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  3. Mineral Resource Data System (MRDS)

Unnamed

Occurrence in Alaska, United States with commodities Copper, Silver
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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 10003272
MRDS ID A106015
Record type Site
Current site name Unnamed

Geographic coordinates

Geographic coordinates: -166.98572, 53.70243 (WGS84)
Relative position West side of head of creek flowing north to Makushin Bay, midway between Tarasof Point and USCGS Point Mist, roughly 2 km inland. Anomaly no. 1 of Christie (1974). Location accurate to within 1 km.

Site location context

Political divisions (FIPS codes)

Aleutians West(Census area)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Unalaska B-3(quadrangle 1:63,360 scale)

Unalaska NW(quadrangle 1:100,000 scale)

Unalaska SE(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

Alaska Maritime National Wildlife Refuge(National Wildlife Refuge)

National Wildlife Refuge FWS(Type of land area)

FWS(Federal land areas administered by FWS)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Copper Primary
Silver Primary

Materials information

Materials Type of material
Chalcopyrite Ore
Pyrite Ore
Magnetite Gangue

Alteration

  • (Local) Alteration of the porphyry consists of chloritized mafic minerals, chalky feldspar, and minor disseminated pyrite. In zones outward from the contact with the porphyry the Unalaska Formation displays pervasive sericitic alteration and contains minor quartz veinlets and pyrite. Peripheral to this the rocks contain sericite and pyrite in fractures which grades to pervasively developed chlorite (propylitic alteration) and pyrite limited to fractures; and finally pervasive epidote and disseminated pyrite. Christie (1974) reports partial leaching, complete in the breccia, however the leached phase is not identified.

Mineral occurrence model information

Model code 53
USGS model code 17
Deposit model name Porphyry Cu
Mark3 model number 4
Model code 105
USGS model code 25a-d
Deposit model name Epithermal vein, generic
Mark3 model number 119

Nearby scientific data

(1) -166.98572, 53.70243
ListMap

Economic information

Comments on the geologic information

  • Geologic Description = Occurrence is a 1,000 by 5,000 ft (300 by 500 m) color anomaly in granodiorite or diorite that intrudes rocks of the Unalaska Formation (see Drewes and others, 1961). A small but well-mineralized breccia-pipe is located nearby, possibly within the area of the color anomaly. The color anomaly is oriented N 30xE, 200-500 ppm copper defined a zone containing more than 2 percent pyrite. Chirstie (1974) reports that areas showing 200-500 ppm copper are confiend to zones having quartz veinlets which occur almost exclusively in the dike-like granodiorite to diorite porphyry. The color anomaly is covered to the northeast. Gold potential was not considered during the Qunitana reconnaissance evaluation conducted by Chritie.
  • Age = Miocene or younger

Economic information about the deposit and operations

Development status Occurrence
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name Aleutians

Comments on the workings information

  • Workings / Exploration = Brief reconnaissance mapping and rock, stream, and soil sampling was reported by Christie (1974). Copper anomalies to 2,400 ppm, molybdenum to 10 ppm, and gold to 0.34 ppm from very limited sampling.

Reference information

Bibliographic references

  • Deposit

    Drewes, Harold, Fraser, G.D., Snyder, G.L., and Barnett, H.F., Jr., 1961, Geology of Unalaska Island and adjacent insular shelf, Aleutian Islands, Alaska: U.S. Geological Survey Bulletin 1028-S, p. 583-676.

  • Deposit

    Christie, J.S., 1974, Aleut-Quintana-Duval 1974 joint venture, final report: Unpublished Quintana Minerals Corporation report, 24 p., 3 appendices, 2 maps. (Report held by the Aleut Corporation, Anchorage, Alaska.)

Comments on the references

  • Primary Reference = Christie, 1974

General comments

Subject category Comment text
Deposit Model Name = Copper porphyry, epithermal gold vein(?)
Deposit Model Number = 17, 25
Deposit Other Comments = According to Christie (1974), the mineralized zone goes under cover to the northeast of the exposure and in his interpretation, if their silt sample W-7 and soil sample W-25 had been strongly anomalous, (which they weren't) a soil survey should have been done. Otherwise, he thought the apparent grade and size were of academic interest only. The goal was a copper porphyry system, hence sampling may not have been appropriate to evaluate gold potential

Reporter information

Type Date Name Affiliation Comment
Reporter 13-MAY-1996 Damon Bickerstaff U.S. Geological Survey
Reporter 13-MAY-1996 F.H. Wilson 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.