High-resolution aeromagnetic survey to image shallow faults, Dixie Valley geothermal field, Nevada / Аэромагнитная съемка с высоким разрешением для получения изображений неглубоких разломов, Геотермальное месторождение Дикси-Вэлли, Невада

Understanding the relations between faults and the flow of thermal fluids is key to successful exploration for new geothermal resources in Dixie Valley and other Basin and Range geothermal systems. Mapping fault patterns within these basins and recognizing their connections at depth are key to improving this understanding. However, most of the faults are shallowly buried, making them difficult to locate and map. Moreover, drill holes and seismic profiles cannot give a comprehensive view of fault attitudes and patterns because the information they provide is only for limited areas.
High-resolution aeromagnetic surveys flown over the Albuquerque basin of the Rio Grande rift, New Mexico, have recently demonstrated that aeromagnetic methods can successfully map concealed and poorly exposed faults in a basin environment (Grauch, 2001). The surveys provided a new view of the overall pattern of faulting and allowed general estimates of the attitudes, depths, and geometries of many of the faults (Grauch et al., 2001). Dixie Valley is situated in an analogous geologic environment to Albuquerque basin and is an excellent case study for a Basin and Range geothermal resource area. To better understand the fault pattern near the geothermal resource area, the Department of Energy contracted the U.S. Geological Survey (USGS) to acquire and process a high-resolution, helicopter-borne magnetic survey (fig. 1). This report briefly describes the acquisition and processing procedures for these data, the interpretation techniques used to image shallow faults, and limitations of these results.  <...>