Palm Spring Formation

{{Short description|Geologic formation in California, United States}} {{Infobox rockunit | name = Palm Spring Formation | image = | caption = | type = Geologic formation | age = Lower Pleistocene | period = Pleistocene | prilithology = | otherlithology = | namedfor = | namedby = | region = Colorado Desert, California | country = United States | coordinates = | unitof = | subunits = | underlies =Vallecito Badlands | overlies = Imperial Formation, Ocotillo Formation | thickness = | extent = | area = | map = | map_caption = }}

The '''Palm Spring Formation''' is a Pleistocene Epoch geologic formation in the eastern Colorado Desert of Imperial County and San Diego County County, Southern California.

==Geology== The Palm Spring Formation is an extensively-exposed delta-plain deposit debouched by the ancestral Colorado River across the subsiding Salton Trough.<ref>[https://web.archive.org/web/20040116070346/http://www2.nature.nps.gov/geology/paleontology/pub/fossil_conference_6/remeika.htm National Park Service: "The FISH CREEK CANYON ICHNOFAUNA: a PLIOCENE (BLANCAN) Vertebrate Footprint Assemblage from Anza-Borrego Desert State Park, California"]; by Paul Remeika.</ref> It records the development of the prehistoric Colorado River delta cone into a barrier excluding marine waters from the Salton Trough.<ref>[https://sdsu-dspace.calstate.edu/handle/10211.10/3 San Diego State University.edu: "Environments of deposition, Pliocene Imperial Formation, Southeast Coyote Mountains, Imperial County, California"] {{Webarchive|url=https://web.archive.org/web/20151004143456/https://sdsu-dspace.calstate.edu/handle/10211.10/3 |date=2015-10-04 }}; Bell, Patricia J.; 1980.</ref>

===Fossils=== It preserves fossils from the Pleistocene Epoch, during the Quaternary Period of the Cenozoic Era.<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|archive-date= 25 March 2022|archive-url= https://web.archive.org/web/20220325060448/http://www.fossilworks.org/cgi-bin/bridge.pl?action=home|url-status= dead}}</ref>

Lower Pliocene sub−period petrified wood is found in Anza-Borrego Desert State Park.<ref name=anzabdsp>{{cite journal | doi=10.1016/0034-6667(88)90057-7 | volume=56 | issue=3–4 | title=Lower Pliocene petrified wood from the Palm Spring Formation, Anza Borrego Desert State Park, California | journal=Review of Palaeobotany and Palynology | pages=183–198| year=1988 | last1=Remeika | first1=Paul | last2=Fischbein | first2=Irwin W. | last3=Fischbein | first3=Steven A. }}</ref> The Lauraceae is represented by petrified ''Umbellularia'', the Salicaceae with petrified ''Populus'' and ''Salix'', and the Juglandaceae with petrified ''Juglans''.<ref name=anzabdsp/>

==See also== {{Portal|California|Paleontology}} * Ocotillo Formation — ''fluvial-alluvial fan Pliocene formation'' * {{C|Quaternary California}} * List of fossiliferous stratigraphic units in California * Paleontology in California

==References== {{Reflist}}

==Further reading== * {{cite book |last=Weber |first=F. Harold |date=1963 |title=Geology and mineral resources of San Diego County, California |url=https://archive.org/details/geologyandminer03webe |publisher=California Division of Mines and Geology |page=32}}

Category:Pleistocene California Category:Pleistocene geology Category:Colorado Desert Category:Geology of Imperial County, California Category:Geology of San Diego County, California Category:Anza-Borrego Desert State Park Category:Pleistocene Series of North America Category:Geologic formations of California