1. Mineral Resources
  2. Online Spatial Data
  3. Mineral Resource Data System (MRDS)

Unnamed

Occurrence in Alaska, United States with commodities Chromium, Molybdenum
Map
XML
JSON
KML
C
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 10000907
MRDS ID A011564
Record type Site
Current site name Unnamed

Geographic coordinates

Geographic coordinates: -151.82894, 62.74453 (WGS84)
Relative position Reed and others (1978, locality 24 and 25) locate this occurrence in the southwest quarter of Section 25, T. 31 N., R. 14 W., of the Seward Meridian on a nunatak within the Dall Glacier in Denali National Park and Preserve.

Site location context

Political divisions (FIPS codes)

Matanuska-Susitna(Borough)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Talkeetna C-4(quadrangle 1:63,360 scale)

Talkeetna NW(quadrangle 1:100,000 scale)

Talkeetna C(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Yentna River(hydrologic unit)

Susitna River(hydrologic accounting unit)

South Central Alaska(hydrologic subregion)

Alaska(hydrologic region)

Federal lands

Denali 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
Chromium Critical Primary
Molybdenum Primary

Materials information

Materials Type of material
Chromite Ore
Molybdenite Ore
Quartz Gangue

Mineral occurrence model information

Model code 15
USGS model code 8a
Deposit model name Podiform chromite (minor)
Mark3 model number none
Model code 79
USGS model code 21a
Deposit model name Porphyry Cu-Mo
Mark3 model number 2
Model code 80
USGS model code 21b
Deposit model name Porphyry Mo, low-F

Host and associated rocks

  • Host or associated Associated
    Rock type Plutonic Rock > Mafic Intrusive Rock > Diorite
    Rock unit name Foraker Pluton
    Rock description Foraker Pluton
    Stratigraphic age (youngest) Pliocene
    Stratigraphic age (youngest) Pliocene
  • Host or associated Host
    Rock type Plutonic Rock > Ultramafic Intrusive Rock > Peridotite > Dunite

Nearby scientific data

(1) -151.82894, 62.74453
ListMap

Economic information

Comments on the geologic information

  • Geologic Description = Reed and others (1978) describe this coincident mineral occurrence of a quartz-molybdenite vein cutting Paleozoic and (or) Mesozoic (Reed and Nelson, 1980) or Late Cretaceous/early Tertiary (?) (Foley and others, 1997) chromite-bearing dunite. The quartz-molybdenite vein is 20 to 50 centimeters thick, with as much as 20 volume percent molybdenite as foliated tabular crystals up to 5 centimeters in diameter. It is probably genetically related to the middle Tertiary (38 m.y.) granodiorite of Mt. Foraker (Reed and Nelson, 1980) and may indicate porphyry molybdenum/copper potential (Reed and others, 1978). The dunite is part of the Dall trend described in TL002, 003, TL009 - 012, and TL055.
  • Age = Mesozoic and (or) Paleozoic (Reed and Nelson, 1980) or Late Cretaceous/early Tertiary (Foley and others, 1997) chromite-bearing dunite. Tertiary; vein hosted quartz-molybdenite presumed to be related to the middle Tertiary (38 m.y.) granodiorite (Reed and others, 1978).

Economic information about the deposit and operations

Development status Occurrence
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name Yentna

Comments on the workings information

  • Workings / Exploration = Reconnaissance mapping, stream silt and rock sampling are all that have been done here. Chromium content of 0.7 to 1% from typical dunite is given in Reed and others (1978). The average of 3 microprobe analyses of one sample was 58.4% Cr2O3, 21.1% FeO, 8.9% MgO, and 9.7% Al2O3.

Reference information

Bibliographic references

  • Deposit

    Reed, B.L., Nelson, S.W., Curtin, G.C., and Singer, D.A., 1978, Mineral resources map of the Talkeetna Quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-870-D, 1 sheet, scale 1:250,000.

  • Deposit

    Reed, B.L., and Nelson, S.W., 1980, Geologic map of the Talkeetna quadrangle: U.S. Geological Survey Miscellaneous Investigations Map I-1174, scale 1:250,000.

  • Deposit

    Foley, J.Y., Light, T.D., Nelson, S.W., and Harris, R.A., 1997, Mineral occurrences associated with mafic-ultramafic and related alkaline complexes in Alaska: Economic Geology, Monograph 9, p. 396-449.

  • Deposit

    MacKevett, E.M., Jr., and Holloway, C.D., 1977, Map showing metalliferous and selected non-metalliferous mineral deposits in the eastern part of southern Alaska: U.S. Geological Survey Open-File Report 77-169-A, 99 p., 1 sheet, scale 1:1,000,000.

Comments on the references

  • Primary Reference = Reed and others, 1978

General comments

Subject category Comment text
Deposit Model Name = Podiform chromite (Cox and Singer, 1986; model 8a); vein is possibly related to Porphyry Cu-Mo (Cox and Singer, 1986; model 21a) or Porphyry Mo, Low-F (Cox and Singer, 1986; model 21b).
Deposit Other Comments = This prospect is located within Denali National Park and Preserve.

Reporter information

Type Date Name Affiliation Comment
Reporter 10-AUG-1998 Madelyn A. Millholland Millholland & Associates

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.