Exploration of a High Temperature, Fault Localized, Nonmeteoric Geothermal System at the Sulphur Bank Mine, California

Abstract

Four exploration test wells have been drilled in the Sulphur Bank Mine and adjoining area to the south and east. Temperatures over 400°F were encountered in three of the four wells. The Bradley Mining No. 1 well produced large quantities of hot water and steam during flow testing. The remaining three wells were either dry or produced only small amounts of geothermal fluids. The productivity of the Bradley Mining No. 1 well resulted from penetration of a steeply north plunging, pipe like zone of permeability at the intersection of three steeply dipping faults. Formation waters form the four deep wells, appear to be genetically related to Sulphur Bank Mine hot springs which White et al (1973) have shown, on the basis of isotope studies, is nometeroic and possibly of metamorphic origin.