Recency of Faulting and Neotechtonic Framework in the Dixie Valley Geothermal Field and Other Geothermal Fields of the Basin and Range

摘要

We studied the role that earthquake faults play in redistributing stresses within in the earths crust near geothermal fields. The geographic foci of our study were the sites of geothermal plants in Dixie Valley, Beowawe, and Bradys Hot Springs, Nevada. Our initial results show that the past history of earthquakes has redistributed stresses at these 3 sites in a manner to open and maintain fluid pathways critical for geothermal development. The approach developed here during our pilot study provides an inexpensive approach to (1) better define the best locations to site geothermal wells within known geothermal fields and (2) to define the location of yet discovered geothermal fields which are not manifest at the surface by active geothermal springs. More specifically, our investigation shows that induced stress concentrations at the endpoints of normal fault ruptures appear to promote favorable conditions for hydrothermal activity in two ways. We conclude that an understanding of the spatial distribution of active faults and the past history of earthquakes on those faults be incorporated as a standard tool in geothermal exploration and in the siting of future boreholes in existing geothermal fields.