Unnamed (near Snipe Bay)

Prospect, Probably inactive

Commodities and mineralogy

Main commodities Cu; Ni
Ore minerals chalcopyrite; magnetite; nickeliferous pyrrhotite; pentlandite; pyrite
Gangue minerals albite; hornblende

Geographic location

Quadrangle map, 1:250,000-scale PA
Quadrangle map, 1:63,360-scale B-3
Latitude 56.42213
Longitude -134.95753
Nearby scientific data Find additional scientific data near this location
Location and accuracy This prospect consists of several claims that were staked over a mineralized area about 125 feet by 265 feet that was explored by several pits and drilled. The prospect is near the mouth of Snipe Bay near Snipe Head and about 0.6 mile southwest of the northeast corner of section 9, T. 63 S., R. 67 E. The location is accurate.

Geologic setting

Geologic description

The Snipe Bay prospect is associated with a small, poorly exposed elongate body (dike?) of Tertiary gabbro or norite that is largely altered to hornblende, albite, and magnetite (Buddington, 1925; Reed and Gates, 1942). The intrusion is in quartzite and quartz schist in Sitka Graywacke of Cretaceous age (Reed and Gates, 1942; Loney and others, 1975). The mineralization is confined to an area of about 125 by 265 feet. Magnetite, nickeliferous pyrrhotite, chalcopyrite, and pentlandite are disseminated through the altered gabbro or norite and there is one small lens of massive sulfides. The deposit probably is a magmatic segregation deposit (Reed and Gates, 1942; Bittenbender and others, 1999).
The deposit was discovered in 1922 (Buddington, 1925; Buddington and Chapin, 1929) and it was prospected intermittently by trenching until 1942 when it was examined by Reed and Gates (1942). The property was acquired by Inspiration Development Company in 1973; they diamond drilled 21 holes and the claims were abandoned in 1979 (Bittenbender and others, 1999). The U.S. Bureau of Mines collected samples for metallurgical testing in 1981 and 1988 (Foley, 1989).
Reed and Gates (1942) estimated that the deposit has a conservative minimum resource of 430,000 tons of material with no more than 0.3 percent each of copper and nickel. Foley (1989) estimated a resource of 94,000 tons of material with an average grade of 0.97 percent copper and 0.33 percent nickel.
Geologic map unit (-134.959310174631, 56.4217506524944)
Mineral deposit model Cu-Ni magmatic segregation deposit.
Age of mineralization Probably Tertiary and deposited during the intrusion of a gabbro or norite.
Alteration of deposit This is a magmatic-segregation deposit in a gabbro or norite that is altered to hornblende, albite, and magnetite.

Production and reserves

Workings or exploration The deposit was discovered in 1922 (Buddington, 1925; Buddington and Chapin, 1929) and it was prospected intermittently by trenching until 1942 when it was examined by Reed and Gates (1942). The property was acquired by Inspiration Development Company in 1973; they diamond drilled 21 holes and the claims were abandoned in 1979 (Bittenbender and others, 1999). The U.S. Bureau of Mines collected samples for metallurgical testing on 1981 and 1988 (Foley, 1989).
Indication of production None
Reserve estimates Reed and Gates (1942) estimated that the deposit has a conservative minimum resource of 430,000 tons of material with no more than 0.3 percent each of copper and nickel. Foley (1989) estimated a resource of 94,000 tons of material with an average grade of 0.97 percent copper and 0.33 percent nickel.

Additional comments

The prospect is in the South Baranof Wilderness Area which is closed to mineral exploration and mining.
MAS number: 0021160025.

References

MRDS Number A013373; W000355

References

Bittenbender, P., Still, J.C., Maas, K., and McDonald, M., Jr., 1999, Mineral resources of the Chichagof and Baranof Islands area, southeast Alaska: Bureau of Land Management, BLM-Alaska Technical Report 19, 222 p.
Foley, J.Y., 1989, Snipe Bay copper-nickel-cobalt deposits: Unpublished U.S. Bureau of Mines Field Report, 19 p. (On file at the Juneau Mineral Information Center, U.S. Bureau of Land Management, Juneau, Alaska.)
Roberts, W.S., 1983, Minerals Availability System property evaluation file report, Nickel, Snipe Bay, Alaska, Update of property evaluation report by Baggs, D.W.: Unpublished report, U.S. Bureau of Mines, 13 p. (On file at the Juneau Mineral Center, U.S. Bureau of Land Management, Juneau, Alaska.)
Reporters Donald J. Grybeck (U.S. Geological Survey)
Last report date 2-Jan-05