Unnamed (west of Togiak Lake)

Occurrence in Alaska, United States with commodity Copper

Geologic information

Identification information

Deposit ID 10307459
Record type Site
Current site name Unnamed (west of Togiak Lake)

Geographic coordinates

Geographic coordinates: -159.67471, 59.65831 (WGS84)
Relative position This occurrence is in the uplands along the west side of Togiak Lake. The map site is at an elevation of about 2,250 feet on a saddle 1/2 mile north-northwest of a local summit with an elevation of 3,547 feet. The location is probably accurate within 1/2 mile. It is included in Hoare and Cobb (1977) under the name 'Togiak Lake'.
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Copper Primary

Materials information

Materials Type of material
Chalcopyrite Ore
Malachite Ore
Quartz Gangue

Alteration

  • (Local) Silicification.

Host and associated rocks

  • Host or associated Associated
    Chronological age 6.7
    Uncertainty 2
    Dating method K-Ar
    Type of media Biotite
    Stratigraphic age (youngest) Late Cretaceous
    Chronological age 67.5
    Uncertainty 3
    Dating method K-Ar
    Type of media Hornblende
    Stratigraphic age (youngest) Late Cretaceous

Nearby scientific data

(1) -159.67471, 59.65831

Comments on the geologic information

  • Geologic Description = The upland between Togiak Lake and Kemuk River is cored by a large, Cretaceous(?) granitic pluton with a well-developed hornfels aureole (Hoare and Coonrad, 1978). Many stream-sediment samples in this area contain anomalous amounts of copper and manganese (Cieutat and others, 1988). At this location, along the east contact of the granitic pluton, chalcopyrite and malachite occur in a small quartz vein cutting quartz diorite (Hoare and Cobb, 1977, p. 49).
  • Age = Probably Late Cretaceous. Mineralization is probably related to the granitic pluton in the area, which is part of a regionally extensive Upper Cretaceous and Lower Tertiary plutonic suite. K/Ar ages for granitic samples from near this locality are 63.7 +/- 2 Ma on biotite and 67.5 +/-3 Ma on hornblende (Hoare and Coonrad, 1978).
  • Age = Chronological age is for granitic pluton in the area.

Economic information

Economic information about the deposit and operations

Development status Occurrence

Comments on exploration

  • Status = Inactive

Mining district

District name Bristol Bay Region

Comments on the workings information

  • Workings / Exploration = Reconnaissance stream-sediment sampling has been completed in the area.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Alaska Resource Data File ARDF GO006

Bibliographic references

  • Deposit

    Hoare, J.M., and Cobb, E.H., 1977, Mineral occurrences (other than mineral fuels and construction materials) in the Bethel, Goodnews, and Russian Mission quadrangles, Alaska: U.S. Geological Survey Open-File Report 77-156, 98 p.

  • Deposit

    Hoare, J.M., and Coonrad, W.L., 1978, Geologic map of the Goodnews and Hagemeister Island quadrangles region, southwestern Alaska: U.S. Geological Survey Open-File Report 78-9-B, two sheets, scale 1:250,000.

  • Deposit

    Cieutat, B.A., Goldfarb, R.J., and Specman, W.S., 1988, Analytical results and sample locality map of stream-sediment, heavy-mineral-concentrate, and organic material samples from the Goodnews, Hagemeister Island, and Nushagak quadrangles, southwest Alaska: U.S. Geological Survey Open-File Report 88-591, 187 p.

Comments on the references

  • Primary Reference = Hoare and Cobb, 1977

General comments

Subject category Comment text
Deposit Model Name = Vein

Reporter information

Type Date Name Affiliation Comment
Reporter 20-MAR-01 Travis L. Hudson Applied Geology