Unnamed (west of Rendu Inlet)

Occurrence in Alaska, United States with commodity Iron

Geologic information

Identification information

Deposit ID 10002263
MRDS ID A013166
Record type Site
Current site name Unnamed (west of Rendu Inlet)
Related records 10209508

Geographic coordinates

Geographic coordinates: -136.65211, 58.91278 (WGS84)
Relative position The occurrence is at an elevation of about 2000 feet on the top of the ridge between Rendu Inlet and Glacier Bay about 0.7 miles northwest of VABM Rendu. The location is accurate within a few hundred feet. The location is number 39 of MacKevett and others (1971), number 32 of Cobb (1972), and number 44 of Kimball and others (1978).
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Iron Primary

Materials information

Materials Type of material
Magnetite Ore
Pyrite Ore
Calcite Gangue
Quartz Gangue

Mineral occurrence model information

Model code 62
USGS model code 18d
Deposit model name Skarn Fe

Host and associated rocks

  • Host or associated Host
    Rock type Metamorphic Rock > Metasedimentary Rock > Marble

Nearby scientific data

(1) -136.65211, 58.91278

Comments on the geologic information

  • Geologic Description = Poddy magnetite-rich skarn deposits occur in limestone-marble units of Devonian-Silurian age at or near medium-coarse-grained intrusions of hornblende quartz diorite of Cretaceous age (Rossman, 1963 B 1121-K; Brew and others, 1978). Calc-silicate rich phases of the skarn consist of tactite composed of grossularite-rich garnet and epidote accompanied by quartz, chlorite, and calcite. Magnetite and pyrite locally form poddy masses. The area is poorly exposed and other deposits--inferred from magnetic anomalies--could be buried by overburden. Based on three samples reported by MacKevett and others, 1971 (locality 39, table 9) the iron content of the skarn ranges from about 5 percent to more than 10 percent. No precious metals were detected and copper and other valuable metals are present at near background levels. Titanium values are low, so magnetite is inferred to be an essentially pure phase.
  • Age = Cretaceous.

Economic information

Economic information about the deposit and operations

Development status Occurrence
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name Juneau

Comments on the workings information

  • Workings / Exploration = There are no workings. MacKevett and others (1971) collected samples and ran magnetic traverses in the occurrence area. Magnetic anomalies of as much as 5500 gammas are attributed to concealed masses of magnetite skarn.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS A013166
USGS Alaska Resource Data File ARDF MF055

Bibliographic references

  • Deposit

    Rossman, Darwin, 1963, Geology of the eastern part of the Mount Fairweather quadrangle, Glacier Bay, Alaska: U.S. Geological Survey Bulletin 1121-K, p. K1-K57.

  • 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

    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

    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 = MacKevett and others, 1971

General comments

Subject category Comment text
Deposit Model Name = Pyrite-magnetite (Fe) skarn (Cox and Singer, 1986; model 18d).
Deposit Other Comments = Deposits appear to be small, but the mixed marble-quartz diorite area is favorable for other deposits. ? the area is in Glacier Bay National Park and Preserve.

Reporter information

Type Date Name Affiliation Comment
Reporter 09-APR-99 Hawley, C.C. Hawley Resource Group