Hall Mountain mineral district

Region West, Northwest
Mineral systems
Deposit types
Other minerals

Information leading to the delineation of this focus area

Basis for focus area REE-bearing veins. Reported REE minerals in veins; polygon drawn to include related USMIN and MRDS localities of similar type and geologic setting.
Identified resources Identified thorium resources.
Production Unknown.
Status Past exploration.
Estimated resources Estimated Th reserves of 104,300 metric tons (115,000 tons) of vein material averaging 4.0% ThO2 and low overall concentrations (average about 0.05%) REO (Staatz, Armbrustmacher and others, 1979).
Geologic maps Newton and others (1960), scale 1:60,730; Miller and Burmester (2004), scale 1:100,000; Burmester and others (2011), scale 1:24,000; Breckenridge and others (2011), scale 1:24,000; Breckenridge and others (2014), scale 1:75,000.
Geophysical data Inadequate aeromagnetic and aeroradiometric coverage.
Favorable rocks and structures Veins cutting Mesoproterozoic fine-grained arkose and quartz diorite.
Deposits Hall Mountain (MRDS dep_id: 10143778), Hall Mountain Group (1 to 14) (USMIN Site_ID: ID00025).
Evidence from mineral occurrences MRDS; USMIN.
Geochemical evidence Total REE concentrations range from 0.00111 to 0.197%; ThO2 concentrations range from 0.0095 to 21% in Staatz (1972a) and Staatz and others (1974). Staatz, Armbrustmacher and others (1979).
Geophysical evidence Unknown.
Evidence from other sources Thorite, allanite, monazite, sphene, zircon, ilmenite.
Comments Diabase sill hosted, no evidence for felsic rocks. Hydrothermal veins are not really properly classified in this hierarchy.
Cover thickness and description Variable.
Authors Karen Lund, Thomas P. Frost, Joshua M. Rosera.
New data needs Geophysics.
Geologic mapping and modeling needs Quadrangle-scale mapping adequate.
Geophysical survey and modeling needs High-resolution, Rank 1 aeromagnetic and aeroradiometric coverage.
Digital elevation data needs Lidar in progress.