IMPROVING THE GEOLOGIC FRAMEWORK OF LACUSTRINE EVAPORITE MINERAL SYSTEMS IN THE BASIN AND RANGE PROVINCE THROUGH REGIONAL-SCALE AIRBORNE ELECTROMAGNETIC SURVEYS

The Basin and Range province hosts expansive areas prospective for numerous critical minerals, including lacustrine evaporite mineral systems that may host lithium resources. As part of the U.S. Geological Survey Earth Mapping Resources Initiative, airborne electromagnetic (AEM) surveys are being conducted to support mineral resource assessments, mineral system process studies, and geologic mapping efforts. AEM methods excel at locating electrically conductive shallow clays and brines relevant to lithium prospectivity while also providing new images of the subsurface geologic structure. The results of these surveys can improve our understanding of regional fluid flow and the occurrence of mineral, geothermal, and water resources Between 2022 and 2024, more than 35,000 line kilometers of AEM data have been collected over substantial portions of Nevada’s Basin and Range and the western Mojave Desert of California. These surveys encompass several areas with proven lithium resources such as Clayton Valley, Rhyolite Ridge, McDermitt Caldera, and the Hector deposit and type locality for hectorite. Results from this effort will improve our understanding of the geologic conditions and geophysical signatures associated with these known lithium deposits and benefit future mineral resource assessments by identifying regions with similar geophysical and geologic characteristics.