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Bohemia Basin Nickel-Copper Prospect

Occurrence in Alaska, United States with commodities Nickel, Copper, Cobalt
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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. Economic information about the deposit and operations
  11. Mining district
  12. Land status
  13. Reserves and resources
  14. Workings at the site
  15. Links to other databases
  16. Bibliographic references
  17. General comments
  18. Reporter information

Geologic information

Identification information

Deposit ID 10002326
MRDS ID A013237
Record type Site
Current site name Bohemia Basin Nickel-Copper Prospect
Alternate or previous names East and West Tripod, Tunnel, Side Hill, North and South Muskeg Ore Bodies.

Geographic coordinates

Geographic coordinates: -136.42455, 57.9761 (WGS84)
Elevation 290
Relative position 1.0 MI. N OF PEAK 2420

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-8(quadrangle 1:63,360 scale)

Sitka NW(quadrangle 1:100,000 scale)

Sitka W OE(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 B 947-C, PLATE 10; USGS MF-467, LOC. 2; USGS MF-1476 B, LOC. 3. LOCATION IS AT PORTAL OF TUNNEL IN TUNNEL ORE BODY. DEPOSIT CONSISTS OF 6 ORE BODIES EXTENDING OVER 1,600 FT. E-W. 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
Cobalt Critical Tertiary

Comments on the commodity information

  • AU, AG, PGM REPORTED IN USGS B 773, BUT NOT CONFIRMED BY LATER REFERENCES.

Materials information

Materials Type of material
Chalcopyrite Ore
Pentlandite Ore

Analytical data

Result MAXIMUM VALUES FROM DRILLING WERE 3.08% NI AND 0.9% CU, MOST VALUES MUCH LESS. USGS B 947-C, P. 54

Host and associated rocks

  • Host or associated Associated
    Rock type Plutonic Rock > Mafic Intrusive Rock > Diorite
  • Host or associated Associated
    Rock type Plutonic Rock > Mafic Intrusive Rock > Gabbro
  • Host or associated Associated
    Rock type Plutonic Rock > Mafic Intrusive Rock > Gabbro > Norite
  • Host or associated Host
    Rock type Plutonic Rock > Mafic Intrusive Rock > Gabbro > Norite

Nearby scientific data

(1) -136.42455, 57.9761
ListMap

Economic information

Ore body information

  • Thickness 44.81M
    Length 487.68M
    Width 365.76M

Comments on the geologic information

  • NORITE BODY UNDERLAIN BY GABBRO, AMPHIBOLITE SCHIST, HORNFELS. YOUNGER QUARTZ DIORITE IN CONTACT WITH NORITE. GABBRO, NORITE, AND DIORITE BELIEVED TO BE SUCCEEDING DIFFERENTIATES OF MAGMA OF COMPOSITE STOCK.

Economic information about the deposit and operations

Development status Occurrence
Commodity type Metallic
Deposit size Medium
Significant No
Discovery year 1921
Discoverer S.H.P. Vevelstad

Mining district

District name Chichagof

Land status

Ownership category National Forest

Reserves and resources

  • Type In-situ
    Estimate year 1946
    Total resources 9000mt ore
    Commodity Subtype Grade units Group Importance Year
    Nickel Ni 0.33 wt-pct Nickel Major 1946
    Copper Cu 0.21 wt-pct Copper Major 1946
  • Type In-situ
    Estimate year 1983
    Total resources 9000mt ore
    Commodity Subtype Grade units Group Importance Year
    Nickel Ni 0.31 wt-pct Nickel Major 1983
    Copper Cu 0.18 wt-pct Copper Major 1983
    Cobalt Co 0.04 wt-pct Cobalt Trace 1983

Comments on the reserve resource information

  • ESTIMATES ARE FOR TRIPOD, TUNNEL, MUSKEG, SIDE HILL ORE BODIES, AS WELL AS TAKANIS ORE BODIES. LINE 1): ABOUT 35% OF MATERIAL IS BARREN,
  • INDICATED RESERVES ARE FOR EAST AND WEST TRIPOD AND TUNNEL ORE BODIES ONLY. ABOUT 35% OF MATERIAL IS BARREN. SELECTIVE MINING WOULD REDUC
  • USGS B 947-C, P. 54

Workings at the site

  • Type of workings Surface/Underground
    Length 50.6M

Comments on the workings information

  • ONE TUNNEL 166 FT. LONG IN TUNNEL ORE BODY, 19 DIAMOND DRILL HOLES, NUMEROUS OPEN PROSPECT PITS AND TRENCHES.

Comments on development

  • CLAIMS ESTABLISHED. AT LEAST 100 CLAIMS IN YAKOBI CLAIM GROUP, ACTIVE UNTIL 1971. 166 FT. LONG TUNNEL DRIVEN IN TUNNEL ORE BODY BEFORE 1943. DIAMOND DRILLING BY USBM IN 1941-42, MAGNETOMETER SURVEY BY USGS IN 1943.

Reference information

Bibliographic references

General comments

Subject category Comment text
Deposit NORTH AND SOUTH TAKANIS ORE BODIES, 0.7 MI NW OF LOCATION, ARE THOUGHT TO BE CONTINUATIONS OF SAME NORITE ORE BODY, BUT ARE TREATED AS SEPARATE DEPOSIT (DEPOSIT NUMBER SI-2). THEIR POTENTIAL RESERVES ARE INCLUDED IN TONNAGE ESTIMATES OF THIS DEPOSIT. ; INFO.SRC : 1 PUB LIT
Deposit THIS SITE NAME WAS CREATED BY THE REPORTER OR OTHER USGS EMPLOYEE BASED ON PROXIMITY TO SOME MAJOR GEOGRAPHIC FEATURE.
Deposit MAGMATIC SEGREGATIONS OF PYRRHOTITE, PENTLANDITE, CHALCOPYRITE, AND MAGNETITE ERRATICALLY DISTRIBUTED AS BLEBS IN TROUGH-SHAPED DEPOSIT NEAR BASE OF BASIN-SHAPED NORITE BODY. DEPOSITS DIP INWARD TOWARD COMMON CENTER AT ANGLES RANGING FROM 45 DEGREES-70 DEGREES. ALL SULFIDE-BEARING NORITE LIES WITHIN 250 FT. OF NORITE CONTACT WITH GABBRO AND AMPHIBOLITE SCHIST BENEATH. IN WESTERN PART OF NORITE BODY, DEPOSITS FORM BLANKET 100-200 FT. THICK ABOVE BASE OF BODY, WITH UP TO 40 FT. OF BARREN NORITE BETWEEN MINERALIZED NORITE AND UNDERLYING GABBRO. SIX SEPARATE ORE BODIES ARE PRESENT, ALL BELIEVED TO BE PART OF SAME NORITE BODY. ON THE WEST, EAST AND WEST TRIPOD ARE BELIEVED TO BE OUTCROPPING PARTS OF ONE LIMB, AND TUNNEL BODY OF THE OTHER LIMB OF SINGLE TROUGH-SHAPED MINERALIZED NORITE BODY PLUNGING NE. TO THE EAST, NORTH AND SOUTH MUSKEG, AND SIDE HILL BODIES ARE THOUGHT TO BE OUTCROPPINGS OF THE SAME MINERALIZED NORITE BODY.

Reporter information

Type Date Name Affiliation Comment
Reporter 01-MAY-1987 Leonard, Kenneth R. (Huber, Donald F.) U.S. Geological Survey

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.