RECENT EARTH MAPPING RESOURCES INITIATIVE (EMRI) AND OTHER CRITICAL MINERALS-RELATED ACTIVITIES BY THE ALABAMA GEOLOGICAL SURVEY

In 2018, the Department of the Interior published an updated list identifying 35 minerals that are critical to the domestic security and economic prosperity of the United States. Alabama currently contains known deposits, prospects, and occurrences of at least 19 of these commodities, but may have as many as 26. In 2019, the Geological Survey of Alabama (GSA), working in conjunction with the U.S. Geological Survey’s (USGS) Earth Mapping Resources Initiative (EMRI), began a 2-year mapping and sampling project along the eastern Blue Ridge–Inner Piedmont terrane boundary in order to identify potential sources of granite-derived, regolith-hosted rare-earth element (REE)-bearing ion-adsorption clay deposits in east-central Alabama. Mapping for this project is being conducted on four 7.5-minute quadrangles that were previously mapped under the EDMAP component of the USGS’s National Cooperative Geologic Mapping Program (NCGMP) (i.e., Roanoke East, Ala.-Ga., and Roanoke West, Milltown, and Wadley South, Ala.). Fieldwork consists of field-checking, refining, and supplementing the existing EDMAP data in order to ensure compliance with the USGS’s Geologic Map Schema (GeMS). Over the course of this project, ~100 samples of granite-derived regolith will be collected and analyzed from the mapping area, as well as on five adjacent quadrangles (i.e., Lineville East, Mellow Valley, New Site, Ofelia, and Wadley North, Ala.), in order to evaluate the region’s potential for hosting REE-bearing clay deposits. Units targeted for sampling include the Almond Trondhjemite, Bluff Springs Granite, Kowaliga Gneiss, Long Island Creek Gneiss, Rock Mills Granite Gneiss, and Zana Granite. In 2019, the GSA, working in conjunction with the USGS’s National Geological and Geophysical Data Preservation Program (NGGDPP), also reviewed, created site-specific metadata for, and databased over 4,000 unique records of existing GSA critical minerals-related data, as well as scanned, georeferenced, and wrote metadata for 55 of the agency’s county mineral resource maps. Upon completion, the critical minerals database and metadata were uploaded to the USGS’s National Digital Catalog (NDC) and the scanned and georeferenced mineral resource maps were uploaded to the USGS’s National Geologic Mapping Database (NGMDB).