Unnamed (northwest of Mt. Marchainville)

Occurrence in Alaska, United States with commodities Iron, Titanium, Copper

Geologic information

Identification information

Deposit ID 10002230
MRDS ID A013132
Record type Site
Current site name Unnamed (northwest of Mt. Marchainville)

Geographic coordinates

Geographic coordinates: -137.08599, 58.47582 (WGS84)
Relative position The occurrence is at an elevation of about 2000 feet about 3 miles northwest of Mt. Marchainville, and 1.5 miles southeast of Finger Glacier. It is near the approximate center of section 24, T. 39 S., R. 50 E., of the Copper River Meridian. The location is accurate to about 0.1 mile based on transposition of Rossman's (1963) sample no. 40 to the topography of the 1961 edition of the Mt. Fairweather B-4 quadrangle. The location is the same as number 15 of Kimball and others (1978), and location 7 of Cobb (1972). MacKevett and others (1971, p. 52) cite Rossman for authority on copper-staining close to this location. The approximate location of copper-staining reported by MacKevett and others (1971--location 82) is about 0.25 mile southeast of the coordinate position.
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Iron Primary
Titanium Primary
Copper Secondary

Materials information

Materials Type of material
Chalcopyrite Ore
Ilmenite Ore
Malachite Ore

Alteration

  • (Local) Local iron-and copper-(malachite) staining.

Mineral occurrence model information

Model code 5
USGS model code 3
Deposit model name Bushveld Fe-Ti-V

Host and associated rocks

  • Host or associated Associated
    Rock type Plutonic Rock > Mafic Intrusive Rock > Gabbro
    Rock unit name Crillon-La Perouse Stock
    Rock description Crillon-La Perouse Stock
  • Host or associated Host
    Rock type Plutonic Rock > Mafic Intrusive Rock > Gabbro

Nearby scientific data

(1) -137.08599, 58.47582

Comments on the geologic information

  • Geologic Description = The occurrence is within the Fairweather terrane of Brew and others (1978). It is in the southwest part of the Crillon-LaPerouse mafic-ultramafic body which is intruded into biotite and hornblende schist of the upper Chugach terrane of Berg and others (1972). ? At the occurrence, an ilmenite-rich layer in gabbro is approximately 50-feet thick. Its strike length is uncertain because of the extremely rough topography. Rossman (1963) determined X0.0 percent titanium by spectrophic analyses (sample 52A Rm g 40). The sample also contained X0.+ percent iron, but only 0.0X percent of copper, cobalt, or nickel. Ilmenite determined by weight in mineral separates ranged from 5 to 11.4 weight percent. ? A nearby copper (malachite-stained) occurrence is near or at the contact of the intrusion; possibly the occurrence represents oxidized cupriferous amphibolite schist at the contact.
  • Age = Tertiary.

Economic information

Economic information about the deposit and operations

Development status Occurrence
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name Yakutat

Comments on the reserve resource information

  • Reserves = Possibly extensive deposits are suggested by the thickness (50-feet) and by several nearby ilmenite-rich occurrences.

Comments on the workings information

  • Workings / Exploration = No workings, surface outcrop only.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS A013132
USGS Alaska Resource Data File ARDF MF007

Bibliographic references

  • Deposit

    Rossman, Darwin, 1963, Geology and petrology of two stocks of layered gabbro in the Fairweather Range, Alaska: U.S. Geological Survey Bulletin 1121-F, p. F1-F50.

  • Deposit

    MacKevett, E.M., Jr., Brew, D.A., Hawley, C.C., Huff, L.C., and Smith, J.G., 1971, Mineral resources of Glacier Bay National Monument, Alaska: U.S. Geological Survey Professional Paper 632, 90 p., 12 plates, scale 1:250,000.

  • Deposit

    Berg, H.C., Jones, D. L., and Richter, D. H., 1972, Gravina-Nutzotin Belt-tectonic significance of an Upper Mesozoic sedimentary and volcanic sequence in southern and southeastern Alaska: U.S. Geological Survey Professional Paper 800-D, p. D1-D24.

  • Deposit

    Brew, D.A., Johnson, B.R., Grybeck, D., Griscom, A., Barnes, D.F., Kimball, A.L., Still, J.C., and Rataj, J.L., 1978, Mineral resources of the Glacier Bay National Monument Wilderness Study Area, Alaska: U.S. Geological Survey Open-File Report 78-494, 670 p.

  • Deposit

    Kimball, A.L., Still, J.C., and Rataj, J.L., 1978, Mineral resources, in Brew, D. A., and others, Mineral resources of the Glacier Bay National Monument wilderness study area, Alaska: U.S. Geological Survey Open-File Report 78-494, p. C1-C375.

  • Deposit

    Cox, D.P., and Singer, D.A., 1986, Mineral deposit models: U.S. Geological Survey Bulletin 1693, 379 p.

  • 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

    Cobb, E.H., 1972, Metallic mineral resources map of the Mount Fairweather quadrangle, AK: U.S. Geological Survey Miscellaneous Field Study Map MF-436, 1 sheet, scale 1:250,000.

Comments on the references

  • Primary Reference = Rossman, 1963 (B 1121-F)

General comments

Subject category Comment text
Deposit Model Name = Possibly Bushveld Fe-Ti-V (Cox and Singer, 1986; model 3). Magmatic segregation of ilmenite in layered mafic-ultramafic intrusion. The mafic intrusion is synorogenic (Foley and others, 1997).
Deposit Other Comments = Chugach terrane. The ilmenite locality and the nearby copper-stained sites are in Glacier Bay National Park and Preserve.

Reporter information

Type Date Name Affiliation Comment
Reporter 04-APR-99 Hawley, C.C. Hawley Resource Group