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Dufrene

Prospect in Amador county in California, United States with commodity Manganese
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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. Nearby scientific data
  9. Ore body information
  10. Economic information about the deposit and operations
  11. Ownership information
  12. Links to other databases
  13. Bibliographic references
  14. Reporter information

Geologic information

Identification information

Deposit ID 10097002
MRDS ID M004877
Record type Site
Current site name Dufrene
Related records 10187583

Geographic coordinates

Geographic coordinates: -120.86769, 38.34184 (WGS84)
Relative position 4.7 MI. BY ROAD ON STATE HIGHWAY 88 W OF MARTELL.

Site location context

Political divisions (FIPS codes)

Amador(county)

California(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Jackson(quadrangle 1:24,000 scale)

San Andreas(quadrangle 1:100,000 scale)

Sacramento(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Upper Mokelumne(hydrologic unit)

San Joaquin(hydrologic accounting unit)

San Joaquin(hydrologic subregion)

California(hydrologic region)

Geographic areas

Country State County
United States California Amador

Public Land Survey System information

Meridian Township Range Section Fraction State
Mount Diablo 006N 010E 27 California

Comments on the location information

  • LOCATED IN SW 1/4 SECTION 27

Commodities

Commodity Importance
Manganese Critical Tertiary

Materials information

Materials Type of material
Psilomelane Ore
Pyrolusite Ore
Rhodonite Ore
Magnetite Gangue

Nearby scientific data

(1) -120.86769, 38.34184
ListMap

Economic information

Ore body information

  • Strike N 5 - 15 W
    Dip 65 - 75 E
    Thickness 2.44M
    Length 82.3M

Comments on the geologic information

  • GEOL.DESC: ORE LIES IN BED OF MANGANIFEROUS META-CHERT 5 TO 8 FT. THICK; STRIKING N 5 - 15 W; DIPPING 65 - 75 E. THE METACHERT IS ENCLOSED IN METAVOLCANICS (IN PAST GREENSTONE) AND META-TUFFS. THE FORMATION IS THOUGHT TO BE THE AMADOR GROUP. THE META-CHERT IS MASSIVE AND THICK BEDDED; IN PART CHALCEDONIC TO OPALINE; IN PART CRYSTALLIZED TO FINE GRAINED QUARTZITE. MANGANESE OXIDES OCCUR AS BANDS, CRUSTS, AND POCKETS IN THE METACHERT. AMOUNT OF OXIDE PRESENT SMALL AND SMALL AMOUNT OF RHODONITE IS PRESENT. OXIDE WHERE IDENTIFIED IS HARD, BLUE BLACK PSILOMELANE. AT SOME PLACES META-CHERT IS CUT BY BANDS OR VEINLETS 1/2 TO 1 IN. WIDE OF MAGNETITE

Economic information about the deposit and operations

Development status Prospect
Commodity type Metallic
Significant No

Ownership information

  • Type Operator
    Owner Fred Dufrene

Comments on the production information

  • THE BEST EXPOSURE OF MANGANESE OXIDES IS IN THE SOUTHERN MOST CUT WHERE THE CENTER OF THE METACHERT IS MOSTLY OF OXIDES, CHIEFLY HARD BLUE-BLACK PSILOMELANE; THIS BED PROBABLY CONTAINS 45 PERCENT MANGANESE. SOME OF THE BLACK OXIDE ORE IS GOOD GRADE BUT THE AMOUNT AVAILABLE IS SMALL

Comments on the workings information

  • SMALL SHAFT AND A SERIES OF OPEN CUTS

Reference information

Bibliographic references

  • Deposit

    CALIF. JOUR. MINES & GEOL. V. 50, NO. 1, JAN. 1954, P.268, PL. 1

  • Deposit

    DOM BULL. 152, P.28

Reporter information

Type Date Name Affiliation Comment
Reporter 01-JUN-1972 Gere, W. U.S. Geological Survey
Updater 01-APR-1977 Von Dohlen, E.; 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.