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  3. Mineral Resource Data System (MRDS)

Unnamed

Occurrence in Alaska, United States with commodities Manganese, Iron
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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. Alteration
  8. Mineral occurrence model information
  9. Host and associated rocks
  10. Nearby scientific data
  11. Economic information about the deposit and operations
  12. Mining district
  13. Links to other databases
  14. Bibliographic references
  15. General comments
  16. Reporter information

Geologic information

Identification information

Deposit ID 10001650
MRDS ID A012424
Record type Site
Current site name Unnamed

Geographic coordinates

Geographic coordinates: -154.84293, 63.05947 (WGS84)
Relative position The unamed manganese occurrence is situated along the banks of the Kuskokwim River at an elevation of 380 feet in Section 15, T. 28 S., R. 21 E., of the Kateel River Meridian. Patton and Moll (1983) located the occurrence within a 2,500 feet (762 m) radius. Th reporter visited the site in 1988.

Site location context

Political divisions (FIPS codes)

Yukon-Koyukuk(Census area)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Medfra A-4(quadrangle 1:63,360 scale)

Medfra S(quadrangle 1:100,000 scale)

Medfra C(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Stony River(hydrologic unit)

Upper Kuskokwim River(hydrologic accounting unit)

Southwest(hydrologic subregion)

Alaska(hydrologic region)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Manganese Critical Primary
Iron Secondary

Comments on the commodity information

  • Ore Material = Manganese carbonate

Materials information

Materials Type of material
Pyrolusite Ore

Alteration

  • (Local) Extensive development of iron and manganese oxides.

Mineral occurrence model information

Model code 242
USGS model code 34b
Deposit model name Sedimentary Mn

Host and associated rocks

  • Host or associated Host
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Sandstone

Nearby scientific data

(1) -154.84293, 63.05947
ListMap

Economic information

Comments on the geologic information

  • Geologic Description = Both iron and manganese oxides are strongly developed in deformed shale and sandstone for about 500 feet along the banks of the Kukokwim River. The age of the shale is unknown and could be either Paleozoic (Nixon Fork subterrane) or Late Cretaceous (Kuskokwim Group). The apparant beding in the shale is N 55 E with steep southeasterly dips. A strong shear zone plunges N 25 E at 20 degrees. The main ore minerals present are pyrolusite and goetthite, both of which occur as coatings and impregnations on fracture surfaces in the shear zone. A distinct N 10 E lineament, which controls the trend of the hills north of the river, runs through the manganiferous area. Although Patton and Moll (1983) suggest this is a sedimentary manganese deposit, field evidence suggests that it may also be an accumulation of iron and manganese oxides within a shear zone. Surface samples have yielded up to 23.00 percent manganses (Berg and Cobb, 1967).

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 = Surface samples contained up to 23 percent manganese. (Berg and Cobb, 1967).

Reference information

Bibliographic references

  • Deposit

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

  • Deposit

    Patton, W.W., Jr., and Moll, E.J., 1983, Mineral resource assessment map of the Medfra quadrangle, Alaska: U.S. Geological Survey Open-File Report 80-811-G, 3 sheets, scale 1:250,000.

  • Deposit

    Bundtzen, T.K., and Miller, M.L., 1997, Precious metals associated with Late Cretaceous-early Tertiary igneous rocks of southwestern Alaska, in Goldfarb, R.J., and Miller, L.D., eds., Economic Geology Monograph #9, Mineral Deposits of Alaska, p. 242-286.

Comments on the references

  • Primary Reference = Berg and Cobb, 1967

General comments

Subject category Comment text
Deposit Model Name = Sedimentary Manganese(?) or unknown (Cox and Singer, 1986; model no. 34b(?))
Deposit Other Comments = In Nixon Fork subterrane of Farewell Composite Terrane (Bundtzen and others, 1997), or Cretaceous Kuskokwim Group.

Reporter information

Type Date Name Affiliation Comment
Reporter 07-JUN-98 Bundtzen, T.K. Pacific Rim Geological Consulting

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.