Unnamed (near the south end of Kataguni Island)

Occurrence in Alaska, United States with commodities Silver, Gold, Copper, Zinc

Geologic information

Identification information

Deposit ID 10308233
Record type Site
Current site name Unnamed (near the south end of Kataguni Island)

Geographic coordinates

Geographic coordinates: -135.25208, 59.00975 (WGS84)
Relative position This occurrence is in beach cliffs on the western coast of Kataguni Island about 0.2 miles from the southern tip of the island. It is shown as localities 48 to 52 in Still (1988).
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Silver Primary
Gold Primary
Copper Primary
Zinc Primary

Materials information

Materials Type of material
Bornite Ore
Chalcopyrite Ore
Malachite Ore
Pyrite Ore
Sphalerite Ore
Calcite Gangue
Epidote Gangue
Quartz Gangue

Alteration

  • (Local) Epidotization, silicification.

Host and associated rocks

  • Host or associated Host
    Stratigraphic age (youngest) Late Triassic

Nearby scientific data

(1) -135.25208, 59.00975

Comments on the geologic information

  • Geologic Description = Still (1988) indicates that, 'Mineralization is located in metabasalt sea cliffs up to 50 feet high that contain numerous narrow shear zones at various orientations. Some of the shears are silicified and contain copper or copper-zinc mineralization. Samples collected from these 0.2- to 1.4-foot-thick shear-controlled veins contain up to 2.54 ppm gold, 22.5 ppm silver, 6.9% copper, and 2.14% zinc.'. Plafker, Hudson, and Silberling (1979) and Plafker and Hudson (1980) note that on the Chilkat Peninsula the same metabasalts are vesicular and/or amygdaloidal and that well-developed pillow textures are locally present. Based in part on fossil evidence that supports a Late Triassic (Karnian) age, they suggest that the metavolcanics and carbonates may correlate with similar rocks of the Wrangellia terrane. The age of the mineralization is not well established, but can be no older than the Late Triassic age of the host rocks. If the shearing and mineralization are both related to the nearby Chilkat Fault, then the age of the mineralization is probably Tertiary or younger as most movement on the Chilkat Fault has been post-Mesozoic (Lanphere, 1978).
  • Age = the age of the mineralization is not well established, but must be no older than the Late Triassic (Karnian) age of the metabasalts that host the deposit (Plafker, Hudson and Silberling, 1979; Plafker and Hudson, 1980). If the shearing and mineralization are both related to the nearby Chatham Strait Fault, then the age of the mineralization is probably Tertiary or younger as most movement on the Chilkat Fault has been post-Mesozoic (Lanphere, 1978).

Economic information

Economic information about the deposit and operations

Development status Occurrence

Comments on exploration

  • Status = Inactive

Mining district

District name Juneau (Skagway subdistrict)

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Alaska Resource Data File ARDF SK001

Bibliographic references

  • Deposit

    Lanphere, M.A., 1978, Displacement history of the Denali fault system, Alaska and Canada: Canadian Journal of Earth Sciences, v. 115, p. 817-822

  • Deposit

    Plafker George, Hudson, T.L., and Silberling, N.J., 1979, Upper Triassic fossils from a sequence of volcanic and sedimentary rocks on the Chilkat Peninsula, southeastern Alaska, in Johnson, K.M., and Williams, J.R., eds., The United States Geological Survey in Alaska: Accomplishments during 1978: U.S. Geological Survey Circular 804-B, p. B107-B110.

  • Deposit

    Plafker, George, and Hudson, T., 1980, Regional implications of Upper Triassic metavolcanic and metasedimentary rocks on the Chilkat Peninsula, southeastern Alaska: Canadian Journal of Earth Sciences, v. 17, p. 681-689.

  • Deposit

    Still, J.C., 1988, Gold-copper Mineralization of the Chilkat Peninsula and Islands: U.S. Bureau of Mines Open-File Report 49-88, 39 p., 11 sheets.

  • Deposit

    Still, J.C., 1991, Bureau of Mines mineral investigations in the Juneau mining district, Alaska, 1984 - 1988, v. 2, Detailed mine, prospect, and mineral occurrence descriptions, section A, Haines-Klukwan-Porcupine subarea: U.S. Bureau of Mines of Mines Special Publication, 214 p.

  • Deposit

    Still, J.C., Hoekzema, R.B., Bundtzen, T.K., Gilbert, W.G., Wier, K.R., Burns, L.E., and Fechner, S.A., 1991, Economic geology of Haines-Klukwan-Porcupine area, southeastern Alaska: Alaska Division of Geological and Geophysical Surveys Report of Investigations 91-4, 156 p., 5 sheets, scale 1:63,360.

Comments on the references

  • Primary Reference = Still, 1988

General comments

Subject category Comment text
Deposit Model Name = Au-Ag-Cu-Zn in shear zones in metabasalt.
Deposit Other Comments = This occurrence is within the Chilkat Islands, State Marine Park.

Reporter information

Type Date Name Affiliation Comment
Reporter 04-FEB-01 T.C. Crafford T. Crafford & Associates