range
Argus Range
The Argus Range is a mountain range located in Inyo County, California, southeast of the town of Darwin, between the Coso Range and the Panamint Valley, with the Panamint Range to the east .-Geography:The range contains Maturango Peak, at above sea level...
. The southern part of the range lies in the restricted Naval Air Weapons Station China Lake
Naval Air Weapons Station China Lake
- About : is part of under Commander, Navy Installation Command and is located in the Western Mojave Desert region of California, approximately north of Los Angeles. Occupying three counties – Kern, San Bernardino and Inyo – the installation’s closest neighbors are the cities of Ridgecrest,...
. The mountains include Coso Peak, at 8160 feet (2,487 m)above sea level, as well as Silver Peak and Silver Mountain, both more than 7400 ft (2,255.5 m) in height.
The range is underlain principally by Mesozoic
Mesozoic
The Mesozoic era is an interval of geological time from about 250 million years ago to about 65 million years ago. It is often referred to as the age of reptiles because reptiles, namely dinosaurs, were the dominant terrestrial and marine vertebrates of the time...
granitic rocks that are partly veneered by upper Cenozoic
Cenozoic
The Cenozoic era is the current and most recent of the three Phanerozoic geological eras and covers the period from 65.5 mya to the present. The era began in the wake of the Cretaceous–Tertiary extinction event at the end of the Cretaceous that saw the demise of the last non-avian dinosaurs and...
volcanic rocks of the Coso Volcanic Field
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 Owens River. They are currently within the Naval Air Weapons...
. The volcanic units (in apparent decreasing age) include (1) widespread 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...
ic flows, (2) dacitic flows and tuff
Tuff
Tuff is a type of rock consisting of consolidated volcanic ash ejected from vents during a volcanic eruption. Tuff is sometimes called tufa, particularly when used as construction material, although tufa also refers to a quite different rock. Rock that contains greater than 50% tuff is considered...
, and (3) rhyolitic
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...
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 24 miles (40 km) east to west and 45 km 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
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
and, with associated active fumarole
Fumarole
A fumarole is an opening in a planet's crust, often in the neighborhood of volcanoes, which emits steam and gases such as carbon dioxide, sulfur dioxide, hydrochloric acid, and hydrogen sulfide. The steam is created when superheated water turns to steam as its pressure drops when it emerges from...
s, occupy a north-trending structural and topographic ridge about 18 km by 10 km near the center of the basin. The ring structure and associated volcanic rocks suggest a large underlying magma chamber
Magma chamber
A magma chamber is a large underground pool of molten rock found beneath the surface of the Earth. The molten rock in such a chamber is under great pressure, and given enough time, that pressure can gradually fracture the rock around it creating outlets for the magma...
that has periodically erupted lava
Lava
Lava refers both to molten rock expelled by a volcano during an eruption and the resulting rock after solidification and cooling. This molten rock is formed in the interior of some planets, including Earth, and some of their satellites. When first erupted from a volcanic vent, lava is a liquid at...
to the surface during the past few million years.
Prehistory
Numerous rock art sites (the Coso Rock Art DistrictCoso Rock Art District
Coso Rock Art District, containing the Big and Little Petroglyph Canyons, is a rock art site containing over 20,000 of Paleo-Indian and/or Native American Petroglyphs The Coso Range is between the Sierra Nevada and the Argus Range. Indian Wells Valley lies to the south of this location...
) are found in the range, left by the ancient Coso People
Coso People
The Coso people are an indigenous people of the Americas and Native American tribe associated with the Coso Range in the Mojave Desert of California in the southwestern U.S.. They are of the Uto-Aztecan language and spoke one of several Numic languages, related to that of the Northern Paiute.They...
. The prehistoric Coso inhabitants exported volcanic glass (Coso obsidian) and this highly valued toolstone has been found as far distant as the Channel Islands, California.