Larsen

Occurrence, Inactive

Commodities and mineralogy

Main commodities Cu
Other commodities Au; Zn
Ore minerals chalcopyrite; pyrrhotite

Geographic location

Quadrangle map, 1:250,000-scale SR
Quadrangle map, 1:63,360-scale B-3
Latitude 60.2678
Longitude -147.8489
Nearby scientific data Find additional scientific data near this location
Location and accuracy The occurrence is located in the tidal zone on the east end of Copper Bay, Knight Island. It is in the NW1/4 section 14, T. 2 N., R. 9 E., of the Seward Meridian. This is location 235 of Tysdal (1978 [MF-880-A]) and location S-44 of Jansons and others (1984). This location is accurate to within a quarter of a mile.

Geologic setting

Geologic description

Nelson and others (1985) mapped the greenstone in this vicinity as Orca Group of early Tertiary age. Greenstone at the occurrence was visually estimated to contain 1 percent chalcopyrite and 1 to 5 percent pyrrhotite (Kurtak and Jeske, 1986). A single random chip sample of greenstone contained 94 ppm copper, 78 ppm zinc, and 0.25 ppm silver (Kurtak and Jeske, 1986).
Geologic map unit (-147.850975836437, 60.2672452634429)
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 No workings are reported. In the early 1980s, the U.S. Bureau of Mines searched for signs of prospecting but found none. They collected a single random chip sample from mineralized greenstone; it contained 94 ppm copper, 78 ppm zinc, and 0.25 ppm silver (Kurtak and Jeske, 1986).
Indication of production None

References