The Desert Peak Reservoir

In this report the term reservoir is considered to be that volume of rock above a depth of 10,000 feet which gives an isothermal temperature profile with a temperature near 400 F. Wells deeper than 10,000 feet in this area are unlikely to be profitable at the present time. The isothermal profile is assumed to be the result of geothermal fluids convecting in fractures. Of course, large fractures, which are referred to as producing zones within the reservoir, must be intersected if a well is to...

History

Due to the desolate nature of the Hot Springs Mountains, the history of the area has been dominated by a series of people passing through, or by people searching for and attempting to produce a wide variety of mineral resources. Although there is a lack of known archaeological sites and artifacts in the Hot Springs Mountains, Indians probably visited nearby Brady's Hot Springs regularly. Early explorers visited Brady's Hot Springs but rapidly moved on in search of more productive land. The...

Shallow Temperaturegradient Holes

After a seven-year hiatus, geothermal exploration in the Brady's area resumed in 1973. The U. S. Geological Survey and the U. S. Bureau of Reclamation drilled 21 FIGURE 6. Three of Brady's geothermal wells flowing photo from Garside, 1974 . shallow test holes to determine shallow subsurface temperatures and temperature gradients and to evaluate the movement of ground water Olmsted and others, 1975 . Most of these drill holes hereafter referred to as holes are located within 1 mile of Brady's...

Geologic Structure And The Geothermal Reservoir

Silo Field Fault Map

Post-discovery geologic mapping in the northern part of the Hot Springs Mountains shows that the area underlain by the Desert Peak geothermal field is structurally higher than other parts of the northern Hot Springs Mountains. Most of the surface in this area is covered by alluvium, but where bedrock is exposed it consists mostly of rocks of the lower Chloropagus Formation or of units of the unnamed rhyolite sequence. The subsurface temperature distribution is areally nonlinear based on present...

Roving Dipole Electrical Resistivity Survey

During the latter stages of the shallow temperature-gradient program a roving dipole resistivity reconnaissance survey was run over the entire thermal anomaly by an independent contractor. In addition, ten depth soundings were made to provide more detailed information on lateral and vertical resistivity variations. Two plates from this survey are included as plates 4 and 5, an apparent resistivity anomaly map and a total-field apparent conductance map. There were six dipole source locations...