Mountain Boy

Prospect, Inactive

Alternative names

Montana Boy

Commodities and mineralogy

Main commodities Cu
Other commodities Ag; Au
Ore minerals bornite; chalcocite; chalcopyrite; gold
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale VA
Quadrangle map, 1:63,360-scale C-1
Latitude 61.659
Longitude -144.0246
Nearby scientific data Find additional scientific data near this location
Location and accuracy This prospect is located on the west side of the upper valley of East Fork Copper Creek (Van Alstine and Black, 1946, plate 30); it is at an elevation of 4,700 feet in the SE1/4 section 30, T. 2 S., R. 8 E., of the Copper River Meridian. This prospect is approximately located, probably to within one-quarter mile. It is included in locality 72 of Cobb and Matson (1972) and locality 58 of Winkler and others (1981 [OFR 80-892-B]).

Geologic setting

Geologic description

Vertical veins, the largest a few inches thick, and irregular pods of bornite and chalcopyrite occur in Triassic Nikolai Greenstone at this locality (Van Alstine and Black, 1946, p. 131). Malachite coatings are present in nearby fractures. Moffit and Mertie (1923, p. 103) noted that free gold was reported to have been panned from an iron-stained quartz vein in this area. A 10-foot-long adit and several open cuts explored the prospect, which is about 150 feet below the base of overlying Triassic Chitistone Limestone. The copper mineralization is believed to be related to the regional mineralizing event that produced the rich Kennecott copper deposits in the McCarthy quadrangle (MacKevett and others, 1997).
Geologic map unit (-144.026694234391, 61.6585344082273)
Mineral deposit model Thin veins, impregnations, and fracture fillings in greenstone; probably related to Kennecott-type copper deposits (Mackevett and others, 1997)
Age of mineralization The copper mineralization is believed to be related to the mineralizing event that produced the rich Kennecott copper deposits in the McCarthy quadrangle to the east (MacKevett and others, 1997). This event is interpreted to have accompanied Late Jurassic or Early Cretaceous deformation and metamorphism (MacKevett and others 1997, p. 88).

Production and reserves

Workings or exploration A 10-foot-long adit and several open cuts explored the prospect (Van Alstine and Black, 1946).
Indication of production None

Additional comments

This prospect is within the Wrangell-St. Elias National Park.

References