Copper Chief

Prospect, Inactive

Commodities and mineralogy

Main commodities Au; Cu
Ore minerals chalcopyrite; pyrite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale SI
Quadrangle map, 1:63,360-scale D-1
Latitude 57.9401
Longitude -134.3013
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Copper Chief prospect is at sea level about 2.5 miles north of the mouth of Pack Creek. The prospect is 0.7 mile northeast of the southwest corner of sec. 30, T. 45 S., R. 69 E. It is location 65 of Cobb (1972, 1978) and MAS no. 0021140077 (U.S. Bureau of Land Management, 2002). The location is accurate within 0.2 mile.

Geologic setting

Geologic description

The rocks in the vicinity of the Copper Chief prospect are part of the Triassic Hyd Formation which consists of volcanic rocks, limestone, slate, chert, and conglomerate (Lathram and others, 1965). The Copper Chief prospect has been known since before 1906. Wright (1906) described it as quartz stringers with chalcopyrite, pyrite, and possibly gold in a zone 20 feet wide in quartz schist. The zone is exposed for 200 feet. The deposit was explored by a 60-foot shaft and a 20-foot crosscut prior to 1906. Race and Rose (1967) mostly cite Wright's information but indicate that the ore contains 1 to 1.7 percent copper.
Geologic map unit (-134.303054600622, 57.9397637320187)
Mineral deposit model Quartz veinlets with copper in schist.
Age of mineralization Triassic or younger based on the age of the host rock.

Production and reserves

Workings or exploration The only workings are a 60-foot shaft and a 20-foot crosscut driven before 1906.
Indication of production None

Additional comments

The prospect is now within the Wilderness of the Admiralty Island National Monument and is closed to mineral exploration and development.

References

MRDS Number A013311

References

Reporters Donald Grybeck (U.S. Geological Survey)
Last report date 5/5/2005