Mineral Hill

Region West, Northwest
Mineral systems
Deposit types
Critical minerals
Other minerals

Information leading to the delineation of this focus area

Basis for focus area Polygons extracted and merged from National Assessment tract NR48, previously categorized as Homestake stratiform Au (Long and others, 1998).
Identified resources Indicated resources of gold. Historical production of arsenic, copper, gold, lead, silver, and tungsten.
Production Past production: 1,916,000 total metric tons ore, yielding 14 metric tons Au, 1 metric ton Ag, negligible Cu and Pb, and unknown amounts of As and W (Long and others, 1998). Production included over 200,000 oz Au, with Ag, As, and W before 1948. Approximately 240,000 oz Au from 1800s to 1948. From 1989 to 1996: 270,000 oz Au from a 430,000 oz Au resource at Crevice Mountain deposit.
Status Past mining; mines are currently shut down and reclaimed.
Estimated resources Estimate of 1,295,000 total tons of ore including 12 metric tons Au (Long and others, 1998).
Geologic maps Ruppel and others (1993), scale 1:250,000; Kellogg and Williams (2005), scale 1:100,000; O'Neill and Christiansen (2004), scale 1:100,000; Berg and others (1999), scale 1:100,000.
Geophysical data Inadequate aeromagnetic and aeroradiometric coverage.
Favorable rocks and structures Stratabound Au in iron-formation. Mineralization is hosted by 3.0 to 3.2 Ga lower amphibolite facies grunerite-bearing banded iron-formation and metaturbidites on the Wyoming Craton. Three types of ore have been mined: 1) dominant style where Au is contained in marginal wall rock altered envelopes of arsenopyrite, pyrrhotite, hornblende and grunerite sandwiching 0.01 to 1 m-thick quartz veins within iron-formation; 2) in generally less than 5 m thick banded quartz veins with little or no accompanying wall rock alteration; and 3) in deformed quartz boudins.
Deposits Mineral Hill mine (Jardine mine) (MRDS dep_id: 10245632).
Evidence from mineral occurrences MRDS.
Geochemical evidence Arsenopyrite veins associated with cummingtonite. Arsenopyrite, pyrrhotite, pyrite, and scheelite accompany Au mineralization.
Geophysical evidence Unknown.
Evidence from other sources Unknown.
Cover thickness and description Unknown.
Authors Allen K. Andersen, Kaleb C. Scarberry.
New data needs Geologic mapping, geophysical, and geochemical surveys.
Geologic mapping and modeling needs Targeted 1:24,000 mapping and mine-site mapping.
Geophysical survey and modeling needs High resolution, Rank 1 aeromagnetic and aeroradiometric coverage.