| Basis for focus area |
Drum Mountain mining district (Krahulec, 2018b) began as a copper, gold, and silver producer in 1872, but by the time active mining ended in 1976 the district had become the state’s largest manganese producer and produced minor amounts of halloysite clay, iron, and bismuth. Small porphyry Mo-Cu deposit with surrounding polymetallic (Cu-Au-Ag) vein, distal disseminated gold, and manganese carbonate replacement deposits. |
| Identified resources |
Historical production (and Utah's largest producer) of manganese. |
| Production |
Nearly 50 million lbs Mn, mainly from the Staats and Pratt mines around Mt. Laird Eocene quartz monzonite porphyry stock; distal disseminated deposits produced 3.2 Mt at 1.23 ppm Au. |
| Status |
Past mining; active exploration. |
| Estimated resources |
Porphyry Basin (EDM) porphyry Mo-Cu deposit, estimated resources 4 Mt at 0.22% Cu (Krahulec, 2015). |
| Geologic maps |
Hintze and Davis (2002b), scale 1:100,000. |
| Geophysical data |
Inadequate aeromagnetic and aeroradiometric coverage. |
| Favorable rocks and structures |
Eocene quartz monzonite porphyry stocks and dikes, Cambrian dolomitic beds at the base of the thick sequence of carbonate rocks (Crittenden and others, 1961). |
| Deposits |
Staats mine (MRDS dep_id: 10020440), Pratt mine (MRDS dep_id: 10020439), Copperhead, Black Jack (MRDS dep_id: 10020234), Black Diamond, Last Chance. |
| Evidence from mineral occurrences |
MRDS; UMOS (Utah Geological Survey, 2021). |
| Geochemical evidence |
Largest producer of Mn in Utah; minor Bi production; Cu-Au-Ag ores anomalous in As, Bi, Sb, Sn, Te; distal disseminated Au ore weakly anomalous in As, Bi, Sb (Lovering and McCarthy, 1978; Zimbelman and others, 1991; Krahulec, 2011a, 2015). |
| Geophysical evidence |
Unknown. |
| Evidence from other sources |
Crittenden and others (1961), Lovering and McCarthy (1978), Krahulec (2018b). |
| Comments |
Drum Mountains is the largest producing Mn mining district in Utah, also has produced Bi. Multiple eras of Au (sedimentary rock-hosted/Carlin style) and Cu (porphyry) exploration, including current active Au and Cu exploration. |
| Cover thickness and description |
Variable. |
| Authors |
Stephanie Mills. |
| New data needs |
Regional aeromagnetic, detailed mapping; airborne hyperspectral would be useful in this area. |
| Geologic mapping and modeling needs |
1:24,000 scale mapping. |
| Geophysical survey and modeling needs |
High-resolution, Rank 1 aeromagnetic and radiometric surveys. |
| Digital elevation data needs |
Lidar inadequate. |
