Central Wasatch Mountains

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

Information leading to the delineation of this focus area

Basis for focus area Mining districts in central Wasatch Mountains including Park City, Big and Little Cottonwood, American Fork, and White Pine from Krahulec (2018b).
Identified resources Identified resources of molybdenum, silver, and zinc. Historical production of copper, gold, lead, silver, and zinc.
Production Park City district (1875-1978): 16,721,723 tons ore containing 1,453,867 oz Au, 253,344,128 oz Ag, 2,708,146,385 lbs Pb, 1,487,843,818 lbs Zn, and 128,967,698 lbs Cu (John, 2006); Cottonwood districts 1867-1976): ~830,023 tons ore containing 30,609 oz Au, 17,476,243 oz Ag, 18,110,308 lbs Cu, 251,811,521 lbs Pb, and 24,487,428 lbs Zn (James, 1979); American Fork district: ~175,000 tons ore at >500 ppm Ag, 9 ppm Au, 11% Pb, 2.6% Zn, and 1% Cu (Krahulec, 2018b).
Status Past mining.
Estimated resources Ontario mine 1980 reserves: 1,328,000 tons @ 4.5 opt Ag, 5.9% Pb, 9.2% Zn; White Pine Fork Mo deposit: 16 million tons @ 0.1% MoS2 resources.
Geologic maps Bryant and Nichols (1990), scale 1:100,000; Bromfield and others (1981), scale 1:48,000; Calkins and others (1943), scale 1:25,000; Baker and others (1966), scale 1:24,000; Bromfield and others (1970), scale 1:24,000; Bromfield and Crittenden (1971), scale 1:24,000; Crittenden (1965a, b), scale 1:24,000; Crittenden and others (1966), scale 1:24,000; James (1979), scale 1:24,000.
Geophysical data Inadequate Rank 4 aeromagnetic coverage.
Favorable rocks and structures Eocene-Oligocene granitic plutons and hypabyssal intrusions, Proterozoic to Jurassic sedimentary rocks (mostly carbonates, shales, and quartzites), Eocene-Oligocene volcanic rocks on east side of focus area (Elkhorn district).
Deposits Park City district (Ag, Pg, Zn, Cu, Au): Ontario, Silver King, Daly, Daly West and Judge, Park Utah, Park City Consolidated, Mayflower; Big and Little Cottonwood districts (Ag, Au, Pb): Emma, Flagstaff.
Evidence from mineral occurrences MRDS; UMOS (Utah Geological Survey, 2021).
Geochemical evidence Zinc produced from most deposits in focus area. Ore samples from Big Cottonwood district locally have high As contents (James, 1979). No data on other critical minerals.
Geophysical evidence Unknown.
Evidence from other sources See Krahulec (2018b).
Comments Park Premier porphyry Cu-Au system in Elkhorn district largely covered by Jordanelle Reservoir.
Cover thickness and description No significant cover.
Authors David A. John.
New data needs Digitization and synthesis of existing maps to identify gaps.
Geologic mapping and modeling needs Digitization and synthesis of existing maps to identify gaps.
Geophysical survey and modeling needs None requested at this time.
Digital elevation data needs Lidar complete over all but northwestern portion of the focus area. Small areas of inadequate lidar in eastern portion.