A thick sequence of limestone, dolomite, and minor sandstone assigned to the Pennsylvanian and lower Permian Bird Spring Formation is exposed in the Ship Mountains about 85 kilometers (km) southwest of Needles, California, in the eastern Mojave Desert.
Stone, Paul pastone@usgs.gov,Stevens, Calvin H.,Howard, Keith A. khoward@usgs.gov,et al. Stratigraphy and paleogeographic significance of the Pennsylvanian-Permian Bird Spring Formation in the Ship Mountains, southeastern California. 2013-01-01.