The Last Chance Mine is a fluorine-fluorite mine located in Chaffee county, Colorado at an elevation of 7,799 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
Elevation: 7,799 Feet (2,377 Meters)
Commodity: Fluorine-Fluorite
Lat, Long: 38.65194, -106.06611
Map: View on Google Maps
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Last Chance Mine MRDS details
Site Name
Primary: Last Chance Mine
Secondary: Kramer Mine
Secondary: Lower Adit
Secondary: Adit No. 1
Secondary: Adit No. 2
Secondary: Commercial Minerals, Inc., claims
Commodity
Primary: Fluorine-Fluorite
Tertiary: Manganese
Location
State: Colorado
County: Chaffee
District: Browns Canyon District
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.
Holdings
Not available
Workings
Type: Surface/Underground
Ownership
Owner Name: Commercial Minerals, Inc.
Years: 1969 -
Production
Year: 1944
Time Period: 1942-1944
Mined: 9842.000 mt
Material type: FLUORSPAR CONCENTRATES
Year: 1942
Time Period: BEFORE 1942
Mined: 984.200 mt
Material type: FLUORSPAR CONCENTRATES
Deposit
Record Type: Site
Operation Category: Past Producer
Operation Type: Unknown
Year First Production: 1927
Year Last Production: 1949
Discovery Year: 1923
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: Fluorspar deposits (fluorite veins)
Orebody
Not available
Structure
Type: R
Description: Southern Mosquito Range, Arkansas Valley Graben
Type: L
Description: Folds, Faults; N-Trending Fault Bounding Arkansas Valley
Alterations
Alteration Type: L
Alteration Text: Silicification, Fluoritization
Rocks
Name: Gneiss
Role: Associated
Age Type: Associated Rock Unit
Age Young: Neoproterozoic
Name: Gneiss
Role: Associated
Age Type: Host Rock Unit
Age Young: Neoproterozoic
Name: Gneiss
Role: Associated
Age Type: Associated Rock
Age Young: Neoproterozoic
Name: Gneiss
Role: Associated
Age Type: Host Rock
Age Young: Neoproterozoic
Analytical Data
Analytical Data: AVERAGE GRADE OF ORE MINED WAS 30% CAF2
Analytical Data: EARLIER HAND PICKED METALLURGICAL-GRADE PRODUCT CONTAINE 80-95% CAF2 AND 2.5-15% SIO2
Analytical Data: FLOTATION CONCENTRATES AVERAGED 93-98% CAF2 AND 1-5% SIO2
Analytical Data: ONE SAMPLE CONTAINED 59.2% CAF2, 24.6% FE2O3, 9.8% SIO2, 3.8% CACO3, 1.7% H2O-MOST ORE, HOWEVER CONTAINED MORE SILICA AND LT 1% CACO3
Materials
Ore: Fluorite
Gangue: Montmorillonite
Gangue: Goethite
Gangue: Pyrite
Gangue: Manganite
Gangue: Pyrolusite
Gangue: Quartz
Gangue: Chalcedony
Gangue: Hematite
Gangue: Barite
Gangue: Calcite
Gangue: Psilomelane
Gangue: Kaolinite
Gangue: Opal
Comments
Comment (Deposit): IN PLACES FAULT CONSISTS OF SHEETED ZONE CONTAINING MANY VEINS OF FLUORSPAR, SOME 6 IN THICK; TWO MAIN ORE BODIES, EACH ABOUT 460X12X25 FT THICK
Comment (Development): FLOTATION MILL OPERATED 1942-1944
Comment (Geology): NW-TRENDING FAULT LOCALIZED ORE BODIES IN PRECAMBRIAN GNEISSIC QUARTZ MONZONITE.
Comment (Location): NE OF HECLA JUNCTION, EAST OF US HWY 285, WEST OF ARKANSAS RIVER; SE/4 SEC. 22, T 51 N, R 8 E. INFO FROM LAND.ST :(1976)
Comment (Production): FLOTATION MILL PRODUCED CERAMIC-GRADE AND A SMALL QUANTITY OF ACID-GRADE CONCENTRATES BEFORE IT BURNED IN 1944
Comment (Workings): ADITS, PITS, TRENCHES
References
Reference (Deposit): VAN ALSTINE, R.E. AND COX, D.C., 1969, FLUORSPAR MINES AND PROSPECTS, IN, GEOLOGY AND MINERAL DEPOSITS OF THE PONCHA SPRINGS NE QUADRANGLE, CHAFFEE COUNTY, COLORADO: USGS PROFESSIONAL PAPER 626, P. 38-43
Reference (Deposit): BRADY, B.T., 1975, MAP SHOWING FLUORSPAR DEPOSITS IN COLORADO: USGS MAP MR-70, 1:500,000, TEXT
Reference (Deposit): VAN DIVER, B.B., 1957, GEOLOGY OF THE CALUMET MINING DISTRICT, CHAFFEE COUNTY, COLORADO: UNIVERSITY OF COLORADO THESIS, P. 83.
Reference (Deposit): VANDERWILT, 1947, COLO. MINERAL RES. BOARD
Reference (Deposit): ARGALL, 1949, COLO. SCH. MINES QUART., V. 44, NO. 2
Reference (Deposit): CONSV. DIV. COMP. DATE, 1,64
Reference (Deposit): USBM MINERAL EXAM. FILE
Reference (Deposit): MINE MAP REPO 404956
Reference (Deposit): RECK, W. H., 1943, KRAMER MINES, INC.: DECO TREFOIL MAGAZINE, ENGINEERING NOTEBOOK BULL. M4-B28, MAY 1943, 12 PP.
Reference (Deposit): VAN ALSTINE, R.E., 1969, GEOLOGY AND MINERAL DEPOSITS OF THE PONCHA SPRINGS NE QUADRANGLE, CHAFFEE COUNTY, COLORADO: USGS PROFESSIONAL PAPER 626, 52 P.
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