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Unnamed (near the north end of Shikosi Island)

Occurrence in Alaska, United States with commodities Silver, Copper, Zinc, Gold
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Sections on this page
  1. Identification information
  2. Geographic coordinates
  3. Site location context
  4. Geographic areas
  5. Commodities
  6. Materials information
  7. Alteration
  8. Host and associated rocks
  9. Nearby scientific data
  10. Economic information about the deposit and operations
  11. Mining district
  12. Links to other databases
  13. Bibliographic references
  14. General comments
  15. Reporter information

Geologic information

Identification information

Deposit ID 10308234
Record type Site
Current site name Unnamed (near the north end of Shikosi Island)

Geographic coordinates

Geographic coordinates: -135.27208, 59.03975 (WGS84)
Relative position This occurrence is about 0.15 miles south of the narrow northern tip of Shikosi Island.

Site location context

Political divisions (FIPS codes)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Skagway A-1 SW(quadrangle 1:24,000 scale)

Skagway SE(quadrangle 1:100,000 scale)

Skagway(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Lynn Canal(hydrologic unit)

Northern Southeast Alaska(hydrologic accounting unit)

Southeast Alaska(hydrologic subregion)

Alaska(hydrologic region)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Silver Primary
Copper Primary
Zinc Critical Primary
Gold Secondary

Materials information

Materials Type of material
Chalcopyrite Ore
Epidote Gangue
Quartz Gangue

Alteration

  • (Local) Epidotization, silicification.

Host and associated rocks

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

Nearby scientific data

(1) -135.27208, 59.03975
ListMap

Economic information

Comments on the geologic information

  • Geologic Description = Still and others (1991) describe this occurrence as, 'A narrow epidotized and silicified shear zone that contains chalcopyrite and chalcopyrite hosted in metabasalt.' Samples contained up to 0.05 ppm gold, 6.7 ppm silver, 3,000 ppm zinc, and 2.74% copper. This zone is similar to the unnamed occurrence (SK001) to the south on Kataguni Island. 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 structure that localizes the mineralization is related to the 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 this occurrence is not well established, but can be no older than the Late Triassic age of the host rocks (Plafker, Hudson and Silberling, 1979; Plafker and Hudson, 1980). If the structure that localizes the mineralization is related to the 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 about the deposit and operations

Development status Occurrence

Comments on exploration

  • Status = Inactive

Mining district

District name Juneau (Skagway subdistrict)

Reference information

Bibliographic references

Comments on the references

  • Primary Reference = Still and others, 1991 (BOM, v. 2, sec. A)

General comments

Subject category Comment text
Deposit Model Name = Very little information. Base and precious metal mineralization localized along a shear zone 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

Beyond USGS

Supplemental information added by qvyshift.com. Not part of the original USGS MRDS record.

Maps centered on this site

Authoritative Alaska resources

These are landing pages for further research — the state agencies don't currently expose per-mine deep links.