Devils Mountain

Occurrence, Inactive

Commodities and mineralogy

Main commodities Cu
Ore minerals chalcopyrite; pyrrhotite
Gangue minerals actinolite; garnet

Geographic location

Quadrangle map, 1:250,000-scale NB
Quadrangle map, 1:63,360-scale B-4
Latitude 62.4171
Longitude -142.9398
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is on the creek draining the northwest side of Devils Mountain. It is at an elevation of about 3,100 feet, about 6,000 feet southwest of the summit of Devil Mountain. This is locality 11 of Richter and others (1975) and National Park Service locality WRST-5 (unpublished data). It was included as an 'Unnamed occurrence' by Cobb and Richter (1980). It is located to within several hundred feet.

Geologic setting

Geologic description

Large boulders up to 6 feet or more in diameter of massive pyrrhotite, chalcopyrite, actinolite, and garnet occur at this locality (Richter and others, 1975). The source of these boulders is unknown. Quaternary deposits cover much of the lower areas of this drainage but a Cretaceous hornblende quartz diorite and diorite stock that intrudes upper Paleozoic metavolcanic rocks makes up most of the bedrock in the headwaters of the drainage (Richter, 1971 [I-656]; 1976).
Geologic map unit (-142.941936366947, 62.4167249739459)
Mineral deposit model Cu skarn (Cox and Singer, 1986; model 18b)
Mineral deposit model number 18b
Age of mineralization Cretaceous? The parent deposit may be a skarn related to a hornblende quartz diorite and diorite stock in the headwaters of this drainage. This pluton is though to be mid-Cretaceous in age like the Nabesna pluton several miles to the south (Richter, Lanphere, and Matson, 1975).
Alteration of deposit Calc-silicate and sulfide replacement.

Production and reserves

Workings or exploration The source of the mineralization has not been identified.
Indication of production None

Additional comments

The occurrence is in the Wrangell-St. Elias National Preserve.