Unnamed (northern Chenega Island)

Occurrence, Inactive

Commodities and mineralogy

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

Geographic location

Quadrangle map, 1:250,000-scale SR
Quadrangle map, 1:63,360-scale B-3
Latitude 60.3479
Longitude -148.0617
Nearby scientific data Find additional scientific data near this location
Location and accuracy The occurrence is located near the top of hill 1981 at an elevation of 1,800 feet, about a mile west of the head of Masked Bay. It is in the SE1/4 section 16, T. 3 N., R. 8 E., of the Seward Meridian. This is location 219 of Tysdal (1978 [MF-880-A]) and location S-89 of Jansons and others (1984). This location is accurate to within a quarter of a mile.

Geologic setting

Geologic description

The occurrence consists of a 50-foot-wide zone of slightly altered iron-stained, sheared greenstone that is exposed along the top of the hill. The greenstone contains a thin interbed of shale with disseminated pyrite and some thin quartz veins that are parallel to bedding (Kurtak and Jeske, 1986). The host rock is part of the Orca Group of early Tertiary age (Nelson and others, 1985). Four random chip samples from the occurrence contained from 17 to 100 ppm copper and from 780 to 1,450 ppm manganese (Kurtak and Jeske, 1986).
Geologic map unit (-148.063779699091, 60.3473338284737)
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.
Alteration of deposit The greenstone is iron-stained.

Production and reserves

Workings or exploration Four random chip samples from the occurrence contained from 17 to 100 ppm copper and from 780 to 1,450 ppm manganese (Kurtak and Jeske, 1986).
Indication of production None

References