Drier Bay

Mine, Inactive

Alternative names

Knights Island Alaska Copper

Commodities and mineralogy

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

Geographic location

Quadrangle map, 1:250,000-scale SR
Quadrangle map, 1:63,360-scale B-2
Latitude 60.3109
Longitude -147.7428
Nearby scientific data Find additional scientific data near this location
Location and accuracy The mine is located between the elevations of 300 and 1,100 feet about three-quarters of a mile south of Northeast Cove at the head of Drier Bay. It is in the NE1/4 section 32, T. 3 N., R. 10 E., of the Seward Meridian. This is location 25 of Condon and Cass (1958), location 107 of Cobb and Richter (1972), location 135 of MacKevett and Holloway (1977), location 229 of Cobb and Tysdal (1980), and location S-52 of Jansons and others (1984). This location is accurate to within a quarter of a mile.

Geologic setting

Geologic description

Two major rock types occur at the mine site: a light-gray, aphanitic, intermediate volcanic rock, and a porphyritic, dark gray-green greenstone. Some thin layers of slate are interbedded with the volcanic rock (Kurtak and Jeske, 1986). The prospect is within the Nellie shear zone, which is a northeast-trending, nearly vertical zone exposed for about 5 miles (Kurtak and Jeske, 1986). The greenstone and slate are Orca Group of early Tertiary age (Nelson and others, 1985).
The mine workings consist of three adits and several open cuts. The mineralization consists of several massive sulfide lenses within several shear zones that are from 1 to 10 feet wide. One lens of massive sulfides is 30 feet wide by 40 feet high and consists of massive chalcopyrite and pyrrhotite. This lens is exposed above the upper adit (Grant, 1906). In the middle adit, the mineralization consists of a 1- to 5-foot-wide shear zone containing 1 to 5 percent disseminated chalcopyrite and pyrrhotite (Kurtak and Jeske, 1986).
Samples from the workings and surface exposures contained from 15 ppm to 1.6 percent copper and from less than 1 ppm to 5.1 ppm silver (Kurtak and Jeske, 1986). A one-ton bulk sample shipped in 1911 contained 240 pounds of copper, 2 ounces of gold, and 3 ounces of silver (Kurtak and Jeske, 1986).
Geologic map unit (-147.744848143493, 60.3103338232465)
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 mine workings consist of three adits and several open cuts. A 78-foot adit is at 300 feet elevation; a 113-foot adit is at 900 feet elevation; and a 117-foot adit is at 1,100 feet elevation. Richter (1965) indicated that there were many ruined buildings, large piles of rusting pipe, mine rails, and other mining equipment on site.
Samples from the workings and surface exposures contained from 15 ppm to 1.6 percent copper and from less than 1 ppm to 5.1 ppm silver (Kurtak and Jeske, 1986). A one-ton bulk sample shipped in 1911 contained 240 pounds of copper, 2 ounces of gold, and 3 ounces of silver (Kurtak and Jeske, 1986).
Indication of production Yes
Production notes One ton of ore was shipped in 1911 as a bulk test. The ore contained 240 pounds of copper, 2 ounces of gold, and 3 ounces of silver (Kurtak and Jeske, 1986).

Additional comments

Mineral Survey 736 was done in 1906 (Kurtak and Jeske, 1986). Cobb and Tysdal (1980) called this mine Knights Island Alaska Copper Co.

References

References

Reporters Jeff A. Huber and Carol S. Huber (Anchorage)
Last report date 2/7/2002