Holokuk Mountain

Prospect, Inactive

Commodities and mineralogy

Main commodities Ag; Au; Sb
Other commodities As; Bi; Cd; Cu; W
Ore minerals arsenopyrite; boulangerite; kermesite; stibnite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale SM
Quadrangle map, 1:63,360-scale B-7
Latitude 61.39006
Longitude -158.2615
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Holokuk Mountain prospect is at an elevation of about 2,350 feet about 0.4 mile northwest of peak 3229 at the southwest end of Holokuk Mountain. The prospect is about 0.3 mile west of the center of sec. 16, T. 15 N., R. 50 W., of the Seward Meridian. The location is accurate.

Geologic setting

Geologic description

The Holokuk Mountain prospect consists of auriferous, sulfide-sulfosalt-bearing quartz veins in an altered porphyritic felsic intrusion with pyrite and sericite. The intrusion is associated with dark gray hornfels derived from the Upper Cretaceous, Kuskokwim Group (Cady and others, 1955). Quartz float is abundant in the area and is spread along the hill slope for about 250 feet in elevation. The prospect consists of quartz stockwork veins in an area of rubble-crop area at least 100 feet by 480 feet in size. A breccia zone in the hornfels which strikes N70W, has quartz-sulfide veins up to 4 inches thick. A north-south trending, barren mafic dike cuts both the porphyritic felsic intrusive and the hornfels with the quartz-sulfide veins. The quartz veins contain disseminations and masses of 1 to 5 percent stibnite, arsenopyrite, boulangerite?, pyrite, and kermesite. The quartz-sulfide veins comprise about 2 to 5 percent of the host rock. About 50 percent of the mineralization is in rubble-crop and talus. The mineralized zone is open-ended to the east. Twelve samples contain up to 2,700 parts per billion (ppb) gold, 35.4 parts per million (ppm) silver, 4,130 ppm arsenic, 1.06 ppm mercury, 3.0 ppm cadmium, 105 ppm bismuth, 307 ppm lead, more than 6,000 ppm antimony, 204 ppm copper, 13 ppm tin, and 12.0 ppm tungsten (T.K. Bundtzen and M.L. Miller, unpublished analytical data, 1998).
Geologic map unit (-158.263853348013, 61.3893491372703)
Mineral deposit model Polymetallic vein (Cox and Singer, 1986; model 22c).
Mineral deposit model number 22c
Age of mineralization Unknown. Plutonic rocks on the east end of Holokuk Mountain have a 40K/40Ar age of 68.0 Ma (Decker and others, 1995).
Alteration of deposit Pervasive sericite (phyllic) alteration adjacent to veins and in intrusive host rocks.

Production and reserves

Workings or exploration The prospect was discovered during surface sampling and mapping investigations carried out by the U.S. Geological Survey,in 1998 (T.K. Bundtzen and M.L. Miller, unpublished field data, 1998).
Indication of production None