CRITICAL MINERALS IN THE UNITED STATES - EARTH MAPPING RESOURCES INITIATIVE (EARTH MRI) STATUS REPORT

Earth MRI was established by the U.S. Geological Survey (USGS) in 2019 as a collaborative effort with the Association of American State Geologists to define and prioritize areas for the acquisition of new geologic framework data (geologic mapping, geochemistry, lidar, and geophysics) to identify potential domestic resources of critical minerals. The USGS worked with representatives from State geological surveys and other institutions to delineate a series of focus areas that have potential for containing critical mineral resources. The focus areas are used as screening tools to guide selection of areas for new data acquisition. A mineral systems approach relating deposits, commodities, and critical minerals was adopted to identify focus areas that do, or could, contain mineral deposits that host the 35 critical minerals as defined by the USGS in 2018 and updated with 15 more commodities in 2022. Lacustrine evaporite system focus areas, for example, outline areas of known and potential lithium clays and residual brines. More than 800 focus areas have been defined for 24 mineral systems. About half of the focus areas contain documented critical mineral deposits, most of which produced small amounts of ore prior to 1950. A comprehensive table documenting the rationale for delineation, known deposits, critical mineral occurrences, historical production, and other data, supported by more than 4,000 references, is accompanied by GIS data that show the geographic distribution of the focus areas. More than 40 geologic mapping projects are underway along with 7 reconnaissance geochemistry projects by State surveys to provide the data needed to evaluate domestic critical mineral resource potential. Approximately 30 airborne geophysical surveys are planned or underway to enhance mapping interpretation and provide key information for subsurface mineral potential. More than 7,000 multi-element geochemical analyses have been completed; these data provide new insights into byproduct critical mineral potential such as vanadium in black shale and individual rare-earth elements enrichments, such as elevated (>1,000 ppm) neodymium in the Gallinas Mountains, NM and the Wet Mountains, CO. All Earth MRI data and project descriptions are available at https://www.usgs.gov/special-topics/earth-mri.