The Graysill Mine is a vanadium and uranium mine located in San Juan county, Colorado at an elevation of 10,879 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: 10,879 Feet (3,316 Meters)
Commodity: Vanadium, Uranium
Lat, Long: 37.71278, -107.89722
Map: View on Google Maps
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Graysill Mine MRDS details
Site Name
Primary: Graysill Mine
Secondary: Graysill Group
Secondary: Claims: Graysill 1-9
Commodity
Primary: Vanadium
Primary: Uranium
Location
State: Colorado
County: San Juan
District: Hermosa Peak Area
Land Status
Land ownership: National Forest
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.
Administrative Organization: San Juan N. F.
Holdings
Not available
Workings
Not available
Ownership
Owner Name: Vanadium Corp. Of America
Home Office: Durango, Co.
Years: 1967 -
Production
Year: 1971
Time Period: 1950-1971
Description: Cp_Grade: ^2.41% V2o5, 0.08% V3o8 (Graysill No.2)
Year: 1971
Time Period: 1950-1971
Description: Cp_Grade: ^1.907% V2o5, 0.049% V3o8 (Graysill No. 1)
Deposit
Record Type: Site
Operation Category: Past Producer
Operation Type: Unknown
Year First Production: 1947
Discovery Year: 1945
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: San Juan Uplift
Type: L
Description: Rico Dome, Unnamed Faults
Alterations
Not available
Rocks
Name: Rhyodacite
Role: Associated
Age Type: Host Rock Unit
Age Young: Late Jurassic
Name: Rhyodacite
Role: Associated
Age Type: Host Rock
Age Young: Late Jurassic
Name: Rhyodacite
Role: Associated
Age Type: Associated Rock
Age Young: Pliocene
Analytical Data
Not available
Materials
Ore: Roscoelite
Ore: Carnotite
Comments
Comment (Production): PARTIAL PRODUCTION RECORD. PRODUCTION PRIOR TO 1950 UNKNOWN; NO PRODUCTION IN 1954; NO CDM PRODUCTION FIGURES AFTER 1964; EXPLORATION AND DEVELOPMENT CITED BY CDM RECORDS FOR 1960-1963, 1965-1967.
Comment (Development): DEPOSIT DISCOVERED IN 1945 BY EXPLORATORY DRILLING. FOUR TUNNELS DEVELOPED BY 1947, AND FIVE ADDITIONAL TUNNELS BY 1949. DEPOSIT MINED BY ROOM-AND-PILLAR METHODS, WITH SOME TUNNELS EVENTUALLY CONNECTING THROUGH CROSSCUTS AND LARGER ROOMS. ORE FIRST SHIPPED TO VANADIUM COMPANY OF AMERICA'S REDUCTION PLANT IN NATURITA, BUT BY 1950S ORE WAS SHIPPED TO TO VCA'S DURANGO MILL, A SALT ROAST-CARBONATE LEACH-ACID LEACH EXTRACTION PLANT. EXPLORATION AND DEVELOPMENT, ASSESSMENT, AND REHAB DONE IN 1960-63 AND 1965-67.
Comment (Deposit): ROSCOELITE ORE AND POSSIBLY CARNOTITE ASSOCIATED WITH CARBON TRASH IN ESSENTIALLY FLAT-LYING ENTRADA SANDSTONE IN LAYER 2 TO 6 FT THICK. MINERALIZATION MAY HAVE BEEN INFLUENCED BY PROXIMITY OF SILLS AROUND HERMOSA MTN, SLIDEROCK RIDGE, AND WEST SIDE OF GRAYSILL MTN. FAULTS IN MINE AREA TREND N 20 AND 70 E.
Comment (Workings): SURFACE EXCAVATION; NINE TUNNELS FROM 75 TO 500 IN LENGTH, SOME INTERCONNECTED BY CROSSCUTS AND ROOMS AND PILLARS
Comment (Location): (LAND STATUS AND ADMINISTRATIVE AREA LOCATIONS CALCULATED USING GIS OVERLAY ANALYSIS FOR SAN JUAN N. F.). NW OF GRAYSILL MTN NEAR HEAD OF HERMOSA CREEK 0.4 MILE SOUTH OF BOLAM PASS. CLAIMS PROBABLY EXTEND INTO ADJACENT UNSURVEYED SECTIONS AND INTO DOLORES CO. ; INFO FROM LAND.ST :1975
References
Reference (Deposit): NELSON-MOORE, J.L., AND OTHERS, 1978, RADIOACTIVE MINERAL OCCURRENCES OF COLORADO AND BIBLIOGRAPHY: CGS BULL. 40, P. 398.
Reference (Deposit): CROSS, WHITMAN, AND HOLE, A.D., 1910, DESCRIPTION OF THE ENGINEER MOUNTAIN QUADRANGLE: USGS FOLIO 171.
Reference (Deposit): FINCH, W.I., 1967, GEOLOGY OF EPIGENETIC URANIUM DEPOSITS IN SANDSTONE IN THE UNITED STATES: USGS PROF. PAPER 538, P. 141.
Reference (Deposit): COLORADO DIV. MINES INF. REPTS. AND ANNUAL OPERATOR REPTS.
Reference (Deposit): PRATT, W.P., 1976, PRELIMINARY GEOLOGIC MAP OF THE HERMOSA PEAK QUADRANGLE, DOLORES, SAN JUAN, LA PLATA, AND MONTEZUMA COUNTIES, COLORADO: USGS OF-76-314.
Reference (Production): COLO. DIV. MINES ANNUAL OPERATOR REPTS. (1950-1964 ANNUALS); NELSON-MOORE, 1978, P.398 (CUMULATIVES)
Colorado Mining Photos
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