Cotopaxi District

The Cotopaxi District is a zinc and copper mine located in Fremont county, Colorado at an elevation of 7,598 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

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Site Name

Primary: Cotopaxi District

Commodity

Primary: Zinc
Primary: Copper
Secondary: Lead
Secondary: Gold
Secondary: Silver

Location

State: Colorado
County: Fremont
District: Cotopaxi District

Land Status

Land ownership: BLM Administrative Area
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

Not available

Deposit

Record Type: District
Operation Category: Past Producer
Operation Type: Unknown
Year First Production: 1850
Year Last Production: 1945
Discovery Year: 1875
Discovery Method: Ore-Mineral In Place
Years of Production:
Organization:
Significant: N
Deposit Size: S

Physiography

General Physiographic Area: Rocky Mountain System
Physiographic Province: Southern Rocky Mountains

Mineral Deposit Model

Model Name: Stratabound Precambrian sulfide, Colorado and Wyoming

Orebody

Form: LENSOID

Structure

Type: R
Description: Thirtynine Mile Volcanic Field, Wet Mountains

Type: L
Description: Cotopaxi Fault

Alterations

Not available

Rocks

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

Name: Diorite
Role: Associated
Age Type: Host Rock Unit
Age Young: Neoproterozoic

Analytical Data

Not available

Materials

Ore: Chalcopyrite
Ore: Sphalerite
Ore: Silver
Ore: Gold
Ore: Galena
Ore: Gahnite
Gangue: Biotite
Gangue: Garnet
Gangue: Gypsum
Gangue: Hornblende
Gangue: Quartz

Comments

Comment (Location): Locational point is near Cotopaxi Mine, which is 0.5 mi northwest of the small town of Cotopaxi on the Arkansas River. Two smaller Proterozoic base-metal sulfide occurrences, the Sand Gulch No. 2 and the Carson Mining Company prospect, are located in similar rocks about 3 mi north-northeast of the Cotopaxi Mine.

References

Reference (Deposit): LINDGREN, WALDEMAR, 19078 NOTES ON COPPER DEPOSITS IN CHAFFEE, FREMONT, AND JEFFERSON COUNTIES, COLORADO: USGS BULLETIN 340, P. 157-174.

Reference (Deposit): HEINRICH, E.W., 1981, PRECAMBRIAN TUNGSTEN AND COPPER-ZINC SKARN DEPOSITS OF SOUTH-CENTRAL COLORADO: CGS RESOURCE SERIES 21, P. 30, 83-88

Reference (Deposit): HARRER, C.M. AND TESCH, W.J., JR., 1959, RECONNAISSANCE OF IRON OCCURRENCES IN COLORADO: USBM IC 7918, 82 P.

Reference (Deposit): Sheridan, D.M., and Raymond, W.H., 1984, Precambrian deposits of zinc-copper-lead sulfides and zinc spinel (gahnite) in Colorado: U.S. Geological Survey Bulletin 1550, 31 p.

Reference (Deposit): TAYLOR, R.B., SCOTT, G.R., WOBUS, R.A., EPIS, R.C., 1975, RECONNAISSANCE GEOLOGIC MAP OF THE COTOPAXI 15-MINUTE QUADRANGLE, FREMONT AND CUSTER COUNTIES, COLORADO: USGS MAP T-900, 1:62,500.

Reference (Deposit): Sheridan, D.M., Raymond, W.H., Taylor, R.B., and Hasler, J.W., 1990, Metallogenic map of stratabound exhalative and related occurrences in Colorado: U.S. Geological Survey Miscellaneous Investigations Series Map I-1971, scale 1:1,000,000.

Reference (Geology): Heimann, Adriana, 2002, The composition of zinc-rich spinels associated with metamorphosed massive sulfide deposits - a reexamination: Society of Economic Geologists Abstracts, 2002 Denver Annual Meeting.

Reference (Production): VANDERWILT, J.W., 1947, P. 84

Reference (Deposit): VANDERWILT, J.W., 1947, MINERAL RESOURCES OF COLORADO: COLORADO MINERAL RESOURCES BOARD, P. 83-85.

Colorado Mining Photos

Check out this collection of Colorado's best historic mining photos: Incredible Photos of Colorado Mining Scenes.