Lithostratigraphy of the State 2–14 Borehole: Salton Sea Scientific Drilling Project

Sedimentary rocks from the (California) State 2–14 research borehole of the Salton Sea Scientific Drilling Project, located in the Imperial Valley of southern California, were deposited in the continental basin of the Salton Trough. Lacustrine shale and siltstone are the dominant lithologies. Sandstones were deposited in lake margin, meander channel fill, and lacustrine delta environments. Framework modal clast compositions of the sandstones indicate a dominant Colorado River provenance. Rare pebbly mudstones were deposited as storm‐induced debris flows. Primary depositional structures in the sediments are commonly disrupted by seismic disturbances. Nonmarine gastropods and ostrocods are relatively uncommon, and occurrences of stratabound sulfides suggest periods of brackish water conditions. Bedded anhydrite and centimeter‐scale mudcracks record intervals of dessication. The State 2–14 sedimentary rocks are interpreted as the basinward facies of the Borrego and Brawley formations which range from Pliocene to Pleistocene in age.