Chatsworth Formation

{{Short description|Cretaceous geologic formation in Southern California}} {{Infobox rockunit | name = Chatsworth Formation | image = Stoney Point California.jpg | caption = Chatsworth Formation at Stoney Point California | type = Formation | age = Campanian & Maestrichtian epochs of Cretaceous | period = Late Cretaceous | prilithology = | otherlithology = | namedfor = | namedby = | region = Los Angeles County and Ventura County, California | country = United States | coordinates = | unitof = | subunits = | underlies = | overlies = | thickness = | extent = Simi Hills, Santa Susana Mountains | area = | map = | map_caption = }}

The '''Chatsworth Formation''' is a Cretaceous period sandstone geologic formation in the Simi Hills and western Santa Susana Mountains of southern California.<ref name=aapg>[http://archives.datapages.com/data/pac_sepm/036/036001/pdfs/103.htm AAPG Archives: Paleographic Interpretation of the Chatsworth Formation]</ref> <ref>[http://www.cleanuprocketdyne.org/documents/curo_eir/Chatsworth%20Groundwater%20to%20surface.pdf Cleanuprocketdyne.org: Santa Susana Field Lab links to Chatsworth Formation groundwater contamination]</ref>

It is found in western Los Angeles County and eastern Ventura County. The formation's thickness can be more than {{convert|610|m|ft}}.<ref name=usgsmap>[https://pubs.usgs.gov/of/1995/0829/report.pdf USGS.gov: "Preliminary geologic map of the Santa Susana quadrangle, Southern California"]</ref>

==Fossils== The sedimentary marine formation preserves fossils dating from the Middle Campanian to Early Maestrichtian epochs of the Cretaceous period.<ref name=aapg/><ref>{{cite web|title= Fossilworks: Gateway to the Paleobiology Database|author= ((Various Contributors to the Paleobiology Database))|url= https://www.fossilworks.org|access-date= 17 December 2021}}</ref> It has diverse molluscan faunas.<ref name=usgsmap/>

The most common taxa are:<ref>[https://gsa.confex.com/gsa/2001CD/finalprogram/abstract_3852.htm Overview of late cretaceous marine gastropods from the Simi Hills], by Mary Stecheson, Department of Geological Sciences, California State Univ, Northridge.</ref> *ringiculid Biplica *naticids Gyrodes and Euspira *trochid Atira *aporrhaids Anchuras and Lispodesthes *turritellid Turritella *perissityid Perissitys

==See also== {{Portal|Earth sciences|California|Paleontology}} * Stoney Point (California) — ''Chatsworth Formation landmark''. * {{C|Cretaceous California}} * {{C|Geology of Los Angeles County, California}} * List of fossiliferous stratigraphic units in California * Paleontology in California

==References== {{Reflist|2}}

Category:Cretaceous California Category:Sandstone formations of the United States Category:Campanian Stage Category:Maastrichtian Stage of North America Category:Geology of Los Angeles County, California Category:Geology of Ventura County, California Category:Simi Hills Category:Santa Susana Mountains Category:Cretaceous fossil record Category:Upper Cretaceous Series of North America Category:Paleontology in California Category:Chatsworth, Los Angeles Category:Geography of Simi Valley, California Category:West Hills, Los Angeles Category:Geologic formations of California