| Basis for focus area |
Precambrian mafic/ultramafic metasedimentary and metavolcanic belts, associated dike, sill, vein, and pegmatite complexes, and derived placers – all with similar depositional and metamorphic histories not included within other focus areas included here; This deposit type includes volcanogenic massive sulfide deposits units in the Black Hills, Hartville Uplift and at South Pass. With the exception of the somewhat better-understood South Pass greenstone belt, these metasedimentary and metavolcanic rocks have generally poorly constrained mineral potential. |
| Identified resources |
Historical production of copper, gold, and iron. |
| Production |
Unknown. |
| Status |
Past mining. |
| Estimated resources |
Unknown. |
| Geologic maps |
Harris and others (1985), scale 1:500,000; Love and Christiansen (1985), scale 1:500,000; Mineral system-specific maps include: Wind Rivers/South Pass: Hausel (1991), scale 1:48,000; Houston and others (1992), scale 1:1,000,000; Scott and Sutherland (2009), scale 1:100,000; Sutherland and Hausel (2006), scale 1:100,000); Hartville Uplift: Day and others (1999), scale 1;24,000; Houston and others (1992), scale 1:1,000,000; McLaughlin and Harris (2005), scale 1:100,000; McLaughlin and others (2011), scale 1:100,000; Sims and Day (1999), scale 1;48:000; Sims and others (1997), scale 1:24,000; Black Hills: Sutherland (2007b), scale 1:100,000. |
| Geophysical data |
Inadequate aeromagnetic and aeroradiometric coverage. |
| Favorable rocks and structures |
Metadacite and iron-formation at South Pass; Graphitic metapelite, cherty exhalite, and carbonate layers in muscovite schist at Hartville Uplift; hornblende schist in Black Hills. |
| Deposits |
Green Hope mine (MRDS dep_id: 10278837), Tabor Grand mine (MRDS dep_id: 10279201), Carissa mine (MRDS dep_id: 10111268), B&H Mining Company (MRDS dep_id: 10278683), Diana mine (MRDS dep_id: 10254726), Midas mine (MRDS dep_id: 10132968); Barite: Sunrise mine (MRDS dep_id: 10254298). |
| Evidence from mineral occurrences |
MRDS. |
| Geochemical evidence |
From Hausel (1988): assay of 3 volcanogenic massive sulfide samples at McCann Pass in Hartville Uplift only analyzed for Au, Ag; although no other analyses available, potential for elevated Ba and Mn in most volcanogenic massive sulfide deposits exists. From Houston and others (1992), 40 ft of "silver-rich pyrite-sphalerite massive sulfide were found by a single drill hole into a deeply buried sulfide body." From Sutherland and others (2018): elevated Sb concentrations (at least 5 times crustal abundance) in the Hartville Uplift Whalen Group. |
| Geophysical evidence |
No data. |
| Evidence from other sources |
No data. |
| Cover thickness and description |
Variable, mix of good exposure to thick surficial cover and heavily forested areas. |
| Authors |
Rachel N. Toner, Patricia M. Webber, Benjamin J. Drenth. |
| New data needs |
New Rank 1 geophysics-supported and modern geochronology-supported mapping could be a game-changer. Could use new reconnaissance geochemistry. |
| Geologic mapping and modeling needs |
Variable, but new, modern 1:24,000 scale mapping generally needed, supported by Rank 1 geophysics and modern geochronology. |
| Geophysical survey and modeling needs |
Rank 1 aeromagnetics and aeroradiometrics. |
| Digital elevation data needs |
Lidar complete in Wyoming. |
