Negrillos Mine

Past Producer in Oruro, Bolivia with commodities Silver, Lead, Zinc, Copper, Manganese
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. Controls for ore emplacement
  14. Economic information about the deposit and operations
  15. Mining district
  16. Land status
  17. Ownership information
  18. Production statistics
  19. Workings at the site
  20. Links to other databases
  21. Bibliographic references
  22. General comments
  23. Reporter information

Geologic information

Identification information

Deposit ID 10005848
MRDS ID BL10009
Record type Site
Current site name Negrillos Mine
Alternate or previous names La Plata

Geographic coordinates

Geographic coordinates: -68.62785, -18.83819 (WGS84)
Elevation 3900
Relative position 14 KM N OF CARANGAS, 207 KM BY ROAD FROM ORURO

Site location context

Political divisions (FIPS codes)

Oruro(province)

Bolivia(country)

South America(continent)

Land(continent)

Federal lands

Federal(land status)

Geographic areas

Country State
Bolivia Oruro

Commodities

Commodity Importance
Silver Primary
Lead Tertiary
Zinc Critical Tertiary
Copper Tertiary
Manganese Critical Tertiary

Materials information

Materials Type of material
Chalcopyrite Ore
Galena Ore
Polybasite Ore
Pyrargyrite Ore
Sphalerite Ore
Tetrahedrite Ore
Chalcedony Gangue
Pyrite Gangue
Quartz Gangue
Rhodonite Gangue

Alteration

  • (Local) Argillic, Propylitic. Ore Is Oxidized From 8 To 15 M Depth.

Analytical data

Result ORE ANALYSES BY GUERRA ET. AL. (1965): OXIDE ORE: 5 SAMPLES, CHANNELS UP TO 22 CM, 3.87% PB 1.04% ZN 800 G/T AG, VEIN SULPHIDE ORE: 2 SAMPLES, CHANNELS UP TO 19 CM, 3.35% PB, 7.4% ZN, 1040 G/T AG
Result DISSEMINATED SULFIDE ORE: 4 SAMPLES, CHANNELS UP TO 26 CM, 2.0% PB 26.0% AN 270 G/T AG
Result TAQUEOS: 1 GRAB SAMPLE, 1.2% PB 400 G/T AG. USGS (1990): UP TO 1000 G/MT AG, 20% PB, 10% ZN, 0.7% CU

Mineral occurrence model information

Model code 77
USGS model code 20b
Deposit model name Sn-polymetallic vein

Host and associated rocks

  • Host or associated Associated
    Rock type Volcanic Rock (Aphanitic) > Pyroclastic Rock > Tuff
    Stratigraphic age (youngest) Holocene
  • Host or associated Associated
    Rock type Volcanic Rock (Aphanitic) > Intermediate Volcanic Rock > Andesite
  • Host or associated Host
    Rock type Volcanic Rock (Aphanitic) > Pyroclastic Rock > Tuff
  • Host or associated Host
    Rock type Volcanic Rock (Aphanitic) > Intermediate Volcanic Rock > Andesite

Nearby scientific data

(1) -68.62785, -18.83819

Economic information

Geologic structures

Type of structure Regional
Structure description N-S Syncline With Axis 1 Km W Of Town Of Negrillos
Type of structure Local
Structure description N80e 65n Fault Zones

Ore body information

  • General form IRREGULAR
    Depth to top 0M

Controls for ore emplacement

  • Fractures

Comments on the geologic information

  • AT SURFACE OUTCROPS OF VEINS MN OXIDES ARE FOUND AS MASSES AND NODULES. DISSEMINATED ORE IS FOUND BELOW 30M.

Economic information about the deposit and operations

Development status Past Producer
Commodity type Metallic
Deposit size Small
Significant No
Discovery year 1600
Discoverer Spanish Colonists
Year of first production 1600

Mining district

District name Negrillos

Land status

Ownership category Federal

Ownership information

  • Type Owner-Operator
    Owner Empresa Minera La Plata

Production statistics

  • Year 1948
    Accuracy Accurate
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Trace Conc. Lead Lead 52wt-pct
  • Year 1949
    Accuracy Accurate
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Trace Conc. Lead Lead 60wt-pct
  • Year 1964
    Accuracy Accurate
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Major Conc. Silver Silver 1700g/mt
    Trace Conc. Lead Lead 60wt-pct

Comments on the production information

  • IN 1945-47 SOME 15,000 TO 20,000 MT OF ESCORIAS WERE PRODUCED

Workings at the site

  • Type of workings Underground
    Length 148M

Comments on the workings information

  • 3 ADITS; MANY OTHER PITS

Comments on development

  • MINED BY SPANISH 1600 TO 1650. WORKED BY PERUVIAN CONCERN IN 1850, ORE SHIPPED TO PERU VIA ARICA. EXPLORED BY COROCORO CO. 1920, PATI%O CO. 1933, WORKED BY JORGE IRMAS 1945 TO 1947 WHO SHIPPED ORE TO HOCHSCHILD, PURCHASED BY ANTONIO IRMAS AS LA PLATA MINE 1948, SOLD TO ADOLFO BALIVIAN SALES IN 1958.

Reference information

Bibliographic references

  • Deposit

    AVILA SALINAS BALDIVIESO, WALDO ARTURO, 1965, GEOLOGIA DEL DISTRITO MINERO DE CARANGAS Y SUS ALREDADORES: UNPUBLISHED TESIS DEL GRADO, UNIVERSIDAD MAYOR DE SAN ANDRES, FACULTAD DE CIENCIAS GEOLOGICAS, 150P., MAP 1:50,000.

  • Deposit

    GUERRA, M., URIBE, H., AND OTAZO, N., 1965, INFORME SOBRE ORIENTACION TECNICA MINA DE PLATA EMPRESA MINERA LA PLATA: SERVICIO GEOLOGICO DE BOLIVIA INFORME GB-M-463, 13P., MAPS 1:2,000, 1:500.

  • Deposit

    GEOLOGICAL INVESTIGATIONS BY GUERRA ET AL (1965)

  • Deposit

    THESIS BY AVILA-SALINAS (1965)

  • Deposit

    VISITED BY USGS/GEOBOL GEOLOGISTS SEPT 1990

  • Other Database

    CIMRI

  • Production

    GUERRA ET AL (1965)

General comments

Subject category Comment text
Deposit DEPOSIT CONSISTS OF THREE VEINS. VETA A AND C ARE ORIENTED N70W 85 NE, ARE 300 M LONG AND 1 TO 40 CM WIDE. VEIN B IS OREINTED N50E 85NW TO VERTICAL, IS 1000 M LONG AND UP TO 1 M WIDE.

Reporter information

Type Date Name Affiliation Comment
Reporter 01-MAY-1990 Long, Keith R. U.S. Geological Survey
Updater 01-DEC-1990 Ratte, Jim And Gamble, Bruce U.S. Geological Survey

Beyond USGS

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