Unnamed (near Yellow Hill)

The Unnamed (near Yellow Hill) is a chromium 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 (near Yellow Hill)

Commodity

Primary: Chromium

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

Model Name: Alaskan Cr-Pt (PGE)

Orebody

Not available

Structure

Not available

Alterations

Alteration Type: L
Alteration Text: Serpentinization of dunite hostrock.

Rocks

Not available

Analytical Data

Not available

Materials

Ore: Magnetite
Ore: Chromite

Comments

Comment (Geology): Age = Probably Cretaceous.

Comment (Reference): Primary Reference = Karl, 1992

Comment (Workings): Workings / Exploration = Samples of chromite- and magnetite-bearing dunite contained up to 1000 ppm Ni, 200 ppm Co, and more than 5000 ppm Cr (Karl, 1992, loc. 50a-f).

Comment (Deposit): Model Name = Alaskan PGE (Cox and Singer, 1986; model 9)

Comment (Geology): Geologic Description = The country rocks in the area of this site are serpentinized dunite and subordinate clinopyroxenite, probably of Cretaceous age (Berg, 1972 [I 684]; Berg and others, 1988). The occurrences consist of serpentinized dunite containing disseminated magnetite and chromite, and stringers of chromite. The disseminated metalliferous minerals constitute about 3 percent of the dunite. Samples of the dunite contained up to 1000 ppm Ni, 200 ppm Co, and more than 5000 ppm Cr (Karl, 1992, loc. 50a-f).

References

Reference (Deposit): Karl, S.M., 1992, Map and table of mineral deposits on Annette Island, Alaska: U.S. Geological Survey Open-File Report 92-690, 57 p., 1 map, scale 1:63,360.

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): Berg, H.C., 1972, Geologic map of Annette Island, Alaska: U.S. Geological Survey Miscellaneous Geologic Investigations Map I-684, 8 p., 1 sheet, scale 1:63,360,

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