Unnamed (southwest shore of Portage Arm)

Occurrence, Probably inactive

Commodities and mineralogy

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

Geographic location

Quadrangle map, 1:250,000-scale SI
Quadrangle map, 1:63,360-scale B-3
Latitude 57.3526
Longitude -134.9397
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence on northeast Baranof Island is at sea level on the southwest shore of Portage Arm. The occurrence is 0.2 mile northeast of the center of sec. 23, T. 52 S., R. 65 E. It is location 60 of Cobb (1972, 1978). Several of the old publications include this with the Brown prospect which is on Admiralty Island some distance away (SI163). The location probably is accurate within 0.2 mile.

Geologic setting

Geologic description

The rocks in the vicinity of this occurrence are part of the Jurassic and/or Triassic, Kelp Bay Group which consists of phyllite, quartzite, greenschist, greenstone, graywacke, and semischist (Loney and others, 1975). There is little information on this occurrence other than that it consists of quartz veins and siliceous rocks that contain chalcopyrite, covellite, and bornite. (Loney and others, 1963).
Geologic map unit (-134.94146121655, 57.3522605852616)
Age of mineralization Triassic or younger based on the age of the host rock.

Production and reserves

Workings or exploration Only limited surface sampling by government geologists.
Indication of production None

References