California Coast Ranges
The Coast Ranges of California span from Del Norte County, California, Del Norte or Humboldt County, California, south to Santa Barbara County, California, Santa Barbara County. The other three coastal California mountain ranges are the Trans ...
, at the southwestern extremity of the
San Joaquin Valley
The San Joaquin Valley ( ; Spanish language in California, Spanish: ''Valle de San Joaquín'') is the southern half of California's Central Valley (California), Central Valley. Famed as a major breadbasket, the San Joaquin Valley is an importa ...
in
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 ...
in the United States. It runs in a northwest-southeasterly direction along the borders of
Kern County
Kern County is a county (United States), county located in the U.S. state of California. As of the 2020 United States census, 2020 census, the population was 909,235. Its county seat is Bakersfield, California, Bakersfield.
Kern County compris ...
and San Luis Obispo County. The name of the range is from Spanish ''temblor'' meaning "tremor", referring to earthquakes. The
San Andreas Fault Zone
The San Andreas Fault is a continental right-lateral strike-slip transform fault that extends roughly through the U.S. state of California. It forms part of the tectonic boundary between the Pacific plate and the North American plate. Trad ...
oil field
A petroleum reservoir or oil and gas reservoir is a subsurface accumulation of hydrocarbons contained in porous or fractured rock formations. Such reservoirs form when kerogen (ancient plant matter) is created in surrounding rock by the prese ...
s, lies to the northeast.
Peaks within the Temblor Range average about above sea level. The highest point is McKittrick Summit at , located in the center of the range about west of
Bakersfield
Bakersfield is a city in and the county seat of Kern County, California, United States. The city covers about near the southern end of the San Joaquin Valley, which is located in the Central Valley region.
Bakersfield's population as of the ...
. The summit on State Route 58, which crosses the range, is at above sea level. The lowest crossing of the range is at Polonio Pass at by State Route 46 at its northern end and is separated by the Diablo Range to the north near Cholame.
Origin and composition
The Temblor Range and surrounding region contains extensive outcrops of the
Monterey Formation
The Monterey Formation is an extensive Miocene oil-rich geology, geological sedimentary formation in California, with outcrops of the formation in parts of the California Coast Ranges, Peninsular Ranges, and on some of California's off-shor ...
(
Miocene
The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...
age, about 20 to 9 million years). Rocks from the Monterey formation consist mostly of
silicate
A silicate is any member of a family of polyatomic anions consisting of silicon and oxygen, usually with the general formula , where . The family includes orthosilicate (), metasilicate (), and pyrosilicate (, ). The name is also used ...
shale
Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of Clay mineral, clay minerals (hydrous aluminium phyllosilicates, e.g., Kaolinite, kaolin, aluminium, Al2Silicon, Si2Oxygen, O5(hydroxide, OH)4) and tiny f ...
fossil
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...
plankton
Plankton are the diverse collection of organisms that drift in Hydrosphere, water (or atmosphere, air) but are unable to actively propel themselves against ocean current, currents (or wind). The individual organisms constituting plankton are ca ...
in an intermediate to deep-water marine setting). Fossils and sediments from the Monterey Formation show that the Carrizo Plain region was a marine basin with shallow to intermediate depths (marine waters covered the southern
San Joaquin Valley
The San Joaquin Valley ( ; Spanish language in California, Spanish: ''Valle de San Joaquín'') is the southern half of California's Central Valley (California), Central Valley. Famed as a major breadbasket, the San Joaquin Valley is an importa ...
region). Marine sediments younger than about 9 million years are not preserved in the
Carrizo Plain National Monument
The Carrizo Plain (Obispeño language, Obispeño: ''tšɨłkukunɨtš'', "Place of the rabbits") is a large enclosed grassland plain, approximately long and up to across, in southeastern San Luis Obispo County, California, United States, abo ...
area, but they occur throughout the Kettleman Hills region (about north of the park). The
Pliocene
The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58Etchegoin Formation contains marine fossils to about 4 million years old. Fossils of the Etchegoin Formation are supporting evidence that the Coast Ranges and the Temblor Range are young, having been uplifted mostly during the
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 ...
Epoch (or Quaternary Period) in the past several million years. Much of that ongoing uplift is due to
tectonics
Tectonics ( via Latin ) are the processes that result in the structure and properties of the Earth's crust and its evolution through time. The field of ''planetary tectonics'' extends the concept to other planets and moons.
These processes ...
associated with the San Andreas Fault and other fault systems in the region.
During the Pleistocene, sometime more recently than 1.8 million years ago, an enormous block of the Temblor Range – a swath of Monterey shale more than long, a mile across, and over thick, about three cubic miles of rock in all – slid down the northeastern side of the range, covering a distance of approximately three miles and descending . This mass movement completely covered the McKittrick Oil Field, giving it a highly unusual geology for an oil field, as the petroleum deposits in most oil fields are in structural or stratigraphic traps; this field is capped by an enormous mass of rock that moved off of the adjacent mountain range.J.A. Taff: "Geology of the McKittrick Oil Field and Vicinity, Kern County, California." American Association of Petroleum Geologists Bulletin, 193 (abstract available here) /ref>
The Temblor Range is delineated from the
San Emigdio Mountains
The San Emigdio Mountains are a part of the Transverse Ranges in Southern California, extending from Interstate 5 at Lebec and Gorman on the east to Highway 33–166 on the west. They link the Tehachapis and Temblor Range and form the southe ...
and the
Santa Ynez Mountains
The Santa Ynez Mountains are a portion of the Transverse Ranges, part of the Pacific Coast Ranges of the west coast of North America. It is the westernmost range in the Transverse Ranges.
The range is a large fault block of Cenozoic age created ...
Taft, California
Taft (formerly Moron, Moro, and Siding Number Two) is a city in the foothills at the extreme southwestern edge of the San Joaquin Valley, in Kern County, California. Taft is located west-southwest of Bakersfield, California, Bakersfield, at an ...
. Although there are numerous unofficial routes into the area, legal public access is currently limited.