Jimmy Lake

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

Geologic information

Identification information

Deposit ID 10002171
MRDS ID A013068
Record type Site
Current site name Jimmy Lake
Related records 10283044

Geographic coordinates

Geographic coordinates: -153.20055, 61.73337 (WGS84)
Relative position This occurrence is at ane elevation of about 5,000 feet, in the head of a cirque valley, 1.4 miles northeast of Jimmy Lake. The map site is in the southwest 1/4 of section 13, T 19 N, R 22 W, of the Seward Meridian. This is locality 12 of Cobb (1972 [MF 412]; 1976 [OF 76-485]) and locality 11 and 12 of Gamble and others (1989). The location is probably accurate to within 1/4 mile.
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Silver Primary
Copper Primary
Molybdenum Primary
Lead Primary
Zinc Primary

Materials information

Materials Type of material
Arsenopyrite Ore
Chalcopyrite Ore
Galena Ore
Molybdenite Ore
Sphalerite Ore
Albite Gangue
Fluorite Gangue
Kaolinite Gangue
Quartz Gangue
Sericite Gangue

Alteration

  • (Local) Granite locally replaced by quartz-sericite-kaolinite-albite assemblages.

Mineral occurrence model information

Model code 79
USGS model code 21a
Deposit model name Porphyry Cu-Mo
Mark3 model number 2
Model code 85
USGS model code 22c
Deposit model name Polymetallic veins
Mark3 model number 46

Host and associated rocks

  • Host or associated Associated
    Rock type Plutonic Rock > Granitoid > Granite
    Rock unit name Styx River Batholith
    Rock description Styx River Batholith
    Stratigraphic age (youngest) Pliocene
    Stratigraphic age (youngest) Pliocene
    Stratigraphic age (youngest) Pliocene
  • Host or associated Host
    Rock type Plutonic Rock > Granitoid > Granite

Nearby scientific data

(1) -153.20055, 61.73337

Comments on the geologic information

  • Geologic Description = Reed and Elliott (1970) reported that an altered and mineralized biotite granite stock is present at this locality. Mineralization, mostly identified in float boulders and cobbles, includes (1) altered granite that contains less than 5 percent disseminated galena and sphalerite, (2) altered granite that contains veinlets of quartz, sphalerite, galena, and chalcopyrite, and (3) altered granite that contains a 1-inch-wide quartz-molybdenite vein. The alteration consists of variably developed replacement of granite by quartz, sericite, kaolinite, and albite. Samples contain as much as 15,000 ppm copper, 300 ppm silver, and greater than 20,000 ppm lead, 2,000 ppm molybdenum, and 10,000 ppm zinc. Stream sediment samples from the area contain high contents of silver, arsenic, copper, lead, and zinc. The biotite granite stock contains accessory fluorite and intrudes upper Mesozoic clastic sedimentary rocks and possibly overlying Tertiary volcanic rocks (Cobb and Reed, 1981).
  • Age = Tertiary. Mineralization crosscuts Tertiary granite.

Economic information

Economic information about the deposit and operations

Development status Occurrence
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name McGrath

Comments on the workings information

  • Workings / Exploration = Reconnaissance sampling has been completed in this area (Reed and Elliott, 1970).

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS A013068
USGS Alaska Resource Data File ARDF LH012

Bibliographic references

  • Deposit

    Gamble, B.M., Bailey, E. A., and Reed, B. L., 1989, Gold occurrences near Snowcap Mountain, Lime Hills B-2 quadrangle, Alaska: U.S. Geological Survey Open-File Report 89-0646, 8 p.

  • Deposit

    Reed, B.L., and Elliott, R.L., 1970, Reconnaissance geologic map, analyses of bedrock and stream sediment samples, and an aeromagnetic map of parts of the southern Alaska Range: U.S. Geological Survey Open-File Report 70-217, 145 p., 1 sheet, scale 1:250,000. (Also published as U.S. Geological Survey Open-File Report 413).

  • Deposit

    Cobb, E.H., and Reed, B.L., 1981, Summaries of data on and lists of references to metallic and selected nonmetallic mineral occurrences in the Iliamna, Lake Clark, Lime Hills, and McGrath quadrangles, Alaska; Supplement to Open-File Report 76-485; Part A, Summaries to January 1, 1981: U.S. Geological Survey Open-File Report 81-1343-A, 25 p.

  • Deposit

    Cobb, E.H., 1972, Metallic mineral resources map of the Lime Hills quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-412, 1 sheet, scale 1:250,000.

  • Deposit

    Cobb, E.H., 1976, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Iliamna, Lake Clark, Lime Hills, and McGrath quadrangles, Alaska: U.S. Geological Survey Open-File Report 76-485, 101 p.

Comments on the references

  • Primary Reference = Cobb and Reed, 1981

General comments

Subject category Comment text
Deposit Model Name = Polymetallic veins? and porphyry Cu-Mo? (Cox and Singer, 1986, models 22c and 21a)
Deposit Model Number = 21a?, 22c?

Reporter information

Type Date Name Affiliation Comment
Reporter 10-JUN-2001 Travis L. Hudson Applied Geology
Reporter 10-JUN-2001 Travis L. Hudson Applied Geology