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  3. Mineral Resource Data System (MRDS)

Black Oak

Past Producer in El Dorado county in California, United States with commodity Gold
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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. Host and associated rocks
  9. Nearby scientific data
  10. Geologic structures
  11. Ore body information
  12. Economic information about the deposit and operations
  13. Links to other databases
  14. Bibliographic references
  15. General comments
  16. Reporter information

Geologic information

Identification information

Deposit ID 10007027
MRDS ID C008022
Record type Site
Current site name Black Oak
Related records 10187630

Geographic coordinates

Geographic coordinates: -120.84824, 38.85768 (WGS84)
Elevation 616
Relative position 3/4 MI NE OF GARDEN VALLEY SCHOOL

Site location context

Political divisions (FIPS codes)

El Dorado(county)

California(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Garden Valley(quadrangle 1:24,000 scale)

Placerville(quadrangle 1:100,000 scale)

Sacramento(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

South 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 012N 010E 27,34 California

Comments on the location information

  • UTM ACC NE 1/4

Commodities

Commodity Importance
Gold Primary

Materials information

Materials Type of material
Gold Ore
Pyrite Ore
Calcite Gangue
Feldspar Gangue
Quartz Gangue

Host and associated rocks

  • Host or associated Associated
    Rock type Metamorphic Rock > Metasedimentary Rock > Slate
    Rock unit name Mariposa Formation
    Rock description Mariposa Formation
    Stratigraphic age (youngest) Late Jurassic
    Stratigraphic age (youngest) Late Jurassic
  • Host or associated Host
    Rock type Metamorphic Rock > Metasedimentary Rock > Slate

Nearby scientific data

(1) -120.84824, 38.85768
ListMap

Economic information

Geologic structures

Type of structure Local
Structure description Struct Of Gen Area Is Of Tightly Compressed, Steeply Plunging Folds With Thrust Faults Dipping 20 To 35 E Have Disrupted Contacts And In Some Cases Localized Gold Mineralization. Main Fault Offset Vein And Ore Shoot 200 Ft Btwn. 400 And 500 Ft Level. Small Amt. Of Gold Recovered Below Fault.

Ore body information

  • Strike NW
    Dip NE
    Plunge 80
    Plunge direction S
    Thickness 3.66M
    Length 33.53M
    Depth to top 0M
    Depth to bottom 115.82M

Comments on the geologic information

  • DEPOSIT IS JUST N OF WHERE MOTHER LODE SPLIT INTO TWO BRANCHES, ONE TO N, THE OTHER TWD. THE NW VEIN IN AMPHIBOLITE SCHIST THAT LIES BETWEEN TWO BELTS OF MARIPOSA SLATE IN AREA. A STRIP OF GRAPHITIC SLATE 50 FT WIDE FORMS THE HANGING WALL. MAIN ORE SHOOT OF GOLD BEARING STRINGERS AND VEINS OF CALCITE AND QUARTZ WIDE AT N AND PINCHED OUT AT S. SHOOT FOLLOWS OR IS NEAR CONTACT BTWN. GRAPHITIC SLATE AND AMPHIBOLITE. NO ORE BELOW 500 FT LEVEL.

Economic information about the deposit and operations

Development status Past Producer
Commodity type Metallic
Deposit size Small
Significant No
Production years 1934 - 1942

Comments on the production information

  • ACTIVE PRIOR TO 1934 , 1934 - 1942

Comments on the workings information

  • DEVELOPED BY EXTENSIVE CROSSCUTTING FROM 400 FT VERTICLE SHAFT. ANOTHER SHAFT TO NW, 6000 FT OF DRIFTS AND CROSSCUTS. BOTH SHAFTS CONNECTED BY CROSSCUTS.

Reference information

Bibliographic references

  • Deposit

    CLARK, W. B., AND CARLSON, D. W., 1956 , MINES AND MINERAL RESOURCES OF EL DORADO CO., CALIF.: CALIF. JOUR. OF MINES AND GEOL., VOL. 52 , NO. 4 , PG. 409 - 411 , 488 AND PL 10 .

  • Deposit

    LOGAN, C. A., 1935 , MOTHER LODE GOLD BELT OF CALIF.: CALIF. DIV. MINES BULL. 108 , PG. 20 - 21 .

  • Deposit

    LOGAN, C. A., 1938 , MIN. RESOURCES OF EL DORADO CO.: CALIF. JOUR. OF MINES AND GEOL., VOL. 34 , NO. 3 , PG. 223 - 224 , 259 .

  • Production

    CLARK ( 1956 )

General comments

Subject category Comment text
Deposit VEIN-BLACK OAK VEIN 250 FT E CLARK VEIN AND 100 FT TO E IS DAVENPORT VEIN ZONE
Deposit IN REFERENCES SEE ALSO CLARK, DAYTON CONS ; INFO.SRC : 1 PUB LIT

Reporter information

Type Date Name Affiliation Comment
Reporter 01-MAY-1979 Mateik, R.; Albers, John P. U.S. Geological Survey ADDED GRAPHITIC SLATE TO HOST ROCK TYPE.
Updater 17-OCT-1991 Mosier, Dan U.S. Geological Survey PARSED HOST ROCK AND ASSOCIATED ROCK INFORMATION FROM OLD SINGLE VALUED FIELD TO NEW MULTIVALUED FIELD
Editor 27-APR-1995 Mosier, Dan 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.