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  3. Mineral Resource Data System (MRDS)

Union Gulch

Past Producer in Marin county in California, United States with commodities Copper, Silver, 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. Ore body information
  11. Controls for ore emplacement
  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 10030803
MRDS ID M009226
Record type Site
Current site name Union Gulch
Alternate or previous names Bolinas, Chetco, Pearson and Bros.
Related records 10187864

Geographic coordinates

Geographic coordinates: -122.73245, 37.97156 (WGS84)
Relative position 0.7 MI. NE OF WOODVILLE. LOCATION OF WORKINGS ARE PROBABLY THOSE SHOWN IN "COPPER MINE GULCH", NE OF WOODVILLE, ON USGS QUAD. BOLINAS, CALIF. 1954.

Site location context

Political divisions (FIPS codes)

Marin(county)

California(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Bolinas(quadrangle 1:24,000 scale)

San Francisco(quadrangle 1:100,000 scale)

San Francisco(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Tomales-Drake Bays(hydrologic unit)

San Francisco Bay(hydrologic accounting unit)

San Francisco Bay(hydrologic subregion)

California(hydrologic region)

Federal lands

Point Reyes National Seashore(National Seashore)

National Seashore NPS(Type of land area)

NPS(Federal land areas administered by NPS)

Geographic areas

Country State County
United States California Marin

Public Land Survey System information

Meridian Township Range Section Fraction State
Mount Diablo 001N 008W 12 California

Commodities

Commodity Importance
Copper Primary
Silver Secondary
Gold Secondary

Materials information

Materials Type of material
Chalcopyrite Ore
Pyrite Ore
Quartz Gangue

Host and associated rocks

  • Host or associated Host
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Sandstone

Nearby scientific data

(1) -122.73245, 37.97156
ListMap

Economic information

Ore body information

  • Strike NW
    Dip VERTICAL
    Thickness 0.61M

Controls for ore emplacement

  • Fractures

Economic information about the deposit and operations

Development status Past Producer
Commodity type Metallic
Deposit size Small
Significant No
Discovery year 1863
Production years 1863 , 1918

Ownership information

  • Type Operator
    Owner J. G. Wilkins

Comments on the production information

  • SOME ORE SHIPPED IN EARLY DAYS BY UNION GULCH MINING CO.

Workings at the site

  • Type of workings Underground
    Overall depth 54.86M

Comments on the workings information

  • SHAFT, MORE THAN 2500 FT. OF DRIFTS ON 100 AND 180 FT. LEVEL

Reference information

Bibliographic references

  • Deposit

    AUBURY, L.E., 1908 ; COPPER RESOURCES OF CALIFORNIA BULL. 50 ; CALIF. MIN. BUR., P. 168 - 169

  • Deposit

    ERIC, J.H., 1948 : COPPER IN CALIFORNIA BULL. 144 ; DIV. OF MINES, P. 264

  • Deposit

    PLANCK, WM. E. VER., 1955 : MINES AND MINERAL RESOURCES OF MARIN COUNTY, CA.; CALIF. JOUR. MINES AND GEOLOGY, VOL. 51 , NO. 3 ; DIV. OF MINES, P. 279 .

  • Production

    ERIC, J.H., 1948 .

General comments

Subject category Comment text
Deposit NINE PARALLEL VEINS 6 INCHES TO 2 FT.
Deposit MOST OF THE WORKINGS ARE NOW CAVED (1954) AND LITTLE REMAINS OF BUILDINGS AND EQUIPMENT.

Reporter information

Type Date Name Affiliation Comment
Reporter 01-JUN-1973 Gere, W. U.S. Geological Survey
Updater 01-MAR-1979 Fraticelli, L. A. (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.