In response to Executive Order 13817 of December 20, 2017, the U.S. Geological Survey (USGS) coordinated with the Bureau of Land Management (BLM) to identify 35 nonfuel minerals or mineral materials considered critical to the economic and national security of the United States (U.S.) (https://pubs.usgs.gov/of/2018/1021/ofr20181021.pdf). Acquiring information on possible domestic sources of these critical minerals is the rationale for the USGS Earth Mapping Resources Initiative (Earth MRI). The program, which partners the USGS with State Geological Surveys, federal agencies, and the private sector, aims to collect new geological, geophysical, and topographic (lidar) data in key areas of the U.S. to stimulate mineral exploration and production of critical minerals. The first phase of Earth MRI focused on the study of rare-earth elements (REE) (https://pubs.er.usgs.gov/publication/ofr20191023A). Phase 2 version 2 (this report) focuses on the following minerals: aluminum, cobalt, graphite, lithium, niobium, platinum group elements (PGE), rare earth elements, tantalum, tin, titanium, and tungsten. The USGS has identified broad areas within the U.S. to target acquisition of geologic mapping, geophysical data, and (or) detailed topographic information to aid research, mineral exploration, and evaluation of mineral potential in these areas. Focus areas were defined using existing geologic data including data on known deposits in the U.S. The focus areas are provided as geospatial data supported by tables that summarize what is known about the mineral potential and brief descriptions of data gaps that could be addressed by the Earth MRI program. A full discussion of Earth MRI and the rationale and methods used to develop the geospatial data are provided in the following report: Hammarstrom, J.M., and others (in review)

In response to Executive Order 13817 of December 20, 2017, the U.S. Geological Survey (USGS) coordinated with the Bureau of Land Management (BLM) to identify 36 nonfuel minerals or mineral materials considered critical to the economic and national security of the United States (U.S.) (https://pubs.usgs.gov/of/2018/1021/ofr20181021.pdf). Acquiring information on possible domestic sources of these critical minerals is the rationale for the USGS Earth Mapping Resources Initiative (Earth MRI). The program, which partners the USGS with State Geological Surveys, Federal agencies, and the private sector, aims to collect new geological, geophysical, and topographic (lidar) data in key areas of the U.S. to stimulate mineral exploration and production of critical minerals. The USGS has identified broad areas within the United States to target acquisition of geologic mapping, geophysical data, and (or) detailed topographic information to aid research, mineral exploration, and evaluation of mineral potential in these areas. Focus areas were defined using existing geologic data including data on known deposits in the United States. The focus areas are provided as geospatial data supported by tables that summarize what is known about the mineral potential and brief descriptions of data gaps that could be addressed by the Earth MRI program. A full discussion of Earth MRI and the rationale and methods used to develop the geospatial data are provided in the following report: Hammarstrom, J.M., Dicken, C.L., Woodruff, L.G., Andersen, A.K., Brennan, S., Day, W.C., Drenth, B.J., Foley, N.K., Hall, S., Hofstra, A.H., McCafferty, A.E., Shah, A.K., and Ponce, D.A., 2022, Focus areas for data acquisition for potential domestic resources of 13 critical minerals in the conterminous United States and Puerto Rico—Antimony, barite, beryllium, chromium, fluorspar, hafnium, helium, magnesium, manganese, potash, uranium, vanadium, and zirconium, chap. D of U.S. Geological Survey, Focus areas for data acquisition for potential domestic sources of critical minerals: U.S. Geological Survey Open-File Report 2019–1023, 65 p., https://doi.org/10.3133/ofr20191023D.

In response to Executive Order 13817 of December 20, 2017, the U.S. Geological Survey (USGS) coordinated with the Bureau of Land Management (BLM) to identify 36 nonfuel minerals or mineral materials considered critical to the economic and national security of the United States (U.S.) (https://pubs.usgs.gov/of/2018/1021/ofr20181021.pdf). Acquiring information on possible domestic sources of these critical minerals is the rationale for the USGS Earth Mapping Resources Initiative (Earth MRI). The program, which partners the USGS with State Geological Surveys, Federal agencies, and the private sector, aims to collect new geological, geophysical, and topographic (lidar) data in key areas of the U.S. to stimulate mineral exploration and production of critical minerals. The USGS has identified broad areas within the United States to target acquisition of geologic mapping, geophysical data, and (or) detailed topographic information to aid research, mineral exploration, and evaluation of mineral potential in these areas. Focus areas were defined using existing geologic data including data on known deposits in the United States. The focus areas are provided as geospatial data supported by tables that summarize what is known about the mineral potential and brief descriptions of data gaps that could be addressed by the Earth MRI program. A full discussion of Earth MRI and the rationale and methods used to develop the geospatial data are provided in the following report: Hammarstrom, J.M., Dicken, C.L., Woodruff, L.G., Andersen, A.K., Brennan, S., Day, W.C., Drenth, B.J., Foley, N.K., Hall, S., Hofstra, A.H., McCafferty, A.E., Shah, A.K., and Ponce, D.A., 2022, Focus areas for data acquisition for potential domestic resources of 13 critical minerals in the conterminous United States and Puerto Rico—Antimony, barite, beryllium, chromium, fluorspar, hafnium, helium, magnesium, manganese, potash, uranium, vanadium, and zirconium, chap. D of U.S. Geological Survey, Focus areas for data acquisition for potential domestic sources of critical minerals: U.S. Geological Survey Open-File Report 2019–1023, 65 p., https://doi.org/10.3133/ofr20191023D.

In response to Executive Order 13817 of December 20, 2017, the U.S. Geological Survey (USGS) coordinated with the Bureau of Land Management (BLM) to identify 35 nonfuel minerals or mineral materials considered critical to the economic and national security of the United States (U.S.) (https://pubs.usgs.gov/of/2018/1021/ofr20181021.pdf). Acquiring information on possible domestic sources of these critical minerals is the rationale for the USGS Earth Mapping Resources Initiative (Earth MRI). The program, which partners the USGS with State Geological Surveys, Federal agencies, and the private sector, aims to collect new geological, geophysical, and topographic (lidar) data in key areas of the U.S. to stimulate mineral exploration and production of critical minerals. Phase 1 - rare earth elements (REE) - https://pubs.er.usgs.gov/publication/ofr20191023A. Phase 2 - aluminum, cobalt, graphite, lithium, niobium, platinum group elements (PGE), rare earth elements, tantalum, tin, titanium, and tungsten - https://pubs.er.usgs.gov/publication/ofr20191023B. Phase 3 (this report) - antimony, barite, beryllium, chromium, fluorspar, hafnium, helium, magnesium, manganese, potash, uranium, vanadium, and zirconium - https://pubs.er.usgs.gov/publication/ofr20191023D. The USGS has identified broad areas within the United States to target acquisition of geologic mapping, geophysical data, and (or) detailed topographic information to aid research, mineral exploration, and evaluation of mineral potential in these areas. Focus areas were defined using existing geologic data including data on known deposits in the United States. The focus areas are provided as geospatial data supported by tables that summarize what is known about the mineral potential and brief descriptions of data gaps that could be addressed by the Earth MRI program. A full discussion of Earth MRI and the rationale and methods used to develop the geospatial data are provided in the following report: Hammarstrom, J.M., and others (in review)

In response to Executive Order 13817 of December 20, 2017, the U.S. Geological Survey (USGS) coordinated with the Bureau of Land Management (BLM) to identify 35 nonfuel minerals or mineral materials considered critical to the economic and national security of the United States (U.S.) (https://pubs.usgs.gov/of/2018/1021/ofr20181021.pdf). Acquiring information on possible domestic sources of these critical minerals is the rationale for the USGS Earth Mapping Resources Initiative (Earth MRI). The program, which partners the USGS with State Geological Surveys, Federal agencies, and the private sector, aims to collect new geological, geophysical, and topographic (lidar) data in key areas of the U.S. to stimulate mineral exploration and production of critical minerals. Phase 1 - rare earth elements (REE) - https://pubs.er.usgs.gov/publication/ofr20191023A. Phase 2 - aluminum, cobalt, graphite, lithium, niobium, platinum group elements (PGE), rare earth elements, tantalum, tin, titanium, and tungsten - https://pubs.er.usgs.gov/publication/ofr20191023B. Phase 3 (this report) - antimony, barite, beryllium, chromium, fluorspar, hafnium, helium, magnesium, manganese, potash, uranium, vanadium, and zirconium - https://pubs.er.usgs.gov/publication/ofr20191023D. The USGS has identified broad areas within the United States to target acquisition of geologic mapping, geophysical data, and (or) detailed topographic information to aid research, mineral exploration, and evaluation of mineral potential in these areas. Focus areas were defined using existing geologic data including data on known deposits in the United States. The focus areas are provided as geospatial data supported by tables that summarize what is known about the mineral potential and brief descriptions of data gaps that could be addressed by the Earth MRI program. A full discussion of Earth MRI and the rationale and methods used to develop the geospatial data are provided in the following report: Hammarstrom, J.M., and others (in review)

In response to Executive Order 13817 of December 20, 2017, the U.S. Geological Survey (USGS) coordinated with the Bureau of Land Management (BLM) to identify 35 nonfuel minerals or mineral materials considered critical to the economic and national security of the United States (U.S.). Acquiring information on possible domestic sources of these critical minerals is the basis of the USGS Earth Mapping Resources Initiative (Earth MRI). The program, which partners the USGS with State Geological Surveys, federal agencies, and the private sector, aims to collect new geological, geophysical, and topographic (lidar) data in key areas of the U.S. to stimulate mineral exploration and production of critical minerals. The first phase of Earth MRI focuses on the study of rare-earth elements (REE). The USGS has identified broad areas within the U.S. to target acquisition of geologic mapping, geophysical data, and (or) detailed topographic information to aid research, mineral exploration, and evaluation of REE potential in these areas. Focus areas were defined using existing geologic data on known REE deposits in the U.S. The focus areas are provided as geospatial data supported by tables that summarize what is known about the REE potential and brief descriptions of data gaps that could be addressed by the Earth MRI program. A full discussion of Earth MRI and the rationale and methods used to develop the geospatial data are provided in the following report: Hammarstrom, J.H., and Dicken, C.L., 2019, Focus areas for data acquisition for potential domestic sources of critical minerals—Rare earth elements, chap. A of U.S. Geological Survey, Focus areas for data acquisition for potential domestic sources of critical minerals: U.S. Geological Survey Open-File Report 2019–1023, 11 p., https://doi.org/10.3133/ofr20191023A.

This data release provides descriptions of more than 60 mineral regions, mines, and mineral deposits within the United States and its territories that are reported to contain enrichments of cobalt (Co). To focus the scope of this data release, we report only mined deposits and exploration prospects with past production, or resource and reserve estimates of 1,000 metric tons or more of cobalt. Cobalt has diverse uses because of its properties, which include ferromagnetism, hardness, wear-resistance, low conductivity, and high melting point. The primary uses for cobalt are in rechargeable battery electrodes, and in superalloys used to make gas turbine engines. In 2017, the United States had a net import reliance as a percentage of apparent consumption of 72 percent for cobalt, and cobalt is considered a critical mineral. Cobalt mineralogy is diverse; it occurs in a variety of sulfide, arsenide, sulfarsenide, and oxyhydroxide minerals. In the United States, cobalt could be derived as a byproduct from mineral deposits that primarily produce other metals, including nickel, copper, zinc, and lead. The inclusion of a particular mineral deposit or prospect in this database is not meant to imply that it has economic potential. Rather, these entries were included to capture the characteristics of the deposits and prospects in the United States and its territories that have the largest cobalt resources. These deposits and prospects occur in Alaska, California, Idaho, Maine, Michigan, Minnesota, Missouri, Montana, North Carolina, New Mexico, Oregon, Pennsylvania, Puerto Rico and Tennessee. Several deposits and prospects were not included in this database, because they contain less than 1,000 metric tons of cobalt. A prime example is the Bunkerville project in Nevada (Ludington and others, 2006). The Stillwater deposit in Montana produced cobalt, but this was a byproduct, and to our knowledge, there are no published records of the amount of cobalt produced, or the amount of cobalt contained within the deposit. Analyses of rock chips from 47 outcrops of the Katahdin deposit in Maine indicates that the deposit locally contains approximately 0.1 percent cobalt (Miller, 1945), but a thorough analysis of the deposit is lacking. Mine La Motte in Missouri and the Stone Corral project in California were not included because of a lack of ore reserve information in publicly available references. However, we are aware that cobalt is present in the area and we welcome further information on these sites. The entries and descriptions in the database were derived from published papers, reports, data, and internet documents, published from 1908 to 2018, representing a variety of sources, including geologic and exploration studies described in State, Federal, and industry reports. Although an attempt was made to capture as many examples as possible, this dataset is a progress report that is part of an ongoing effort. The authors welcome additional published information in order to continually update and refine this dataset.