Unnamed (South Marble Island)

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

Geologic information

Identification information

Deposit ID 10307816
Record type Site
Current site name Unnamed (South Marble Island)

Geographic coordinates

Geographic coordinates: -136.04408, 58.64273 (WGS84)
Relative position The site is on South Marble Island in Glacier Bay. Its location is approximate, but probably correct within 0.1 mile. It is location number 51 of Cobb (1972) and number 25 of MacKevett and others (1978).
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Copper Primary
Iron Primary
Titanium Primary

Materials information

Materials Type of material
Chalcopyrite Ore
Pyrite Ore
Quartz Gangue

Alteration

  • (Local) Marble is locally silicified.

Nearby scientific data

(1) -136.04408, 58.64273

Comments on the geologic information

  • Geologic Description = The site is within the marble-rich province of Devonian and Silurian age that extends northwesterly from Willoughby Island to Queen Inlet (MacKevett and others, 1971; Brew and others, 1978). Bathymetric contours near South and North Marble Island indicate a barely submerged mass, inferred to be mostly marble, that is also aligned northwest. The exposures on the two small islands are the surface expressions of the inferred marble mass. The island was investigated as a marble prospect Burchard (1914 and 1920). The marble on South Marble island is locally cut by mafic dikes as much as 50 feet across that contain disseminated pyrite; pyrite also occurs in silicified marble near the dike rocks. Reed (1938) reported copper sulfide (chalcopyrite) occurrences. of four pyritic samples collected by the U.S. Geological Survey, three contained more than 10 percent iron and one contained about 7 percent iron; titanium content ranged from 0.5 to 1 percent in the same samples (MacKevett and others, 1971, table 9). The sulfide deposits and silicification probably are related to the emplacement of the mafic dikes, possibly in Cretaceous or Tertiary time (Brew and others, 1978).
  • Age = Cretaceous or younger.

Economic information

Economic information about the deposit and operations

Development status Prospect

Comments on exploration

  • Status = Probably inactive

Mining district

District name Juneau

Comments on the workings information

  • Workings / Exploration = No workings. MacKevett and others (1971) reported iron content as greater than 10 percent in three of four selected samples of marble and dike material. Maximum titanium content is 1 percent. All four samples contained 100 ppm nickel, and ranged from 150-200 ppm copper. It is doubtful if any of the samples reported by MacKevett and others represent the copper sulfide-bearing material seen by Reed (1938).

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Alaska Resource Data File ARDF MF063

Bibliographic references

  • Deposit

    Burchard, E.F., 1920, Marble resources of southeastern Alaska: U.S. Geological Survey Bulletin 682, 118 p.

  • 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

    Burchard, E.F., 1914, Marble resources of the Juneau, Skagway, and Sitka districts, Alaska: U.S. Geological Survey Bulletin 592-C, p. 95-107.

  • 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.

  • Deposit

    Reed, J.C., 1938, Some mineral deposits of Glacier Bay and vicinity, Alaska: Economic Geology, v. 33, p. 52-80.

Comments on the references

  • Primary Reference = Reed, 1938

General comments

Subject category Comment text
Deposit Other Comments = the site is in Glacier Bay National Park and Preserve.

Reporter information

Type Date Name Affiliation Comment
Reporter 03-JAN-99 Hawley, C.C. Hawley Resource Group