Unnamed (on tributary to South Fork of Kuskokwim River)

Occurrence, Inactive

Commodities and mineralogy

Main commodities As; Au
Other commodities W
Ore minerals pyrite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale MG
Quadrangle map, 1:63,360-scale A-1
Latitude 62.014
Longitude -153.409
Nearby scientific data Find additional scientific data near this location
Location and accuracy This unnamed occurrence is located in the steep canyon of a northeast-flowing tributary to the South Fork of the Kuskokwim River; it is at an elevation of 3,950 feet (1,204 m) in the NW1/4 sec. 12, T. 22 N., R. 23 W., of the Seward Meridian. The reporter investigated the site in 1988; at station no. 88BT165.

Geologic setting

Geologic description

This unnamed occurrence is a series of sheeted quartz-pyrite veins in Lower Cretaceous Kahiltna flysch adjacent to several, east-west-trending rhyolite dikes cutting the flysch (Bundtzen, Harris, and Gilbert, 1997). The quartz veins dip south and are parallel to the east-west-trending dikes. The Kahiltna flysch is locally thermally upgraded to slate. One sample contained 830 ppm arsenic, 180 ppb gold, and 710 ppm tungsten. A panned concentrate taken just below the mineralized dike swarm contained 1.00 percent tin and 1,400 ppm tungsten.
Geologic map unit (-153.41123141373, 62.0133853881935)
Mineral deposit model Polymetallic vein (Cox and Singer, 1986; model 22c).
Mineral deposit model number 22c

Production and reserves

Workings or exploration The reporter visited and sampled the site in 1988; anomalous pan concentrate samples were collected by Ellen E. Harris. One sample of sheeted veining contained 830 ppm arsenic, 180 ppb gold, and 710 ppm tungsten. A panned concentrate taken just below the mineralized dike swarm contained 1.00 percent tin and 1,400 ppm tungsten (Bundtzen, Harris, and Gilbert, 1997).
Indication of production None
Reserve estimates None.

References