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Pillikin Area 3

Past Producer in El Dorado county in California, United States with commodities Chromium, Nickel
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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. Ore body information
  13. Economic information about the deposit and operations
  14. Mining district
  15. Land status
  16. Reserves and resources
  17. Links to other databases
  18. Bibliographic references
  19. General comments
  20. Reporter information

Geologic information

Identification information

Deposit ID 10043680
MRDS ID M100579
Record type Site
Current site name Pillikin Area 3
Alternate or previous names West Basin

Geographic coordinates

Geographic coordinates: -121.09242, 38.78128 (WGS84)
Relative position APPROX. 5.5 AIRLINE MI SW OF PILOT HILL

Site location context

Political divisions (FIPS codes)

El Dorado(county)

California(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Pilot Hill(quadrangle 1:24,000 scale)

Sacramento(quadrangle 1:100,000 scale)

Sacramento(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

North Fork American(hydrologic unit)

Lower Sacramento(hydrologic accounting unit)

Sacramento(hydrologic subregion)

California(hydrologic region)

Geographic areas

Country State County
United States California El Dorado

Public Land Survey System information

Meridian Township Range Section Fraction State
Mount Diablo 011N 008E 21,28 California

Commodities

Commodity Importance
Chromium Critical Primary
Nickel Critical Tertiary

Materials information

Materials Type of material
Chromite Ore
Chlorite Gangue
Magnesite Gangue
Opal Gangue
Talc Gangue

Alteration

  • (Local) Serpentinization, Silicification, Alteration To Talc And Magnesite.

Analytical data

Result MAJORITY OF ORE BODIES CONTAIN 10-20% CR2O3

Host and associated rocks

  • Host or associated Associated
    Rock type Plutonic Rock > Mafic Intrusive Rock > Diorite
  • Host or associated Associated
    Rock type Plutonic Rock > Ultramafic Intrusive Rock > Pyroxenite
  • Host or associated Host
    Rock type Plutonic Rock > Ultramafic Intrusive Rock > Peridotite > Dunite
  • Host or associated Host
    Rock type Plutonic Rock > Ultramafic Intrusive Rock > Peridotite > Lherzolite

Nearby scientific data

(1) -121.09242, 38.78128
ListMap

Economic information

Geologic structures

Type of structure Local
Structure description Two Schistose Metadiorite Dike Systems Are Ijected Along Faults That Trend N45w And N65e Across The West Basin.

Ore body information

  • General form LAYERS, GRAINS, NODULES, AND LENTICULAR MASSES
    Strike N 35 W
    Dip E
    Thickness 30.48M
    Length 579.12M
    Width 60.96M

Comments on the geologic information

  • PILLIKIN DEPOSITS OCCUR IN A TABULAR, NNW TRENDING ULTRAMAFIC BODY, 3/4 MI WIDE AND 4 MI LONG, THAT DIPS STEEPLY TO THE EAST. THE GENERAL ORIENTATION OF THE ORE BODIES IS PARALLEL TO THE WESTERN CONTACT OF THE ULTRAMAFIC AND METAMORPHIC ROCKS.

Economic information about the deposit and operations

Development status Past Producer
Commodity type Metallic
Deposit size Small
Significant No

Mining district

District name Flagstaff Hill Area

Land status

Ownership category Private

Reserves and resources

  • Type In-situ
    Estimate year 1951
    Total resources 64000mt ore
    Commodity Subtype Grade units Group Importance Year
    Chromium Cr2O3 8 wt-pct Chromium Major 1951

Comments on the workings information

  • WORKINGS CONSIST OF A LARGE PIT OF DIMENSIONS 200 FT X 50 FT X 50 FT; 9 SMALLER PITS, NUMEROUS BULLDOZER CUTS AND TRENCHES.

Reference information

Bibliographic references

  • Deposit

    CDMG BULL 134, P. 139-141

  • Deposit

    USGS BULL. 922-0, P. 447-451.

  • Production

    CDMG BULL 134, P. 140.

  • Reserve-Resource

    COMG BULL 134, P. 140

General comments

Subject category Comment text
Deposit THERE ARE AT LEAST THREE MAJOR ORE ZONES CONSISTING OF 13 OREBODIES AND MANY SMALLER ONES.
Deposit SOME OF THE SILICIFIED AND DEEPLY WEATHERED DUNITE IN SHOVEL PIT NO. 7 IS SLIGHTLY NICKELIFEROUS. ; INFO.SRC : 1 PUB LIT

Reporter information

Type Date Name Affiliation Comment
Reporter 01-JUL-1980 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.