Moghoweyik River

Occurrence in Alaska, United States with commodity Molybdenum

Geologic information

Identification information

Deposit ID 10003123
MRDS ID A015656
Record type Site
Current site name Moghoweyik River
Related records 10282113

Geographic coordinates

Geographic coordinates: -171.74514, 63.46801 (WGS84)
Relative position This site is on the north bank of the Moghoweyik River, 3/4 mile upstream from the mouth on the west coast of St. Lawrence Island. It is located within 1/4 mile and is locality 4 of Cobb (1972). Cobb (1980) summarized relevant references under the name 'Moghoweyik R., lower'.
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Molybdenum Primary

Materials information

Materials Type of material
Molybdenite Ore
Pyrite Gangue
Quartz Gangue

Alteration

  • (Local) Pyrite is apparently abundant and disseminated in the biotite quartz monzonite as well as accompanying molybdenite in veins. Pyrite oxidation is well-developed and other alteration is probably present although not described.

Mineral occurrence model information

Model code 80
USGS model code 21b
Deposit model name Porphyry Mo, low-F

Host and associated rocks

  • Host or associated Host
    Chronological age 108
    Uncertainty 3.2
    Stratigraphic age (youngest) Early Cretaceous

Nearby scientific data

(1) -171.74514, 63.46801

Comments on the geologic information

  • Geologic Description = Molybdenite mineralization here is in the Sevuokuk pluton, a mid-Cretaceous (108 +/- 3.2 Ma) composite body that includes biotite hornblende quartz monzonite and biotite quartz monzonite phases (Csejtey, Patton, and Miller, 1971; Patton and Csejtey, 1980). At this site, molybdenite occurs in thin veinlets cutting highly oxidized pyritiferous biotite quartz monzonite. The quartz monzonite is also cut by quartz veins and aplite dikes (Patton and Csejtey, 1971, p. C10). Three grab samples contained 7, 500, and 1,500 ppm molybdenum and 700, 150, and 15 ppm copper respectively (Patton and Csejtey, 1971. p. C8). A pan concentrate from the riverbed gravels at this locality contained 70 ppm molybdenum and 5,000 ppm tungsten (Patton and Csejtey, 1971, p. C10).
  • Age = Mid-Cretaceous, the age of the host Sevuokuk pluton (108 +/- 3.2 Ma; Patton and Csejtey, 1980).
  • Age = Chron age is for Host Rock.

Economic information

Economic information about the deposit and operations

Development status Occurrence
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name Bering Sea

Comments on the workings information

  • Workings / Exploration = Three grab samples contained 7, 500, and 1,500 ppm molybdenum and 700, 150, and 15 ppm copper respectively (Patton and Csejtey, 1971. p. C8). A pan concentrate from the riverbed gravels at this locality contained 70 ppm molybdenum and 5,000 ppm tungsten (Patton and Csejtey, 1971, p. C10).

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS A015656
Unknown MF MF 465-4
USGS Alaska Resource Data File ARDF SL006

Bibliographic references

  • Deposit

    Csejtey, Bela, Jr., Patton, W.W., Jr., and Miller, T.P., 1971, Cretaceous plutonic rocks of St. Lawrence Island, Alaska, a preliminary report: U.S. Geological Survey Professional Paper 750-D, p. D68-D76.

  • Deposit

    Cobb, E.H., 1972, Metallic mineral resources map of the Saint Lawrence quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-465, 1:250,000 scale.

  • Deposit

    Patton, W.W., Jr., and Csejtey, Bela, Jr., 1980, Geologic map of St. Lawrence Island, Alaska: U.S. Geological Survey Miscellaneous Investigation Series Map I-1203, 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

    Patton, W.W., Jr., and Csejtey, Bela, Jr., 1971, Preliminary geologic investigations of western St. Lawrence Island, Alaska: U.S. Geological Survey Professional Paper 684-C, p. C1-C15.

Comments on the references

  • Primary Reference = Patton and Csejtey, 1971 (PP 684-C)

General comments

Subject category Comment text
Deposit Model Name = Fracture fillings, veins, and disseminations of moyldenite in granitic rock. Deposit model 21b (?); porphyry Mo, low-F

Reporter information

Type Date Name Affiliation Comment
Reporter 10-SEP-1998 Travis L. Hudson Applied Geology