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  3. Mineral Resource Data System (MRDS)

Union

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. Ore body information
  11. Economic information about the deposit and operations
  12. Workings at the site
  13. Links to other databases
  14. Bibliographic references
  15. General comments
  16. Reporter information

Geologic information

Identification information

Deposit ID 10101079
MRDS ID C007696
Record type Site
Current site name Union
Alternate or previous names Springfield
Related records 10162684

Geographic coordinates

Geographic coordinates: -120.82824, 38.64712 (WGS84)
Relative position 2 MI. SE OF EL DORADO

Site location context

Political divisions (FIPS codes)

El Dorado(county)

California(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Placerville(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)

Geographic areas

Country State County
United States California El Dorado

Public Land Survey System information

Meridian Township Range Section Fraction State
Mount Diablo 009N 010E 12 California

Comments on the location information

  • UTM ACC. CTR W 1/2

Commodities

Commodity Importance
Gold Primary

Materials information

Materials Type of material
Gold Ore
Quartz Gangue

Host and associated rocks

  • Host or associated Host
    Rock type Metamorphic Rock > Metasedimentary Rock > Slate
    Stratigraphic age (youngest) Late Jurassic

Nearby scientific data

(1) -120.82824, 38.64712
ListMap

Economic information

Ore body information

  • Strike NNW
    Dip 69.5 E
    Thickness 3.05M
    Depth to top 0M

Comments on the geologic information

  • 5 - 10 FT. THICK MAIN VEINS, POUNDSTONE, KLONDIKE AND MCCOSMIC VEIN, THE LATTER 200 FT. W OF OTHER MAIN VEINS. A SERIES OF LESSER VEINS TO W OF MAIN VEINS. VEINS DIP 60 - 79 E. SPRINGFIELD SHAFT IS 320 FT. E OF POUNDSTONE VEIN AT SURFACE, CUTTING IT AT 1200 FT. VERT. DEPTH.

Economic information about the deposit and operations

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

Comments on the production information

  • ESTIMATED VALUE OF TOTAL OUTPUT IS FROM $2700000 TO $5000000. IN EARLY 1850S RICH SURFACE OUTCROPS WERE WORKED, PRIOR TO 1868 THE UNION & CHURCH CLAIMS WERE WORKED TOGETHER, AFTERWARDS SEPERATLY. INTERMITTENT OPERATION IN 1930S. MCCOSMIC VEIN ORE YIELDED UP TO $25/TON: ORE FROM POUNDSTONE VEIN YIELDED $8/TON, AND HAD THE GREATEST PRODUCTION. AN ORE SHOOT SAID TO HAVE YIELDED $450,000 FROM 15000 TONS ORE PRIOR TO 1868 W SHALLOW WORKINGS PRODUCING $150000 MORE.

Workings at the site

  • Type of workings Surface/Underground
    Area 24.687HA
    Overall depth 609.6M

Comments on the workings information

  • 2000 FT. SPRINGFIELD SHAFT CUTS POUNDSTONE VEIN AT 1200 FT., MCCOSMIC ABOUT 1540 FT. 2ND SHAFT, CLEMENT, FT. DEEP IS 750 FT. N. 200 FT. BEYOND IS 500 FT. KLONDIKE SHAFT. SEVERAL XCUT ADITS DRIVEN TO W. ONE 700 FT. LONG NEAR SPRINGFIELD SHAFT, AND ONE NEAR KLONDIKE SHAFT, ABOUT 600 FT. OVER 21000 FT. OF DRIFTS.

Reference information

Comments on the other database information

  • RECORD NUMBER 354 IS A POTENTIAL DUPLICATE OF THIS RECORD

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. 427 , 428 , 536 .

  • Deposit

    LOGAN, C. A., 1938 , MIN. RESOURCES OF EL DORADO CO.: CALIF. JOUR. MINES AND GEOL., VOL. 34 , NO. 3 , PL. 2 .

  • Deposit

    LOGAN, C. A., 1935 , MOTHER LODE GOLD BELT OF CALIF.: CALIF. DIV. MINES BULL. 108 , PG. 42 , 43 .

  • Production

    CLARK AND CARLSON, 1956 , LOGAN, 1935 .

General comments

Subject category Comment text
Deposit VEINS, ORE SHOOT

Reporter information

Type Date Name Affiliation Comment
Reporter 01-MAY-1979 Hayden, F. (Albers, J.) 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.