| Title | Geothermal Resource Exploration, NAF El Centro--Superstition Mountain Area, Imperial Valley, California |
|---|---|
| Authors | Bjornstad, Steven C.; Hall, Bethiah; Unruh, Jeff; Richards-Dinger, Keith |
| Year | 2006 |
| Conference | Geothermal Resources Council Transactions |
| Keywords | Salton Trough; Superstition Mountain, Imperial Valley, West Mesa, geothermal, neotectonic, seismogenic, kinematic |
| Abstract | The geothermal potential of West Mesa has historically been assumed to be small because it is thought to be dominated by a left-stepping transpressional regime that is generally tight and not conducive to open fluid pathways. This may not be the complete picture, however. The 85 MWe Heber geothermal project appears to be located in a right stepover from the northwest trending seismogenic extension of the Cerro Prieto fault, placing it outside the Imperial-San Andreas fault system and on a separate, sub-parallel, extensional trend to the west. A similar right stepover appears to be present at Superstition Mountain where shallow drilling in the 1980’s found temperature gradients exceeding 300ºC/km (17.5ºF/100 ft.). Through the use of detailed surface mapping, electrical and potential fields geophysical methods and analysis of a relocated earthquake catalog for the region, the Navy Geothermal Program Office is beginning to define the hydrothermal history and the structural and tectonic framework of this thermal anomaly and to delineate active transtensional areas and critically stressed fractures which may serve as conduits for upwelling geothermal fluids. |