|Quadrangle map, 1:250,000-scale||CR|
|Quadrangle map, 1:63,360-scale||A-2|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This prospect consists of a flooded shaft just above tidewater, about 0.3 mile south-southwest of the west head of Keete Inlet. It is about 0.4 mile northwest of the center of section 29, T. 78 S., R. 86 E.|
Geologic descriptionChapin (1916) originally described this deposit as a 'shear zone' with chalcopyrite, pyrite, and possibly bornite. The only working is a (shallow?) shaft that was flooded in 1915. Maas and others (1991, 1995) describe the deposit as a 1- to 2-foot-thick, copper-bearing, massive sulfide layer between altered chlorite schist and sericite schist of the Wales Group of Late Proterozoic and Cambrian age (Herreid and others, 1978). The sulfides also are disseminated in the wall rock. A 1.1-foot sample near the old shaft contained 1.23 parts per million (ppm) gold, 10.7 ppm silver, and 0.29 percent copper (Maas and others, 1991). There is no record of production. Recent detailed geochemical and isotopic work by Slack and others (2002) confirm that the deposit is of Late Proterozoic or Cambrian age.
|Geologic map unit||(-132.490657313813, 55.0808677468775)|
|Mineral deposit model||Volcanogenic massive sulfide (Cox and Singer, 1986; model 28a).|
|Mineral deposit model number||28a|
|Age of mineralization||Probably contemporaneous with deposition of the Late Proterozoic or Cambrian host rocks.|
|Alteration of deposit||Unspecified alteration of schist host rocks.|
|Workings or exploration||The only working is a shaft sunk before 1916.|
|Indication of production||None|
Chapin, Theodore, 1916, Mining developments in southeastern Alaska: U.S. Geological Survey Bulletin 642-B, p. 73-104.
Cobb, E. H., 1978, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Craig quadrangle, Alaska: U.S. Geological Survey Open-File Report 78-869, 262 p.
Herreid, Gordon, Bundtzen, T.K., and Turner, D.L., 1978, Geology and geochemistry of the Craig A-2 quadrangle, Prince of Wales Island, southeastern Alaska: Alaska Division of Geological and Geophysical Surveys Geologic Report 48, 49 p.
Maas, K.M., Bittenbender, P E., and Still, J.C., 1995, Mineral investigations in the Ketchikan mining district, southeastern Alaska: U.S. Bureau of Mines Open-File Report 11-95, 606 p.
Maas, K.M., Still, J.C., Clough, A.H., and Oliver, L.K., 1991, Mineral investigations in the Ketchikan mining district, Alaska, 1990: southern Prince of Wales Island and vicinity: U.S. Bureau of Mines Open-File Report 33-91, 139 p., 12 sheets, scale 1:63,360.
Slack, J.F., Shanks, W.C. III, Karl, S.M., Ridley, W.I., and Bittenbender, P.E., 2002, Geochemical and sulfur isotope compositions of Late Proterezoic and early Paleozoic volcanogenic massive sulfide deposits, Prince of Wales Island and vicinity, southeastern Alaska (abs.): Geological Society of America, Abstracts with Programs, v. 34 (6), p. 113.
|Reporters||D.J. Grybeck (Applied Geology)|
|Last report date||5/1/2004|