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Island Mountain Consolidated

Past Producer in Trinity county in California, United States with commodities Copper, Gold, Silver, Iron
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Sections on this page
  1. Identification information
  2. Geographic coordinates
  3. Site location context
  4. Geographic areas
  5. Public Land Survey System information
  6. Commodities
  7. Materials information
  8. Alteration
  9. Host and associated rocks
  10. Nearby scientific data
  11. Geologic structures
  12. Ore body information
  13. Controls for ore emplacement
  14. Economic information about the deposit and operations
  15. Land status
  16. Production statistics
  17. Links to other databases
  18. Bibliographic references
  19. General comments
  20. Reporter information

Geologic information

Identification information

Deposit ID 10072353
MRDS ID W017588
Record type Site
Current site name Island Mountain Consolidated
Alternate or previous names Annex, Leach, Merritt Gore, Shotgun

Geographic coordinates

Geographic coordinates: -123.48528, 40.03318 (WGS84)
Elevation 229
Relative position SW CORNER OF TRINITY COUNTY, AT ISLAND MTN.

Site location context

Political divisions (FIPS codes)

Trinity(county)

California(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Lake Mountain(quadrangle 1:24,000 scale)

Garberville(quadrangle 1:100,000 scale)

Redding(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Lower Eel(hydrologic unit)

Northern California Coastal(hydrologic accounting unit)

Klamath-Northern California Coastal(hydrologic subregion)

California(hydrologic region)

Geographic areas

Country State County
United States California Trinity

Public Land Survey System information

Meridian Township Range Section Fraction State
Humboldt 005S 006E 09,10,15 California

Commodities

Commodity Importance
Copper Primary
Gold Secondary
Silver Secondary
Iron Tertiary

Comments on the commodity information

  • MOST ABUNDANT IS PYRITE; MOST IMPORTANT COPPER MINERAL IS CHALCOPYRITE

Materials information

Materials Type of material
Cubanite Ore
Pyrrhotite Ore
Sphalerite Ore
Calcite Gangue
Gypsum Gangue
Quartz Gangue

Alteration

  • (Local) Silicification

Host and associated rocks

  • Host or associated Associated
    Rock type Volcanic Rock (Aphanitic) > Intermediate Volcanic Rock > Andesite
  • Host or associated Host
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Shale
  • Host or associated Host
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Siltstone

Nearby scientific data

(1) -123.48528, 40.03318
ListMap

Economic information

Geologic structures

Type of structure Local
Structure description Homocline With Beds Of Shale And Graywacke, Paralleling General Strike Of Graywacke And Shale Are Several Notable Faults Marked By Depressions, Shear Zones And Landslides.

Ore body information

  • General form LENTICULAR
    Thickness 42.67M
    Length 137.16M
    Width 36.58M

Controls for ore emplacement

  • Shear Zone

Comments on the geologic information

  • GEOL.DESC: SHALE AND GRAYWACKE ARE MEMBERS OF THE FRANCISCAN FORMATION, ROCKS STRIKE N 30 W AND DIP STEEPLY NE. MOST WIDE SPREAD ROCK TYPE IN AREA IS THE WELL BEDDED GRAYWACKE. A ZONE OF GRAYWACKE ALONG PINE CREEK BELOW THE BRIDGE CONSISTS OF ALTERNATE LAYERS OF FINE-GRAINED GRAYWACKE AND GRAYWACKE CONTAINING ROUNDED, ROUGHLY ALIGNED PEBBLES OF BLACK SHALE. MOST OF THE PROMINENT RIDGES ARE COMPOSED OF GRAYWACKE. THE BLACK SHALE BODIES ENCLOSED BY THE GRAYWACKE ARE NARROW AND LENTICULAR WITH AVG. WIDTH OF 100 FT.. IN LANDSLIDE AREA NEAR MINE, SHALE HAS BEEN SILICIFIED AND RECEMENTED TO FORM MASSIVE BOULDERS. OTHER ROCK TYPES IN THE VICINITY INCLUDE RED AND BROWN CHERT WITHIN GRAYWACKE, JAGGED PINNACLES OF GREENSTONE, A SMALL BODY OF DIABASE 1/3 MILE SE OF NORTH END OF RAILROAD TUNNEL, 3 SMALL OUTCROPS OF ANDESITE ALONG WITH A LARGER MASS OF ANDESITE FARTHER WEST AND SEVERAL ISOLATED MASSES OF GLAUCOPHANE SCHIST.

Economic information about the deposit and operations

Development status Past Producer
Commodity type Metallic
Deposit size Large
Significant No
Production years 1915 - 1930

Land status

Ownership category National Forest

Production statistics

  • Year 1914
    Material ORE
    Accuracy Estimate
    Description Ap_Grade: ^3 1/2 % Cu, 1 1/2 Oz Ag And $2 Au Per Ton
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Ore Copper Copper 4wt-pct
    Ore Silver Silver 42g/mt
  • Year 1930
    Period - 1930
    Material AU
    Accuracy Accurate
    Description Cp_Grade: ^Avg., .065 Oz/Ton From 131,600 Tons Of Ore
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Major Gold Gold 2g/mt
  • Year 1930
    Period - 1930
    Material AG
    Accuracy Accurate
    Description Cp_Grade: ^Avg., 1.09 Oz/Ton From 131,600 Tons Of Ore
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Silver Silver 31g/mt
  • Year 1930
    Period - 1930
    Material CU
    Accuracy Accurate
    Description Cp_Grade: ^Avg., 3.3 % Cu From 131,600 Tons Of Ore
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Copper Copper 3wt-pct

Comments on the production information

  • PRINCIPAL COPPER PRODUCER IN TRINITY COUNTY: HUGE BOULDERS OF FLOAT ORE CONTAINED 5 - 20 % CU, FOUND BELOW MAIN ORE BODY: AVG. GRADE FOR FIRST 5 YRS. OF PRODUCTION WAS 7 % CU.

Comments on the reserve resource information

  • IN 1965 : ABOUT 158,000 TONS OF ORE IS ESTIMATED TO REMAIN IN THE ISLAND MTN. MINE.

Comments on the workings information

  • 6 ADITS AND 5 SHAFTS AND HAS SEVERAL THOUSAND FEET OF DRIFTS, CROSSCUTS AND RAISES

Reference information

Bibliographic references

  • Deposit

    O'BRIEN, J.C., 1965 : MINES AND MINERALS, TRINITY COUNTY, CA.: CALIF. DIV. MINES AND GEOLOGY, COUNTY REPT. 4, P. 21 , 62

  • Deposit

    STINSON, M.C., 1957 : GEOLOGY OF THE ISLAND MOUNTAIN COPPER MINE, TRINITY COUNTY, CA.: CALIF. JOUR. MINES AND GEOLOGY, VOL. 53 , NOS. 1 & 2 : DIV. OF MINES, P. 9 - 33

  • Production

    O'BRIEN, J.C., 1965 , P. 21

General comments

Subject category Comment text
Deposit COMPRISED OF 266 ACRES.
Deposit LARGE KIDNEY-SHAPED BODY OF MASSIVE SULFIDE, IT PLUNGED INTO MOUNTAIN AT A LOW ANGLE. ORE BODY IS DEFICIENT IN GANGUE MINERALS, ORE BODY APPEAR TO BE IN FAULT CONTACT WITH ENCLOSING SHALE AND GRAYWACKE

Reporter information

Type Date Name Affiliation Comment
Reporter 01-JAN-1976 Weeks, Robert U.S. Geological Survey
Updater 01-DEC-1978 Fraticelli, L. A. (Albers, J.) 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 California resources

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