Jump to content

Pico Formation

From Wikipedia, the free encyclopedia
Pico Formation
Stratigraphic range: Late Pliocene to early Pleistocene, 3.6–1.8 Ma
TypeGeologic formation
Unit ofLos Angeles Basin
UnderliesSaugus Formation
OverliesRepetto Formation. Sisquoc Formation
Location
RegionLos Angeles Basin, Santa Monica Mountains
Los Angeles County,  California
Country 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.

Geology

[edit]

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

[edit]

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

[edit]

References

[edit]
  1. ^ a b 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.