Unnamed (DeLangle Mountain)

Prospect in Alaska, United States with commodities Iron, Titanium, Copper, Nickel
Sections on this page
  1. Identification information
  2. Geographic coordinates
  3. Site location context
  4. Geographic areas
  5. Commodities
  6. Materials information
  7. Host and associated rocks
  8. Nearby scientific data
  9. Economic information about the deposit and operations
  10. Mining district
  11. Links to other databases
  12. Bibliographic references
  13. General comments
  14. Reporter information

Geologic information

Identification information

Deposit ID 10002236
MRDS ID A013138
Record type Site
Current site name Unnamed (DeLangle Mountain)
Related records 10161032

Geographic coordinates

Geographic coordinates: -136.9332, 58.4086 (WGS84)
Relative position Magnetite deposits occur on the southern peaks of DeLangle Mountain. Deposits are found in the SE 1/4 section 11 and the NE 1/4 section 14 (T. 40 S., R. 51 E., of the Copper River Meridian). They probably extend into adjacent parts of sections 12 and 13 of the same township and range. The coordinates are the approximate center of a group of samples collected by the U.S. Bureau of Mines (Kimball and others, 1978, samples 046-050, fig. C-35) near elevation 2700-ft on DeLangle Mountain. The occurrences are about 1.5 miles southwest of the summit of DeLangle Mountain. ? Leo Mark-Anthony (1977) reported another magnetite occurrence at the head of Boussole Bay approximately in the SW 1/4 NW 1/4, section 13 and the NW 1/4 SW 1/4 of the same section (T. 40 S., R. 51 E.).

Site location context

Political divisions (FIPS codes)

Hoonah-Angoon(Census area)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Mount Fairweather B-3(quadrangle 1:63,360 scale)

Mount Fairweather SE(quadrangle 1:100,000 scale)

Mount Fairweather(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Glacier Bay(hydrologic unit)

Northern Southeast Alaska(hydrologic accounting unit)

Southeast Alaska(hydrologic subregion)

Alaska(hydrologic region)

Federal lands

Glacier Bay 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
Iron Primary
Titanium Critical Primary
Copper Secondary
Nickel Critical Secondary

Materials information

Materials Type of material
Chalcopyrite Ore
Ilmenite Ore
Magnetite Ore
Pyrrhotite Ore

Host and associated rocks

  • Host or associated Associated
    Rock type Metamorphic Rock > Gneiss
  • Host or associated Host
    Rock type Plutonic Rock > Mafic Intrusive Rock > Diorite
    Rock unit name Astrolabe-Delangle Stock;Astrolabe-Delangle Stock
    Rock description Astrolabe-Delangle Stock;Astrolabe-Delangle Stock

Nearby scientific data

(1) -136.9332, 58.4086

Economic information

Comments on the geologic information

  • Geologic Description = The mineralized sites are in the Astrolobe-DeLangle mafic stock, the southernmost layered mafic pluton exposed in the rugged Fairweather Range of Glacier Bay National Park and Preserve (Brew and others, 1978). The magmatic oxide minerals occur in a sub-horizontal hornblende-plagioclase pegmatite body that is approximately 100 feet wide and 20 feet thick. The body crops out discontinuously for 1,000 feet in gabbro near the northern contact of the Astrolobe-DeLangle layered mafic stock. Hornblende forms crystals to 1 foot in length in the pegmatitic phase. Segregations of magnetite less than 0.2 inch (5 mm) long are concentrated near larger hornblende and plagioclase crystals (Kimball and others, 1978, p. C120). The magnetite-rich body produces an extreme magnetic deviation.? Four chip samples, ranging from 18 to 40 feet in length, across the pegmatite body contained more than 10 percent iron and more than 1 percent titanium. Maximum copper content was 500 ppm. ? At Boussole Bay, about one mile south of the pegmatite occurrence, a two-foot-wide band exposed over 225 feet contained 64 percent iron, 20 percent titanium, and 0.28 percent nickel (Kimball and others, 1978, p. C122-123). At this location, Mark-Anthony (1977) reported that an intrusive exposed over an area of approximately 1500 x 4000 feet contains about 10 percent iron.
  • Age = Tertiary.

Economic information about the deposit and operations

Development status Prospect
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name Yakutat

Comments on the workings information

  • Workings / Exploration = A few claims are reported to have been staked on the south part of DeLangle Mountain, but there are no workings or evidence of mine activity. An occurrence chip-sampled by Kimball and others (1978, p. C120) contained greater than 10 percent iron, greater than 1 percent titanium and 150-500 ppm copper. The samples ranged from18 to 40 feet in length.? Mark-Anthony (1977) reported samples from the head of Boussole Bay to contain as much as 64 percent iron and 0.28 percent nickel.

Reference information

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

    Mark-Anthony, Leo, 1977, Maps and notes on investigations in Glacier Bay, 1958-1960. (Unpublished material available at U.S. Bureau of Land Management library, Juneau, Alaska).

  • 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

    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.

Comments on the references

  • Primary Reference = Kimball and others, 1978

General comments

Subject category Comment text
Deposit Model Name = Cumulus layered mafic intrusion with iron-titanium enriched hornblende-plagioclase pegmatites (segregations), possibly localized near the contact of the Astolobe-DeLangle synorogenic intrusion with schistose rocks of the Chugach terrane (Foley and others, 1997; Berg and others, 1972).
Deposit Other Comments = Chugach terrane. The sites are in Glacier Bay National Park and Preserve.

Reporter information

Type Date Name Affiliation Comment
Reporter 05-APR-99 Hawley, C.C. Hawley Resource Group

Beyond USGS

Supplemental information added by qvyshift.com. Not part of the original USGS MRDS record.

Authoritative Alaska resources

These are landing pages for further research — the state agencies don't currently expose per-mine deep links.