Prospect, Inactive

Commodities and mineralogy

Main commodities Cu
Ore minerals chalcopyrite; copper
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale SR
Quadrangle map, 1:63,360-scale A-3
Latitude 60.2313
Longitude -147.7602
Nearby scientific data Find additional scientific data near this location
Location and accuracy The prospect is located at about 700 feet elevation about one-half mile east of the head of Northeast Arm, Mummy Bay. It is in the SW1/4 section 29, T. 2 N., R. 10 E., of the Seward Meridian. This is location 250 of Tysdal (1978 [MF-880-A]) and location S-30 of Jansons and others (1984). This location is accurate to within a quarter of a mile.

Geologic setting

Geologic description

The country rock is greenstone of the Orca Group of early Tertiary age (Kurtak and Jeske, 1986). The prospect consists of a 145-foot-long adit driven along a north-trending shear zone. The shear zone is 2 to 3 feet wide and dips 80 E. The mineralization consists of massive chalcopyrite stringers with some quartz veins containing disseminated chalcopyrite (Kurtak and Jeske, 1986). As much as 1 percent native copper was identified in parts of the shear (Johnson, 1915). Two chip samples, each 3 feet wide, were collected from the adit. The samples contained 300 ppm and 0.25 percent copper, respectively (Kurtak and Jeske, 1986).
Geologic map unit (-147.76225502854, 60.2307355341111)
Mineral deposit model Cyprus massive sulfide (Cox and Singer, 1986; model 24a)
Mineral deposit model number 24a
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 workings on the prospect consist of a single south-trending adit that is 145 feet long. It is at an elevation of 700 feet. Two 3-foot-wide chip samples from the adit contained 300 ppm and 0.25 percent copper, respectively (Kurtak and Jeske, 1986).
Indication of production None
Reserve estimates The U.S. Bureau of Mines estimated inferred reserves of 200 tons of ore at a grade of 0.25 percent copper (Kurtak and Jeske, 1986).