The Palm Spring Formation is an extensively-exposed delta-plain deposit debouched by the ancestral Colorado River across the subsiding Salton Trough.[1] It records the development of the prehistoric Colorado River delta cone into a barrier excluding marine waters from the Salton Trough.[2]
^ abRemeika, Paul; Fischbein, Irwin W.; Fischbein, Steven A. (1988). "Lower Pliocene petrified wood from the Palm Spring Formation, Anza Borrego Desert State Park, California". Review of Palaeobotany and Palynology. 56 (3–4): 183–198. doi:10.1016/0034-6667(88)90057-7.