Interpretation of geophysical data from the Colado KGRA, Pershing County, Nevada

Abstract

The Colado geothermal area is evidenced by hot water wells in alluvium along the west flank of the West Humboldt Range. The exploration of this geothermal system has progressed into advanced stages with completion of shallow thermal gradient drilling, two intermediate-depth exploration drill holes, one deep exploration drill hole, detailed geologic mapping, dipole-dipole resistivity, gravity, ground magnetics, MT-AMT, TDEM and assorted uncommon electrical resistivity techniques. A thermal anomaly was outlined by the shallow drilling. Dipole-dipole resistivity and gravity data along with detailed geologic mapping have suggested that this anomaly is structurally controlled. Other geophysical techniques employed do not appear to contribute to an understanding of the geothermal anomaly. The two intermediate-depth exploration holes (IGH-1, IGH-2) and the one deep hole (44x-10) may not have been located in the most favorable portions of the geothermal anomaly. The area having the greatest exploration potential for intermediate-depth drilling appears to be centered on the shallow drill hole 14 to 22. An intermediate-depth drill hole located near DH14-22 is most likely to encounter one of the conduits that allow thermal waters to rise near the surface.