Unnamed (east of Kashoto Glacier)

Occurrence in Alaska, United States with commodities Copper, Gold, Molybdenum

Geologic information

Identification information

Deposit ID 10002241
MRDS ID A013143
Record type Site
Current site name Unnamed (east of Kashoto Glacier)
Related records 10233957

Geographic coordinates

Geographic coordinates: -137.03823, 58.87472 (WGS84)
Relative position The most probable location of this occurrence is near tidewater in Johns Hopkins Inlet, north and east of the foot of Kashoto Glacier; the coordinates are probably within a 0.25 mile radius of the occurrence. An element of uncertainty is present because MacKevett and others (1971) say the location is east of Hoonah Glacier, the next glacier to the south. It is apparently the same location as number 33 of Kimball and others (1978). Location number 32 of Kimball and others (1978) is about 0.75 mile to the north.
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Copper Primary
Gold Secondary
Molybdenum Secondary

Comments on the commodity information

  • Ore Material = 'gray' sulfides
  • Ore Material = 'gray' sulfides

Materials information

Materials Type of material
Chalcopyrite Ore
Pyrite Ore

Alteration

  • (Local) Contact metamorphism and formation of hornfels. Sulfidation; abundant secondary iron-staining.

Host and associated rocks

  • Host or associated Associated
    Rock type Plutonic Rock > Mafic Intrusive Rock > Diorite
    Stratigraphic age (youngest) Late Cretaceous
    Stratigraphic age (youngest) Late Permian
  • Host or associated Host
    Rock type Metamorphic Rock > Hornfels

Nearby scientific data

(1) -137.03823, 58.87472

Comments on the geologic information

  • Geologic Description = Disseminated pyrite and a trace of chalcopyrite occur in an altered zone several hundred feet thick of biotite hornfels adjacent to a granodiorite intrusion of Cretaceous age (Brew and others, 1978). The altered zone is conspicuously iron stained. The area was not well examined; grab samples contained as much as 700 ppm copper. The U.S. Bureau of Mines (Kimball and others, 1978, location 32, p. C173) reported disseminated pyrite, pyrrhotite and occasional bornite at a location about 0.75 miles north of the probable location of the occurrence. Copper content was less than 200 ppm in two chip samples collected from that area, and the report of bornite may be erroneous.
  • Age = Tertiary.

Economic information

Economic information about the deposit and operations

Development status Occurrence
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name Juneau

Comments on the workings information

  • Workings / Exploration = There are no workings or pits. Two samples of hornfels (Location 77, MacKevett and others, 1971, table 9) contained 300 and 700 ppm copper.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS A013143
USGS Alaska Resource Data File ARDF MF044

Bibliographic references

  • Deposit

    MacKevett, E.M., Jr., Brew, D.A., Hawley, C.C., Huff, L.C., and Smith, J.G., 1971, Mineral resources of Glacier Bay National Monument, Alaska: U.S. Geological Survey Professional Paper 632, 90 p., 12 plates, scale 1:250,000.

  • Deposit

    Brew, D.A., Johnson, B.R., Grybeck, D., Griscom, A., Barnes, D.F., Kimball, A.L., Still, J.C., and Rataj, J.L., 1978, Mineral resources of the Glacier Bay National Monument Wilderness Study Area, Alaska: U.S. Geological Survey Open-File Report 78-494, 670 p.

  • Deposit

    Kimball, A.L., Still, J.C., and Rataj, J.L., 1978, Mineral resources, in Brew, D. A., and others, Mineral resources of the Glacier Bay National Monument wilderness study area, Alaska: U.S. Geological Survey Open-File Report 78-494, p. C1-C375.

  • Deposit

    Cobb, E.H., 1972, Metallic mineral resources map of the Mount Fairweather quadrangle, AK: U.S. Geological Survey Miscellaneous Field Study Map MF-436, 1 sheet, scale 1:250,000.

Comments on the references

  • Primary Reference = MacKevett and others, 1971

General comments

Subject category Comment text
Deposit Model Name = Disseminated deposit, igneous-affiliated contact metamorphism.
Deposit Other Comments = Only a small part of altered zone was examined, hence there may be richer sites. The U.S. Bureau of Mines party failed to thoroughly examine the occurrence because of attacks by vicious seagulls. The occurrence is in Glacier Bay National Park and Preserve.

Reporter information

Type Date Name Affiliation Comment
Reporter 08-APR-94 Hawley, C.C. Hawley Resource Group