Unnamed (western edge of Buckstock Mountains)

Occurrence, Inactive

Commodities and mineralogy

Main commodities As; Sb
Ore minerals arsenopyrite; stibnite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale SM
Quadrangle map, 1:63,360-scale A-8
Latitude 61.17877
Longitude -158.83934
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is located on a north-south-trending ridge line on the western side of the Buckstock Mountains to the east of an unnamed tributary of the Buckstock River. The occurrence is about 0.2 mile south of hill 2170, in the NE1/4 sec. 31, T. 13 N., R. 53 W., of the Seward Meridian. The location is accurate.

Geologic setting

Geologic description

This occurrence consists of a quartz-sulfide vein and sulfides disseminated in granite porphyry that is part of a dense dike swarm that intrudes shale and sandstone of the Upper Cretaceous, Kuskokwim Group (Cady and others, 1955). The swarm strikes east-west, dips vertically, and includes granite porphyry, granodiorite, and minor mafic dikes. Most dikes have undergone various degrees of sericitic alteration. At least 10 different dikes, each ranging from 10 to 50 feet thick cross a ridge over a distance of about 1,600 feet. One quartz vein, which strikes about N80W and dips vertically, contains masses of up to 20 percent arsenopyrite and 1 to 3 percent stibnite (T.K. Bundtzen, unpublished data, 1992). One sample reported by Gray, Motooka, and Theodorakos (1997) contained 73 parts per million (ppm) bismuth, 130 ppm arsenic, and 48 ppm copper.
Geologic map unit (-158.841670652491, 61.1780572092731)
Mineral deposit model Polymetallic vein (Cox and Singer, 1986; model 22c).
Mineral deposit model number 22c
Alteration of deposit Sericitization of dikes.

Production and reserves

Workings or exploration An old, shallow, caved-in prospect pit exposed some of the arsenopyrite bearing mineralized. This occurrence was investigated and sampled in 1992 (T.K. Bundtzen, unpublished data, 1992).
Indication of production None