Unnamed (southwest forks of Buckstock River)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Ag; Au
Other commodities As; Cd; Sb; W
Ore minerals arsenopyrite; pyrite; stibnite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale SM
Quadrangle map, 1:63,360-scale A-8
Latitude 61.16768
Longitude -158.74411
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is at an elevation of about 2,100 feet on the crest of an east-west trending ridge between two, unnamed, northeast flowing tributaries of the Buckstock River. It is about 0.4 mile west-northwest of hill 2280 near the southwest corner of section 35, T. 13 n., R. 53 W., of the Seward Meridian. The location is accurate.

Geologic setting

Geologic description

This occurrence consist of quartz-sulfide veins and stringers that cut altered sandstone and siltstone of either the Upper Cretaceous, Kuskokwim Group or the Mesozoic Gemuk Group (Cady and others, 1955; M.L. Miller, W. Keith, and T.K. Bundtzen, unpublished field data, 1999). The occurrence is near the projected (fault?) contact between the Gemuk and Kuskokwim Groups. Pyrite is ubiquitous in the quartz veins and stringers; arsenopyrite and stibnite, which occur as isolated grains and blades, are less common. One grab sample of stibnite- and arsenopyrite-bearing vein material contained 14,800 parts per billion (ppb) gold, 5,700 ppb silver, 1,090 parts per million (ppm) antimony, 1.38 percent arsenic, and 13.7 ppm tungsten (W. J. Keith and T.K. Bundtzen, unpublished analytical data, 1999).
Geologic map unit (-158.746440796353, 61.166966732776)
Mineral deposit model Polymetallic vein (Cox and Singer, 1986; model 22c).
Mineral deposit model number 22c
Alteration of deposit Vein appears to be hydrothermally bleached.

Production and reserves

Workings or exploration The U.S. Geological Survey investigated the site in 1999.
Indication of production None



Reporters T.K. Bundtzen (Pacific Rim Geological Consulting, Inc.) and M.L. Miller (U.S. Geological Survey)
Last report date 5/9/2003