Core logs from Owens, China, Searles, and Panamint basins, California

Detailed logs of drill cores are presented in this report. The drill cores are of sediments from four basins that were occupied during the Pleistocene by a continuous chain of lakes. Owens Lake basin (one hole, 920 feet) contains fine-grained sediments and includes locally many diatoms and ostracodes. China Lake basin (one hole, 700 feet) contains silt- to sand-sized clastic sediments and some calcite and gaylussite; a few diatoms, ostracodes, and mollusks are present. Searles Lake basin (one hole, 875 feet) contains many layers of gaylussite- or pirssonite-bearing sediments intercalated with beds of halite, trona, and lesser amounts of other minerals peculiar to Searles Lake; the top 120 feet consists of thicker evaporite bodies with a more complex mineralogy. Panamint basin (three holes, 500, 375, and 995 feet) contains clastic deposits ranging from clay to gravel, a small amount of gypsum, anhydrite, a trace of bassanite, and thick bodies of halite in the basin center; a few diatoms and ostracodes are present.