A CASE STUDY OF THE GEOTHERMAL PROJECT AT CARSON LAKE, NEVADA

Abstract

The Carson Lake thermal area is located about 18km southeast of Fallon, Nevada. The western part of the thermal anomaly extends into the Naval Air
Station located at Fallon. Although no natural surface-thermal features exist, an artesian-flowing drill hole produces hot water at 72?C.

The ground surface consists of Quaternary alluvial deposits and Tertiary volcanic rocks. The main part of the thermal anomaly is coincident with a complex horst block that is approximately nine square miles in aerial extent. Gravity, magnetics, self-potential and seismic reflection surveys assist in defining the structure and geology.

The thermal anomaly was discovered by shallow temperature-gradient drilling during the early 1970's. Subsequent shallow drilling, in the 1980's
and 1990's, confirmed and further delineated the thermal anomaly. Five intermdatedepth holes have been drilled within or on the flanks of the
anomaly. The deepest hole, completed to a depth of 2119 meters, has a static temperature of 191?C and reportedly produced geothermal fluids. The most recent hole, located near the center of the thermal anomaly, was drilled to a depth of 427 meters. The disappointing result of over twenty years of exploration is that a commercial reservoir has yet to be discovered