Unnamed (vicinity Kane Peak)

Occurrence in Alaska, United States with commodity PGE

Geologic information

Identification information

Deposit ID 10000290
MRDS ID A010336
Record type Site
Current site name Unnamed (vicinity Kane Peak)

Geographic coordinates

Geographic coordinates: -133.09883, 56.98363 (WGS84)
Relative position Well known mafic-ultramafic body centered about 13 miles north-northwest of Petersburg. Consists of slightly elongate pluton about two and a half square miles in outcrop that extend from just east of Kane Peak northeast to exposures for about a mile along the shoreline southeast of Cape Strait. The coordinates above are approximately the center of the body. Locality 16 and 17 of Grybeck, Berg, and Karl (1984). Often informally referred to as the Kane Peak deposit, or ultramafic complex.
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
PGE Primary

Comments on the commodity information

  • Ore Material = pyrrhotite (but see geologic description below)

Materials information

Materials Type of material
Chalcopyrite Ore
Chromite Ore
Magnetite Ore
Pentlandite Ore
Pyrrhotite Ore

Alteration

  • (Local) None.

Host and associated rocks

  • Host or associated Associated
    Rock type Plutonic Rock > Mafic Intrusive Rock > Gabbro
  • Host or associated Associated
    Rock type Plutonic Rock > Ultramafic Intrusive Rock > Peridotite
  • Host or associated Associated
    Rock type Plutonic Rock > Ultramafic Intrusive Rock > Peridotite > Dunite
  • Host or associated Associated
    Rock type Plutonic Rock > Ultramafic Intrusive Rock > Pyroxenite
  • Host or associated Host
    Rock type Plutonic Rock > Ultramafic Intrusive Rock > Pyroxenite

Nearby scientific data

(1) -133.09883, 56.98363

Comments on the geologic information

  • Geologic Description = Kane Peak is a classic 'zoned' or Alaska-type mafic-ultramafic complex with a dunite-wherlite (olivine-clinopyroxenite peridotite) core bordered by a hornblendite shell about 300 feet thick. About 80% of the body is dunite and wehrlite that grade into one another. Small-scale cumulus layering is present but the body is poorly exposed and its overall structure is uncertain. The body probably has steeply dipping contacts and extends under Frederick Sound to the northeast a half mile or more. The mafic-ultramafic complex intrudes Late Jurassic and Early Cretaceous, metamorphosed pelites of the Semour Canal Formation, and is bordered to the northwest and and south by Cretaceous migmatite. The Kane Peak complex has been dated at from 93.4 to 102.0 Ma by K-Ar methods. (The foregoing description is based mainly on Himmelberg and Loney, 1995; but also see Walton, 1951; Taylor, 1967; and Taylor and Noble, 1969, for earlier interpretations of this and other Alaska-type bodies in southeastern Alaska.)? Pyrrhotite, pentlandite, and chalcopyrite are sporadically disseminated through the peridotite; sparse disseminated chromite occurs widely in the dunite; and the hornblendite locally contains titaniferous magnetite. Himmelberg and Loney (1995) provide trace metal content for several metals including Co, Ni, and Cr. However, to date neither the sulfide occurrences nor the published analyses indicate that ore minerals are more than trace or accessory minerals. There are persistent rumors of anomalous Pt-group values in a sample or samples collected somewhere on the body but this may only reflect that the body has been sampled for these elements.
  • Age = Late to Early Cretaceous based on 93.4 to 102.0 Ma, K-Ar age dates (Himmelberg and Loney, 1995).

Economic information

Economic information about the deposit and operations

Development status Occurrence
Commodity type Metallic

Mining district

District name Kupreanof

Comments on the production information

  • Production Notes = None

Comments on the reserve resource information

  • Reserves = None

Comments on the workings information

  • Workings / Exploration = Two claims were staked on the body for Fe in 1960 along the coast near near Cape Strait, probably on magnetite-bearing hornblendite that crops out there (U. S. Bureau of Mines, 1980). In addition, the Kane Peak body has repeatedly been visited by geologists over the years as a potential site for Fe, Cu, and Pt-group deposits and for its scientific value. With the possible exception of the claims staked for Fe along Frederick Sound, there is little evidence at present (1998) of anything close to an economic deposit within the complex.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS A010336
USGS Alaska Resource Data File ARDF PE010

Bibliographic references

  • Deposit

    Walton, M.S., 1951, The Blashke Island ultrabasic complex with notes on related areas in southeastern Alaska: U.S. Geological Survey Open-File Report 126, 266 p.

  • Deposit

    Taylor, H.P., 1967, The zoned ultramafic complexes of southeastern Alaska, in Wyllie, P.J., ed., UIltramafic and related rocks: New York, J. Wiley and Sons, p. 97-121.

  • Deposit

    Taylor, H.P., Jr., and Noble, J.A., 1969, Origin of magnetite in the zoned ultramafic complexes of southeastern Alaska, in Wilson, H. D .B., ed., Magmatic ore deposits: Economic Geology Monograph 4, p. 209-230.

  • Deposit

    Cobb, E.H., 1978, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Petersburg quadrangle, Alaska: U.S. Geological Survey Open-File Report 78-870, 53 p.

  • Deposit

    Cobb, E.H., 1972, Metallic mineral resources map of the Petersburg quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-415, 1 sheet, scale 1:250,000.

  • Deposit

    U.S. Bureau of Mines, 1980, Claim map, Petersburg quadrangle, Alaska: U.S. Bureau of Mines Map 117, 1 sheet, scale 1:250,000.

  • Deposit

    Brew, D. A., Ovenshine, A. T., Karl, S. M., and Hunt, S. J., 1984, Preliminary reconnaissance geologic map of the Petersburg and parts of the Port Alexander and Sumdum 1:250,000 quadrangles, southeastern Alaska: U.S. Geological Survey Open-File Report 84-405, 43 p., 2 sheets, scale 1:250,000.

  • Deposit

    Grybeck, D.J., Berg, H.C., and Karl, S.M., 1984, Map and description of the mineral deposits in the Petersburg and eastern Port Alexander quadrangles: U.S. Geological Survey Open-File Report 84-837, 86 p., 1 sheet, scale 1:250,000.

  • Deposit

    Himmelberg, G.R., and Loney, R.A., 1995, Characteristics and petrogenesis of Alaskan-type ultramafic-mafic intrustions, southeastern Alaska: U.S. Geological Survey Professional Paper 1564, 47 p.

  • Deposit

    Cobb, E. H., 1972, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Petersburg Quadrangle, Alaska: U.S. Geological Survey Open-File Report 78-870, 53 p.

Comments on the references

  • Primary Reference = Taylor and Noble, 1969; Himmelberg, Loney, and Craig, 1995

General comments

Subject category Comment text
Deposit Model Name = Zoned or Alaska-type ultramafic complex with disseminated, magmatic sulfides and oxides.

Reporter information

Type Date Name Affiliation Comment
Reporter 01-NOV-1998 H.C. Berg U.S. Geological Survey
Reporter 01-NOV-1998 D.J. Grybeck U.S. Geological Survey