Unnamed (near tributary to South Fork of Kuskokwim River)

Occurrence, Inactive

Commodities and mineralogy

Main commodities As; Au; W
Other commodities Co; Sb
Ore minerals arsenopyrite; galena; pyrite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale MG
Quadrangle map, 1:63,360-scale A-1
Latitude 62.044
Longitude -153.411
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is located on a north-facing spur overlooking an unnamed tributary of the South Fork of the Kuskokwim River. It is at an elevation of 5,100 feet (1,555 m) in the NW1/4 sec. 36, T. 23 N., R. 23 W., of the Seward Meridian. The location is based on field mapping by D.N. Solie, formerly of the Alaska Division of Geological and Geophysical Surveys; at station no. 88DNS107. The occurrence corresponds to map number 35 in Bundtzen, Harris, and Gilbert (1997).

Geologic setting

Geologic description

This unnamed occurrence is a stockwork of pyrite-galena-quartz that cuts a small granodiorite porphyry intrusion and altered dacitic tuffs. The mineralized zone occurs near the contact between igneous rocks of the Terra Cotta Volcanic Field and Lower Cretaceous Kahiltna flysch (Bundtzen, Harris, and Gilbert, 1997). No precise structural or size measurements of the mineralized zone are available. Grab samples from talus contain up to 4,000 ppm arsenic, 2,100 ppb gold, 66 ppm cobalt, 110 ppm antimony, and 550 ppm tungsten (Bundtzen, Harris, and Gilbert, 1997).
Geologic map unit (-153.413231237005, 62.0433866554053)
Mineral deposit model Creede epithermal vein? (Cox and Singer, 1986; model 25b?).
Mineral deposit model number 25b?
Alteration of deposit Sericite.

Production and reserves

Workings or exploration D.N. Solie discovered the mineralized area during geologic mapping for the Alaska Division of Geological and Geophysical Surveys in 1988. Grab samples from the talus contain up to 4,000 ppm arsenic, 2,100 ppb gold, 66 ppm cobalt, 110 ppm antimony, and 550 ppm tungsten (Bundtzen, Harris, and Gilbert, 1997).
Indication of production None
Reserve estimates None.

References