Unnamed (north of Upper Copper Lake)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Cu; Mo
Other commodities Ag
Ore minerals chalcopyrite; molybdenite; pyrite

Geographic location

Quadrangle map, 1:250,000-scale IL
Quadrangle map, 1:63,360-scale C-4
Latitude 59.61
Longitude -154.1378
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is at an elevation of about 800 feet on an unnamed north tributary of Upper Copper Lake. The site is in the NE1/4 SW1/4 sec. 36, T. 6 S., R. 29 W., Seward Meridian. The location is accurate within about 0.5 mile. It is locality 12 of Detterman and Cobb (1972).

Geologic setting

Geologic description

An unnamed north tributary to Upper Copper Lake drains a Tertiary, pyrite-rich granitic pluton that also contains disseminated flakes of molybdenite and chalcopyrite(?) (Reed, 1967). Stream-sediment samples collected by Reed in the area contained anomalous concentrations of copper, molybdenum, and silver, but he apparently did not analyze the mineralized intrusive rock. The granitic rock is extensively argillized and possibly sericitized.
Geologic map unit (-154.139951450336, 59.6093282824502)
Mineral deposit model Porphyry Cu-Mo? (Cox and Singer, 1986; model 21a).
Mineral deposit model number 21a?
Age of mineralization Tertiary.
Alteration of deposit Granitic host rock is extensively argillized and possibly sericitized. Reed (1967) noted extensive 'hydrogen metasomatism.'

Production and reserves

Workings or exploration Exploration in the area is limited to reconnaissance geologic mapping and collection of stream-sediment and possibly outcrop samples (Reed, 1967). Stream-sediment samples contained anomalous concentrations of copper, molybdenum, and silver.
Indication of production None

References