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La Piedra Azul

Past Producer in Sonora, Mexico with commodity Antimony
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Sections on this page
  1. Identification information
  2. Geographic coordinates
  3. Site location context
  4. Geographic areas
  5. Commodities
  6. Materials information
  7. Alteration
  8. Mineral occurrence model information
  9. Host and associated rocks
  10. Nearby scientific data
  11. Geologic structures
  12. Ore body information
  13. Economic information about the deposit and operations
  14. Mining district
  15. Production statistics
  16. Reserves and resources
  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 10049197
MRDS ID MX00450
Record type Site
Current site name La Piedra Azul
Related records 10255544

Geographic coordinates

Geographic coordinates: -112.58378, 30.73626 (WGS84)

Site location context

Political divisions (FIPS codes)

Pima(county)

Arizona(state)

United States(country)

North America(continent)

Land(continent)

Geographic areas

Country State
Mexico Sonora

Comments on the location information

  • ESTIMATE TO WITHIN 0.5 KM.

Commodities

Commodity Importance
Antimony Critical Primary

Materials information

Materials Type of material
Chalcedony Gangue
Quartz Gangue

Alteration

  • (Local) Siltstone And Sandstone Leached To White Kaolinite And Sand In Zone Extending 60-70 Cm From Vein Walls.

Analytical data

Result LARGE ORE BODY N OF MAIN SHAFT CONTAINED AN AVERAGE OF 20% SB
Result MOST OF THE ORE BODIES CONTAINED 5-15% SB.

Mineral occurrence model information

Model code 180
USGS model code 27d
Deposit model name Simple Sb (veins, pods, etc)

Host and associated rocks

  • Host or associated Host
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Siltstone
    Stratigraphic age (youngest) Late Triassic
  • Host or associated Host
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Sandstone

Nearby scientific data

(1) -112.58378, 30.73626
ListMap

Economic information

Geologic structures

Type of structure Local
Structure description Veins Are Cross-Cut Or Terminated By Premineral Faults, Locally Containing Vein Material, That Strike N 25-35 E And Dip 5-55 E. Veins Also Cut By Postmineral Faults That Strike N 30 E But Generally Steeper In Dip Than Parallel Premineral Faults. Postmineral Movement Has Occurred Locally Along Premineral Faults.

Ore body information

  • Strike N 45-90 E
    Dip 20-50 S

Comments on the geologic information

  • LATE FAULTING OCCURRED AFTER DEPOSITION OF ANTIMONY DEPOSITS, AS INDICATED BY SLICKENSIDED ORE. IN ONE PLACE, EUHEDRAL CALCITE CRYSTALS DEPOSITED ALONG A POSTMINERAL FAULT WERE DISTURBED AND POLISHED BY RECURRENCE OF FAULTING. WEST SIDES OF LATE FAULTS MOVED RELATIVELY SOUTHWARD. STRIATIONS ON LATE FAULT SURFACES ARE SUBHORIZONTAL OR PLUNGE GENTLY NORTH.

Economic information about the deposit and operations

Development status Past Producer
Commodity type Metallic
Deposit size Small
Significant No
Discovery year 1936
Year of first production 1942

Mining district

District name El Antimonio/La Montana

Production statistics

  • Year 1943
    Period -1943
    Material ORE SB
    Accuracy Estimate
    Description Cp_Grade: ^40% Sb
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Major Ore Antimony Antimony 40wt-pct
  • Year 1943
    Period -1943
    Material ORE SB
    Accuracy Estimate
    Description Cp_Grade: ^40% Sb
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Major Ore Antimony Antimony 40wt-pct

Comments on the production information

  • ITEM 1: LARGE ORE BODY NORTH OF MAIN SHAFT. ITEM 2: MINE AS A WHOLE.

Reserves and resources

  • Type In-situ
    Estimate year 1943
    Total resources 400000000mt ore
    Commodity Subtype Grade units Group Importance Year
    Antimony Sb 40 wt-pct Antimony Major 1943

Comments on the reserve resource information

  • LARGE ORE BODY NORTH OF MAIN SHAFT. SEE GENERAL COMMENTS.

Workings at the site

  • Type of workings Underground
    Length 290M
    Overall depth 25.3M

Comments on the workings information

  • TWO LEVELS: 18 AND 25 M BELOW SURFACE. TOTAL LENGTH OF DRIFTS + CROSSCUTS: 290 M. MAIN SHAFT: VERTICAL, 25.3 M DEEP. WATER TABLE ESTIMATED TO BE 30 M BELOW LOWEST WORKINGS.

Comments on development

  • VEIN DISCOVERED, 1936. FIRST ORE BODY NOT FOUND UNTIL 1941 OR 1942. IN 1943, BECAME LARGEST PRODUCER IN THE DISTRICT, PRODUCING 2-3 TONS OF HIGH-GRADE ORE AND ABOUT 8 TONS OF LOW-GRADE MILLING ORE PER DAY.

Reference information

Bibliographic references

  • Deposit

    WHITE, D.E. AND GUIZA, REINALDO, 1949, ANTIMONY DEPOSITS OF EL ANTIMONIO DISTRICT, SONORA, MEXICO: U.S. GEOLOGICAL SURVEY BULLETIN 962-B, P.104-105, PLATES 15, 20

  • Production

    WHITE AND GUIZA, 1949.

General comments

Subject category Comment text
Deposit VEINS STRIKE N 45-90 E AND DIP 20-50 S; GENERALLY CUT ACROSS BEDDING OF WALL ROCKS, LOCALLY AT LARGE ANGLES. VEINS CONSIST MAINLY OF CHALCEDONY WITH HIGHER ANTIMONY OXIDE CONTENT AND LOWER PROPORTION OF COARSE-GRAINED QUARTZ THAN ANY OTHER MINE IN THE DISTRICT. HIGH-GRADE BODIES OF YELLOW TO CREAM-COLORED ANTIMONY OXIDEORE ARE GENERALLY SURROUNDED BY LOW-GRADE INTERMIXTURES OF CHALCEDONY AND OLIVE-GREEN ANTIMONY OXIDE. HIGH-GRADE BODIES OF ANTIMONY OXIDE ORE CONTAIN SMALL DISSEMINATED EUHEDRAL QUARTZ CRYSTALS AND IRREGULAR VEINLETS AND MASSES OF CHALCEDONY THAT APPARENTLY REPLACED THE ORE MINERALS.
Deposit IN LARGEST ORE BODY, NORTH OF THE MAIN SHAFT, ABOUT 400 TONS OF HIGH-GRADE ORE WERE MINED BEFORE JUNE, 1943. WHITE AND GUIZA, (1949), ESTIMATED THAT AN EQUAL OR GREATER AMOUNT OF ORE REMAINED AT THAT TIME. THEY ALSO ESTIMATED THAT THE MINE AS A WHOLE HAD PRODUCED AT LEAST 1,000 TONS OF HIGH-GRADE ORE. THEY DESCRIBED THE HIGH-GRADE ORE OF THE DISTRICT AS HAND-SORTED MATERIAL GRADING NOT LESS THAN 40% SB. MATERIAL OF LOWER GRADE, RANGING FROM ABOUT 5 TO 15% SB, THAT COULD NOT BE HAND-SORTED TO A 40% SB PRODUCT, WAS DESCRIBED AS "MILLING ORE". ; INFO.SRC : 1 PUB

Reporter information

Type Date Name Affiliation Comment
Reporter 01-DEC-1987 Leonard, Kenneth R. (Page, Norman J.) U.S. Geological Survey

Beyond USGS

Supplemental information added by qvyshift.com. Not part of the original USGS MRDS record.

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