The Mann Ranch is a uranium mine located in Jefferson county, Colorado at an elevation of 5,801 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: 5,801 Feet (1,768 Meters)
Commodity: Uranium
Lat, Long: 39.63417, -105.16889
Map: View on Google Maps
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Mann Ranch MRDS details
Site Name
Primary: Mann Ranch
Secondary: Mann Mine
Secondary: Vanadium Queen Mine
Commodity
Primary: Uranium
Tertiary: Molybdenum
Location
State: Colorado
County: Jefferson
District: Foothill 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: Underground
Ownership
Not available
Production
Year: 1958
Material type: 030 U
Description: Ap_Grade: ^0.14% U308
Year: 1956
Material type: U308
Description: Ap_Grade: ^0.36% U308
Year: 1955
Material type: ORE U
Description: Ap_Grade: ^0.21% U308
Year: 1961
Time Period: 1955-1961
Material type: ORE U
Description: Cp_Grade: ^0.27% U308
Deposit
Record Type: Site
Operation Category: Past Producer
Operation Type: Unknown
Year First Production: 1955
Year Last Production: 1961
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
Form: WEDGE
Structure
Type: R
Description: Denver Basin, Front Range Uplift
Type: L
Description: Golden Fault, Damming Fault
Alterations
Not available
Rocks
Name: Sandstone
Role: Host
Age Type: Host Rock Unit
Age Young: Late Cretaceous
Name: Sandstone
Role: Host
Age Type: Host Rock
Age Young: Late Cretaceous
Analytical Data
Analytical Data: ORE GRADES RANGED FROM 0.21 TO 0.27% U308
Materials
Ore: Uraninite
Gangue: Pyrite
Gangue: Ilsemannite
Comments
Comment (Location): ON SOUTH SIDE OF TURKEY CREEK AT BOTTOM OF HOGBACK, JUST ACROSS CREEK FROM FOUR CORNERS MINE ; INFO FROM LAND.ST :(1976)
Comment (Production): ESTIMATED FIGURES FOR 1961 CALCULATED FROM DIFFERENCE BETWEEN RICHTER'S TOTAL FOR 1955-60 AND NELSON-MOORE AND OTHERS' CUMULATIVE TOTAL FOR 1955-61.
Comment (Development): PRODUCTION FROM OLDER ADIT WAS 6 TONS AT 0.21% U308. TOTAL PRODUCTION THRU 1961 WAS 2893 TONS AT 0.27% U308 YIELDING 15579 LB U308
Comment (Deposit): URANIFEROUS ASPHALTIC MATERIAL (PROBABLY RELATED TO OIL SEEPS IN AREA) OCCURS IN ELONGATED WEDGES IN EITHER KASSLER OR UPPER SANDSTONE MEMBERS OF SOUTH PLATTE FM ON FOOTWALL OF DAMMING FAULT. ORE EXTENDS DOWNWARD ALONG BEDDING 10 TO 30 FT FROM FAULT. SIZE AND GRADE OF ORE DECREASE UPWARD ALONG FAULT PLANE. GOLDSTEIN (1957) BELIEVED URANIUM TO BE OF PRIMARY ORIGIN AND WAS PRECIPITATED FROM ASCENDING HYDROTHERMAL SOLUTIONS ALONG DAMMING FAULT AT ZONES OF FAVORABLE SANDSTONE PERMEABILITY.
Comment (Workings): 50-FT TUNNEL DRIVEN SE AND SSE. SECOND TUNNEL DRIVEN N80E FOR 320 FT, THENCE INTO APPROX 300 FT OF DRIFTS TO NW AND SE
References
Reference (Deposit): NELSON-MOORE, J.L., COLLINS, D.B., AND HORNBAKER, A.L., 1978, RADIOACTIVE MINERAL OCCURRENCES OF COLORADO AND BIBLIOGRAPHY: COLORADO GEOLOGICAL SURVEY BULL. 40, P. 193
Reference (Deposit): SCOTT, GLENN R., 1972, GEOLOGIC MAP OF THE MORRISON QUADRANGLE, JEFFERSON COUNTY, COLORADO: USGS MAP I-790-A, 1:24,000.
Reference (Production): RICHTER, 1964, P. 102; NELSON-MOORE AND OTHERS, 1978, P. 193
Reference (Deposit): RICHTER, D.H., 1964, MANN NO. 1 MINE, IN SIMS, P.K., AND SHERIDAN, D.M., GEOLOGY OF URANIUM DEPOSITS IN FRONT RANGE, COLORADO: USGS BULL. 1159, P. 104, PL. 5.
Reference (Deposit): GOLDSTEIN, E.H., 1957, GEOLOGY OF THE DAKOTA FORMATION URANINITE DEPOSIT NEAR MORRISON, COLORADO: ECON, GEOLOGY, V. 52, NO. 7, P. 775-785
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