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Cobol Pinta Bay Gold Mine

Past Producer in Alaska, United States with commodities Gold, Zinc, Lead, Copper

Geologic information

Identification information

Deposit ID 10002334
MRDS ID A013247
Record type Site
Current site name Cobol Pinta Bay Gold Mine
Alternate or previous names Cox, Bolyan and Loberg Mine, Pinta Bay Mining Co., Cobol-Mine Mountain Mine
Related records 10160943

Geographic coordinates

Geographic coordinates: -136.21315, 57.85527 (WGS84)
Elevation 229
Relative position 4 MI. N OF GOULDING HARBOR
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Geographic areas

Country State
United States Alaska

Comments on the location information

  • USGS MF-467, LOC. 11; USGS B 1058-E, PLATE 12. LOCATION IS TUNNEL IN VEIN NO. 1. USGS MF-1476-B IS BEST LOCATION. LAND STATUS VALUE CALCULATED 6-94 USING GIS OVERLAY ANALYSIS WITH BLM 1:2,500,000 SCALE OWNERSHIP STATUS MAP (1991).

Commodities

Commodity Importance
Gold Primary
Zinc Tertiary
Lead Tertiary
Copper Tertiary

Materials information

Materials Type of material
Chalcopyrite Ore
Galena Ore
Sphalerite Ore
Dolomite Gangue
Pyrite Gangue
Pyrrhotite Gangue
Quartz Gangue

Analytical data

Result SAMPLES IN STOPED PORTION OF VEIN NO. 1 RANGED FROM 0-2.45 OZ/TON AU-USGS MF-1476-B, P. 8.

Host and associated rocks

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

Nearby scientific data

(1) -136.21315, 57.85527

Ore body information

  • Strike VEIN NO. 1: NE; VEIN NO. 2: NE
    Dip VEIN NO. 1: 70 DEGREES NW; VEIN NO. 2: 80 DEGREES SE
    Thickness 15.24M
    Width 0.46M
    Length 60.96M
  • Strike VEIN NO. 1: NE; VEIN NO. 2: NE
    Dip VEIN NO. 1: 70 DEGREES NW; VEIN NO. 2: 80 DEGREES SE

Comments on the geologic information

  • CRET-JUR DIORITE NEAR CONTACT WITH PAL GREENSTONE, CHERTY QUARTZITE, SILICEOUS LIMESTONE.

Economic information

Economic information about the deposit and operations

Development status Past Producer
Commodity type Metallic
Deposit size Small
Significant No
Discovery year 1921
Discoverer Frank And Ed Cox, Ollie Loberg, Mr. Bolyan
Year of first production 1933
Year of last production 1935

Mining district

District name Chichagof

Land status

Ownership category National Forest

Workings at the site

  • Type of workings Surface/Underground
    Length 73.15M

Comments on the workings information

  • VEIN NO. 1: 70 FT. LONG AND 40 FT. HIGH STOPE, AND 200 FT. OF SURFACE TRENCHES. VEIN NO. 2: 28 FT. CROSSCUT TUNNEL, 40 FT. OF SURFACE TRENCHES. 5 MI. LONG RAILROAD TRAMWAY, SAWMILL, TRACTORS, AND GIBSON MILL ALSO INSTALLED. MILL AND MACHINERY REMOVED 1936, RAILROAD IN DISREPAIR AS OF 1941.

Comments on development

  • 9 CLAIMS LOCATED IN 1921 BY PINTA BAY MINING CO. TUNNEL AND RAILROAD-TRAMWAY BUILT IN 1923. MILL INSTALLED IN 1933 AND OPERATED THROUGH 1935. MILL AND EQUIPMENT REMOVED IN 1936.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS A013247

Bibliographic references

  • Deposit

    USGS MF-1476-B, LOC. 8, P. 8 (1982)

  • Deposit

    USGS B 773, P. 121-123 (1925)

  • Deposit

    USGS B 929, P. 142-143 (1941)

  • Deposit

    USGS B 1058-E, P. 209-210, PLATE 12 (1959)

  • Deposit

    USGS OF 78-450, P. 33-34 (1978)

  • Deposit

    USGS MF-467, LOC. 11 (1972)

  • Other Database

    BAG-MF-1476-B-8

General comments

Subject category Comment text
Deposit DEPOSIT CONSISTS OF TWO MAIN QUARTZ VEINS. VEIN NO. 1 IS 6-18 IN WIDE, AVERAGING 10-14 IN. WIDE IN TUNNEL, AND IS TRACED ON SURFACE OVER 200 FT. LONG, WITH VERTICAL DISTANCE OF 50 FT. VEIN IS IN ALBITIZED DIORITE AND GREENSTONE, AND CONSISTS OF MILKY-WHITE QUARTZ, A LITTLE DOLOMITE, ARSENOPYRITE, SPHALERITE, GALENA, FREE GOLD, AND A LITTLE PYRITE AND CHALCOPYRITE. CLAY GOUGE 1-1 1/2 IN WIDE BETWEEN VEIN AND HANGING WALL CARRIES FREE GOLD. 4 FT. OF ALTERED GREENSTONE AT ENTRANCE OF TUNNEL CARRIES VEINLETS OF QUARTZ, PYRRHOTITE, AND CHALCOPYRITE. VEIN NO. 2 LIES 300 FT. SW, AND IS QUARTZ FISSURE VEIN CUTTING ACROSS GREENSTONE, CHERTY QUARTZITE, AND SILICEOUS LIMESTONE AT ANGLE TO BEDDING. VEIN EXPOSED AT SURFACE FOR LENGTH OF 40 FT., AND IS 6-8 IN. WIDE AT SURFACE, 1 FT. WIDE IN TUNNEL. VEIN CONSISTS OF QUARTZ, SPHALERITE, GALENA, FREE GOLD, AND TRACE OF PYRITE.
Deposit 24 CLAIMS LISTED AS ACTIVE THROUGH 1974, ACCORDING TO USBM OFR 20-73. ; INFO.SRC : 1 PUB LIT

Reporter information

Type Date Name Affiliation Comment
Reporter 01-MAY-1987 Leonard, Kenneth R. (Huber, Donald F.) U.S. Geological Survey
Editor 02-SEP-1994 Mosier, Dan U.S. Geological Survey PARSED OUT HOST ROCK AND ASSOCIATED ROCK TYPES, AGES, UNIT NAMES, AND UNIT AGES.