Unnamed (on Lincoln Island) (ARDF #JU100) Cu

Unnamed (on Lincoln Island)

Prospect, Inactive

Commodities and mineralogy

Main commodities	Cu
Ore minerals	pyrite; pyrrhotite

Geographic location

Quadrangle map, 1:250,000-scale	JU
Quadrangle map, 1:63,360-scale	C-4
Latitude	58.5145
Longitude	-135.0233
Nearby scientific data	Find additional scientific data near this location
Location and accuracy	This prospect is near the northern tip of Lincoln Island at an elevation of about 300 feet. It is in the SW1/4 section 4, T. 39 S., R. 63 E. of the Copper River Meridian. The location is accurate within 1/4 mile.

Geologic setting

Geologic description The country rocks are a sequence of chert, tuff, argillite and mafic volcanic rocks, presumably of Late Jurassic or Cretaceous age (Gehrels and Berg, 1994). All of the rocks contain varying amounts of disseminated sulfides, chiefly pyrite or pyrrhotite. The U.S. Bureau of Mines conducted limited ground geophysics in 1986 and noted good conductivity related to the exposure. U.S. Bureau of Mines samples contained up to 1,900 ppm copper (Clough and Hayden, 1988). Wells and others (1986) noted claims at this site in 1956.
Geologic map unit	(-135.02510226351, 58.5141696565459)

Geologic description

The country rocks are a sequence of chert, tuff, argillite and mafic volcanic rocks, presumably of Late Jurassic or Cretaceous age (Gehrels and Berg, 1994). All of the rocks contain varying amounts of disseminated sulfides, chiefly pyrite or pyrrhotite. The U.S. Bureau of Mines conducted limited ground geophysics in 1986 and noted good conductivity related to the exposure. U.S. Bureau of Mines samples contained up to 1,900 ppm copper (Clough and Hayden, 1988). Wells and others (1986) noted claims at this site in 1956.

Geologic map unit

(-135.02510226351, 58.5141696565459)

Production and reserves

Workings or exploration	Surface sampling and limited geophysics.
Indication of production	None

References

References Clough, A.H., and Hayden, T.J., 1988, 1985-1986 mineral investigations in the southern Chilkat Range, southeast Alaska: U.S. Bureau of Mines Open-File Report 13-88, 25 p. Gehrels, G.E., and Berg, H.C., 1994, Geology of southeastern Alaska, in Plafker, George, and Berg, H. C., eds., The geology of Alaska: Geological Society of America, DNAG, The geology of North America, Vol. G-1, p. 451-467. Wells, D.E., Pittman, T.L., Brew, D.A. and Douglass, S.L., 1986, Map and description of the mineral deposits in the Juneau, Taku River, Atlin, and part of the Skagway quadrangles, Alaska: U.S. Geological Survey Open-File Report 85-717, 332 p., 1 sheet, scale 1:250,000.
Reporters	J.C. Barnett and L.D. Miller (Juneau, Alaska )
Last report date	12/15/2001