Unnamed (southeast of confluence of Chickamin River and South Fork)

The Unnamed (southeast of confluence of Chickamin River and South Fork) is a copper mine located in Alaska.

About the MRDS Data:

All mine locations were obtained from the USGS Mineral Resources Data System. The locations and other information in this database have not been verified for accuracy. It should be assumed that all mines are on private property.

Mine Info

Satelite View

MRDS mine locations are often very general, and in some cases are incorrect. Some mine remains have been covered or removed by modern industrial activity or by development of things like housing. The satellite view offers a quick glimpse as to whether the MRDS location corresponds to visible mine remains.

Site Name

Primary: Unnamed (southeast of confluence of Chickamin River and South Fork)

Commodity

Primary: Copper

Location

State: Alaska
District: Ketchikan

Land Status

Not available

Holdings

Not available

Workings

Not available

Ownership

Not available

Production

Not available

Deposit

Record Type: Site
Operation Category: Occurrence
Operation Type: Unknown
Years of Production:
Organization:
Significant:

Physiography

Not available

Mineral Deposit Model

Not available

Orebody

Not available

Structure

Not available

Alterations

Alteration Type: L
Alteration Text: Conspicuous iron-staining.

Rocks

Not available

Analytical Data

Not available

Materials

Ore: Chalcopyrite
Ore: Magnetite
Ore: Pyrite

Comments

Comment (Workings): Workings / Exploration = Thirty-six chip samples collected at three locations along the outcrop of this 3-mile-long, 1000-foot-wide band of rusty-weathering gneiss assayed up to 700 ppm Cu, 150 ppm Pb, 200 ppm Zn, 70 ppm Mo, and 5 ppm Ag (Berg and others, 1977, table 13). A rock grab sample from the band contained up to 450 ppm Pb and 0.05 ppm Ag, and a stream-sediment sample from a creek draining the band was anomalous in Cu, Pb, Zn, Mo, Au, and Ag (Berg and others, 1977, fig. 9 and table 13).

Comment (Reference): Primary Reference = Berg and others, 1977

Comment (Deposit): Other Comments = Site is in Misty Fiords National Monument Wilderness.

Comment (Deposit): Model Name = Disseminated base-metal sulfides in rusty-weathering paragneiss

Comment (Geology): Geologic Description = The country rocks in the area of this occurrence consist chiefly of Tertiary or Cretaceous foliated granodiorite of the Coast Range batholith, and of rusty-weathering pelitic paragneiss that forms roof pendants, screens, and inclusions in the batholith (Berg and others, 1977, p. 129-132; Berg and others, 1977). The paragneiss probably represents marine argillaceous and clastic strata that underwent high-grade regional metamorphism in Cretaceous or Tertiary time. The premetamorphic age of the strata is uncertain, but they probably are mainly Paleozoic and may be as old as Precambrian (Berg and others, 1988, p. 26; Gehrels and others, 1990; Crawford and others, in press).? the occurrence consists of a conspicuous band of rusty-weathering pyritic gneiss about 1000 feet wide that strikes northwest and dips northeast, and can be traced in outcrop for about 3 miles (Berg and others, p. 129-132 and pl. 2). The rocks include quartzofeldspathic gneiss, which is gradational with the foliated plutonic rocks of the Coast Range batholith, and subordinate pelitic schist and paragneiss. The rocks contain pyrite in amounts up to several volume percent, and sparse grains of chalcopyrite. Thirty-six chip samples collected at three locations along the outcrop of the band assayed up to 700 ppm Cu, 150 ppm Pb, 200 ppm Zn, 70 ppm Mo, and 5 ppm Ag (Berg and others, 1977, table 13). A rock grab sample from the band contained up to 450 ppm Pb and 0.05 ppm Ag, and a stream-sediment sample from a creek draining the band was anomalous in Cu, Pb, Zn, Mo, Au, and Ag (Berg and others, 1977, fig. 9 and table 13).

References

Reference (Deposit): Berg, H.C., Elliott, R.L., Smith, J.G., Pittman, T.L., and Kimball, A. L., 1977, Mineral resources of the Granite Fiords wilderness study area, Alaska, with a section on aeromagnetic data by Andrew Griscom: U.S. Geological Survey Bulletin 1403, 151 p.

Reference (Deposit): Elliott, R.L., Berg, H.C., and Karl, Susan, 1978, map and table describing metalliferous and selected nonmetalliferous mineral deposits, Ketchikan and Prince Rupert quadrangles, Alaska: U.S. Geological Survey Open-file Report, 78-73-B,17 p., scale 1:250,000.

Reference (Deposit): Berg, H.C., Elliott, R.L., and Koch, R.D., 1988, Geologic map of the Ketchikan and Prince Rupert quadrangles, southeastern Alaska: U.S. Geological Survey Mineral Investigations Series Map MF-1807,27 p., scale 1:250,000.

Reference (Deposit): Gehrels, G.E., McClelland, W.C., Samson, S.D., Patchett, P.J., and Jackson, J.L., 1990, Ancient continental margin assemblage in the northern Coast Mountains, southeast Alaska and northwest Canada: Geology, v. 18, p. 208-211.

Reference (Deposit): Crawford, M.L., Crawford, W.A., and Gehrels, G.E., 2000, Terrane assembly and structural relationships in the eastern Prince Rupert quadrangle, British Columbia, in H.H. Stowell and W.C.McClelland, eds., Tectonics of the Coast Mountains, southeastern Alaska and British Columbia: Boulder, Colorado, Geological Society of America Special Paper 343, p. 1-21.?

The Top Ten Gold Producing States

These ten states contributed the most to the gold production that built the West from 1848 through the 1930s. The Top Ten Gold Producing States.