Henry Prather

Prospect, Inactive

Commodities and mineralogy

Main commodities Cu
Ore minerals bornite; chalcopyrite
Gangue minerals calcite; quartz

Geographic location

Quadrangle map, 1:250,000-scale VA
Quadrangle map, 1:63,360-scale C-1
Latitude 61.6477
Longitude -144.0998
Nearby scientific data Find additional scientific data near this location
Location and accuracy This prospect is near Rainbow Creek on the north side of Elliott Creek valley (Moffit and Maddren, 1909, p. 64); it is at an elevation of about 4,100 feet in the SW1/4 section 35, T. 2 S., R. 7 E., of the Copper River Meridian. This prospect is approximately located, perhaps to within one-half mile. It is included in locality 65 Cobb and Matson (1972) and locality 55 of Winkler and others (1981 [OFR 80-892-B]).

Geologic setting

Geologic description

Triassic Nikolai Greenstone hosts lenticular, fault-bounded bodies that contain bornite and chalcopyrite (Mendenhall and Schrader, 1903; Moffit and Mertie, 1923). Individual sulfide-bearing bodies can be 5 feet wide and 30 feet long. At this site, a later cross-cutting calcite vein, 8 to 12 inches wide, also contains bornite and chalcopyrite. The lenticular mineralization at the Henry Prather prospect may be a faulted segment of the sulfide-bearing body at the Goodyear prospect (VA030). The Nikolai Greenstone and overlying Chitistone Limestone are deformed into a large, asymmetric anticline with its axis approximately parallel to Elliott Creek. 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 (-144.101894861856, 61.6472328682113)
Mineral deposit model Veins, disseminations, 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 Open cuts were used to explore this prospect.
Indication of production None

Additional comments

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

References