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Cosumnes

Past Producer in El Dorado county in California, United States with commodities Gold, Copper, Silver, Lead, Molybdenum
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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. Economic information about the deposit and operations
  12. Ownership information
  13. Links to other databases
  14. Bibliographic references
  15. General comments
  16. Reporter information

Geologic information

Identification information

Deposit ID 10030332
MRDS ID M008385
Record type Site
Current site name Cosumnes
Alternate or previous names Middle End
Related records 10236662

Geographic coordinates

Geographic coordinates: -120.60073, 38.60962 (WGS84)
Relative position SE1/4 SW1/4 24, NW1/4 25. 4 MI. NW OF FAIRPLAY. SOME OF WORKINGS ARE SHOWN IN E1/2 NW1/4 OF SEC. 25 ON USGS QUAD. OMO RANCH, CALIF., 1952.

Site location context

Political divisions (FIPS codes)

El Dorado(county)

California(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Omo Ranch(quadrangle 1:24,000 scale)

Placerville(quadrangle 1:100,000 scale)

Sacramento(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Upper Cosumnes(hydrologic unit)

San Joaquin(hydrologic accounting unit)

San Joaquin(hydrologic subregion)

California(hydrologic region)

Federal lands

Bureau of Land Management(Bureau of Land Management CA)

Bureau of Land Management CA BLM(Type of land area)

BLM(Federal land areas administered by BLM)

Geographic areas

Country State County
United States California El Dorado

Public Land Survey System information

Meridian Township Range Section Fraction State
Mount Diablo 009N 012E 24,25 California

Commodities

Commodity Importance
Gold Primary
Copper Secondary
Silver Secondary
Lead Secondary
Molybdenum Secondary

Materials information

Materials Type of material
Bornite Ore
Chalcopyrite Ore
Magnetite Ore
Powellite Ore
Silver Ore
Calcite Gangue
Epidote Gangue
Garnet Gangue
Quartz Gangue

Host and associated rocks

  • Host or associated Associated
    Rock type Plutonic Rock > Mafic Intrusive Rock > Diorite
  • Host or associated Host
    Rock type Sedimentary Rock > Carbonate > Limestone

Nearby scientific data

(1) -120.60073, 38.60962
ListMap

Economic information

Ore body information

  • Width 9.14M

Comments on the geologic information

  • GEOL.DESC: OTHER ROCKS IN AREA ARE AMPHIBOLITE AND MICA SCHIST

Economic information about the deposit and operations

Development status Past Producer
Commodity type Metallic
Deposit size Small
Significant No
Discovery year 1859

Ownership information

  • Type Operator
    Owner Lee Miller
    First year 1955

Comments on the production information

  • WORKED ORIGINALLY IN 1850; ACTIVE AROUND 1896 AND DURING WWI. DURING WWII A SMALL AMOUNT OF ORE PRODUCED FROM THE OPEN CUTS; REOPENED EARLY IN 1955 AND SEVERAL TONS OF ORE PRODUCED HAVE BEEN STOCKPILED. THREE MEN WORKING IN 1955.

Comments on the workings information

  • 150 FT. CROSSCUT ADIT, DRIVEN WESTWARD WITH DRIFTS RUNNING NE AND SW. 30 FT. RAISE JUST SOUTH OF ADIT - DRIFT INTERSECTION. LOWER CROSSCUT ADIT ABOUT 40 FT. BELOW MAIN ADIT, TWO LEVELS CONNECTED BY WINZE. NUMEROUS OPEN CUTS ABOVE ADIT PORTALS.

Reference information

Bibliographic references

  • Deposit

    CLARK, W. B. AND CARLSON, D. W., 1956 : MINES AND MINERAL RESOURCES, EL DORADO COUNTY, CA.: CALIF. JOUR MINES AND GEOLOGY, VOL. 52 , NO. 4 : DIV. OF MINES, P. 394 - 395 .

  • Deposit

    GOODWIN, J. G., 1957 , LEAD AND ZINC IN CALIFORNIA: CALIF. JOUR. MINES AND GEOLOGY, VOL. 53 , NOS. 3 & 4 : DIV. OF MINES, P. 441 .

  • Deposit

    USGS BULL. 1182E P. 35-36.

General comments

Subject category Comment text
Deposit COPPER MINERALS OCCUR IN A CONTACT METAMORPHIC ZONE: TACTITE ZONE - SOME IS RADIOACTIVE.

Reporter information

Type Date Name Affiliation Comment
Reporter 01-JUN-1972 Gere, W. U.S. Geological Survey
Updater 01-DEC-1978 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.