Unnamed (east flank of Takotna Mountain)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Ag; Cu
Other commodities Pb
Ore minerals chalcopyrite; pyrite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale MG
Quadrangle map, 1:63,360-scale D-6
Latitude 62.946
Longitude -155.984
Nearby scientific data Find additional scientific data near this location
Location and accuracy This unnamed occurrence is located on a northeast flank of Takotna Mountain; at an elevation of 2,350 feet (716 m) in the SE1/4 sec. 18, T. 33 N., R. 36 W., of the Seward Meridian. The reporter visited the site in 1978; at station no. 78BT467.

Geologic setting

Geologic description

This unnamed occurrence consists of disseminated chalcopyrite and pyrite in silicified zones of a border phase of the Takotna Mountain composite pluton, which was radiometrically dated at 71.2 Ma (Bundtzen and Laird, 1983). The occurrence is near a faulted contact between the pluton and somewhat older andesitic stratovolcano of the Takotna Mountain volcanic-plutonic complex, one of thirteen known in the Kuskokwim Mineral Belt of southwest Alaska (Bundtzen and Miller, 1997). No estimates of the size of the mineralized zone are available. Two grab samples from the mineralized zone contained up to 222 ppm copper, 0.6 grams/tonne silver, and 100 ppm lead (Bundtzen and Laird, 1983).
Geologic map unit (-155.986358355677, 62.9453712022106)
Mineral deposit model Polymetallic vein (Cox and Singer, 1986; model 22c).
Mineral deposit model number 22c
Age of mineralization Unknown; host pluton is 71.2 Ma (Bundtzen and Laird, 1983).
Alteration of deposit Sericitic and secondary biotite.

Production and reserves

Workings or exploration The unnamed occurrence was investigated by the reporter in 1978 during a 1:63,360 scale geologic mapping effort for the Alaska Division of Geological and Geophysical Surveys in the McGrath quadrangle (Bundtzen and Laird, 1983). Two grab samples from the mineralized zone contained up to 222 ppm copper, 0.6 grams/tonne silver, and 100 ppm lead.
Indication of production None
Reserve estimates None.

References

MRDS Number 10307821

References

Bundtzen, T.K., and Miller, M.L., 1997, Precious metals associated with Late Cretaceous-early Tertiary igneous rocks of southwestern Alaska, in Goldfarb, R.J., and Miller, L.D., eds., Mineral Deposits of Alaska: Economic Geology Monograph 9, p. 242-286.
Reporters T.K. Bundtzen (Pacific Rim Geological Consulting)
Last report date 12/13/1998