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Unnamed (on western Tigalda Island)

Occurrence in Alaska, United States with commodities Silver, Gold, 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 10308479
Record type Site
Current site name Unnamed (on western Tigalda Island)

Geographic coordinates

Geographic coordinates: -165.1424, 54.10914 (WGS84)
Relative position This site represents several color anomalies on the west end of the island between Derkin and Kelp Bays. Site location is accurate to within 1 mile.

Site location context

Political divisions (FIPS codes)

Aleutians East(Borough)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Unimak A-4(quadrangle 1:63,360 scale)

Akutan Island(quadrangle 1:100,000 scale)

Unimak(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Fox Islands(hydrologic unit)

Aleutian Islands(hydrologic accounting unit)

Southwest(hydrologic subregion)

Alaska(hydrologic region)

Federal lands

The Akutan Corporation(ANCSA Village)

ANCSA Village NTVPIC(Type of land area)

NTVPIC(Federal land areas administered by NTVPIC)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Silver Primary
Gold Primary
Lead Secondary
Zinc Critical Secondary

Materials information

Materials Type of material
Gold Ore
Pyrite Ore
Calcite Gangue
Quartz Gangue

Alteration

  • (Local) Country rocks are propylitized, pyritized, and locally argillized.

Mineral occurrence model information

Model code 106
USGS model code 25b
Deposit model name Epithermal vein, Creede
Mark3 model number 58

Nearby scientific data

(1) -165.1424, 54.10914
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Economic information

Comments on the geologic information

  • Geologic Description = This occurrence consists of several color anomalies along a northwest-trending fault which crosses the island between Derkin and Kelp Bays. Rocks in these areas are mostly Tertiary andesites and dacite porphyries which have been intruded by diorite 'bodies' and basalt dikes (Butherus and others, 1979). Within the color anomalies the andesite and diorite are fractured, pyritized, and moderately argillically altered. Quartz-calcite veins, some up to 2 feet thick, are common in the altered and fractured areas. A sample of quartz-calcite vein material collected by Resource Associates of Alaska contained values of up to 85 ppm copper, 1.2 ppm gold, 96 ppm lead, 18.1 ppm silver, and 176 ppm zinc (Butherus and others, 1979). They also reported values to 8700 ppm arsenic, 250 ppm copper, and 7 ppm mercury from an unknown location on the south side of the island. Kennecott collected 15 samples of vein material in 1985 (Simpson, 1986). They reported gold in quantities up to 4.6 ppm.
  • Age = Tertiary.

Economic information about the deposit and operations

Development status Occurrence

Comments on exploration

  • Status = Inactive

Mining district

District name Aleutian Islands

Comments on the workings information

  • Workings / Exploration = Sampling by Resource Associates of Alaska of one vein returned metal values of 85 ppm copper, 1.2 ppm gold, 96 ppm lead, 18.1 ppm silver, and 176 ppm zinc (Butherus and others, 1979). Kennecott collected 15 samples of vein material and reported gold values up to 4.6 ppm (Simpson, 1986).

Reference information

Bibliographic references

  • Deposit

    Butherus, D.L, Gressitt, E.E., Pray, J., Corner, N.G., Lindberg, P.H., and Fankhauser, R.E., 1979, Exploration and evaluation of the Aleut Native Corporation lands; Volume III: Resource Associates of Alaska, 69 p. 90 sheets, various sacales. (Report held by the Aleut Native Corporation, Anchorage, Alaska.)

  • Deposit

    Randolph, D.B., 1990, Unalaska, 1990 final report: Battle Mountain Exploration Company, 72 p. (Report held by the Aleut Native Corporation, Anchorage, Alaska).

  • Deposit

    Simpson, D.F., 1986, Aleutian Islands project, 1985 final report: Kennecott Alaska Exploration Company, 54 p. (Report held by the Aleut Native Corporation, Anchorage, Alaska.)

Comments on the references

  • Primary Reference = Butherus and others, 1979

General comments

Subject category Comment text
Deposit Model Name = Epithermal gold veins or Creede epithermal veins(?) (Cox and Singer, 1986; model 25b)
Deposit Other Comments = This site is on lands selected by the Aleut Native Corporation.

Reporter information

Type Date Name Affiliation Comment
Reporter 27-JAN-00 S.H. Pilcher 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.