Bunker Mine

Past Producer in Placer county in California, United States with commodities Chromium, Iron
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. Mining district
  12. Mineral rights holdings
  13. Land status
  14. Ownership information
  15. Workings at the site
  16. Links to other databases
  17. Bibliographic references
  18. General comments
  19. Reporter information

Geologic information

Identification information

Deposit ID 10164443
MRDS ID W024412
MAS/MILS ID 0060610527
Record type Site
Current site name Bunker Mine
Alternate or previous names Blue Bird Mine
Related records 10077039

Geographic coordinates

Point of reference Trench
Geographic coordinates: -120.75962, 39.03709 (WGS84)
Elevation 1045
Location accuracy 10(meters)

Site location context

Political divisions (FIPS codes)

Placer(county)

California(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Foresthill(quadrangle 1:24,000 scale)

Truckee(quadrangle 1:100,000 scale)

Chico(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

North Fork American(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 Placer

Public Land Survey System information

Meridian Township Range Section Fraction State
Mount Diablo 014 N 011 E 20 SWSESE California

Commodities

Commodity Importance
Chromium Critical Tertiary
Iron Tertiary

Materials information

Materials Type of material
Chromite Unknown
Olivine Unknown
Pyroxene Unknown
Serpentine Unknown
Uvarovite Unknown

Nearby scientific data

Trench (1) -120.75962, 39.03709

Economic information

Ore body information

  • Strike N00S
    Dip 00N
    Thickness 5M
    Length 240M
    Width 60M
    Area 8.7HA
    Depth to top 0M
    Field Value
    Type of Orebody #1 DISSEMINATED
    Shape of Orebody #1 LENTICULAR
    Shape of Orebody #2 TABULAR
    Shape of Orebody #3 OTHER
    Primary mode of Origin MAGMATIC DIFFER
    Primary Ore Control LITHOLOGY
    Secondary Ore Control FRACTURING
    Degree of Wallrock Alter. INTENSE
    Type of Wallrock Alter. #1 CARBONITIZATION
    Type of Wallrock Alter. #2 SILICIFICATION
    Strike And Dip N00S:00N
    Minimum Depth to Top 0
    Avg. Thick. Unconsol. Mat. 0
    Min. Thick. Unconsol. Mat. 0
    Total Surface Area (HA) 8.6999
    Date of Last Modification 820521

Economic information about the deposit and operations

Operation type Surface-Underground
Development status Past Producer
Commodity type Metallic
Significant No
Discovery year 1880
Year of first production 1917

Mining district

District name Forest Hill Divide Area

Mineral rights holdings

Type of mineral rights Private Lease

Land status

Ownership category National Forest

Ownership information

  • Type Owner
    Owner U.S. Forest Service - Tahoe National Forest
    Interest 100
    Home office California
    Year 1976
  • Type Operator
    Owner Embree, L. G.
    Home office California
    Year 1976
    First year 1942
    Last year 1943

Workings at the site

  • Type of workings Surface
    Area 8.7HA
    Field Value
    MAS Development Schedule # 1
    Mining Record # 1
    Mining Method OPEN PIT
    Swell Factor .6
    Avg. Overburden Thickness 0
    Primary Material Cover M-HARD ROCKS
    Percentage 100
    Hardness of Ore M-HARD ROCKS
  • Type of workings Underground
    Field Value
    MAS Development Schedule # 1
    Mining Record # 1
    Mining Method GOPHERING (COYOTING) 10-29
    Swell Factor .6
    Hardness of Rock HARDROCK FISSURED WITH EXCESSIVE WATER
    Rock Characteristics MULTIPLE SYSTEMS OF WEAKNESS PLANES
    Rock Support Chars. SUPPORTING MAY BACK SLAB
    Mine Support Chars. POST, HEADBOARD, CAPS, ROOF BOLTS
    1st Condition of Workings NO MINE ENTRY
    2nd Condition of Workings FLOODED
    3rd Condition of Workings CAVED AT PORTAL

Reference information

Bibliographic references

  • Deposit

    RYNEARSON,GA 1953. CAL DIV MINES BULL 134,PT 3,CH 5. PP 224-

  • Deposit

    BRADLEY,WW ET AL 1918,MN&CR IN CAL.CAL ST MINING BUR BULL 76

General comments

Subject category Comment text
Deposit AVERAGE GRADE SHIPPED 1942-43 WAS 40.64% CR2O3,12.23% FE WIT FE RATIO OF 2.27 MINE IDLE SINCE 1943. NO ESTIMATES OF RES N LITERATURE--NO ORE IN PLACE SEEN AT MINE INSUFFICIENT DATA FOR MATRIX CALCULATIONS. ANALYSIS BY CDMG IN 1976 GAVE FOLLOWING PERCENTAGES-EAST WOR ASSIVE ORE=S102 1.46,CR2O3 49.33,FEO 10.52,TOTAL FE 14.47,AL 09,MGO 16.58,CR/FE 3.00.EAST WORKINGS MODULAR ORE=S102 2.30, 4.08,FEO 13.04,TOTAL FE 15.44,AL203 12.28,MGO 15.75,CR/FE 3. IVE ORE,WEST WORKINGS=S102 4.02,CR2O3 42.02,FEO 13.34,TOTAL 0,AL203 14.09,MGO 12.85,CR/FE 1.92.

Reporter information

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

Beyond USGS

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

Authoritative California resources

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