An Update of Tectonics and Geothermal Resource Magnitude of the Salton Sea Geothermal Resource

Abstract

We have synthesized geological and geophysical data to determine the tectonics of the Salton Sea Geothermal Field region and to re-evaluate its geothermal resource potential. Based upon the existing data, we believe that the Salton Sea high heat flow zone is above a tectonic gap characterized by a depth to the crust mantle interface of about 14 km, by extensive faulting, and by a subsidence rate which is much higher at the present than the average geological rate. The tectonic gap is bounded by the Wister and Westmoreland faults on the east and west respectively and by the transverse discontinuity and a set of en echelon faults to the north and south. Two epochs of magmatism have taken place in the region within the upper Pleistocene. The stored heat energy within the hydrothermal reservoir at a depth range of 1 to 3 km is about 1.4 x 10-20 calories which is larger than previous estimates. A large hot dry rock zone must also underlie the hydrothermal resource.