Mine detail: Cotopaxi Mine

Previously called 'Gumaer MineCotopaxi LodeFannie LodeFannie Mill'

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Location

Lat / long: 38.38001, -105.69836

Resource(M)

Primary: Copper, Zinc
Secondary: Gold, Silver, Lead
Tertiary: Iron, Molybdenum, Tungsten
Ore: Anglesite, Bornite, Chalcopyrite, Chrysocolla, Covellite, Cuprite, Gahnite, Galena, Goethite, Gold, Hematite, Limonite, Magnetite, Malachite, Molybdenite, Pyrite, Pyrrhotite, Scheelite, Silver, Sphalerite, Tetrahedrite
Gangue: Actinolite, Amazonstone, Anthophyllite, Biotite, Calcite, Clinohumite, Cordierite, Diopside, Garnet, Gypsum, Hornblende, Phlogopite, Quartz, Thulite
Orebody form: LENSOID
Discovery year: 1875

Production

Operation type: Surface-Underground
Production size: Small
Development status: Past Producer
First production started: 1875
Last production ended: 1967

Geology

Host rock:Biotite gneiss and migmatitic gneiss
Host type:Amphibolite,Biotite Gneiss,Schist,Gneiss,Skarn (Tactite)
Associated type:Granodiorite
Structure:Cotopaxi Fault; Subsidiary North-, Nne-, And Ew-Trending Faults, Thirtynine Mile Volcanic Field
Alteration processes:Surficial Oxidation, gahnite mineralization present (zinc spinel)

References

MRDSD009464
DEP10087764
Reference{Deposit:: VANDERWILT, J.W., 1947, MINERAL RESOURCES OF COLORADO: COLORADO MINERAL RESOURCES BOARD, P. 83-85.}{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 I-900, 1:62,500.}{Deposit:: LINDGREN, W., 1908, NOTES ON COPPER DEPOSITS IN CHAFFEE, FREMONT, AND JEFFERSON COUNTIES, COLORADO: USGS BULLETIN 340, P. 157-174.}{Deposit:: HEINRICH, E.W., 1981, PRECAMBRIAN TUNGSTEN AND COPPER-ZINC SKARN DEPOSITS OF SOUTH-CENTRAL COLORADO: CGS RESOURCE SERIES 21, 115 P.}{Deposit:: 6) HARRER, C.M. AND TESCH, W.J., JR., 1959, RECONNAISSANCE OF IRON OCCURRENCES IN COLORADO: USBM INFORMATION CIRCULAR 7918, 82 P.}{Deposit:: SALOTTI, C.A., 1965, MINERALOGY AND PARAGENESIS OF THE COTOPAXI, COLORADO COPPER-ZINC SKARN DEPOSIT: AMERICAN MINERALOGIST, V. 50, NO. 9, P. 1179-1212.}{Deposit:: COKER, R.J., 1982, MINERAL RESOURCES OF THE ARKANSAS CANYON PLANNING UNIT WITH SPECIAL EMPHASIS ON THE FORMER GRAPE CREEK WILDERNESS STUDY AREAS AND THE MCINTYRE HILLS WILDERNESS STUDY AREA: US BLM MINERAL REPORT, P. 50-52.}{Deposit:: Sheridan, D.M., and Raymond, W.H., 1984. Preliminary report on the geology of the Sedalia mine are and its Proterozoic deposits of base-metal sulfides and gahnite, Chaffee County, Colorado: U.S. Geological Survey Open-File Report 84-0800, 27 p., 1 plate.}{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.}{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}{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.}{Production:: COLORADO DIVISION MINES INSPECTION RECORDS; COKER, 1982}
ReporterCollins, Donna B., Keller, John W.