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Cotopaxi Mine

Past Producer in Fremont county in Colorado, United States with commodities Copper, Zinc, Gold, Silver, Lead, Molybdenum, Iron, Tungsten
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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. Mineral occurrence model information
  10. Host and associated rocks
  11. Nearby scientific data
  12. Geologic structures
  13. Ore body information
  14. Controls for ore emplacement
  15. Economic information about the deposit and operations
  16. Mining district
  17. Land status
  18. Ownership information
  19. Production statistics
  20. Workings at the site
  21. Links to other databases
  22. Bibliographic references
  23. General comments
  24. Reporter information

Geologic information

Identification information

Deposit ID 10087764
MRDS ID D009464
Record type Site
Current site name Cotopaxi Mine
Alternate or previous names Gumaer Mine, Cotopaxi Lode, Fannie Lode, Fannie Mill

Geographic coordinates

Geographic coordinates: -105.69836, 38.38001 (WGS84)
Elevation 2067
Relative position 1.1 MILES N35W OF COTOPAXI

Site location context

Political divisions (FIPS codes)

Fremont(county)

Colorado(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Arkansas Mountain(quadrangle 1:24,000 scale)

Canon City(quadrangle 1:100,000 scale)

Pueblo(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Arkansas Headwaters(hydrologic unit)

Upper Arkansas(hydrologic accounting unit)

Upper Arkansas(hydrologic subregion)

Arkansas-White-Red(hydrologic region)

Geographic areas

Country State County
United States Colorado Fremont

Public Land Survey System information

Meridian Township Range Section Fraction State
New Mexico 048N 011E 25 CENTER OF SW OF NE Colorado

Comments on the location information

  • Located about 0.5 mi northwest of the bridge across the Arkansas River at Cotopaxi, in the E1/2 SE1/4 sec. 25, T. 48 N., R. 11 E.

Commodities

Commodity Importance
Copper Primary
Zinc Critical Primary
Gold Secondary
Silver Secondary
Lead Secondary
Molybdenum Tertiary
Iron Tertiary
Tungsten Critical Tertiary

Comments on the commodity information

  • Zinc occurs mainly as sphalerite and gahnite, a zinc spinel mineral. Copper occurs as chalcopyrite. Minor galena and molybdenite are present. Pyrite, pyrhotite, and magnetite are locally common.

Materials information

Materials Type of material
Anglesite Ore
Bornite Ore
Chalcopyrite Ore
Chrysocolla Ore
Covellite Ore
Cuprite Ore
Gahnite Ore
Galena Ore
Goethite Ore
Gold Ore
Hematite Ore
Limonite Ore
Magnetite Ore
Malachite Ore
Molybdenite Ore
Pyrite Ore
Pyrrhotite Ore
Scheelite Ore
Silver Ore
Sphalerite Ore
Tetrahedrite Ore
Actinolite Gangue
Amazonstone Gangue
Anthophyllite Gangue
Biotite Gangue
Calcite Gangue
Clinohumite Gangue
Cordierite Gangue
Diopside Gangue
Garnet Gangue
Gypsum Gangue
Hornblende Gangue
Phlogopite Gangue
Quartz Gangue
Thulite Gangue

Alteration

  • (Local) Surficial Oxidation
  • (Local) gahnite mineralization present (zinc spinel)

Analytical data

Result SORTED ORE (1883) 58 % ZN, 4.6 % CU, 10 OZ/TON AG

Mineral occurrence model information

Model code 271
USGS model code Unassigned
Deposit model name Stratabound Precambrian sulfide, Colorado and Wyoming

Host and associated rocks

  • Host or associated Host
    Rock type Metamorphic Rock > Amphibolite
    Stratigraphic age (youngest) Paleoproterozoic
  • Host or associated Host
    Rock type Metamorphic Rock > Gneiss > Felsic Gneiss > Biotite Gneiss
    Stratigraphic age (youngest) Paleoproterozoic
  • Host or associated Host
    Rock type Metamorphic Rock > Schist
    Stratigraphic age (youngest) Paleoproterozoic
  • Host or associated Host
    Rock type Metamorphic Rock > Gneiss
    Rock unit name Biotite gneiss and migmatitic gneiss
    Stratigraphic age (youngest) Paleoproterozoic
    Stratigraphic age (youngest) Paleoproterozoic
  • Host or associated Host
    Rock type Metamorphic Rock > Skarn (Tactite)
    Stratigraphic age (youngest) Paleoproterozoic
  • Host or associated Host
    Rock type Metamorphic Rock > Schist
    Stratigraphic age (youngest) Paleoproterozoic
  • Host or associated Host
    Rock type Metamorphic Rock > Amphibolite
    Stratigraphic age (youngest) Paleoproterozoic
  • Host or associated Associated
    Rock type Plutonic Rock > Granitoid > Granodiorite
    Stratigraphic age (youngest) Paleoproterozoic
  • Host or associated Associated
    Rock type Plutonic Rock > Granitoid > Granodiorite
    Stratigraphic age (youngest) Paleoproterozoic

Nearby scientific data

(1) -105.69836, 38.38001
ListMap

Economic information

Geologic structures

Type of structure Local
Structure description Cotopaxi Fault; Subsidiary North-, Nne-, And Ew-Trending Faults
Type of structure Regional
Structure description Thirtynine Mile Volcanic Field

Ore body information

  • General form LENSOID
    Strike N E
    Dip N45W
    Length 91.44M
    Width 15.24M

Controls for ore emplacement

  • Leucocratic Bands, Amphibolite

Comments on the geologic information

  • Cotopaxi is thought to be a metamorphosed massive sulfide deposit similar to the Sedalia mine near Salida and the Betty (Lone Chimney) mine near Guffey (Sheridan and Raymond, 1984). Gahnite, a zinc spinel, is present in large quantities. Zinc spinels are indicative of metamorphosed massive sulfide deposits (Heimann, 2002).
  • Heinrich (1981) described the Cotopaxi deposit and the Sedalia deposit as skarns.
  • Maps indicate that the strike of the deposit is generally north-northeast and the dip is about 45 degrees to the SE (Heinrich, 1981).

Economic information about the deposit and operations

Operation type Surface-Underground
Development status Past Producer
Commodity type Metallic
Deposit size Small
Significant No
Discovery year 1875
Year of first production 1875
Year of last production 1967

Mining district

District name Cotopaxi District

Land status

Ownership category Private

Ownership information

  • Type Operator
    Owner Tombstone Mining Co.
    Home office Box 491, Canon City, Co
    First year 1975
  • Type Owner
    Owner Brown Mineral Research, Inc.
    Home office Box 491, Canon City, Co
    First year 1975

Production statistics

  • Year 1950
    Period 1915-1950
    Material ore
    Ore mined 15747.2mt
    Accuracy Accurate
    Description Cp_Grade: ^1.11% Cu, 0.58% Pb, 10.41% Zn, 0.97 Oz/Ton Ag, 0.01 Oz/Ton Au
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Minor Lead Lead 1wt-pct
    Minor Silver Silver 33g/mt
    Minor Gold Gold 0g/mt
    Major Zinc Zinc 10wt-pct
    Major Copper Copper 1wt-pct

Comments on the production information

  • Workings consist of lower adit, upper adit, and an open cut. The adits access several hundred feet of drifts and stopes (Heinrich, 1981).
  • Lindgren (1908) visited the property in 1907 and noted that the cotopaxi Mine had been idle for many years, but at one time was a "considerable shipper of ore".

Workings at the site

  • Type of workings Unknown
    Area 0.613HA
    Overall depth 0M
    Overall length 152.4M
    Overall width 42.67M
  • Type of workings Underground
    Length 304.8M

Comments on the workings information

  • OPEN PIT, DRILLING

Reference information

Bibliographic references

General comments

Subject category Comment text
Deposit DEPOSIT LIES ON WEST SIDE OF ANTICLINE

Reporter information

Type Date Name Affiliation Comment
Reporter 01-AUG-1982 Collins, Donna B. Colorado Geological Survey
Updater 02-JUN-2004 Keller, John W. Colorado Geological Survey

Beyond USGS

Supplemental information added by qvyshift.com. Not part of the original USGS MRDS record.

Maps centered on this site

Authoritative Colorado resources

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