Pyramid Peak, Ruby Mine

The Pyramid Peak, Ruby Mine is a gold, copper, and silver mine located in Alaska.

About the MRDS Data:

All mine locations were obtained from the USGS Mineral Resources Data System. The locations and other information in this database have not been verified for accuracy. It should be assumed that all mines are on private property.

Mine Info

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Site Name

Primary: Pyramid Peak, Ruby Mine

Commodity

Primary: Gold
Primary: Copper
Primary: Silver
Secondary: Zinc
Secondary: Lead

Location

State: Alaska
District: Aleutians

Land Status

Not available

Holdings

Not available

Workings

Not available

Ownership

Not available

Production

Not available

Deposit

Record Type: Site
Operation Category: Past Producer
Operation Type: Unknown
Years of Production:
Organization:
Significant:

Physiography

Not available

Mineral Deposit Model

Model Name: Epithermal vein, generic

Orebody

Not available

Structure

Not available

Alterations

Alteration Type: L
Alteration Text: Regional propylitic alteration; wall rocks show little or no wall rock alteration.

Rocks

Name: Andesite
Role: Associated
Age Type: Host Rock
Age Young: Pliocene

Name: Andesite
Role: Associated
Age Type: Associated Rock Unit
Age Young: Pliocene

Name: Andesite
Role: Associated
Age Type: Associated Rock
Age Young: Pliocene

Name: Andesite
Role: Associated
Age Type: Associated Rock
Age Young: Pliocene

Analytical Data

Not available

Materials

Ore: Chalcopyrite
Ore: Gold
Ore: Pyrite
Gangue: Limonite
Gangue: Quartz

Comments

Comment (Geology): 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)."

Comment (Deposit): Model Name = Epithermal gold vein

Comment (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).

Comment (Reference): Primary Reference = Simpson, 1986

Comment (Workings): 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.

Comment (Geology): Age = Late Tertiary or younger

Comment (Exploration): Status = Inactive

Comment (Production): 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.

References

Reference (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.)

Reference (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.

Reference (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.

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

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

Reference (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.

Reference (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.

Reference (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.

Reference (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.

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

Reference (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.

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