Johnson; Johnson and Martin Prospect, Fairbanks District, Fairbanks North Star Borough, Alaska, USA
Location: Cobb (1972, MF-413), loc. 38; NW1/4NE1/4 sec. 25, T. 3 N., R. 1 E., of the Fairbanks Meridian. The Johnson prospect is near the mouth of Willow Creek, a headwater tributary of Cleary Creek. Accuracy is within 1,000 feet.
Geology: In 1942, a placer cut on Willow Creek exposed high-grade stibnite in several parts of a wide quartz zone (Joesting, 1943). The vertical vein of stibnite with occasional quartz and other sulfides is 6 to 8 inches wide and was traced N 40 E for 75 feet (Killeen and Mertie, 1951). Nearby in 1912, a shaft was sunk 16 feet on a narrow quartz stringer carrying stibnite (Killeen and Mertie, 1951). Massive stibnite was identified on the dumps at the Johnson and Martin prospect with coarse grained scheelite (Byers, 1957). The prospect was examined by Metz and Robinson (1980) who noted that massive stibnite and scheelite were in quartz muscovite schist striking N 60 E and dipping 25 NW. Ore exposed in a 28-inch-thick horizon in a small pit on the prospect contained abundant coarse- to fine-grained stibnite, discrete bands of coarse scheelite grains to 0.8 inches across, and minor pyrite and arsenopyrite. By volume, stibnite constitutes 95% of the lens, scheelite 4% and arsenopyrite and pyrite constitute 1% each. In 1986 the prospect was examined by Fairbanks Exploration Inc. (Fairbanks Exploration Inc., unpublished report, 1986). The deposit consisted of disseminated to massive coarse-bladed stibnite with coarse-grained scheelite crystals disseminated in the stibnite. Gold values ranged from 420 ppb to 2450 ppb, silver values ranged from trace to 2.21 ounces of silver per ton, antimony values were greater than 10,000 ppm and arsenic values ranged from 600 to 800 ppm. Extensive trenching was conducted by Yukon Tanana Mining Company in the vicinity of the Johnson and Martin prospect in 1988, however the results of this work are not known (Freeman, 1992).
Workings: In 1912, a shaft was sunk 16 feet on a narrow quartz stringer carrying stibnite (Killeen and Mertie, 1951). Extensive trenching was conducted by Yukon Tanana Mining Company in the vicinity of the Johnson and Martin prospect in 1988 (Freeman, 1992).
Production: No record of production.
Commodities (Major) - Sb; (Minor) - W
Development Status: Undetermined
Deposit Model: Stibnite vein (Cox and Singer, 1986; model 27d).
ReferencesBerg, H.C., and Cobb, E.H., 1967, Metalliferous lode deposits of Alaska: U.S. Geological Survey Bulletin 1246, 254 p. Byers, F.M., Jr., 1957, Tungsten deposits in the Fairbanks district, Alaska: U.S. Geological Survey Bulletin 1024-I, p. 179-216. Chapman, R.M., and Foster, R.L., 1969, Lode mines and prospects in the Fairbanks district, Alaska: U.S. Geological Survey Professional Paper 625-D, 25 p., 1 plate. Cobb, E.H., 1972, Metallic mineral resources map of the Livengood quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-413, 2 sheets, scale 1:250,000. Cobb, E.H., 1975, Mineral resources of Alaska, in Yount, M.E., ed., U.S. Geological Survey Alaska Program, 1975: U.S. Geological Survey Circular 722, p. 37. Cobb, E.H., 1976, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Livengood quadrangle, Alaska: U.S. Geological Survey Open-File Report 76-819, 241 p. Freeman, C.J., 1992, 1991 Golden Summit project final report, volume 2: Historical summary of lode mines and prospects in the Golden Summit project area, Alaska: Avalon Development Corp., 159 p. (Report held by Freegold Recovery Inc. USA, Vancouver, British Columbia.) Joesting, H.R., 1943, Strategic mineral occurrences in interior Alaska, supplement to pamphlet no. 1: Alaska Territorial Department of Mines Pamphlet 2, 26 p. Killeen, P.L., and Mertie, J.B., 1951, Antimony ore in the Fairbanks District, Alaska: U.S. Geological Survey Open-File Report 51-46, 43 p. Metz, P.A., and Robinson, M.S., 1980, Investigations of mercury-antimony-tungsten metal provinces in Alaska: University of Alaska, Fairbanks, Mineral Industry Research Laboratory Open-File Report 80-8, 39 p., map. Thorne, R.L., Muir, N.M., Erickson, A.W., Thomas, B. I., Hedie, H. E., and Wright, W. S., 1948, Tungsten deposits of Alaska: U.S. Bureau of Mines Report of Investigation 4174, 51 p.
| Arsenopyrite|| Pyrite|| Scheelite|| Stibnite|
4 entries listed. 4 valid minerals.
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New Locality Added: Osterberg district, Gernrode, Harz, Saxony-Anhalt, GermanyFrom Thomas Lühr, 23rd May 2013 20:47:57