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Shafer Lease Occurrence

Past Producer in Tuolumne county in California, United States with commodity Chromium
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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. Alteration
  9. Host and associated rocks
  10. Nearby scientific data
  11. Ore body information
  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. Reporter information

Geologic information

Identification information

Deposit ID 10043708
MRDS ID M100613
Record type Site
Current site name Shafer Lease Occurrence
Alternate or previous names Pereira Mine 1918

Geographic coordinates

Geographic coordinates: -120.49544, 37.90186 (WGS84)
Relative position APPROX, 9 MILES SW OF SONORA, CA.

Site location context

Political divisions (FIPS codes)

Tuolumne(county)

California(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Sonora(quadrangle 1:24,000 scale)

Oakdale(quadrangle 1:100,000 scale)

San Jose(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Upper Stanislaus(hydrologic unit)

San Joaquin(hydrologic accounting unit)

San Joaquin(hydrologic subregion)

California(hydrologic region)

Geographic areas

Country State County
United States California Tuolumne

Public Land Survey System information

Meridian Township Range Section Fraction State
Mount Diablo 001N 013E 36 NW OF NE California

Comments on the location information

  • LEASE LOCATED ON FLAT VALLEY FLOOR A SHORT DISTANCE NORTH OF TABLE MTN.

Commodities

Commodity Importance
Chromium Critical Primary

Comments on the commodity information

  • ASSAY BY USBM, 1918

Materials information

Materials Type of material
Chromite Ore

Alteration

  • (Local) Serpentinized Host Rock

Analytical data

Result 23.6% CR2O3

Host and associated rocks

  • Host or associated Host
    Rock type Plutonic Rock > Ultramafic Intrusive Rock > Peridotite > Dunite
    Stratigraphic age (youngest) Late Jurassic

Nearby scientific data

(1) -120.49544, 37.90186
ListMap

Economic information

Ore body information

  • General form LENSE
    Strike NW
    Dip 90
    Length 12.19M
    Width 1.52M

Comments on the geologic information

  • THE DEPOSIT OCCURS IN THE NORTHERN PART OF THE WESTERN MOST OF TWO SERPENTINE BELTS THAT TREND NW ACROSS THE COUNTY. THE BELT IS EXPOSED OVER AN AREA 30 KM BY 6 KM.

Economic information about the deposit and operations

Development status Past Producer
Commodity type Metallic
Deposit size Small
Significant No
Year of last production 1918

Mining district

District name Peoria Flat Area

Land status

Ownership category Private

Ownership information

  • Type Owner
    Owner Rosasco

Production statistics

  • Year 1918
    Material ORE
    Accuracy Accurate
    Description Ap_Grade: ^30.5% Cr2o3
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Major Cr2O3 Chromium Chromium 31wt-pct

Comments on the workings information

  • WORKINGS CONSIST OF A FLOODED SHAFT AND AN OPEN CUT APPROX. 30 FT LONG, 6 FT DEEP AND 5-6 FT WIDE.

Comments on development

  • A FEW HUNDRED TONS OF MILLING ORE REMAIN ON THE LEASE.

Reference information

Bibliographic references

  • Deposit

    CATER, F. W. JR., 1948, CDMG BULL 134, PART 3, CHAP. 1, P. 26

  • Production

    CDMG BULL 134, PT. 3, CHAPT. 1, P. 26.

Reporter information

Type Date Name Affiliation Comment
Reporter 01-JUL-1982 Oster, Karel L. (Albers, John P.) U.S. Geological Survey

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.