Unnamed (north tributary to Unaluk River)

Occurrence in Alaska, United States with commodities Gold, Platinum

Geologic information

Identification information

Deposit ID 10307615
Record type Site
Current site name Unnamed (north tributary to Unaluk River)

Geographic coordinates

Geographic coordinates: -161.45468, 58.89126 (WGS84)
Relative position This occurrence is on the south side of an east-west oriented mountain between the Kinegnak River and the headwaters of the Unaluk River. It is at an elevation of about 750 feet on the north side of a saddle, in the E1/2 of section 9, T 15 S, R 73 W, of the Seward Meridian. It is probably located to within about 1/3 mile. It is locality 2 of Cobb (1972 [MF 362]; 1980 [OF 80-909]).
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Gold Primary
Platinum Secondary

Materials information

Materials Type of material
Gold Ore

Nearby scientific data

(1) -161.45468, 58.89126

Comments on the geologic information

  • Geologic Description = On June 1, 1972, Allen L. Clark (U. S. G. S.) told E. H. Cobb that lode gold had been found at this location (Cobb, 1980, p.33 [OF 80-909]). Cobb (1972 [MF 362]) showed this location to be on the the south side of an east-west oriented mountain between the Kinegnak River and the headwaters of the Unaluk River. It is at an elevation of about 750 feet on the north side of a saddle marking the approximate south contact of a mafic pluton and sedimentary rocks (Hoare and Coonrad, 1979). The mafic plutons in the general area are gabbroic rocks that locally contain olivine and show compositional layering. They have yielded Jurassic K/Ar ages that range from 159 to 187 Ma (Hoare and Coonrad, 1978). The country rocks intruded by the pluton are Paleozoic to Mesozoic sedimentary rocks that include limestone near the contact just to the west of this locality. Fechner (1988) mapped and sampled the general area. A pan-concentrate sample from a saddle within the pluton contained 240 ppb Au and 125 ppb Pt; a chert sample from the contact zone at this location contained 70 ppb Au; and three small flakes of gold were recovered from a 0.1-cubic-yard sample of alluvium from a creek draining the east side of the pluton.
  • Age = If the mineralization is epigenetic, then it is probably Early Jurassic or younger. It can be as old as the nearby pluton, which is correlated with nearby mafic plutons that have been K/Ar dated as Jurassic in age (Hoare and Coonrad, 1978).

Economic information

Economic information about the deposit and operations

Development status Occurrence

Comments on exploration

  • Status = Inactive

Mining district

District name Goodnews Bay

Comments on the workings information

  • Workings / Exploration = No workings have been reported at this occurrence.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Alaska Resource Data File ARDF HG017

Bibliographic references

  • 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

    Cobb, E.H., 1980, Summaries of data and lists of references to metallic and selected nonmetallic mineral deposits in fifteen quadrangles in southwestern and west-central Alaska: U.S. Geological Survey Open-File Report 80-909, 103 p.

  • Deposit

    Fechner, S.A., 1988, Bureau of Mines mineral investigation of the Goodnews Bay mining district, Alaska: U.S. Bureau of Mines Open-File Report 1-88, 230 p.

  • Deposit

    Cobb, E.H., 1972, Metallic mineral resources map of the Hagemeister Island quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-362, 1 sheet, scale 1:250,000.

Comments on the references

  • Primary Reference = Fechner, 1988

Reporter information

Type Date Name Affiliation Comment
Reporter 18-MAR-01 Travis L. Hudson Applied Geology