Blackney

Prospect, Inactive

Alternative names

Blakney

Commodities and mineralogy

Main commodities Cu
Ore minerals chalcopyrite; pyrite

Geographic location

Quadrangle map, 1:250,000-scale VA
Quadrangle map, 1:63,360-scale B-1
Latitude 61.4513
Longitude -144.331
Nearby scientific data Find additional scientific data near this location
Location and accuracy This prospect is on an unnamed east tributary to Taral Creek about 1.1 miles north of the pass at the head of Taral Creek. It is at an elevation of about 3,500 feet and about 1,000 feet east of the center of section 9, T. 5 S., R. 6 E., of the Copper River Meridian, where a cabin is shown on the topographic map. This prospect is probably accurately located. It is locality 57 of Cobb and Matson (1972) and locality 48 of Winkler and others (1981[OFR 80-892-B]).

Geologic setting

Geologic description

A 3-foot-wide shear zone in Triassic Nikolai Greenstone contains sheeted from 0.5 to 18 inches thick veins with pyrite and chalcopyrite (Moffit, 1914; Winkler and others, 1981 [OFR 80-892-A]). The shear zone, which trends N75W and dips 45S, was traced on the surface for a distance of 200 feet. A decline was sunk on the shear zone. The mafic metavolcanic rocks were originally thought to be part of the Paleozoic Skolai Group (Winkler and others, 1981 [OFR 80-892-B]), but Winkler and others (1981 [OFR 80-892-A]) indicated the area consists of Triassic Nikolai Greenstone intruded to the east by Jurassic intermediate plutonic rocks. The copper mineralization may 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 (-144.333086112618, 61.4508254425932)
Mineral deposit model Thin veins, impregnations, and fracture fillings in greenstone; may be related to Kennecott-type copper deposits (Mackevett and others, 1997)
Age of mineralization Post -Triassic; the host rocks are Triassic mafic volcanic rocks. The copper mineralization may 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 decline was sunk on the shear zone, which was traced for a distance of 200 feet on the surface (Moffit, 1914). Lode claims were patented in 1911 or earlier.
Indication of production None

Additional comments

This prospect is in Wrangell-St. Elias National Park.

References