Concentrates mainly magnetite along with rare nuggets of copper and silver (Anderson, 1945, p. 24-46).
Location: Located in canyon between Bismark Mountain and Shungnak Mountain near confluence with Bismark Creek in T. 19 N., R. 7 E., Kateel River Meridian. Shown as locality 19 in Mayfield and Grybeck (1978). Accurate to within 1000 ft. (300 m).
Geology: Creek and bench placers. Creek gravels 1-3 ft. (0.3-1 m) deep in canyon; Au occurs in pockets in bedrock and lower 1 ft. (0.3 m) of gravel. Nephrite jade float along banks of river; nephrite and low-grade asbestos in greenstone and serpentine along river. Gold also occurs on false bedrock above Pleistocene till near confluence with Bismark Creek. Stream gravels are coarse, subangular with abundant boulders up to 3 ft. (1 m) in diameter.
Workings: Most of gravel is not frozen, in benches up to 25 ft. (9 m) above the river; prospect pits in gravel downstream from canyon did not reach bedrock; 40 ft. (13 m) drill hole in gravels below canyon did not reach bedrock (Reed, 1931, p. 15)
Production: Intermittent production during the period 1894 to 1940. May have produced as much as 10,000 oz (311 kg) of gold (Fritts, 1970, p. 54-55).
Commodities (Major) - Au; (Minor) - Ag, asbestos, Cu, jade
Development Status: Yes; small
Deposit Model: Placer
References:
Anderson, Eskil, 1945, Asbestos and jade occurrences in the Kobuk River region, Alaska: Alaska Territorial Department of Mines Pamphlet 3-R, 26 p. Anderson, Eskil, 1947, Mineral occurrences other than gold deposits in northwestern Alaska: Alaska Territorial Division of Mines Pamphlet 5-R, 48 p. Fritts, C.E., 1970, Geology and geochemistry of the Cosmos Hills, Ambler River and Shungnak River quadrangles, Alaska: Alaska Division of Geological and Geophysical Surveys Geological Report 39, 63 p., 4 sheets, scale 1:63,360. Mayfield, C.F., and Grybeck, D., 1978, Mineral occurrences and resource map of the Ambler River quadrangle, Alaska: U.S. Geological Survey Open-File Report 78-120-I, 1 sheet, scale 1:250,000. Reed, I.M., 1931, Report on the placer deposits of the upper Kobuk goldfields: Alaska Territorial Department of Mines Miscellaneous Report 37-1, 57 p. Smith. P.S., 1913, The Noatak-Kobuk region, Alaska: U.S. Geological Survey Bulletin 536, 60 p. Smith, P.S., and Eakin, H.M., 1911, The Shungnak region, Kobuk Valley: U.S. Geological Survey Bulletin 480-J, p. 271-305.
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Map Reference: 67°1'51"N , 157°14'5"W
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Mineral List:4 entries listed. 2 valid minerals.
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