A detailed investigation is reported of cuttings recovered from three wells in the Salton Sea geothermal field located at the southeast end of the Salton Sea, California. The wells, Magmamax No. 2, Magmamax No. 3, and Woolsey No. 1 penetrate 1340 m, 1200 m, and 730 m, respectively, of altered sandstones, siltstones, and shales of the Colorado River delta. The wells are located at the crest of a thermal anomaly, reach a maximum of 320/sup 0/C at 1070 m, and produce a brine containing approximately 250,000 mg/1 of dissolved solids.