Pico Formation

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Pico Formation
Stratigraphic range: Late Pliocene to early Pleistocene, 3.6–1.8  Ma
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Type Geologic formation
Unit of Los Angeles Basin
Underlies Saugus Formation
Overlies Repetto Formation. Sisquoc Formation
Location
Region Los Angeles Basin, Santa Monica Mountains
Los Angeles County, Flag of California.svg  California
CountryFlag of the United States (23px).png  United States

The Pico Formation is a Pliocene epoch stratigraphic unit and geologic formation in the greater Los Angeles Basin, the Santa Monica Mountains, and the Santa Susana Mountains, in Los Angeles County of Southern California.

Contents

Geology

It was formed during the Neogene period of the Cenozoic Era, and overlies the Repetto Formation. [1]

Outcrops of the formation in Santa Monica Mountains National Recreation Area have produced fossil shark teeth from the Pliocene. [2] [3]

In addition to fossils, armored mud balls were found by Cartwright (1928) in possible fluvial or coastal deposits of the Pico Formation, though they were referred to as "pudding balls" in the article. [4]

Classification

The underlying Repetto Formation is equivalent in age to the Fernando Formation, and some researchers consider it as well as the overlying Pico Formation to be a junior synonym based on benthic foraminifera stages. [5] Other researchers maintain that the Repetto and Pico Formations are distinct stratigraphic units, and that the use of the name "Fernando Formation" should be stopped due to several issues with stratigraphic correlation and access to the type section. [1]

See also

Related Research Articles

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The Drake Bay Formation is a Pliocene stratigraphic unit in California. In 1993, paleontologists excavated a whale skeleton associated with fossil shark teeth and fish vertebrae that may have belonged to a giant salmon from Drake Bay sediments at Point Reyes National Seashore.

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The Tulare Formation is a Pliocene to Holocene epoch geologic formation in the central and southern San Joaquin Valley of central California.

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. It is primarily composed of hard sandstone with some inter-bedded siltstone.

The Santa Clara Formation is a geologic formation in the southeastern Santa Cruz Mountains, in Santa Clara County, California.

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

References

  1. 1 2 Blake, Gregg H. 1991. "Review of the Neogene biostratigraphy and stratigraphy of the Los Angeles Basin and implications for basin evolution," In: Biddle, Kevin T. (ed), "Active Margin Basins", AAPG Memoir 52, 319pp.
  2. "Santa Monica Mountains National Recreation Area," Hunt, Santucci, and Kenworthy (2006); page 67.
  3. Hunt, ReBecca K., Vincent L. Santucci and Jason Kenworthy. 2006. "A preliminary inventory of fossil fish from National Park Service units." in S.G. Lucas, J.A. Spielmann, P.M. Hester, J.P. Kenworthy, and V.L. Santucci (ed.s), Fossils from Federal Lands. New Mexico Museum of Natural History and Science Bulletin 34, pp. 63–69.
  4. Cartwright, Lon D. Jr. (March 1, 1928). "Sedimentation of the Pico Formation in the Ventura Quadrangle, California". AAPG Bulletin. 12 (3): 235–269 via GeoScience World.
  5. Sorlien, Christopher C.; Seeber, Leonardo; Broderick, Kris G.; Luyendyk, Bruce P.; Fisher, Michael A.; Sliter, Ray W.; Normark, William R. (June 2013). "The Palos Verdes anticlinorium along the Los Angeles, California coast: Implications for underlying thrust faulting". Geochemistry, Geophysics, Geosystems. 14 (6): 1866–1890. doi:10.1002/ggge.20112.