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Thomas Mine

Past Producer in Mendocino county in California, United States with commodities Manganese, Silica
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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. Nearby scientific data
  9. Ore body information
  10. Economic information about the deposit and operations
  11. Mineral rights holdings
  12. Land status
  13. Ownership information
  14. Links to other databases
  15. Bibliographic references
  16. Reporter information

Geologic information

Identification information

Deposit ID 10285652
MRDS ID M045326
MAS/MILS ID 0060450052
Record type Site
Current site name Thomas Mine
Alternate or previous names North Thomas Mine,Round Mountain, Round Mountain
Related records 10038056

Geographic coordinates

Point of reference Trench
Geographic coordinates: -123.17529, 39.31047 (WGS84)
Elevation 552
Location accuracy 100(meters)

Site location context

Political divisions (FIPS codes)

Mendocino(county)

California(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Redwood Valley(quadrangle 1:24,000 scale)

Ukiah(quadrangle 1:100,000 scale)

Ukiah(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Russian(hydrologic unit)

Northern California Coastal(hydrologic accounting unit)

Klamath-Northern California Coastal(hydrologic subregion)

California(hydrologic region)

Geographic areas

Country State County
United States California Mendocino

Public Land Survey System information

Meridian Township Range Section Fraction State
Mount Diablo 017 N 012 W 22 SWSE California

Commodities

Commodity Importance
Manganese Critical Tertiary
Silica Tertiary

Materials information

Materials Type of material
Chert Unknown
Psilomelane Unknown
Pyrolusite Unknown

Nearby scientific data

Trench (1) -123.17529, 39.31047
ListMap

Economic information

Ore body information

  • Strike N15W
    Dip 60N
    Thickness 5M
    Length 190M
    Width 50M
    Depth to top 5M
    Field Value
    MAS Matrix # 1
    Type of Orebody #1 SHEAR ZONE
    Shape of Orebody #1 IRREGULAR
    Type of Orebody #2 FISSURE VEIN
    Type of Orebody #3 DISSEMINATED
    Primary mode of Origin RESIDUAL CONCENT
    Secondary mode of Origin SEDIMENTATION
    Primary Ore Control BEDDING
    Secondary Ore Control FAULTING
    Degree of Wallrock Alter. NONE
    Strike And Dip N15W:60N
    Minimum Depth to Top 0
    Avg. Thick. Unconsol. Mat. 3
    Min. Thick. Unconsol. Mat. 1
    Date of Last Modification 830316
  • Area 10HA
    Field Value
    Total Surface Area (HA) 10
    Date of Last Modification 910418

Economic information about the deposit and operations

Operation type Surface-Underground
Development status Past Producer
Commodity type Metallic
Deposit size Small
Significant No
Discovery year 1912
Year of first production 1914

Mineral rights holdings

Type of mineral rights Fee Ownership

Land status

Ownership category Private

Ownership information

  • Type Owner
    Owner Robert A,Lorena M. Ford
    Interest 100
    Home office California
    Year 1975

Reference information

Bibliographic references

  • Deposit

    CDMG BULLETINS:152,1950, #125,1943, #76,1918

  • Deposit

    USBM R.I.5579,1960

  • Deposit

    USGS FILE,1917-18

Reporter information

Type Date Name Affiliation Comment
Reporter 27-FEB-1984 Deino, Al U.S. Bureau of Mines

Beyond USGS

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

Maps centered on this site

Authoritative California resources

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