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Plomosa Placers

Past Producer in La Paz county in Arizona, United States with commodities Gold, Platinum
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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. Mineral occurrence model information
  9. Host and associated rocks
  10. Nearby scientific data
  11. Ore body information
  12. Controls for ore emplacement
  13. Economic information about the deposit and operations
  14. Mining district
  15. Land status
  16. Ownership information
  17. Workings at the site
  18. Links to other databases
  19. Bibliographic references
  20. General comments
  21. Reporter information

Geologic information

Identification information

Deposit ID 10038172
MRDS ID M045468
Record type Site
Current site name Plomosa Placers
Related records 10234991

Geographic coordinates

Geographic coordinates: -114.11911, 33.62923 (WGS84)
Elevation 457
Relative position ABOUAT 6 MI SOUTHEAST OF QUARTZSITE

Site location context

Political divisions (FIPS codes)

La Paz(county)

Arizona(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Plomosa Pass(quadrangle 1:24,000 scale)

Blythe(quadrangle 1:100,000 scale)

Salton Sea(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Tyson Wash(hydrologic unit)

Lower Colorado(hydrologic accounting unit)

Lower Colorado(hydrologic subregion)

Lower Colorado(hydrologic region)

Federal lands

Bureau of Land Management(Bureau of Land Management AZ)

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

BLM(Federal land areas administered by BLM)

Geographic areas

Country State County
United States Arizona La Paz

Public Land Survey System information

Meridian Township Range Section Fraction State
Gila and Salt River 003N}004N 018W}018W 03,04}33 NW4 (03) Arizona

Comments on the location information

  • LOCATION GIVEN IS ON PLACER TAILINGS IN S/2 SEC. 4. GOLD-BEARING GRAVELS ARE FOUND FOR ABOUT 3-4 MI ALONG THE WEST EDGE OF THE PLOMOSA MOUNTAINS IN AND NEAR PLOMOSA WASH.

Commodities

Commodity Importance
Gold Primary
Platinum Critical Tertiary

Comments on the commodity information

  • UNVERIFIED REPORT OF PGE

Materials information

Materials Type of material
Gold Ore

Mineral occurrence model information

Model code 119
USGS model code 39a
Deposit model name Placer Au-PGE
Mark3 model number 54

Host and associated rocks

  • Host or associated Associated
    Rock type Metamorphic Rock > Schist
    Stratigraphic age (youngest) Pliocene
  • Host or associated Host
    Rock type Unconsolidated Deposit > Gravel

Nearby scientific data

(1) -114.11911, 33.62923
ListMap

Economic information

Ore body information

  • General form PROBABLY POCKETS AND BARS
    Thickness 42.67M
    Length 6437.2M

Controls for ore emplacement

  • Stream Hydraulics

Comments on the geologic information

  • THE SCHIST, WHICH CONTAINS GOLD-BEARING QUARTZ VEINS AND STRINGERS, IS MOST LIKELY SOURCE OF AU

Economic information about the deposit and operations

Development status Past Producer
Commodity type Metallic
Deposit size Large
Significant No
Discovery year 1860
Year of first production 1865
Production years 1860'S-1950'S

Mining district

District name Southern Plomosa District

Land status

Ownership category BLM Administrative Area

Ownership information

  • Type Operator
    Owner Frank Magini
    Home office Phoenix, Az.
    First year 1986

Comments on the production information

  • ESTIMATES OF AVERAGE VALUE OF GOLD RANGE FROM $0.71-1.77/CY. PRODUCTION RECORDS NOT AVAILABLE FROM 1860 TO 1900

Workings at the site

  • Type of workings Surface/Underground
    Overall depth 15.24M

Comments on the workings information

  • IN SOME LOCALITIES PITS HAVE BEEN SUNK TO DEPTHS OF 20 TO >50 FT TO BEDS OF CEMENT WHICH ARE RICHER THAN THE GRAVEL.

Comments on development

  • PREVIOUS OPERATORS INCLUDE YUMA CONSOLIDATED CO., PLOMOSA PLACER CO. LARGE-SCALE DRYWASHING UNSUCCESSFUL IN 1910'S.

Reference information

Bibliographic references

  • Deposit

    BUTLER, G.M., 1937, ARIZONA GOLD PLACERS AND PLACERING (4TH ED.): ARIZONA BUREAU OF MINES BULLETIN 142, P. 29-30.

  • Deposit

    ELSING, M.J., AND HEINEMAN, R.E.S., 1936, ARIZONA METAL PRODUCTION: ARIZONA BUREAU OF MINES BULLETIN 140, P. 104.

  • Deposit

    JOHNSON, M.G., 1972, PLACER GOLD DEPOSITS OF ARIZONA: U.S. GEOLOGICAL SURVEY BULLETIN 1355, P. 80-81.

  • Deposit

    WILSON, E.D., 1961, GOLD PLACERS AND PLACERING IN ARIZONA: ARIZONA BUREAU OF MINES BULLETIN 168, P. 29.

  • Deposit

    QUIRING, HEINRICH, 1962, PLATINMETALLE IN DIE METALLISCHEN ROHSTOFFE 16 BAND: STUTTGART, FERDINAND ENKE VERLAG, P. 245.

  • Deposit

    ORRIS, G.J., AND BLISS, J.D., 1985, GEOLOGIC AND GRADE-VOLUME DATA ON 330 GOLD PLACER DEPOSITS: U.S. GEOLOGICAL SURVEY OPEN-FILE REPORT 85-213, 172 P.

  • Deposit

    NIEMUTH, N.J., 1987, ARIZONA MINERAL DEVELOPMENT 1984-1986: ARIZONA DEPARTMENT OF MINES AND MINERAL RESOURCES DIRECTORY 29, 46 P.

  • Other Database

    CIMRI

  • Production

    WILSON, 1961

  • Reserve-Resource

    ORRIS AND BLISS, 1985

General comments

Subject category Comment text
Deposit GOLD WAS FOUND IN SEVERAL HORIZONS IN THE GRAVEL; CEMENTED GRAVELS WERE ESPECIALLY RICH.

Reporter information

Type Date Name Affiliation Comment
Reporter 01-APR-1972 Gere, W. U.S. Geological Survey ADDED SOME GOLD INFORMATION
Updater 01-FEB-1975 Blair, Will N. U.S. Geological Survey
Updater 01-OCT-1979 Hall, R.K. (Creasey, S.C.) U.S. Geological Survey
Updater 01-DEC-1989 Peterson, Jocelyn A. U.S. Geological Survey
Updater 01-MAR-1993 Orris, Greta 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 Arizona resources

These are landing pages for further research — the state agencies don't currently expose per-mine deep links.