|Quadrangle map, 1:250,000-scale||SM|
|Quadrangle map, 1:63,360-scale||D-4|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||The Fairview prospect is along the the crest of a northwest-trending ridge, about 1.8 miles southwest of the mouth of McCally Creek. It is at an elevation of about 1,000 feet in the NE1/4 sec. 11, T. 19 N., R. 45 W., of the Seward Meridian. The prospect is locality 17 of Miller and others (1989). The location is accurate.|
The Fairview prospect is unusual because it is one of the few cinnabar prospects in the Kuskokwim mineral belt that is wholly in intrusive rock. The host rock is an altered, sericitized, quartz-feldspar-porphyry sill about 120 feet thick and 1,000 feet long that trends northwest, parallel to the strike of the shale and sandstone of the Upper Cretaceous, Kuskokwim Group that contains the sill (Cady and others, 1955; Sainsbury and MacKevett, 1965). The Fairview deposit has a 40Ar/39Ar isochron age of 72.6 Ma (Gray, Gent, and others, 1997); it is the only mercury deposit in the Red Devil area that has been dated.The mineralization consists of cinnabar, stibnite, and quartz that fills several parallel fractures in the central part of the altered felsic sill. In the early 1940s, three trenches were sampled by the U.S. Bureau of Mines (Webber and others (1947). One 50-foot zone in trench 1 averaged 0.15 percent mercury ; one 5-foot zone in trench 2 averaged 0.40 percent mercury.
|Geologic map unit||(-157.376977162573, 61.7566692229778)|
|Mineral deposit model||Silica-carbonate mercury (Cox and Singer, 1986; model 27c).|
|Mineral deposit model number||27c|
|Age of mineralization||The Fairview prospect has a 40Ar/39Ar age of 72.6 Ma (Gray, Gent, and others, 1997).|
|Alteration of deposit||Sericitic alteration in quartz-feldspar porphyry.|
|Workings or exploration||The property was discovered in the 1920s by tracing cinnabar-bearing float up slope from a stream below it. The Fairview prospect was staked in 1935 or 1936 (Webber and others, 1947). The U.S. Bureau of Mines trenched the property in 1943, but by 1959, the trenches were largely filled by vegetation (Sainsbury and MacKevett, 1965). Three trenches were cut normal to the felsic sill. In the early 1940s, the trenches were sampled by the U.S. Bureau of Mines (Webber and others (1947).|
|Indication of production||None|
Cady, W.M., Wallace, R.E., Hoare, J.M., and Webber, E.J., 1955, The central Kuskokwim region, Alaska: U.S. Geological Survey Professional Paper 268, 132 p.
Cobb, E.H., 1972, Metallic mineral resources map of the Sleetmute quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-368, 1 sheet, scale 1:250,000.
Cobb, E.H., 1976, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Dillingham, Sleetmute, and Taylor Mountains quadrangles, Alaska: U.S. Geological Survey Open-File Report 76-606, 92 p.
Gray, J.E., Gent, C.A., Snee, L.W., and Wilson, F.H., 1997, Epithermal mercury-antimony and gold-bearing vein lodes of southwest Alaska, in Goldfarb, R.J., and Miller, L.D., eds., Mineral Deposits of Alaska: Economic Geology Monograph 9, p. 287-305.
MacKevett, E.M., Jr., and Berg, H.C., 1963, Geology of the Red Devil quicksilver mine, Alaska: U.S. Geological Survey Bulletin 1142-G, p. G1-G16.
Miller, M.L., Belkin, H.E., Blodgett, R.B., Bundtzen, T.K., Cady, J.W., Goldfarb, R.J., Gray, J.E., McGimsey, R.G., and Simpson, S.L., 1989, Pre-field study and mineral resource assessment of the Sleetmute quadrangle, southwestern Alaska: U.S. Geological Survey Open-File Report 89-363, 115 p., 3 plates, scale 1:250,000.
Roedder, E., 1972, Compositions of fluid inclusions: U.S. Geological Survey Professional Paper 440-JJ, 164 p.
Sainsbury, C.L., and MacKevett, E.M., Jr., 1965, Quicksilver deposits of southwestern Alaska a description of the quicksilver mines and prospects, with special emphasis on the structural controls of ore deposition: U.S. Geological Survey Bulletin 1187, 89 p.
Webber, B.S., Bjorklund, S.C., Rutledge, F.A., Thomas, B.I., and Wright, W.S., 1947, Mercury deposits of southwestern Alaska: U.S. Bureau of Mines Report of Investigations 4065, 57 p.
Wells, J.T., and Ghiorso, M.S., 1988, Rock alteration, mercury transport, and metal deposition at Sulphur Bank, California: Economic Geology, vol. 83, p. 606-618.
White, D. E., and Robinson, C. E., 1962, Sulphur Bank, California, a major hot spring quicksilver deposit, in Engel, A.E.J., James, H.L., and Leonard, B.F., eds., Petrologic studies: A volume in honor of A.F. Buddington: Boulder, Colorado, Geological Society of America p. 397-428.
|Reporters||T.K. Bundtzen (Pacific Rim Geological Consulting, Inc.) and M.L. Miller (U.S. Geological Survey)|
|Last report date||5/3/2003|