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  3. Mineral Resource Data System (MRDS)

Midas

Past Producer in Alaska, United States with commodities Silver, Gold, Copper
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Sections on this page
  1. Identification information
  2. Geographic coordinates
  3. Site location context
  4. Geographic areas
  5. Commodities
  6. Materials information
  7. Mineral occurrence model information
  8. Host and associated rocks
  9. Nearby scientific data
  10. Economic information about the deposit and operations
  11. Mining district
  12. Links to other databases
  13. Bibliographic references
  14. General comments
  15. Reporter information

Geologic information

Identification information

Deposit ID 10001047
MRDS ID A011725
Record type Site
Current site name Midas
Alternate or previous names Berg Creek

Geographic coordinates

Geographic coordinates: -143.79252, 61.55272 (WGS84)
Relative position Lower workings (2,790 ft elevation) are 1/2 mile southwest of approximate midpoint of Berg Creek, a tributary to Kuskulana River. Coordinates above are for lower workings of Midas. Best location: MacKevett and others, 1978, loc. 36. Accurate within radius of 100 feet.

Site location context

Political divisions (FIPS codes)

Valdez-Cordova(Census area)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

McCarthy C-8(quadrangle 1:63,360 scale)

McCarthy NW(quadrangle 1:100,000 scale)

McCarthy(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Chitina River(hydrologic unit)

Copper River(hydrologic accounting unit)

South Central Alaska(hydrologic subregion)

Alaska(hydrologic region)

Federal lands

Ahtna, Incorporated(ANCSA Region)

ANCSA Region NTVPIC(Type of land area)

NTVPIC(Federal land areas administered by NTVPIC)

Wrangell-St. Elias National Park(National Park)

National Park NPS(Type of land area)

NPS(Federal land areas administered by NPS)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Silver Primary
Gold Primary
Copper Primary

Materials information

Materials Type of material
Chalcopyrite Ore
Gold Ore
Magnetite Ore
Pyrite Ore

Mineral occurrence model information

Model code 59
USGS model code 18b
Deposit model name Skarn Cu
Mark3 model number 8

Host and associated rocks

  • Host or associated Associated
    Rock type Plutonic Rock > Mafic Intrusive Rock > Diorite
    Stratigraphic age (youngest) Late Triassic
    Stratigraphic age (youngest) Late Jurassic
  • Host or associated Host
    Rock type Metamorphic Rock > Skarn (Tactite)
    Rock unit name Chitistone Limestone; Locally Developed Skarn
    Rock description Chitistone Limestone; Locally Developed Skarn

Nearby scientific data

(1) -143.79252, 61.55272
ListMap

Economic information

Comments on the geologic information

  • Geologic Description = At lower (main) workings Au-bearing quartz veins and magnetite and epidote skarn containing irregularly distributed pyrite and chalcopyrite occur in Chitistone Limestone, near contact with Jurassic granodiorite pluton. At upper workings disseminated to small masses of magnetite, pyrite, and chalcopyrite occur in quartz veins and skarn bodies in metamorphosed Triassic Nizina Limestone near contact to same Jurassic granodiorite pluton.
  • Age = Jurassic

Economic information about the deposit and operations

Development status Past Producer
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name Chistochina

Comments on the workings information

  • Workings / Exploration = 5 adits in vicinity, all caved or blocked by ice by 1943. Grab sample of vein assayed: 8 ppm Au (AA), 10 ppm Ag, 1,000 ppm Cu, 20 ppm Mo. Grab sample of skarn assayed: 0.6 ppm Au (AA), 1.5 ppm Ag, 20,000 ppm Cu, 500 ppm Co (MacKevett, 1976). Underground workings.

Reference information

Bibliographic references

  • Deposit

    Moffit, F.H., and Mertie, J.B., Jr., 1923, The Kotsina-Kuskulana district, Alaska: U.S. Geological Survey Bulletin 745, 149 p.

  • Deposit

    Van Alstine, R.E., and Black, R.F., 1946, Copper deposits of the Kotsina-Kuskulana district, Alaska: U.S. Geological Survey Bulletin 947-G, p. 121-141.

  • Deposit

    Berg, H.C., and Cobb, E.H., 1967, Metalliferous Lode Deposits of Alaska. U.S. Geological Survey Bulletin 1246, 254 p.

  • Deposit

    MacKevett, E.M., Jr., 1976, Mineral deposits and occurrences in the McCarthy quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-773-B, scale 1:250,000.

  • Deposit

    MacKevett, E.M., Jr., Smith, J.G., Jones, D.L., and Winkler, G.R., 1978, Geologic map of the McCarthy C-8 quadrangle, Alaska: U.S. Geological Survey Geologic Quadrangle Map GQ-1418, scale 1:63,360.

  • Deposit

    MacKevett, E.M., Jr., Smith, J.G., Jones, D.L., and Winkler, G.R., 1978, Geologic map of the McCarthy C-8 quadrangle, Alaska: U.S. Geological Survey Geologic Quadrangle Map GQ-1418, 1 sheet, scale 1:63,360.

Comments on the references

  • Primary Reference = Moffit and Mertie, 1923

General comments

Subject category Comment text
Deposit Model Name = Cu skarn

Reporter information

Type Date Name Affiliation Comment
Reporter 17-JUL-1997 Leonard, K.R. U.S. Geological Survey
Reporter 17-JUL-1997 Elliott, R.L. U.S. Geological Survey
Reporter 17-JUL-1997 Nokleberg, W.J. U.S. Geological Survey
Reporter 17-JUL-1997 Richter, D.H. U.S. Geological Survey

Beyond USGS

Supplemental information added by qvyshift.com. Not part of the original USGS MRDS record.

Maps centered on this site

Authoritative Alaska resources

These are landing pages for further research — the state agencies don't currently expose per-mine deep links.