The Idledale District is a uranium mine located in Jefferson county, Colorado at an elevation of 6,719 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: 6,719 Feet (2,048 Meters)
Commodity: Uranium
Lat, Long: 39.66528, -105.24778
Map: View on Google Maps
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Idledale District MRDS details
Site Name
Primary: Idledale District
Commodity
Primary: Uranium
Tertiary: Copper
Tertiary: Lead
Tertiary: Zinc
Location
State: Colorado
County: Jefferson
District: Idledale 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: Unknown
Ownership
Not available
Production
Year: 1958
Description: Ap_Grade: ^0.22% U308
Year: 1956
Description: Ap_Grade: ^0.30% U308
Year: 1955
Description: Ap_Grade: ^0.30% U308
Year: 1960
Time Period: 1955-1960
Description: Cp_Grade: ^0.28% U308
Deposit
Record Type: District
Operation Category: Past Producer
Deposit Type: Vein
Operation Type: Unknown
Year First Production: 1955
Year Last Production: 1968
Discovery Year: 1955
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
Not available
Orebody
Not available
Structure
Type: R
Description: Front Range Uplift, Denver Basin
Type: L
Description: Bear Creek Shear Zone, Junction Ranch Fault, Cherry Gulch Fault
Alterations
Alteration Type: L
Alteration Text: Fe Oxidation
Rocks
Name: Gneiss
Role: Host
Age Type: Host Rock
Age Young: Neoproterozoic
Name: Gneiss
Role: Host
Age Type: Host Rock Unit
Age Young: Neoproterozoic
Analytical Data
Analytical Data: WEIGHTED AVERAGE ORE GRADES RANGED FROM 0.22 TO 0.44% U308, WITH OVERALL AVERAGE 0.25 TO 0.28% U308
Materials
Ore: Coffinite
Ore: Pyrite
Ore: Galena
Ore: Sphalerite
Ore: Chalcopyrite
Ore: Pitchblende
Gangue: Chlorite
Gangue: Quartz
Gangue: Calcite
Gangue: Ankerite
Gangue: Fluorite
Comments
Comment (Production): PARTIAL PRODUCTION RECORD. ANNUAL FIGURES FOR 1961-68 NOT AVAILABLE. CUMULATIVES FOR 1955-68 FROM NELSON-MOORE AND OTHERS (1978). ORE GRADES ARE WEIGHTED AVERAGES OF OREGRADES FOR GRAPEVINE MINE AND WRIGHT LEASE.S
Comment (Deposit): COUNTRY ROCK CONSISTS OF VARIOUS GNEISSES, MIGMATITES, AND LENSES OF AMPHIBOLITE AND OTHER ROCKS, WITH FOLIATION TRENDING NW, DIPPING STEEPLY SW. NNW-TRENDING JUNCTION RANCH FAULT INTERSECTS WNW-TRENDING BEAR CREEK SHEAR ZONE AT IDLEDALE. MINERALIZED VEINS IN EACH MAJOR STRUCTURE ARE COMPOUND, BRANCHING, OR ANASTAMOSING FRACTURES SUBPARALLEL TO TREND OF HOST STRUCTURE. SHARPLY DEFINED FISSURE WALLS ENCLOSE QUARTZ-CEMENTED BRECCIA IN CARBONATE MATRIX. PITCHBLENDE COATS FRACTURES, PYRITE GF AMPHIBOLITE AND OTHER ROCKS, WITH FOLIATION TRENDING NW, DIPPING STEEPLY SW, NEW-TRENDING JUNCTION RANCH FAULT INTERSECTS WNW-TRENDING BEAR CREEK SHEAR ZONE AT IDLEDALE, MINERALIZED VEINS IN EACH MAJOR STRUCTURE ARE COMPOUND, BRANCHING, OR ANASTAMOSING FRACTURES SUBPARALLEL TO TREND OF HOST STRUCTURE. SHARPLY DEFINED FISSURE WALLS ENCLOSE QUARTZ-CEMENTED BRECCIA IN CARBONATE MATRIX. PITCHBLENDE COATS FRACTURES, PYRITE GRAINS, AND ALTERED BRECCIA FRAGMENTS. EARLY PERIOD OF BRECCIATION CONSISTS OF
Comment (Deposit): VARIOUSLY SIZED ANGULAR FRAGMENTS OF COUNTRY ROCK IN VUGGY, FINE-GRAINED QUARTZ MATRIX. SECOND BRECCIATION PRODUCED SMALL FRAGMENTS OF RELATIVELY UNIFORM SIZE. TWO-STAGE MINERALIZATION DETERMINED AT WRI
Comment (Workings): ONE INCLINED SHAFT (55-FT), TWO VERTICAL SHAFTS (92-FT AND 186-FT), 1275 FT OF DRIFTS, 720 FT OF CROSSCUTS, SURFACE PROSPECT PITS
Comment (Deposit): INDIVIDUAL RECORDS PREPARED FOR FOLLOWING MINES AND PROPERTIES: GRAPEVINE MINE, QUATMAN LEASE, WRIGHT LEASE (FOOTHILLS MINE). ; INFO.SRC : 1 PUB LIT
Comment (Location): ALONG BEAR CREEK AND SAWMILL GULCH AT IDLEDALE, LAT-LONG GIVEN IS FOR WRIGHT LEASE (FOOTHILLS MINE), DISTRICT'S LARGEST MINE ; INFO FROM LAND.ST :(1976)
References
Reference (Deposit): NELSON-MOORE, J.L., AND OTHERS, 1978, RADIOACTIVE MINERAL OCCURRENCES OF COLORADO AND BIBLIOGRAPHY: CGS BULL. 40, P. 189-196
Reference (Deposit): SCOTT, G.R., 1972, GEOLOGIC MAP OF THE MORRISON QUADRANGLE, JEFFERSON COUNTY, COLORADO: USGS MAP I-790-A
Reference (Deposit): GABLE, D.J., 1968, GEOLOGY OF THE CRYSTALLINE ROCKS IN THE WESTERN PART OF THE MORRISON QUADRANGLE, JEFFERSON COUNTY, COLORADO: USGS BULL. 1251-E
Reference (Deposit): SIMS, P.K., AND SHERIDAN, D.M., 1964, GEOLOGY OF URANIUM DEPOSITS INTHE FRONT RANGE, COLORADO: USGS BULL, 1159, P. 94-100
Reference (Production): SIMS, P.K., AND SHERIDAN, D.M., 1964, P. 96; NELSON-MOORE, J.L., AND OTHERS, 1978, P. 192, 194, 196
Colorado Mining Photos
Check out this collection of Colorado's best historic mining photos: Incredible Photos of Colorado Mining Scenes.
