Fairview

Prospect, Inactive

Commodities and mineralogy

Main commodities Hg
Other commodities Sb
Ore minerals cinnabar; stibnite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale SM
Quadrangle map, 1:63,360-scale D-4
Latitude 61.75736
Longitude -157.3746
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.

Geologic setting

Geologic description

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.

Production and reserves

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

References

MRDS Number A013438

References

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.
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