1. Mineral Resources
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  3. Mineral Resource Data System (MRDS)

Unnamed (Crab Bay area)

Occurrence in Alaska, United States with commodities Silver, Barium-Barite, Lead, Zinc
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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. Mineral occurrence model information
  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 10307688
Record type Site
Current site name Unnamed (Crab Bay area)

Geographic coordinates

Geographic coordinates: -131.39075, 55.11874 (WGS84)
Relative position This site represents five occurrences in about a half-mile-square area, west of the inner arm of Crab Bay. All of the occurrences are about 0.4-0.5 mile inland from the bay: three are at elevations of 100-200 feet, and one is at an elevation of about 400 feet. The occurrences are in section 10, T. 78 S., R. 93 E., of the Copper River Meridian. The map site is at the approximate center of the area of occurrences. The site corresponds to loc. 32a-d in Karl (1992). The location is accurate within 0.1 mile.

Site location context

Political divisions (FIPS codes)

Prince of Wales-Hyder(Census area)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Ketchikan A-5(quadrangle 1:63,360 scale)

Ketchikan SW(quadrangle 1:100,000 scale)

Ketchikan(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Ketchikan(hydrologic unit)

Southern Southeast Alaska(hydrologic accounting unit)

Southeast Alaska(hydrologic subregion)

Alaska(hydrologic region)

Federal lands

Annette Island Indian Reservation(American Indian Reservation)

American Indian Reservation BIA(Type of land area)

BIA(Federal land areas administered by BIA)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Silver Primary
Barium-Barite Critical Primary
Lead Primary
Zinc Critical Primary

Materials information

Materials Type of material
Barite Ore
Galena Ore
Sphalerite Ore
Quartz Gangue

Alteration

  • (Local) Dolomitization of limestone country rock.

Mineral occurrence model information

Model code 85
USGS model code 22c
Deposit model name Polymetallic veins
Mark3 model number 46

Nearby scientific data

(1) -131.39075, 55.11874
ListMap

Economic information

Comments on the geologic information

  • Geologic Description = The country rocks in the area of the site are recrystallized, locally phyllitic, rhyolite, and massive, dolomitic limestone that conformably overlies the rhyolite (Berg, 1972 [I 684]; Berg and others, 1988). These Upper Triassic rocks were regionally metamorphosed to greenschist grade in Late Cretaceous time. The occurrences are quartz fissure veins in dolomite and at a dolomite-rhyolite contact (Karl, 1992a-d). The veins, which contain barite, galena, and sphalerite, have the character of ladder veins, and are most abundant at the dolomite-rhyolite contact. . At a locality informally called 'Cave Creek,' exploration in the 1970s by private interests showed galena and sphalerite in quartz veins up to 3 feet thick, as well as disseminated galena and sphalerite, in a 75-foot-wide zone in dolomite. Their exploration reportedly also showed two other occurrences of sulfide-bearing quartz veins at the dolomite-rhyolite contact. A sample of a quartz vein contained 5000 ppm Ba (Karl, 1992, loc. 32a-d).
  • Age = Probably Late Cretaceous or younger.

Economic information about the deposit and operations

Development status Occurrence

Mining district

District name Ketchikan

Comments on the workings information

  • Workings / Exploration = At a locality informally called 'Cave Creek,' exploration in the 1970s by private interests showed galena and sphalerite in quartz veins up to 3 feet thick, as well as disseminated galena and sphalerite, in a 75-foot-wide zone in dolomite. Their exploration reportedly also showed two other occurrences of sulfide-bearing quartz veins at the dolomite-rhyolite contact. A sample of a quartz vein contained 5000 ppm Ba (Karl, 1992, loc. 32a-d).

Reference information

Bibliographic references

  • 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,

  • 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.

  • 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.

Comments on the references

  • Primary Reference = Karl, 1992

General comments

Subject category Comment text
Deposit Model Name = Polymetallic veins (Cox and Singer, 1986; model 22c)

Reporter information

Type Date Name Affiliation Comment
Reporter 07-JUL-99 H.C. Berg U.S. Geological Survey

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.