GEOTHERMAL EXPLORATION IN DIXIE VALLEY, THE WALKER LANE AND GUAM: NAVY GEOTHERMAL PROGRAM OFFICE

The Navy’s Geothermal Program Office (GPO) is the only government office that manages a geothermal field, supports and performs geothermal research and actively explores for utility-grade geothermal resources. Oversight of the 270 MWe Coso geothermal field situated entirely within the China Lake Naval Air Weapons Station, CA, with revenue generated from this field, combined with a collaborative relationship with our Coso operator, Terra-Gen, provides GPO the unique ability to understand geothermal systems and to apply this knowledge to the aggressive exploration of utility-grade geothermal systems worldwide.

Included among our current exploration projects is Navy-managed ground in Dixie Valley, NV, the island of Guam and the Hawthorne Army Depot in the Walker Lane tectonic province of central NV. A structural and conceptual geothermal model has evolved from a joint GPO-Great Basin Center for Geothermal Energy collaborative effort at Hawthorne. An integration of self-performed and contracted potential field geophysics, a 3d seismic data set, structural mapping, 2m probes, shallow and deep drilling and Quaternary mapping has identified a likely moderate temperature, binary resource.

A similar level of effort with a much more focused timeline is currently being conducted on Naval Air Station Fallon ground in Dixie Valley. The initial vectoring of potential drill targets was generated through an assessment of previously acquired data, field reconnaissance, 2m probes, TGH drilling and the acquisition and interim interpretations (to date) of a large, Recovery Act funded LiDAR and hyperspectral data sets.

Guam is in the forearc of the Izu-Bonin-Mariana Arc system in the southwest Pacific Ocean. This arc stretches over 1,000 miles south-north in the southwestern Pacific Ocean. Guam is an American Territory with electrical generating plants entirely powered by imported fossil fuels. Offshore volcanism, some well mapped faults (potential fluid flow conduits) and it’s (albeit old) volcanic past prompted the systematic assessment of Guam’s geothermal potential. A field assessment of LiDAR data interpreted for this project resulted in the definition of marginal drilling targets.