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Big Ledge Nickel-Copper Prospect

Occurrence in Alaska, United States with commodities Nickel, Copper, Zinc
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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. Ore body information
  10. Controls for ore emplacement
  11. Economic information about the deposit and operations
  12. Mining district
  13. Land status
  14. Links to other databases
  15. Bibliographic references
  16. General comments
  17. Reporter information

Geologic information

Identification information

Deposit ID 10002377
MRDS ID A013295
Record type Site
Current site name Big Ledge Nickel-Copper Prospect
Related records 10282613

Geographic coordinates

Geographic coordinates: -134.9945, 57.80279 (WGS84)
Location accuracy 500(meters)
Relative position 1.75 MI. E OF EAST POINT, ON N SIDE OF TENAKEE INLET

Site location context

Political divisions (FIPS codes)

Hoonah-Angoon(Census area)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Sitka D-3(quadrangle 1:63,360 scale)

Sitka NE(quadrangle 1:100,000 scale)

Sitka(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Central Southeast Alaska(hydrologic accounting unit)

Southeast Alaska(hydrologic subregion)

Alaska(hydrologic region)

Federal lands

Tongass National Forest(National Forest)

National Forest FS(Type of land area)

FS(Federal land areas administered by FS)

Geographic areas

Country State
United States Alaska

Comments on the location information

  • USGS MF-467, LOC. 48. LONGITUDE GIVEN IN USGS OF 78-450 IS INCORRECT. LAND STATUS VALUE CALCULATED 6-94 USING GIS OVERLAY ANALYSIS WITH BLM 1:2,500,000 SCALE OWNERSHIP STATUS MAP (1991).

Commodities

Commodity Importance
Nickel Critical Primary
Copper Primary
Zinc Critical Tertiary

Materials information

Materials Type of material
Chalcopyrite Ore
Pentlandite Ore
Pyrrhotite Ore
Sphalerite Ore
Calcite Gangue
Pyrite Gangue
Quartz Gangue

Host and associated rocks

  • Host or associated Associated
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Conglomerate
    Stratigraphic age (youngest) Late Devonian
  • Host or associated Host
    Rock type Plutonic Rock > Mafic Intrusive Rock > Diorite > Diabase

Nearby scientific data

(1) -134.9945, 57.80279
ListMap

Economic information

Ore body information

  • Width 6.1M

Controls for ore emplacement

  • Dike In Fault Zone

Comments on the geologic information

  • FRACTURES IN DIKE SHOW SLICKEN SLIDING, SIGNIFYING FAULT MOVEMENT SINCE EMPLACEMENT.

Economic information about the deposit and operations

Development status Occurrence
Commodity type Metallic
Deposit size Small
Significant No
Discovery year 1923
Discoverer Alfred Lagergren

Mining district

District name Chichagof

Land status

Ownership category State

Comments on the workings information

  • NATURE OF WORKINGS NOT DEFINED

Comments on development

  • 2 CLAIMS STAKED IN 1923 BY ALFRED LAGERGREN. NO DEVELOPMENT WORK DONE.

Reference information

Bibliographic references

  • Deposit

    USGS B 773, P. 107-108 (1925)

  • Deposit

    USGS MF-467, LOC. 48 (1972)

  • Deposit

    USGS OF 78-450, P. 17 (1978)

  • Other Database

    BAG-MF-467-48

General comments

Subject category Comment text
Deposit DEPOSIT IS IN GABBROIC OR DIABASE DIKE 20 FT. WIDE INTRUSIVE INTO CONGLOMERATE. 6 FT. OF CENTRAL PORTION OF DIKE SHEARED AND HIGHLY FRACTURED AND OXIDIZED, CONTAINS QUARTZ AND CALCITE STRINGERS WITH SULFIDE MINERALS, AND STRINGERS OF SOLID PYRRHOTITE UP TO 6 IN WIDE. DIKE CONTAINS DISSEMINATED PYRRHOTITE, CHALCOPYRITE, PENTLANDITE, SECONDARY NICKEL MINERALS, PYRITE, AND TRACE OF SPHALERITE. CHALCOPYRITE, PYRRHOTITE, AND PENTANDITE OCCUR IN VEIN-LIKE FORMS, AND ARE ASSOCIATED WITH EACH OTHER IN SMALL, VEIN-LIKE BLEBS.

Reporter information

Type Date Name Affiliation Comment
Reporter 01-JUN-1987 Leonard, Kenneth R. (Huber, Donald F.) U.S. Geological Survey
Editor 14-SEP-1994 Waller, Nichelle (Mosier, Dan) U.S. Geological Survey PARSED OUT HOST ROCK AND ASSOCIATED ROCK TYPES, AGES, UNIT NAMES, AND UNIT AGES.

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.