Unnamed (west bank of Togiak River)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Cu; Zn
Other commodities Ag; Au; Hg; Mo
Ore minerals chalcopyrite; pyrite; sphalerite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale GO
Quadrangle map, 1:63,360-scale B-4
Latitude 59.3
Longitude -160.17
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is close to the west bank of Togiak River. It is less than a mile downstream of the Kassianmute village site and about 3 miles upstream of the mouth of Pungokepuk Creek, an east tributary to Togiak River. The map site is in the NE1/4 of section 23, T 10 S, R 65 W, of the Seward Meridian. It is locality 2 of Hoare and Cobb (1977) and of Cobb and Condon (1972).

Geologic setting

Geologic description

At this occurrence, Jurassic or Cretaceous pillow basalt is cut by a 12- to 15-inch-wide, at least 25-foot-long, quartz vein containing coarsely crystalline sphalerite, minor chalcopyrite, and pyrite (Hoare and Coonrad, 1961). A sample of oxidized sphalerite-rich vein material and its altered volcanic hostrock contained 3 ppm Ag, 110 ppm As, 0.35 ppm Au, 390 ppm Cd, 510 ppm Cu, 10.4 ppm Hg, greater than 5,000 ppm Mn, 6.8 ppm Mo, and greater than 1,400 ppm Zn (Kilburn and others, 1992). The occurrence is in lowlands along the Togiak River. Bedrock exposures are minimal, but parts of a gabbro intrusive are exposed across the river from this locality.
Geologic map unit (-160.17221761426, 59.2992381860497)
Mineral deposit model Polymetallic vein (Cox and Singer, 1986; model 22c)
Mineral deposit model number 22c
Age of mineralization Post Early Cretaceous. The host pillow basalt is part of a Jurassic to Lower Cretaceous sedimentary and volcanic assemblage (Hoare and Coonrad, 1978).

Production and reserves

Workings or exploration This occurrence has been reconnaissance mapped and sampled (Kilburn and others, 1992).
Indication of production None

References