Blackburn

Prospect, Inactive

Commodities and mineralogy

Main commodities Cu
Other commodities Au
Ore minerals chalcopyrite; malachite; pyrite

Geographic location

Quadrangle map, 1:250,000-scale MC
Quadrangle map, 1:63,360-scale C-8
Latitude 61.6215
Longitude -143.7897
Nearby scientific data Find additional scientific data near this location
Location and accuracy This prospect is on the west valley wall of Porcupine Creek. It is at an elevation of about 4,200 feet, 4,200 feet northeast of elevation 6437, and 1,200 feet southwest of the center of section 9, T. 3 S., R. 9 E. of the Copper River Meridian. This is locality 135 of MacKevett (1976) and locality 24 of MacKevett and others (1978). The location is accurate to within about 100 feet.

Geologic setting

Geologic description

This deposit consists of malachite-stained fault zones that contain chalcopyrite, pyrite, and possibly gold; the faults cut Triassic Nikolai Greenstone intruded by a diorite apophyses of a Jurassic pluton (Moffit and Mertie, 1923; MacKevett, 1976). The deposits were explored by short adits and opencut. The widespread deposition of copper in Triassic greenstone and limestone of the area is thought to have accompanied regional deformation and low-grade metamorphism in the Late Jurassic or Early Cretaceous (MacKevett and others, 1997). Copper-bearing minerals were deposited in the underlying Nikolai Greenstone at about 112 Ma (Silberman and others, 1980).
Geologic map unit (-143.791787147343, 61.6210391753494)
Mineral deposit model Basaltic Cu (Cox and Singer, 1986; model 23)
Mineral deposit model number 23
Age of mineralization Cretaceous? The widespread deposition of copper in Triassic greenstone and limestone of the area is thought to have accompanied regional deformation and low-grade metamorphism in the Late Jurassic or Early Cretaceous (MacKevett and others, 1997). Copper-bearing minerals were deposited in the underlying Nikolai Greenstone at about 112 Ma (Silberman and others, 1980).
Alteration of deposit Oxidation.

Production and reserves

Workings or exploration The deposits were explored by short adits and opencut.
Indication of production None

Additional comments

The locality is in the Wrangell-Saint Elias National Park and Preserve.

References