Island Mountain Consolidated

The Island Mountain Consolidated is a copper mine located in Trinity county, California at an elevation of 751 feet.

About the MRDS Data:

All mine locations were obtained from the USGS Mineral Resources Data System. The locations and other information in this database have not been verified for accuracy. It should be assumed that all mines are on private property.

Mine Info

Satelite View

MRDS mine locations are often very general, and in some cases are incorrect. Some mine remains have been covered or removed by modern industrial activity or by development of things like housing. The satellite view offers a quick glimpse as to whether the MRDS location corresponds to visible mine remains.

Site Name

Primary: Island Mountain Consolidated
Secondary: Annex
Secondary: Leach
Secondary: Merritt Gore
Secondary: Shotgun

Commodity

Primary: Copper
Secondary: Silver
Secondary: Gold
Tertiary: Iron

Location

State: California
County: Trinity

Land Status

Land ownership: National Forest
Note: the land ownership field only identifies whether the area the mine is in is generally on public lands like Forest Service or BLM land, or if it is in an area that is generally private property. It does not definitively identify property status, nor does it indicate claim status or whether an area is open to prospecting. Always respect private property.

Holdings

Not available

Workings

Not available

Ownership

Not available

Production

Year: 1930
Time Period: - 1930
Material type: AU
Description: Cp_Grade: ^Avg., .065 Oz/Ton From 131,600 Tons Of Ore
Year: 1930
Time Period: - 1930
Material type: AG
Description: Cp_Grade: ^Avg., 1.09 Oz/Ton From 131,600 Tons Of Ore
Year: 1930
Time Period: - 1930
Material type: CU
Description: Cp_Grade: ^Avg., 3.3 % Cu From 131,600 Tons Of Ore
Year: 1914
Material type: ORE
Description: Ap_Grade: ^3 1/2 % Cu, 1 1/2 Oz Ag And $2 Au Per Ton

Deposit

Record Type: Site
Operation Category: Past Producer
Deposit Type: Replacement
Operation Type: Unknown
Years of Production:
Organization:
Significant: N
Deposit Size: L

Physiography

General Physiographic Area: Pacific Mountain System
Physiographic Province: Pacific Border Province
Physiographic Section: California Coast Ranges

Mineral Deposit Model

Not available

Orebody

Form: LENTICULAR

Structure

Type: L
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.

Alterations

Alteration Type: L
Alteration Text: Silicification

Rocks

Not available

Analytical Data

Not available

Materials

Ore: Pyrrhotite
Ore: Sphalerite
Ore: Cubanite
Gangue: Quartz
Gangue: Calcite
Gangue: Gypsum

Comments

Comment (Geology): 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.

Comment (Deposit): COMPRISED OF 266 ACRES.

Comment (Commodity): MOST ABUNDANT IS PYRITE; MOST IMPORTANT COPPER MINERAL IS CHALCOPYRITE

Comment (Reserve-Resource): IN 1965 : ABOUT 158,000 TONS OF ORE IS ESTIMATED TO REMAIN IN THE ISLAND MTN. MINE.

Comment (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

Comment (Workings): 6 ADITS AND 5 SHAFTS AND HAS SEVERAL THOUSAND FEET OF DRIFTS, CROSSCUTS AND RAISES

Comment (Production): 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.

References

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

Reference (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

Reference (Production): O'BRIEN, J.C., 1965 , P. 21

California Gold

"Where to Find Gold in California" looks at the density of modern placer mining claims along with historical gold mining locations and mining district descriptions to determine areas of high gold discovery potential in California. Read more: Where to Find Gold in California.