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Oxford Mine

Past Producer in Sierra 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. Geologic structures
  12. Controls for ore emplacement
  13. Economic information about the deposit and operations
  14. Mining district
  15. Land status
  16. Ownership information
  17. Production statistics
  18. Reserves and resources
  19. Links to other databases
  20. Bibliographic references
  21. General comments
  22. Reporter information

Geologic information

Identification information

Deposit ID 10103909
MRDS ID M100422
Record type Site
Current site name Oxford Mine
Alternate or previous names Oxford Lease and Mill, Gold Bluff, Becky, Mt. Holly, Case and Myers, Good Hope, Good Hope Extension No. 2

Geographic coordinates

Geographic coordinates: -120.84186, 39.58155 (WGS84)
Elevation 1378
Relative position APPROX. 2.5 MILES NORTH OF DOWNIEVILLE, CA., BY ROAD.

Site location context

Political divisions (FIPS codes)

Sierra(county)

California(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Downieville(quadrangle 1:24,000 scale)

Portola(quadrangle 1:100,000 scale)

Chico(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Upper Yuba(hydrologic unit)

Lower Sacramento(hydrologic accounting unit)

Sacramento(hydrologic subregion)

California(hydrologic region)

Federal lands

Tahoe 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 California Sierra

Public Land Survey System information

Meridian Township Range Section Fraction State
Mount Diablo 020N 010E 22 S2 OF NW OF SE California

Comments on the location information

  • MINE LOCATED ON SE FACING SLOPE.

Commodities

Commodity Importance
Chromium Critical Primary

Comments on the commodity information

  • AN UNUSUAL OCCURRENCE OF HIGH GRADE ORE CONTAINING 58% CR2O3 FOUND BETWEEN THE EAST AND WEST ORE ZONES.

Materials information

Materials Type of material
Chromite Ore

Alteration

  • (Local) Partial Serpentinization Of Host Rocks.

Analytical data

Result LUMP ORE: 38.59% CR2O3, CR TO FE RATIO 2.30 TO 1.

Host and associated rocks

  • Host or associated Host
    Rock type Plutonic Rock > Ultramafic Intrusive Rock > Peridotite > Dunite
    Rock unit name Calaveras
    Rock description Calaveras
    Stratigraphic age (youngest) Late Permian
    Stratigraphic age (youngest) Late Cretaceous

Nearby scientific data

(1) -120.84186, 39.58155
ListMap

Economic information

Geologic structures

Type of structure Regional
Structure description Melones Fault Zone

Controls for ore emplacement

  • The Divergence Of Orientation Exhibited By The Ore Zones Within A Relatively Small Area Appears To Be The Result Of Their Distribution Within A Series Of Tight Asymmetric Folds.

Comments on the geologic information

  • THE DEPOSIT OCCURS IN NW TRENDING SILL LIKE PERIDOTITE BODY THAT IS A MINOR, SOUTHERN EXTENSION OF A LARGER MASS EXPOSED TO THE NORTH OF THE DEPOSIT.

Economic information about the deposit and operations

Development status Past Producer
Commodity type Metallic
Deposit size Small
Significant No
Discovery year 1915
Year of first production 1917
Year of last production 1944

Mining district

District name Downieville Area

Land status

Ownership category National Forest

Ownership information

  • Type Operator
    Owner C. L. Best
    First year 1944

Production statistics

  • Year 1943
    Material ORE
    Accuracy Accurate
    Description Ap_Grade: ^1940'S Avg. Ore Grade 40.05% Cr2o3
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Major Cr2O3 Ore Chromium Chromium 40wt-pct

Reserves and resources

  • Type In-situ
    Estimate year 1975
    Total resources 8000mt ore
    Commodity Subtype Grade units Group Importance Year
    Chromium Cr2O3 20 wt-pct Chromium Major 1975

Comments on the reserve resource information

  • STINSON, 1975

Comments on the workings information

  • WORKINGS CONSISTED OF SEVERAL OPEN PITS, SHALLOW CUTS, SHAFTS AND SHORT DRIFTS.

Comments on development

  • IN 1943, SEVERAL HUNDRED FEET OF DIAMOND DRILLING WAS COMPLETED.

Reference information

Bibliographic references

  • Deposit

    STINSON, 1975, CDMG MINERAL PROPERTY REPORT, UNPUBLISHED

  • Deposit

    AVERILL, C. V., 1942, CDMG, MINES AND MINERAL RESOURCES OF SIERRA CO., VOL. 38, NO. 1, PP. 16.

  • Deposit

    RYNEARSON, G. A., 1953, CDMG, BULL 134, PART 3, CHAPT. 5, PP. 254-257.

  • Production

    RYNEARSON, 1953, CDMG BULL 134, PART 3, CHAPT. 5, P. 257

General comments

Subject category Comment text
Deposit CHROMITE DEPOSITS OCCUR IN THREE ZONES: EAST ORE ZONE STRIKES N 45-55 E AND DIPS 60-80N; WEST ORE ZONE STRIKES N20-30W AND DIPS 45 SW; THIRD ORE ZONE STRIKES E-W AND DIPS 60-70 N.
Deposit Discovery Year: 1910'S

Reporter information

Type Date Name Affiliation Comment
Reporter 01-SEP-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.

External references

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.