Twentieth Century Knight Island Copper Mining Co.

Prospect, Inactive

Commodities and mineralogy

Main commodities Cu
Other commodities Ag
Ore minerals chalcopyrite; pyrrhotite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale SR
Quadrangle map, 1:63,360-scale B-2
Latitude 60.3177
Longitude -147.7444
Nearby scientific data Find additional scientific data near this location
Location and accuracy The prospect is located 0.5 mile southwest of the head of Northeast Cove in Drier Bay at an elevation of about 750 feet. It is located in the SE1/4 section 29, T. 3 N., R. 10 E., of the Seward Meridian. This is location 24 of Condon and Cass (1958), location 108 of Cobb and Richter (1972), location 135 of MacKevett and Holloway (1977), location 226 of Cobb and Tysdal (1980), and location S-53 of Jansons and others (1984). This location is accurate to within a quarter of a mile.

Geologic setting

Geologic description

The prospect is in sheared pillow basalt of the Orca Group of early Tertiary age (Cobb and Tysdal, 1980). The shear zone trends north-south and dips nearly vertically. It contains numerous lenses of chalcopyrite and pyrrhotite that range in width from 2 to 6 inches (Kurtak and Jeske, 1986). A random chip sample was collected across a 2-inch-wide sulfide zone in the upper adit at 750 feet of elevation. It contained 2.6 percent copper and 3.2 ppm silver (Kurtak and Jeske, 1986).
Geologic map unit (-147.746448203577, 60.3171340081182)
Mineral deposit model Cyprus massive sulfide (Cox and Singer, 1986; model 24a)
Mineral deposit model number 24a
Age of mineralization Tertiary or younger; the occurrence is in rocks of the Orca Group of Tertiary age.

Production and reserves

Workings or exploration Workings on the prospect consist of a 30-foot-long adit at the 250-foot elevation, a 390-foot-long adit with a 70-foot-high raise at the 350-foot elevation, and a 68-foot-long adit at 750 feet elevation. Grant and Higgins (1909) indicated that a bunk house and a small wharf were located on the shore. The U.S. Bureau of Mines collected a random chip sample across a 2-inch-wide sulfide zone in the upper adit. It contained 2.6 percent copper and 3.2 ppm silver (Kurtak and Jeske, 1986).
Indication of production None
Reserve estimates The U.S. Bureau of Mines estimated an inferred reserve of 30 tons grading 2.6 percent copper (Kurtak and Jeske, 1986).

References

MRDS Number A010558

References

Reporters Jeff A. Huber and Carol S. Huber (Anchorage)
Last report date 11/18/2001