Topanga Canyon Formation

Last updated
Topanga Canyon Formation
Stratigraphic range: Neogene
Type Formation
Underlies Modelo Formation
Location
Region Santa Monica Mountains
Los Angeles County, California
Country United States

The Topanga Canyon Formation is a Miocene epoch geologic formation in the Santa Monica Mountains, Simi Hills, Santa Ana Mountains and San Joaquin Hills, in Los Angeles County, Ventura County, and Orange County, southern California. [1] It is primarily composed of hard sandstone with some inter-bedded siltstone.

The Miocene is the first geological epoch of the Neogene Period and extends from about 23.03 to 5.333 million years ago (Ma). The Miocene was named by Charles Lyell; its name comes from the Greek words μείων and καινός and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene is preceded by the Oligocene and is followed by the Pliocene.

Santa Monica Mountains mountain range in Southern California, United States

The Santa Monica Mountains is a coastal mountain range in Southern California, paralleling the Pacific Ocean. It is part of the Transverse Ranges. Because of its proximity to densely populated regions, it is one of the most visited natural areas in California. Santa Monica Mountains National Recreation Area is located in this mountain range.

Simi Hills mountain range in Southern California, United States

The Simi Hills are a low rocky mountain range of the Transverse Ranges in eastern Ventura County and western Los Angeles County, of southern California, United States.

Contents

Fossils

It preserves fossils dating back to the Miocene epoch of the Neogene period, during the Cenozoic Era. [2] [3]

In geochronology, an epoch is a subdivision of the geologic timescale that is longer than an age but shorter than a period. The current epoch is the Holocene Epoch of the Quaternary Period. Rock layers deposited during an epoch are called a series. Series are subdivisions of the stratigraphic column that, like epochs, are subdivisions of the geologic timescale. Like other geochronological divisions, epochs are normally separated by significant changes in the rock layers to which they correspond.

The Neogene is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period 23.03 million years ago (Mya) to the beginning of the present Quaternary Period 2.58 Mya. The Neogene is sub-divided into two epochs, the earlier Miocene and the later Pliocene. Some geologists assert that the Neogene cannot be clearly delineated from the modern geological period, the Quaternary. The term "Neogene" was coined in 1853 by the Austrian palaeontologist Moritz Hörnes (1815–1868).

See also

Paleontology in California

Paleontology in California refers to paleontologist research occurring within or conducted by people from the U.S. state of California. California contains rocks of almost every age from the Precambrian to the Recent. Precambrian fossils are present but rare in California.

Related Research Articles

Simi Valley (valley)

Simi Valley is a synclinal valley in Southern California in the United States. It is an enclosed or hidden valley surrounded by mountains and hills. It is connected to the San Fernando Valley to the east by the Santa Susana Pass and the 118 freeway, and in the west the narrows of the Arroyo Simi and the Reagan Freeway connect to Moorpark and Ventura, California. The relatively flat bottom of the valley contains soils formed from shales, sandstones, and conglomerates eroded from the surrounding hills of the Santa Susana Mountains to the north, which separate Simi Valley from the Santa Clara River Valley, and the Simi Hills.

Chalk Hills mountain range in Southern California

The Chalk Hills are a north–south-running low 'mountain' range in the San Fernando Valley perpendicular to and adjoining the Santa Monica Mountains. They are located in the Woodland Hills District of the City of Los Angeles in Southern California. They run between DeSoto and Winnetka Avenues, from south of Ventura Boulevard to near Victory Boulevard.

The Chatsworth Formation is a Cretaceous period sandstone geologic formation in the Simi Hills and western Santa Susana Mountains of southern California.

The Claremont Shale is a Miocene epoch geologic formation in the Berkeley Hills of the East Bay region of the San Francisco Bay Area, California.

The Mulholland Formation is a Pliocene epoch geologic formation in the Berkeley Hills and San Leandro Hills of the East Bay region of the San Francisco Bay Area, California. It is found within Alameda County and Contra Costa County.

The Orinda Formation is a Pliocene epoch geologic formation in the Berkeley Hills of the East Bay region of the San Francisco Bay Area, California.

The Briones Formation is a Late/Upper Miocene epoch geologic formation of the East Bay region in the San Francisco Bay Area, California.

The Crowder Formation is a geologic formation in the Central and Western Mojave Desert, in northern Los Angeles County and eastern San Bernardino County, in Southern California.

The Modelo Formation is a Miocene geologic formation in the Simi Hills and western Santa Susana Mountains of southern California.

The Mint Canyon Formation is a Miocene geologic formation in the Sierra Pelona Mountains of Los Angeles County, southern California.

The Santa Margarita Formation is a Neogene Period geologic formation in the San Joaquin Valley of central California.

The San Pablo Formation is a Late/Upper Miocene epoch geologic formation of the East Bay region in the San Francisco Bay Area, California.

The Llajas Formation is a non-marine to marine conglomerate geologic formation in Southern California.

The Martinez Formation is an Eocene Epoch geologic formation in California.

The Santa Susana Formation is a Paleogene period geologic formation in the Simi Hills and western Santa Susana Mountains of southern California.

The Tejon Formation is a Paleogene period geologic formation in California.

The San Francisquito Formation is a geologic formation in northern Los Angeles County, California.

The Harold Formation is a geologic formation in the Central Mojave Desert, west of Victorville and north of the San Gabriel Mountains, in eastern San Bernardino County, Southern California.

The Tick Canyon Formation is a Miocene epoch geologic formation in the Sierra Pelona Mountains of Los Angeles County, California.

The El Cien Formation is a geologic formation in eastern Baja California Sur state, Mexico.

References

  1. USGS.gov: "Preliminary Geologic Map of the Simi 7.5' Quadrangle, Southern California, A Digital Database"; Open-File Report 97-259; compiled by R.F. Yerkes and R.H. Campbell; 1997.
  2. Various Contributors to the Paleobiology Database. "Fossilworks: Gateway to the Paleobiology Database". Archived from the original on 31 July 2014. Retrieved 8 July 2014.
  3. http://research.nhm.org/ip/topanga-formation/