Geology and Geothermal Potential North of Wells, Nevada

The geology north of Wells, Nevada is dominated by approximately 2150 m of Tertiary lacustrine siltstones and conglomerates. The sediments are cut by a high-angle, range-bounding fault and several associated step faults. Hydrothermal alteration and silicification are associated with the high-angle faults. Two ages of Quaternary sediments locally overlie the Tertiary sediments. Lithologic and well log analyses define numerous potential aquifers in the Tertiary sediments. The shallowest of these aquifers is overlain by a tuffaceous siltstone which appears to act as an aquitard for hot water moving through the aquifers. Three possible subsurface hydrologic models can be constructed to explain the spatial relationships of the thermal water near Wells. Cost-effective steps taken to expedite geothermal development in the area might include deepening of an existing domestic well in the city of Wells to at least 180 m in order to penetrate the tuffaceous siltstone aquitard, running borehole logs for all existing wells, and conducting a shallow temperature-probe survey in the Tertiary sediments north of Wells