Big Cottonwood Mine

Site Name

Primary: Big Cottonwood Mine
Secondary: Mountain Lake Group
Secondary: Great Western Mines

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Commodity

Primary: Iron
Secondary: Copper
Tertiary: Tungsten

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Location

State: Utah
County: Salt Lake
District: Big Cottonwood District

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Land Status

Land ownership: Private
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.

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Holdings

Not available

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Workings

Type: Underground

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Ownership

Owner Name: Great Western Mines Co.
Home Office: Ogden, Ut.

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Production

Not available

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Deposit

Record Type: Site
Operation Category: Past Producer
Operation Type: Unknown
Year First Production: 1875
Year Last Production: 1907
Discovery Year: 1875
Discovery Method: Ore-Mineral In Place
Years of Production:
Organization:
Significant: N
Deposit Size: S

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Physiography

General Physiographic Area: Rocky Mountain System
Physiographic Province: Middle Rocky Mountains
Physiographic Detail: Wasatch Mountains

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Mineral Deposit Model

Not available

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Orebody

Form: IRREGULAR

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Structure

Type: R
Description: Vinta-Cottonwood Arch, Sevier Overthrust Belt, Cordilleran Hingeline

Type: L
Description: Grizzly Thrust Fault

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Alterations

Alteration Type: L
Alteration Text: Calc-Silicate Zone Of Skarn Environment, Oxidation

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Rocks

Name: Diorite
Role: Associated
Age Type: Associated Rock
Age Young: Oligocene

Name: Diorite
Role: Associated
Age Type: Host Rock
Age Young: Mississippian

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Analytical Data

Analytical Data: 1.67% CU, 60% RECOVERY OF FE FROM THE ORE

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Materials

Ore: Magnetite
Ore: Chalcopyrite
Ore: Scheelite
Ore: Bornite
Gangue: Talc
Gangue: Epidote
Gangue: Brucite
Gangue: Phlogopite
Gangue: Chlorite
Gangue: Tremolite
Gangue: Actinolite
Gangue: Garnet
Gangue: Serpentine
Gangue: Forsterite

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Comments

Comment (Development): SURFACE RIGHTS ARE OWNED BY WASATCH NATIONAL FOREST. METALURGICAL TESTING BY THE USBM IN 1970, USING STRAIGHT MAGNETIC SEPARATION AND FLOTATION SUCCESSFULLY REMOVED COPPER AND SULFUR FROM IRON ORE. GRINDING TO-100 MESH WAS NECESSARY.

Comment (Commodity): MOSTLY AN IRON (MAGNETITE) PROSPECT WITH LOW GRADE COPPER ASSOCIATED

Comment (Location): TOWNSHIP IS UNSURVEYED. MINE LOCATION IS MISLABELED ON 7.5 TOPOGRAPHIC MAP OF THE BRIGHTON QUADRANGLE ; INFO FROM LAND.ST :1983

Comment (Production): SMALL SHIPMENTS WERE MADE IN 1875. IN 1907 SMALL SHIPMENTS OF COPPER ORE WERE SENT TO THE TINTIC SMELTER

Comment (Reserve-Resource): BULLOCK, K.C., 1970

Comment (Deposit): Discovery Year: LATE 1800'S

Comment (Deposit): DEPOSIT IS A LOW-GRADE COPPER-BEARING MAGNETITE METASOMATIC REPLACEMENT DEPOSIT. THE NORTH ORE BODY IS CRESCENT SHAPED, 375 FT LONG, 50 FT THICK, AND STRIKES EAST-WEST. THE SOUTH ORE BODY STRIKES NNW FOR 315 FT AND IS 20 FT THICK. THE THIRD ORE BODY IS UNDERGROUND, STRIKE, NNW, AND IS OF UNDETERMINED EXTENT

Comment (Workings): THE PORTAL OF THE MINE IS CUT IN GRANODIORITE, THE ADIT EXTENDS SW FOR 700 FT IN GRANODIORITE. THEN A CROSSCUT PASSES THROUGH 110 FT 8F SKARN. A DRIFT THEN CUTS ABOUT 30 FT OF MAGNETITE

Comment (Geology): SOME UNUSUAL BORATES, LUDWIGITE AND MAGNESIOLUDWIGITE, ARE ABUNDANT. OTHER, UNUSUAL MINERALS SUCH AS EPHOSITE, SUSSEXITE, XANTHOPHYLLITE, AND HYDROMAGNESITE MAY ALSO BE PRESENT. CARBONATES FORM A ROOF PENDANT SUSPENDED BETWEEN THE ALTA STOCK TO THE NORTHWEST AND THE CLAYTON PEAK STOCK TO THE SOUTHEAST. THE SKARN ZONE IS ABOUT 50 FT THICK.

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References

Reference (Deposit): JAMES, L.P., 1979, GEOLOGY, ORE DEPOSITS, AND HISTORY OF THE BIG COTTONWOOD MINING DISTRICT, SALT LAKE COUNTY, UTAH: U.G.M.S. BULL. NO. 114.

Reference (Deposit): CALKINS, F.C., AND BUTLER, B.S., 1943, GEOLOGY AND ORE DEPOSITS OF THE COTTONWOOD-AMERICAN FORK AREA, UTAH: U.S. GEOLOGICAL SURVEY PROF. PAPER, NO. 201.

Reference (Deposit): BUTLER, B.S., LOUGHLIN, G.F., HEIKES, V.C., AND OTHERS, 1920, THE ORE DEPOSITS OF UTAH: U.S. GEOLOGICAL SURVEY PROF. PAPER, NO. 111.

Reference (Deposit): BAKER, A.A., CALKINS, F.C., CRITTENDEN, M.D., JR., AND BROMFIELD, C.S., 1966, GEOLOGIC MAP OF THE BRIGHTON QUADRANGLE, UTAH: U.S. GEOLOGICAL SURVEY GEOL. QUAD. MAP GQ-534

Reference (Deposit): BULLOCK, K.C., 1970, IRON DEPOSITS OF UTAH: U.G.M.S. BULL. 88, P. 72

Reference (Deposit): CRAWFORD, A.L., AND BURANEK, A.M., 1957, TUNGSTEN RESERVES DISCOVERED IN THE COTTONWOOD-AMERICAN FORLE MINING DISTRICTS. UTAH: UTAH GEOL. AND MIN. SURVEY REPRINT NO. 55

Reference (Production): BULLOCK, K.C., 1970

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