Unnamed (west of South Arm, Bay of Isles, Knight Island)

Prospect, Inactive

Commodities and mineralogy

Main commodities Cu; Zn
Ore minerals chalcopyrite; pyrite; pyrrhotite; sphalerite
Gangue minerals epidote; quartz

Geographic location

Quadrangle map, 1:250,000-scale SR
Quadrangle map, 1:63,360-scale B-2
Latitude 60.3621
Longitude -147.735
Nearby scientific data Find additional scientific data near this location
Location and accuracy The prospect is located in the saddle on the southeast flank of hill 1870 west of the head of South Arm, Bay of Isles, at an elevation of about 1,350 feet. It is in the SW1/4 section 9, T. 3 N., R. 10 E., of the Seward Meridian. This is location S-63 of Jansons and others (1984). This location is accurate to within a quarter of a mile.

Geologic setting

Geologic description

The occurrence consists of an iron-stained shear zone in schistose greenstone that contains pyrite, pyrrhotite, chalcopyrite, and sphalerite (Kurtak and Jeske, 1986). The shear zone is nearly vertical, strikes N25E, and can be traced for about 6 miles. The zone cuts greenstone of the Orca Group of early Tertiary age (Nelson and others, 1985). Within the zone, a 2.5- by 25-foot outcrop of iron-stained greenstone contains pyrite, pyrrhotite, about 1 percent chalcopyrite, and 20 percent sphalerite. Quartz and epidote veinlets also occur within the zone (Kurtak and Jeske, 1986). Chip and grab samples from this occurrence contained from 20 ppm to 0.8 percent copper and from 30 ppm to 5 percent zinc (Kurtak and Jeske, 1986). The U.S. Bureau of Mines reported some minor digging and scrapings in the area (Kurtak and Jeske, 1986).
Geologic map unit (-147.737033893802, 60.3615243497935)
Mineral deposit model Besshi massive sulfide (Cox and Singer, 1986; model 24b)
Mineral deposit model number 24b
Age of mineralization Tertiary or younger; the mineralization is in rocks of the Orca Group of Tertiary age.

Production and reserves

Workings or exploration The U.S. Bureau of Mines reported some minor digging and scrapings in the area (Kurtak and Jeske, 1986). Chip and grab samples from this occurrence contained from 20 ppm to 0.8 percent copper and from 30 ppm to 5 percent zinc (Kurtak and Jeske, 1986).
Indication of production None

References