|Quadrangle map, 1:250,000-scale||JU|
|Quadrangle map, 1:63,360-scale||B-1|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||The Gold and Curry Mine is an elevation of approximately 3,000 feet on the north side of upper Sheep Creek. It is on the southwest end of Powerline Ridge, 1.2 mile southeast of Sheep Mountain, and 2 miles east of Roberts Peak, near the center of the S1/2 section 27, T. 41 S., R. 68 E. of the Copper River Meridian. The location is accurate.|
The Gould and Curry Mine was discovered before 1890 and was developed by 2 adits, a shaft, and 2 stopes open to the surface (Redman and others, 1989). In 1895, a 4,500-foot tram was used to bring the ore to a 5-stamp mill on the valley floor (Cobb, 1978 [OFR 78-374]). An estimated 1,250 ounces of gold was produced in 1895; there may have been some production in 1894 but production records are not available. The country rocks are amphibolite and black phyllite that have been folded into two synclines and an anticline having wavelengths of about 50 feet. The deposit consists of three large quartz veins up to 150 feet long and 3 feet thick that parallel the axial planes of the folds, but crosscut foliation (Redman and others, 1989). The veins contain native gold, pyrite, pyrrhotite, and sphalerite. The U.S. Bureau of Mines has estimated an inferred resource of 4,000 tons of ore with 0.2 ounce of gold per ton (Redman and others, 1989). Their samples of the veins contained up to 26.2 ppm gold, and 5.2 percent zinc. Some cadmium may also be present (Redman and others, 1989).This mine is in the Juneau Gold Belt, which consists of more than 200 gold-quartz-vein deposits that have produced nearly 7 million ounces of gold. These gold-bearing mesothermal quartz vein systems form a zone 160 km long by 5 to 8 km wide along the western margin of the Coast Mountains. The vein systems are in or near shear zones adjacent to west-verging, mid-Cretaceous thrust faults. The veins are hosted by diverse, variably metamorphosed, sedimentary, volcanic, and intrusive rocks. From the Coast Mountains batholith westward, the host rocks include mixed metasedimentary and metavolcanic sequences of Carboniferous and older, Permian and Triassic, and Jurassic-Cretaceous age. The sequences are juxtaposed along mid-Cretaceous thrust faults (Miller and others, 1994). The sequences are intruded by mid-Cretaceous to middle Eocene plutons, mainly diorite, tonalite, granodiorite, quartz monzonite, and granite. Sheetlike tonalite plutons emplaced just east of the Juneau Gold Belt and undeformed granite and granodiorite bodies that are emplaced farther to the east are between 55 and 48 Ma (Gehrels and others, 1991). The structural grain of the belt is defined by northwest-striking, moderately to steeply northeast-dipping, penetrative foliation that developed between Cretaceous and Eocene time (Miller and others, 1994). The majority of the veins in the Juneau Gold Belt strike northwest. Isotopic dates indicate that the auriferous veins in the Juneau Gold Belt formed between 56 and 55 Ma (Miller and others, 1994; Goldfarb and others, 1997).
|Geologic map unit||(-134.274264595403, 58.2828733440039)|
|Mineral deposit model||Low-sulfide Au-quartz vein (Cox and Singer, 1986; model 36a)|
|Mineral deposit model number||36a|
|Age of mineralization||Isotopic dates indicate that the auriferous veins in the Juneau Gold Belt formed between 56 and 55 Ma (Miller and others, 1994; Goldfarb and others, 1997).|
|Workings or exploration||The Gould and Curry Mine was discovered before 1890 and was developed by 2 adits, a shaft, and 2 stopes open to the surface (Redman and others, 1989). In 1895, a 4,500-foot wire tram was used to bring the ore to a 5-stamp mill on the valley floor.|
|Indication of production||Yes; small|
|Reserve estimates||The U.S. Bureau of Mines has estimated an inferred resource of 4,000 tons of ore with 0.2 ounce of gold per ton.|
|Production notes||An estimated 1,250 ounces of gold was produced in 1895; there may have been some production in 1894 but production records are not available.|
Cobb, E.H., 1978, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Juneau quadrangle, Alaska: U.S. Geological Survey Open-File Report 78-374, 155 p.
Gehrels, G.E., McClelland, W.C., Samson, S.D., and Patchett, P.J., 1991, U-Pb geochronology of detrital zircons from a continental margin assemblage in the northern Coast Mountains, southeastern Alaska: Canadian Journal of Earth Sciences, v. 28, no. 8, p.1285-1300.
Goldfarb, R.J., Miller, L.D., Leach, D.L., and Snee, L.W, 1997, Gold deposits in metamorphic rocks in Alaska, in Goldfarb, R.J., and Miller, L.D., eds., Mineral Deposits of Alaska: Economic Geology Monograph 9, p. 151-190.
Miller, L.D., Goldfarb, R.J., Gehrels, G,E., and Snee, L.W., 1994, Genetic links among fluid cycling, vein formation, regional deformation, and plutonism in the Juneau gold belt, southeastern Alaska: Geology, v. 22, p. 203-206
Redman, E.C., Maas, K.M., Kurtak, J.M., and Miller, L.D., 1991, Section D: Juneau Gold Belt subarea, in U.S. Bureau of Mines, Mineral investigations in the Juneau Mining District, Alaska, 1984-1988: Volume 2 - Detailed mine, prospect, and mineral occurrence descriptions: U.S. Bureau of Mines Special Publication VOL. 2D, 424 p., 19 sheets.
|Reporters||J.C. Barnett and L.D. Miller (Juneau, Alaska )|
|Last report date||12/15/2001|