| Basis for focus area |
Focus area includes Montezuma Canyon, La Sal Creek, White Canyon, Henry Mountains, Circle Cliffs, San Rafael Swell, Lisbon Valley, Dry Valley, La Sal, Browns Hole, Cottonwood Wash, Thompson, Seven Mile Canyon, San Rafael River, Mineral Canyon, Orange Cliffs, Monument Valley, Little Grand, Paria East, Uinta Basin, West San Rafael, Cedar Mountain, Kaparowits, Uravan, and San Juan mining districts from Utah, Colorado, Arizona, and New Mexico. Utah outlines are based on Krahulec (2018b). The Uravan focus area includes the Uravan district, including the Bull Canyon and Slick Rock areas in Colorado (Chenoweth, 1980) and the San Rafael River and Ucolo districts in Utah (Krahulec, 2018b). Uranium deposits are hosted mostly in the Salt Wash and conglomerate-rich portions of the Brushy Basin Members of the Jurassic Morrison Formation. Small deposits are also reported in the Moss Back member of the Chinle Formation in the Slick Rock District (Shawe, 2011). Clusters of tabular deposits with associated small-scale rolls (a few meters high) are associated with paleo channels. Radium, V and U have been mined in succession from the Uravan belt (Chenoweth, 1981; Shawe, 2011). The Shiprock focus area includes the New Mexico Carrizo and Chuska Mountain subdistricts, Shiprock and Tocito Dome district (McLemore, 2011), and the Cove Mesa, West Carrizo and Red Rock uranium districts in Arizona (Chenoweth and Malan, 1973). The uranium focus area was drawn to include U and V deposits in the Jurassic Morrison Formation, and was drawn broadly to include identified occurrences and producers throughout the region. The Grants U district produced over 340 million pounds of U3O8 from hundreds of mines that developed tabular and roll-front sandstone deposits in the Cretaceous Dakota Formation and the Poison Canyon, Westwater Canyon, Jackpile Sandstone, and Recapture Shale members of the Jurassic Morrison Formation. This focus area includes identified deposits within the Morrison Formation, and the boundaries were also informed by subdistrict maps published by the state of New Mexico (McLemore, 2011). Note that deposits mined from the Todilto Limestone within the Grants uranium district are considered as a separate U source area because they are considered a separate mineral system. The Red Basin mine produced U in 1957, with ongoing exploration up to 2014 (Millrock, 2014). The focus area was drawn around identified occurrences including in the Red Basin-Pietown and Hook Ranch-Riley U districts (McLemore, 2017). Deposits are in bleached sandstones and shales at the unconformity between the Cretaceous Crevasse Canyon Formation and the overlying Eocene Baca Formation. |
| Identified resources |
Identified resources and historical production of uranium and vanadium. |
| Production |
Utah has produced an estimated 122 million lbs U3O8 and 136 million lbs V2O5 since 1904. About 240 mines in the AEC Uravan ore reserve area produced about 21 million lbs of U3O8 and 37,000 tV between 1948 and 1990 (Pool, 2017). Before 1947, about 1.7 million kg U3O8 and 12 million kg V2O5 were mined from the Uravan (Chenoweth, 1981). About 134 mines produced about 3.9 million lbs U3O8 and 6,603 tV from the Shiprock AEC ore reserve area district between 1948 and 1967. The largest producer was the Mesa Group near Lukachukai in Arizona that produced 2.7 million lbs U3O8 and 3,996 tV (Pool, 2017). McLemore (2020) reports that 493,510 lbs U3O8 was mined from the Carrizon and Chuska subdistricts from 1948-1982 (159,000 lbs from the Carrizo Mountains and 333,685 lbs from the Chuska Mountains). Enos Johnson mine produced 138,732 lbs U3O8 at a grade of 0.19% U3O8 (McLemore and others, 2013). In all, about 340 million lbs U3O8 was produced from the Grants district between 1947 and 2002 (McLemore, 2011). Lists of mine production in McLemore (1983) and McLemore and others (2013, appendix 1). The Red Basin mine produced about 1,000 lbs U3O8 and 0.22 tV between 1954 and 1957 (Pool, 2017). |
| Status |
Past mining. Permitted mines on standby, established resources, active exploration; exploration at Wray Mesa (estimated exploration targets range between the following: 240,000 and 540,000 lbs U3O8 and 960,000 and 5,400,000 lbs V2O5 at grades ranging from 0.15% and 0.18% U3O8 and 0.6 and 1.8% V2O5 (Hartman, 2019). See McLemore and others (2013), appendix 1. Exploration at the Yellow Cat U-V project in Morrison Formation (Anson Resources, 2020b). |
| Estimated resources |
Utah contains total estimated resources of 49,450,000 lbs U3O8 and 58,340,000 lbs V2O5 (Mills and Jordan, 2021). Estimated In-place resources of about 390 million lbs U3O8 are reported by McLemore (2011) for the Grants Mineral Belt in more than 40 deposits. One of the largest U deposits in the United States is Mt. Taylor with about 100 million lbs U3O8 (UxC, 2019), is in the eastern portion of the Grants mineral belt. Six million lbs 0.05% U3O8 reported at C de Baca (Bersch, 2008). See McLemore and others (2013) for a list of deposits and resources. |
| Geologic maps |
Utah: majority of Utah area is covered by 1:24,000 mapping; New Mexico: Horton and others (2017), scale 1:500,000 and New Mexico Bureau of Geology and Mineral Resources (2003), scale 1:500,000. |
| Geophysical data |
Inadequate aeromagnetic and aeroradiometric coverage. |
| Favorable rocks and structures |
Jurassic Morrison Formation (Salt Wash and Brushy Basin Members) and Summerville Formation; Triassic Chinle Formation (Shinarump, Monitor Butte and Moss Back Members); Permian Moenkopi and Cutler Formations. Upper Jurassic Morrison Formation. Vanadium more prevalent in the Salt Wash and Recapture Members, especially near King Tutt Mesa in New Mexico. Jurassic Morrison Formation, Jurassic Wanakah (Summerville) sandstone, Cretaceous Dakota Formation. More than 90% of the discovered uranium resources are in the Westwater Canyon of the Morrison Formation (McCammon and others, 1986). The vanadium: uranium ratio is higher in the Salt Wash and Recapture members of the Morrison Formation. Paleo-structural highs may be important in focusing and controlling mineralization (Sanford, 1992). Eocene Baca Formation with some mineralization extending into the underlying Cretaceous Crevasse Canyon Formation. |
| Deposits |
Over 1000 U (V) mineral occurrences identified for the Colorado Plateau in the UMOS database (Utah Geological Survey, 2021); Over 240 mines are identified in the AEC database for the Uravan focus area. The largest producers were the King Solomon, Eula Belle, and Long Park Group. New Mexico: Begay Group, Lookout Point, Shadyside, Nelson Point, East Reservation, Oak Springs Gravel Cap, Plot 7 Oak Springs, Enos Johnson Group. Arizona: Rattlesnake, Simpson, Cato Group, Cisco Group, Cove Mesa Group, Flag Mesa 1, Frank 1, Mesa Group (Shiprock), Step Mesa, Frank Jr Cato 1, Jackpile-Paguate, Windwhip, Woodrow mine, Cebolleta-Grant, Saint Anthony, JJ L-Bar Ranch, San Antonio Valley, Marquez Canyon, Bernabe-Montaro, and numerous others, Red Basin mine, Hooks Ranch, C de Baca, Mesa Alta. |
| Evidence from mineral occurrences |
International Atomic Energy Agency (2020b); U.S. Environmental Protection Agency (2006); well known and documented deposits with many publications; UMOS (Utah Geological Survey, 2021); Mills and Jordan (2021). |
| Geochemical evidence |
Multiple geochemical anomalies identified in original NURE stream sediment sampling. |
| Geophysical evidence |
Unknown. |
| Evidence from other sources |
Krahulec (2018b), Mills and Rupke (2020), Mills and Jordan (2021), McCammon and others (1986) estimated a uranium endowment of 2.6 x 106 tonnes of U3O8 in the Westwater Canyon Member of the Morrison Formation in the San Juan basin, the southern portion of which includes the Grants mineral belt. Following a spike in short-term U prices in 2007, and attracted by the large in place resource, the Grants mineral belt was actively explored by a large cast of characters including Uranium Resources Inc., Energy Fuels Inc., Laramide Resources, Uranium Energy Corporation, enCore Energy and others. Work was largely to expand resources near known mineralization and test for potential in situ mining. The Red Basin mine area (central polygon) was the focus of exploration by Millrock Resources Inc. in 2014. Occidental Minerals (in 1980s) and Max Resources (in 2007) explored the C de Baca area 14 miles north of Magdalena, New Mexico (eastern polygon). Historical resources of about 500,000 lbs U3O8 are reported at Casa de Baca, but are not confirmed. Strategic Resources drilled in 2008-2009 (core at New Mexico Bureau of Geology and Mineral Resources). |
| Comments |
The Colorado Plateau is one of the most significant U jurisdictions in the United States, and is the most significant V area. Other metals known in the Plateau include Cu, Mn, Li, Mg, He, and potash (see Paradox Basin focus area) and the area has potential for Co based on limited geochemical sampling and exploration. New Mexico drill core available at the New Mexico Bureau of Geology and Mineral Resources. |
| Cover thickness and description |
Variable. |
| Authors |
Stephanie Mills, Susan Hall, Virginia T. McLemore, Michael O'Keefe, Carson A. Richardson. |
| New data needs |
Modern geochemistry from NURE sediment program; digitized and updated ore deposit mapping; regional aeromagnetic and aeroradiometric survey. |
| Geologic mapping and modeling needs |
Digitization and synthesis of existing maps to identify gaps; Update and digitize (GIS) ore deposit maps that delineate ore deposits mined and ore deposits remaining to be mined. Most areas in New Mexico have been mapped at a scale of 1:24,000. |
| Geophysical survey and modeling needs |
High-resolution, Rank 1 aeromagnetic and radiometric surveys. |
| Digital elevation data needs |
Lidar variable. High-resolution lidar is needed to define mine waste and tailings under reclamation for examination of mining waste potential. |
