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. It records the development of the prehistoric Colorado River delta cone into a barrier excluding marine waters from the Salton Trough.
Fossils
It preserves fossils from the Pleistocene Epoch, during the Quaternary Period of the Cenozoic Era.
Lower Pliocene sub−period petrified wood is found in Anza-Borrego Desert State Park. The Lauraceae is represented by petrified Umbellularia, the Salicaceae with petrified Populus and Salix, and the Juglandaceae with petrified Juglans.