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Pyramid Peak, Ruby Mine

Past Producer in Alaska, United States with commodities Gold, Copper, Silver, 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. Host and associated rocks
  10. Nearby scientific data
  11. Economic information about the deposit and operations
  12. Mining district
  13. Links to other databases
  14. Bibliographic references
  15. General comments
  16. Reporter information

Geologic information

Identification information

Deposit ID 10002322
MRDS ID A013232
Record type Site
Current site name Pyramid Peak, Ruby Mine
Related records 10136650

Geographic coordinates

Geographic coordinates: -166.54239, 53.85744 (WGS84)
Relative position Location is on northwest slope of Pyramid Peak, near Obernoi Point; 2 km southwest of Unalaska Village at elevation of about 1500 feet (50 m), it corresponds to locality 2 of Cobb (1972, MF-446). Latitude and longitude are accurate to within about 200 m.

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 C-2(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

Ounalashka 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
Gold Primary
Copper Primary
Silver Primary
Lead Secondary
Zinc Critical Secondary

Materials information

Materials Type of material
Chalcopyrite Ore
Gold Ore
Pyrite Ore
Limonite Gangue
Quartz Gangue

Alteration

  • (Local) Regional propylitic alteration; wall rocks show little or no wall rock alteration.

Mineral occurrence model information

Model code 105
USGS model code 25a-d
Deposit model name Epithermal vein, generic
Mark3 model number 119

Host and associated rocks

  • Host or associated Associated
    Rock type Volcanic Rock (Aphanitic) > Intermediate Volcanic Rock > Andesite
    Rock unit name Unalaska Formation
    Rock description Unalaska Formation
    Stratigraphic age (youngest) Pliocene
    Stratigraphic age (youngest) Pliocene
    Stratigraphic age (youngest) Pliocene
    Stratigraphic age (youngest) Pliocene
  • Host or associated Host
    Rock type Volcanic Rock (Aphanitic) > Intermediate Volcanic Rock > Andesite

Nearby scientific data

(1) Tuu
ListMap

Economic information

Comments on the geologic information

  • Geologic Description = According to Collier (1905) and Simpson (1986), this historic mine was developed on quartz veins localized on vertical joint sets in andesitic volcaniclastic rocks of the Unalaska Formation. An adit approximately 300 feet (60 m) deep followed the veins and joints in the andesitic rocks. The main vein varies in width from 6 feet (2 m) at widest part to 1 foot (0.3 m) at ends of tunnels and crosscuts. This colorless to tan quartz vein contains very fine-grained visible gold (< 1 mm) and trace pyrite and chalcopyrite. The tan color is thought to be due to very fine-grained oxidized pyrite (Simpson(1986). Underground, the quartz breccia/vein zone varies from 40 feet (12 m) wide to as much as 80 (24 m) on the east. Quartz is similiar to that on surface and also contains open spaces having crystals to 1/4' (6 mm) long. Samples collected by Simpson (1986) underground from a small stockpile near a winze contained visible galena, chalcopyrite, and sphalerite. From this, he concluded that sulfide concentration apparently increases with depth. Numerous dikes cut tuffs and flows of the country rock. Above the adit the bedrock is well exposed, below it "*** exposures are non-existent due to thick vegetation ***(Simpson, 1986)."
  • Age = Late Tertiary or younger

Economic information about the deposit and operations

Development status Past Producer
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name Aleutians

Comments on the production information

  • Production Notes = Construction of a mill and extensive underground workings suggest some production. However, Simpson (1986) expressed opinion that no ore was probably ever shipped.

Comments on the workings information

  • Workings / Exploration = According to Collier (1905) the main tunnel runs east about 20 feet (7 m), then south approximately 150 feet (45 m) crosscutting joints and main ore body, which are developed by short drifts. Tunnel then turns east and follows little-mineralized joint for several hundred feet (> 60 m). A cable tramway had connected mine with 3-stamp mill, both of which were in ruins by 1904. Collier (1905) reports assay of 0.02 oz/ton gold (about 0.7 ppm), and a trace of silver from the face of a drift on the main ore body. Kennecott-Alaska channel samples across vein ranged between 0.1 and 0.9 ppm gold (Simpson, 1986). Undescribed samples collected underground by Kennecott-Alaska (Simpson, 1986) contained up to 1.15 ppm gold, 9.4 ppm silver, 3,000 ppm copper, 8,070 ppm lead, and 4,200 ppm zinc.

Reference information

Bibliographic references

  • Deposit

    Becker, G.F., 1898, Reconnaissance of some gold fields of southern Alaska with some notes on general geology: U.S. Geological Survey 18th annual report, p. 7-86.

  • Deposit

    Collier, A.J., 1905, Recent developments in Alaska tin deposits: U.S. Geological Survey Bulletin 259, p. 120-127.

  • Deposit

    Norton, L.M., editor, 1907, Boston Alaskan (published in the interests of Alaska): Boston-Alaskan Society, v. 1, August, 1906-June 1907, 175 p.

  • Deposit

    Jaggar, T.A., Jr., 1908, Journal of the Technology expedition to the Aleutian Islands, 1907: Technology Review, v. 10, no. 1, p. 1-37.

  • Deposit

    Atwood, W.W., 1909, Mineral resources of southwest Alaska, in Brooks, A.H., and others, Mineral resources of Alaska in 1908: U.S. Geological Survey Bulletin 379, 411 p.

  • Deposit

    Atwood, W.W., 1911, Geology and mineral resources of parts of the Alaska Peninsula: U.S. Geological Survey Bulletin 467, 137 p.

  • 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

    Berg, H.C., and Cobb, E.H., 1967, Metalliferous Lode Deposits of Alaska. U.S. Geological Survey Bulletin 1246, 254 p.

  • Deposit

    Cobb, E.H., 1972, Metallic mineral resources map of the Unalaska quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies MF-446, 1 sheet, scale 1: 250,000.

  • Deposit

    Wedow, Helmuth, Jr., White, M.G., and Moxham, R.M., 1952, Interim report on an appraisal of the uranium possibilities of Alaska: U.S. Geological Survey Open-File Report 52-165, 124 p.

  • 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 = Simpson, 1986

General comments

Subject category Comment text
Deposit Model Name = Epithermal gold vein
Deposit Other Comments = the mill was apparently constructed on the basis of very high assays, which were not realized at the time of milling (Collier, 1905). Mill was apparently moved from the Apollo Mine (PM006) on Unga Island (Norton, 1907). Other undescribed occurrences are nearby according to Simpson (1986).

Reporter information

Type Date Name Affiliation Comment
Reporter 06-MAY-1996 L.P. Niles U.S. Geological Survey
Reporter 06-MAY-1996 S.W. Bie U.S. Geological Survey
Reporter 06-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.