Unnamed Occurrence (ARDF - SM005; northeast of head of Getmuna Creek), Aniak District, Bethel Borough, Alaska, USA

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Location: This occurrence is near the top of hill 3405 in the northeast corner of the Horn Mountains. It is in the NW1/4 sec. 35, T. 20N., R. 51 W., of the Seward Meridian. The location is accurate.
Geology: This occurrence consists of a strong ferricrete gossan, probably formed by the weathering of sulfides, along several high angle fault zones about 4 inches thick. The occurrence is in a dacite-andesite flow of the Horn Mountains volcanic field (Bundtzen and others, 1998). One grab sample gossan with a disseminated gray sulfide mineral contained 24 parts per billion (ppb) gold, 77 parts per million (ppm) copper, 260 ppm zinc, more than 10.00 percent iron, 310 ppm chromium, 320 ppm cerium, 48 ppm niobium, and 9.23 ppm mercury (Bundtzen and others, 1998).
Workings: Surface sampling was conducted in 1990 by Ellie Harris of the Alaska Division of Geological and Geophysical Surveys (Bundtzen and others, 1998).
Age: Undated; may be related to the nearby Horn Mountain pluton which has been dated at 68-69 Ma (Bundtzen and others, 1998).
Alteration: Strong gossan development.

Commodities (Major) - Ce, Hg, Nb, Zn; (Minor) - Au, Cr, Cu
Development Status: None
Deposit Model: Polymetallic vein (Cox and Singer, 1986; model 22c).

References

Bundtzen, T.K., Harris, E.E., Miller, M.L., Layer, P.W., and Laird, G.M., 1998, Geology of the Sleetmute C-7, C-8, D-7, and D-8 quadrangles, Horn Mountains, southwestern Alaska: Alaska Division of Geological and Geophysical Surveys Report of Investigations 98-12, 38 p., one sheet, scale 1:63,360. 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.

Mineral List

No entries listed.