Moghoweyik R.

Occurrence in Alaska, United States with commodities Molybdenum, Copper

Geologic information

Identification information

Deposit ID 10003126
MRDS ID A015658
Record type Site
Current site name Moghoweyik R.
Alternate or previous names Upper
Related records 10160215

Geographic coordinates

Geographic coordinates: -171.6132, 63.44912 (WGS84)
Relative position This site is in the headwaters of the Moghoeyik River on western St. Lawrence Island. The mineralized area is a 1/2 mile wide zone in the eastern part fo the Sevuokuk pluton near its contact with volcanic rocks. The site is located within 1/2 mile and is locality 5 of Cobb (1972). Cobb (1980) summarized relevant references under the name 'Moghoeyik R., upper'.
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Molybdenum Primary
Copper Secondary

Materials information

Materials Type of material
Molybdenite Ore
Pyrite Gangue
Quartz Gangue

Alteration

  • (Local) The biotite quartz monzonite is pyritized, cut by some quartz veins, and locally silicified. It is heavily oxidized and stained with limonite. Other alteration is probably present.

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) -171.6132, 63.44912

Comments on the geologic information

  • Geologic Description = Molybdenite is sparsely distributed throughout a 1/2 mile wide zone in the eastern part of the Sevuokuk pluton near the contact with Cretaceous volcanic rocks. The Sevuokuk pluton is 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). Here, pyritiferous and highly oxidized biotite quartz monzonite is cut by quartz veins and locally silicified. Molybdenite occurs as scales on fractures, in thin veinlets, and as large euhedral crystals in drusy quartz veins (Patton and Csejtey, 1971, p. C11). Three grab samples contained 500, 500, and 7 ppm molybdenum and 20, 150, and 1,000 ppm copper respectively (Patton and Csejtey, 1971, p. C8). Four stream sediment samples from the drainage headwatered in this mineralized area (Patton and Csejtey, 1972) contained only weakly anomalous concentrations of molybdenum (to 15 ppm) and copper (to 200 ppm).
  • 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 500, 500, and 7 ppm molybdenum and 20, 150, and 1,000 ppm copper respectively (Patton and Csejtey, 1971, p. C8). Four stream sediment samples from the drainage headwatered in this mineralized area (Patton and Csejtey, 1972) contained only weakly anomalous concentrations of molybdenum (to 15 ppm) and copper (to 200 ppm).

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS A015658
Unknown MF MF 465-8
USGS Alaska Resource Data File ARDF SL009

Bibliographic references

  • 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.

  • 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

    Patton, W.W., Jr., and Csejtey, Bela, Jr., 1972, Analyses of stream sediment and rock samples from St. Lawrence Island, Alaska, 1966-1971: U.S. Geological Survey Open-File Report 72-293, 78 p.

  • 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

    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 sheet, scale 1:250,000.

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 molybdenite 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