Unnamed (near Weyahok River)

Occurrence in Alaska, United States with commodities Silver, Copper, Lead, Zinc, Antimony

Geologic information

Identification information

Deposit ID 10309019
MRDS ID AO11931
Record type Site
Current site name Unnamed (near Weyahok River)

Geographic coordinates

Geographic coordinates: -155.28353, 67.8596 (WGS84)
Relative position This site represents roughly circular area of about 30 square miles centered at about the midpoint of the Weyahok River, a headwater tributary to the Alatna River. The coordinates are for the approximate center of the area, which is mostly in sec. 4, T. 28 N., R. 16 E., of the Kateel River Meridian. Includes localities 1-4 of Grybeck and Nelson (1981) and is accurate to within 2000 ft.
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Silver Primary
Copper Primary
Lead Primary
Zinc Primary
Antimony Secondary

Materials information

Materials Type of material
Chalcopyrite Ore
Galena Ore
Pyrite Ore
Sphalerite Ore
Quartz Gangue

Alteration

  • None.

Mineral occurrence model information

Model code 85
USGS model code 22c
Deposit model name Polymetallic veins
Mark3 model number 46

Nearby scientific data

(1) -155.28353, 67.8596

Comments on the geologic information

  • Geologic Description = The site consists of a sprinkling of small occurrences of epigenetic quartz veins, lenses, and breccia zones less than 3 feet thick that contain various combinations of galena, sphalerite, chalcopyrite, and pyrite. The occurrences are in an area of about 30 square miles in an otherwise monotonous sequence of feldspathic sandstone of the Hunt Fork Shale (Nelson and Grybeck, 1980; Grybeck and Nelson, 1981). Assays of the sulfide-bearing samples show up to 100 ppm Ag and 200 ppm Sb. Our fieldwork (S.W. Nelson and D. Grybeck, unpublished data, 1977-1980), and geochemical sampling (Cathrall and others, 1981) suggest that many additional such deposits may occur in this area. All the occurrences found to date are small and discontinuous and there is no obvious sign of any large deposit within the area. There are two theories about the origin of the deposits: (1) Grybeck and others,1985) cite geochemical evidence that they may be related to a buried felsic intrusion; (2) Schmidt and Werdon (1993) and Schmidt (1997) believe that they are related to post-depositional dewatering of the sedimentary rock section and are similar in origin to other sedimentary-rock hosted mineral occurrences in the Brooks Range.

Economic information

Economic information about the deposit and operations

Development status Occurrence
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name Noatak

Comments on the workings information

  • Workings / Exploration = The site is defined by a few short traverses and spot stations by USGS in late 1970's, and since closed to exploration.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Alaska Resource Data File ARDF SP001
USGS Mineral Resources Data System MRDS AO11931
USGS Mineral Resources Data System MRDS AO11932

Bibliographic references

  • Deposit

    Nelson, S.W., and Grybeck, D.J., 1980, Geologic map of the Survey Pass quadrangle, Brooks Range, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-1176-A, 2 sheets, scale 1:250,000.

  • Deposit

    Grybeck, D.J., and Nelson, S.W., 1981, Mineral deposit map of the Survey Pass quadrangle, Brooks Range, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-1176-F, 1 sheet, scale 1:250,000.

  • Deposit

    Cathrall, J.B., Billings, T.M., Colley, E.F., and O'Leary, R.M., 1981, Map showing anomalous drainage areas of selected elements in the Survey Pass quadrangle, Brooks Range, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-1176-D, 1 sheet, scale 1:250,000.

  • Deposit

    Grybeck, D.J., Cathrall, J.B., LeCompte, J.R., and Cady, J.W., 1985, Buried felsic plutons in upper Devonian redbeds, central Brooks Range, in Bartsch-Winkler, Susan, and Reed, K.M., eds., The United States Geological Survey in Alaska: Accomplishments during 1983: U.S. Geological Survey Circular 945, p. 8-10.

  • Deposit

    Schmidt, J.M., and Werdon, M.B., 1993, Clastic-hosted stratiform, vein/breccia and disseminated Zn-Pb-Ag deposits of the northwestern Brooks Range, Alaska; are they different expersions of dewatering of the same source basin? [abs.]: Geological Society of America, Abstracts with Programs, v. 24, p. 143.

  • Deposit

    Schmidt, J.M., 1997, Shale-hosted Zn-Pb-Ag and barite deposits of Alaska, in Goldfarb, R.J., and Miller, L.D., eds., Mineral Deposits of Alaska, 1997: Economic Geology Monograph 9, p. 35-65.

Comments on the references

  • Primary Reference = Grybeck and Nelson, 1981

General comments

Subject category Comment text
Deposit Model Name = Polymetallic vein (Cox and Singer, 1986; model 22c. See Schmidt and Werdon, 1993, p. 143)
Deposit Other Comments = The area is within the Gates of the Arctic National Park and Wilderness and has been closed to prospecting since 1981.

Reporter information

Type Date Name Affiliation Comment
Reporter 16-SEP-1999 S.W. Nelson (Anchorage, Alaska) U.S. Geological Survey