Unnamed (near Bingo Mountain)

Occurrences, Undetermined

Commodities and mineralogy

Main commodities Au; Cu
Other commodities Ag
Ore minerals pyrite
Gangue minerals calcite; quartz

Geographic location

Quadrangle map, 1:250,000-scale KC
Quadrangle map, 1:63,360-scale A-5
Latitude 55.228
Longitude -131.543
Nearby scientific data Find additional scientific data near this location
Location and accuracy This site represents three occurrences in a half-mile-square triangular area southeast of Bingo Mountain The occurrences are in section 3, T. 77 S., R. 92 E., of the Copper River Meridian, and section 35, T. 76 S., R. 91 E., of the Copper River Meridian. They range in elevation from about 1950 feet near the top of the mountain, to about 400 feet elevation, 0.5 mile east-southeast and south-southeast of the top. The coordinates are for the approximate center of the area of occurrences. The site corresponds to loc. 7 in Karl (1992). The location is accurate within 0.1 mile.

Geologic setting

Geologic description

The country rocks in the area of this site are Upper Jurassic or Cretaceous flyschlike metasedimentary rocks that are gradationally interbedded with andesitic or basaltic metatuff (Berg, 1972 [i 684]; Karl, 1992). The rocks were regionally metamorphosed to greenschist-grade phyllite and semischist in Late Cretaceous time.
The occurrences are quartz-calcite-pyrite veins in green tuffaceous phyllite that also contains disseminated minute cubes of pyrite (Karl, 1992, loc. 7). Samples of the sulfide-bearing green phyllite contained up to 0.5 ppm Ag, 300 ppm Cu, and 300 ppm Cr; a sample of a quartz-calcite-pyrite vein contained 0.21 ppm Au (Karl, 1992, loc. 7a-c).
Geologic map unit (-131.544681964244, 55.2276545569621)
Mineral deposit model Low-sulfide Au-quartz veins (Cox and Singer, 1986; model 36a)
Mineral deposit model number 36a
Age of mineralization Probably Late Cretaceous or younger.
Alteration of deposit Pyritization of tuffaceous phyllite country rock.

Production and reserves

Workings or exploration Samples of the sulfide-bearing green phyllite contained up to 0.5 ppm Ag, 300 ppm Cu, and 300 ppm Cr; a sample of a quartz-calcite-pyrite vein contained 0.21 ppm Au (Karl, 1992, loc. 7a-c).
Indication of production None

References