Graysill Mine

Past Producer in San Juan county in Colorado, United States with commodities Vanadium, Uranium
Sections on this page
  1. Identification information
  2. Geographic coordinates
  3. Site location context
  4. Geographic areas
  5. Public Land Survey System information
  6. Commodities
  7. Materials information
  8. Host and associated rocks
  9. Nearby scientific data
  10. Geologic structures
  11. Controls for ore emplacement
  12. Economic information about the deposit and operations
  13. Mining district
  14. Land status
  15. Ownership information
  16. Production statistics
  17. Links to other databases
  18. Bibliographic references
  19. General comments
  20. Reporter information

Geologic information

Identification information

Deposit ID 10014146
MRDS ID D010795
Record type Site
Current site name Graysill Mine
Alternate or previous names Graysill Group, Claims: Graysill 1-9
Related records 10118906

Geographic coordinates

Geographic coordinates: -107.89786, 37.71279 (WGS84)
Elevation 3316
Relative position 7.4 MILES N 81 E FROM RICO

Site location context

Political divisions (FIPS codes)

San Juan(county)

Colorado(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Hermosa Peak(quadrangle 1:24,000 scale)

Silverton(quadrangle 1:100,000 scale)

Durango(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Animas(hydrologic unit)

Upper San Juan(hydrologic accounting unit)

San Juan(hydrologic subregion)

Upper Colorado(hydrologic region)

Federal lands

San Juan National Forest(National Forest)

National Forest FS(Type of land area)

FS(Federal land areas administered by FS)

Geographic areas

Country State County
United States Colorado San Juan
United States Colorado Dolores

Public Land Survey System information

Meridian Township Range Section Fraction State
New Mexico 040N 009W 30 NE Colorado

Comments on the location information

  • (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

Commodities

Commodity Importance
Vanadium Critical Primary
Uranium Primary

Materials information

Materials Type of material
Carnotite Ore
Roscoelite Ore

Host and associated rocks

  • Host or associated Associated
    Rock type Volcanic Rock (Aphanitic) > Felsic Volcanic Rock > Rhyodacite
    Rock unit name Biotite Rhyodacite;Pyroxene Lamprophyre
    Rock description Biotite Rhyodacite;Pyroxene Lamprophyre
    Stratigraphic age (youngest) Late Jurassic
    Stratigraphic age (youngest) Late Jurassic
    Stratigraphic age (youngest) Pliocene
  • Host or associated Associated
    Rock type Plutonic Rock > Porphyry > Lamprophyre
  • Host or associated Host
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Sandstone
    Rock unit name Entrada Sandstone
    Rock description Entrada Sandstone

Nearby scientific data

(1) -107.89786, 37.71279

Economic information

Geologic structures

Type of structure Regional
Structure description San Juan Uplift
Type of structure Local
Structure description Rico Dome, Unnamed Faults

Controls for ore emplacement

  • Carbon Trash In Sandstone

Economic information about the deposit and operations

Development status Past Producer
Commodity type Metallic
Deposit size Small
Significant No
Discovery year 1945
Discoverer Vanadium Corporation Of America
Year of first production 1947

Mining district

District name Hermosa Peak Area

Land status

Ownership category National Forest
Area name San Juan N. F.

Ownership information

  • Type Owner-Operator
    Owner Vanadium Corp. Of America
    Home office Durango, Co.
    First year 1967

Production statistics

  • Year 1971
    Period 1950-1971
    Description Cp_Grade: ^2.41% V2o5, 0.08% V3o8 (Graysill No.2)
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Major U3O8 Ore Uranium Uranium 0wt-pct
    Major V2O5 Ore Vanadium Vanadium 2wt-pct
  • Year 1971
    Period 1950-1971
    Description Cp_Grade: ^1.907% V2o5, 0.049% V3o8 (Graysill No. 1)
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Major U3O8 Ore Uranium Uranium 0wt-pct
    Major V2O5 Ore Vanadium Vanadium 2wt-pct

Comments on the production information

  • 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.

Comments on the workings information

  • SURFACE EXCAVATION; NINE TUNNELS FROM 75 TO 500 IN LENGTH, SOME INTERCONNECTED BY CROSSCUTS AND ROOMS AND PILLARS

Comments on 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.

Reference information

Bibliographic references

General comments

Subject category Comment text
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.

Reporter information

Type Date Name Affiliation Comment
Reporter 01-AUG-1983 Schwochow, Stephen D. Colorado Geological Survey

Beyond USGS

Supplemental information added by qvyshift.com. Not part of the original USGS MRDS record.

External references

Authoritative Colorado resources

These are landing pages for further research — the state agencies don't currently expose per-mine deep links.