Poison Basin

Region West, Rocky Mountains
Mineral systems
Deposit types
Critical minerals
Other minerals

Information leading to the delineation of this focus area

Basis for focus area The Maybell focus area includes identified uranium occurrences and the surrounding favorable area identified during the National Uranium Resource Evaluation program (U.S. Department of Energy, 1980). Tabular sandstone uranium deposits formed in locally tuffaceous, fluvial, arkosic sandstone in the Miocene Browns Park Formation (Elevatorski, 1976).
Identified resources Identified resources or uranium and vanadium; historical production of uranium.
Production Poison Basin (Wyoming): ~ 75,000 lbs U3O8 from the Baggs mine from 1955 to 1964 (Pool, 2017).
Status Past mining.
Estimated resources The Juniper Ridge deposit in the Poison Basin (Wyoming) contains ~7.7 million lbs U3O8 (Dahlkamp, 2010). Ore grade from 0.004 to 3.21% U3O8 and 0.6 to 0.16% V2O5 (Elevatorski, 1976).
Geologic maps Horton and others (2017), scale 1:500,000; Barclay (1976), scale 1:24,000; Scott and others (2011), scale 1:100,000; Case and Hallberg (2006), scaleĀ 1:100,000.
Geophysical data Inadequate aeromagnetic and aeroradiometric coverage.
Favorable rocks and structures Miocene Browns Park Formation.
Deposits Poison Basin claim group (MRDS dep_id: 10018832), Cedar Hills 1-12 (MRDS dep_id: 10230279), Teton Group (MRDS dep_id: 10157661), Lucky Strike, School Section.
Evidence from mineral occurrences MRDS; International Atomic Energy Agency (2020b); U.S. Environmental Protection Agency (2006).
Geochemical evidence Unoxidized ores of uraninite and coffinite; oxidized ores of uranophane, meta-autinite, schroeckingerite, and uranyl vanadates.
Geophysical evidence No data.
Evidence from other sources No data.
Cover thickness and description Variable, generally less than 30 m; mostly Browns Park Formation, and Quaternary deposits.
Authors Susan Hall, Robert W. Gregory, Ranie M. Lynds.
New data needs Geologic mapping, airborne electromagnetics and radiometrics could be useful especially as host rocks are shallow.
Geologic mapping and modeling needs 1:24,000 scale mapping needed.
Geophysical survey and modeling needs Electromagnetics and aeroradiometric data may be very helpful.
Digital elevation data needs Lidar complete in Wyoming.