Colorado-American Mine

Past Producer in Chaffee county in Colorado, United States with commodities Fluorine-Fluorite, Manganese
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 10013776
MRDS ID D010253
Record type Site
Current site name Colorado-American Mine
Alternate or previous names American Shaft, Trefone Adit or Tunnel, Mill Adit, Kramer Adit, American Fluorspar Co. Mine, Colorado Fluorspar Co. Mine, Browns Canyon Deposit, Arkansas Claim, Bapp (Bopp) Mine, Browns Canyon or Dostal Mine
Related records 10190307

Geographic coordinates

Geographic coordinates: -106.06671, 38.6325 (WGS84)
Elevation 2353
Location accuracy 100(meters)
Relative position 7.8 MILES S 04 E OF NATHROP

Site location context

Political divisions (FIPS codes)

Chaffee(county)

Colorado(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Nathrop(quadrangle 1:24,000 scale)

Gunnison(quadrangle 1:100,000 scale)

Montrose(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 Chaffee

Public Land Survey System information

Meridian Township Range Section Fraction State
New Mexico 051N 008E 34 NE OF SW OF NE Colorado

Comments on the location information

  • SE OF HECLA JUNCTION, EAST OF US HWY 285, WEST OF ARKANSAS RIVER; N/2 SEC. 34, T 51 N, R 8 E. INFO FROM LAND.ST :(1976)

Commodities

Commodity Importance
Fluorine-Fluorite Critical Primary
Manganese Critical Tertiary

Materials information

Materials Type of material
Fluorite Ore
Barite Gangue
Calcite Gangue
Goethite Gangue
Hematite Gangue
Kaolinite Gangue
Manganite Gangue
Montmorillonite Gangue
Opal Gangue
Psilomelane Gangue
Pyrite Gangue
Pyrolusite Gangue
Quartz Gangue

Alteration

  • (Local) Silicification, Fluoritization

Analytical data

Result EAST VEIN AVERAGES 50% CAF2, WITH LARGE POCKETS AVERAGING 75% CAF2

Mineral occurrence model information

Model code 174
USGS model code 26b
Deposit model name Fluorspar deposits (fluorite veins)

Host and associated rocks

  • Host or associated Associated
    Rock type Metamorphic Rock > Gneiss
    Stratigraphic age (youngest) Neoproterozoic
    Stratigraphic age (youngest) Neoproterozoic
  • Host or associated Associated
    Rock type Volcanic Rock (Aphanitic) > Felsic Volcanic Rock > Rhyolite
    Rock unit name Gneissic Quartz Monzonite;Ash-Flow Tuff
    Rock description Gneissic Quartz Monzonite;Ash-Flow Tuff
  • Host or associated Host
    Rock type Metamorphic Rock > Gneiss
    Rock unit name Banded Gneiss
    Rock description Banded Gneiss
  • Host or associated Host
    Rock type Volcanic Rock (Aphanitic) > Felsic Volcanic Rock > Rhyolite

Nearby scientific data

(1) -106.06671, 38.6325

Economic information

Geologic structures

Type of structure Regional
Structure description Southern Mosquito Range, Arkansas Valley Graben
Type of structure Local
Structure description Folds, Faults; N-Trending Fault Bounding Arkansas Valley; At 100-Ft Level Of Mine Workings Expose Fault With Welded Tuff On One Side, Quartz Monzonite On Other Side

Ore body information

  • General form TABULAR, LENTICULAR, POD-LIKE
    Thickness 137.16M
    Length 688.85M
    Width 4.57M
    Depth to bottom 137.16M

Controls for ore emplacement

  • Fault Breccia; Fault Zone Striking N 30-50 W, Dipping 65-85 Sw; Fractures

Economic information about the deposit and operations

Development status Past Producer
Commodity type Both
Deposit size Medium
Significant No
Discovery year 1923
Discoverer Stephen Trefone?
Year of first production 1927
Year of last production 1949

Mining district

District name Browns Canyon District

Land status

Ownership category Private

Ownership information

  • Type Owner
    Owner Allied Chemical Corp., General Chemical Division
    First year 1969

Production statistics

  • Year 1948
    Period 1930-1948
    Material FLUORSPAR CONCENTRATES
    Ore mined 115151.4mt
    Accuracy Estimate
    Description Cp_Grade: ^50% Caf2

Comments on the production information

  • ABOUT 90% OF FLUORSPAR CONCENTRATES SHIPPED FROM DISTRICT CAME FROM THIS MINE. ALMOST 60% OF THE CONCENTRATES WERE METALLURGICAL-GRADE (85% CAF2), 40% WERE CERAMIC-GRADE (92-97% CAF2), AND 2% WERE ACID-GRADE (98% CAF2).

Workings at the site

  • Type of workings Surface/Underground
    Area 13.121HA
    Length 1828.8M
    Overall depth 137.16M
    Overall length 633.98M
    Overall width 219.46M

Comments on the workings information

  • OPEN PIT, SHAFTS, DRIFTS, ADITS, CROSSCUTS, STOPES;

Comments on development

  • Originally two mines, the American Fluorspar Corp. mine on the NW and the Colorado Fluorspar Co. mine to the SE, these properties were later combined and operated as one mine.

Reference information

Bibliographic references

General comments

Subject category Comment text
Deposit SOUTHERN PART OF MINE HAS BEEN RICHEST PRODUCER;, 3 MAIN VEINS: EAST VEIN, WEST VEIN, AND THE BRANCH OR COLLINS VEIN. EAST AND WEST VEINS STRIKE N 40 W, DIP 65-85 SW; BRANCH VEIN STRIKES WEST, DIPS 45 S. EAST AND WEST VEINS ARE 120-200 FT APART AND WEST AND BRANCH VEINS INTERSECT NEAR SOUTH END OF MINE. EAST VEIN IS ALONG FAULT IN PRECAMBRIAN ROCKS. WEST AND BRANCH VEINS FOLLOW FAULT ZONES BETWEEN PRECAMBRIAN AND TERTIARY FAULTS. EAST VEIN IS PRINCIPAL ORE BODY. IN THE OPEN PIT THE BRANCH VEIN REACHES WIDTHS OF 50 FT OR MORE.

Reporter information

Type Date Name Affiliation Comment
Reporter 01-FEB-1983 Collins, Donna B. Colorado Geological Survey
Reporter 17-NOV-1983 Intermountain Field Operations Center (IFOC) U.S. Bureau of Mines
Reporter 01-OCT-1972 Conservation Division Files U.S. Geological Survey
Updater 10-MAR-2006 Beach, Richard A. Colorado Geological Survey

Beyond USGS

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

Authoritative Colorado resources

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