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Black Hill

Past Producer in Mariposa 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. Ownership information
  14. Workings at the site
  15. Links to other databases
  16. Bibliographic references
  17. General comments
  18. Reporter information

Geologic information

Identification information

Deposit ID 10102847
MRDS ID M009294
Record type Site
Current site name Black Hill
Alternate or previous names Pumpkin
Related records 10284989

Geographic coordinates

Geographic coordinates: -120.20766, 37.71964 (WGS84)
Relative position 1 MI. NW OF COULTERVILLE

Site location context

Political divisions (FIPS codes)

Mariposa(county)

California(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Coulterville(quadrangle 1:24,000 scale)

Oakdale(quadrangle 1:100,000 scale)

San Jose(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Upper Merced(hydrologic unit)

San Joaquin(hydrologic accounting unit)

San Joaquin(hydrologic subregion)

California(hydrologic region)

Geographic areas

Country State County
United States California Mariposa

Public Land Survey System information

Meridian Township Range Section Fraction State
Mount Diablo 002S 016E 33 California

Comments on the location information

  • E 1/2 . UTM EST.

Commodities

Commodity Importance
Gold Primary

Comments on the commodity information

  • LOW GRADE ORE

Materials information

Materials Type of material
Gold Ore
Pyrite Ore

Host and associated rocks

  • Host or associated Host
    Rock type Metamorphic Rock > Serpentinite

Nearby scientific data

(1) -120.20766, 37.71964
ListMap

Economic information

Geologic structures

Type of structure Local
Structure description En Echelon Vein System

Ore body information

  • Strike N 35 W
    Dip 45 NE
    Thickness 6.1M

Comments on the geologic information

  • GEOL.DESC: SERPENTINE IS NEAR SLATE. LOW GRADE ORE ALSO FOUND AS PYRITIC IMPREGNATIONS IN SERPENTINE WALL ROCK ADJACENT TO THE VEIN.

Economic information about the deposit and operations

Development status Past Producer
Commodity type Metallic
Deposit size Small
Significant No
Discovery year 1867
Production years 1900 - 1902

Ownership information

  • Type Operator
    Owner Louise A. Boyd

Comments on the production information

  • LITTLE RECORD OF ACTIVITY BEFORE 1890'S WHEN CONSIDERABLE DEVELOPMENT WORK MUST HAVE BEEN DONE. MINE REOPENED IN 1900 AND SOME RICH ORE WAS DISCOVERED.VERY LITTLE HAS BEEN DONE ON THE PROPERTY SINCE 1902 AND WORKINGS WERE CAVED AND INACCESSIBLE IN SEPTEMBER, 1954.

Workings at the site

  • Type of workings Underground
    Area 16.188HA

Comments on the workings information

  • MAIN INCLINED SHAFT SURMOUNTED BY A WOODEN HEADFRAME AND ORE BIN, TWO TUNNELS, SEVERAL AUXILLIARY SHAFTS AND STOPES.

Reference information

Bibliographic references

  • Deposit

    BOWEN, O. E., JR., & GRAY, H., JR., 1957 , MINES AND MINERAL DEPOSITS OF MARIPOSA COUNTY, CALIF.: CALIF. JOUR. MINES & GEOL., VOL. 53 , NOS. 1 & 2 , P. 78 - 79 , 241 .

  • Deposit

    RANSOME, F. L., 1900 , MOTHER LODE DISTRICT FOLIO: USGS GEOL. ATLAS OF THE US, FOLIO 63 , CLAIM SHEET 2 , SEC 4 (LOC.).

  • Production

    BOWEN AND GRAY, 1957 .

General comments

Subject category Comment text
Deposit VEIN
Deposit PATENTED LAND. THIS MINE IS THE MOST NORTHERLY MINE IN THE MARY HARRISON GROUP WHICH IS ALIGNED ON A BRANCH OF THE MOTHER LODE VEIN SYSTEM COMMONLY CALLED THE EAST BRANCH.

Reporter information

Type Date Name Affiliation Comment
Reporter 01-JUN-1973 Gere, W. U.S. Geological Survey
Updater 01-DEC-1978 Hayden, F. (Albers, J.) 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.