Effectiveness of Shallow Temperature Surveys to Target a Geothermal Reservoir at Previously Explored Site at McGee Mountain, Nevada: Final Report for U.S. Department Of Energy Grant EE-0002830

The McGee Mountain geothermal area was selected to test early-stage shallow temperature survey techniques and drill two slim holes to test the resource. Geothermal Technical Partners, Inc. was able to complete only a small portion of the project before lack of funding prevented further exploration work. This work included a shallow (2-meter) temperature survey, a Geoprobe survey, a close-spaced gravity survey, and several reports on geologic and transmission viability.

The 18-page report includes a description of the geothermal geology of the area, geochemistry and geothermometry of nearby springs and wells, and findings from the shallow temperature survey, Geoprobe survey, close-spaced gravity survey, heat-in-place estimate, transmission viability, and an archeological survey. The report makes the following conclusions:

Both the shallow 2-meter and the Geoprobe surveys are cost-effective methods to detect subsurface thermal anomalies in early-stage exploration, prior to more expensive temperature gradient drilling.
The major advantages of the 2-meter survey are its extreme portability (no roads needed), cost per site measurement, and low environmental impact.
The 2-meter survey's disadvantages are its inability to penetrate hard substrates and the noise effects due to solar heating of the ground.
The Geoprobe's advantages are its ability to collect temperature and uncontaminated water samples, greater depth of penetration (to 60m), relatively low cost, and low environmental impact.
The Geoprobe's disadvantages are its inability to go off-road or to penetrate hard substrates.
Costs to perform both types of surveys are low, together less than the cost of one conventional temperature gradient well. Given the potential increase in data that these surveys can provide, this is extreme value for the exploration dollar.