Fazenda Brasileiro

Producer in Bahia, Brazil with commodity Gold

Geologic information

Identification information

Deposit ID 10106956
MRDS ID TC00087
Record type Site
Current site name Fazenda Brasileiro

Geographic coordinates

Geographic coordinates: -39.0778, -11.4603 (WGS84)
Elevation 330
Location accuracy 1000(meters)
Relative position 12 KM WEST OF TEOFILANDIA; 20 KM SW OF ARACI; ABOUT 185 KM NNW OF SALVADOR.
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Geographic areas

Country State
Brazil Bahia

Comments on the location information

  • 200 KM NW OF SALVADOR

Commodities

Commodity Importance
Gold Primary

Materials information

Materials Type of material
Chalcopyrite Ore
Galena Ore
Gold Ore
Pyrite Ore
Pyrrhotite Ore
Sphalerite Ore
Albite Gangue
Goethite Gangue
Gypsum Gangue
Hematite Gangue
Jarosite Gangue
Melanterite Gangue
Quartz Gangue

Alteration

  • (Local) Decrease In Chlorite Content And Increase In Albite, Carbonates, And Sulfides

Analytical data

Result ROCK CHEMISTRY, FLUID INCLUSION DATA GIVEN BY TEIXEIRA AND OTHERS (1990). THREE TYPES OF INCLUSION: MONOPHASE CARBONIC INCLUSIONS COMMON IN QUARTZ-ALBITE-SULFIDE VEINS, H2O-CO2 INCLUSIONS
Result LIQUID-VAPOR 2 PHASE INCLUSIONS WITH TEMPERATURES BETWEEN 130 TO 400
Result HIGHEST FREQUENCY 200-240 DEGREES C. SALINITIES LESS THAN 10 EQUIVALENT WT% NACL. CONCLUDES THAT LIQUIDS ARE LOW SALINITY CO2-CH4 FLUIDS FORMING AT 400 DEGREES AND 3 KBARS TO 300 DEGREES C AND LESS THAN 1.4 KBARS.

Mineral occurrence model information

Model code 273
USGS model code 36a
Deposit model name Low-sulfide Au-quartz vein
Mark3 model number 27

Host and associated rocks

  • Host or associated Associated
    Rock type Plutonic Rock > Mafic Intrusive Rock > Diorite
  • Host or associated Associated
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Siltstone
  • Host or associated Associated
    Rock type Plutonic Rock > Granitoid > Granite
    Rock unit name Fazenda Brasileiro Unit;Fazenda Brasileiro;Riacho Do Ingo Unit;Fazenda Cantount;Santa Luz
    Rock description Fazenda Brasileiro Unit;Fazenda Brasileiro;Riacho Do Ingo Unit;Fazenda Cantount;Santa Luz
    Chronological age 2000
    Uncertainty 200
    Stratigraphic age (youngest) Proterozoic
  • Host or associated Host
    Rock type Metamorphic Rock > Schist
    Rock unit name Canto Sequence;Canto Sequence;Fazenda Brasileiro Sequence;Fazenda Brasileiro Sequence;Riacho Do Inco Sequence
    Rock description Canto Sequence;Canto Sequence;Fazenda Brasileiro Sequence;Fazenda Brasileiro Sequence;Riacho Do Inco Sequence

Nearby scientific data

(1) -39.0778, -11.4603

Ore body information

  • Name of the ore body CORPO C
    Thickness 40M
    Width 30M
    Length 180M

Comments on the geologic information

  • PREDOMINANTLY GREENSCHIST FACIES METAMORPHISM. HIGH GRADE ORE OCCURS IN QUARTZOFELDSPATHIC BRECCIA WHICH IS HOSTED BY CHLORITE-MAGNETITE QUARTZ SCHIST. RIACHO DO INCO UNIT OVERLIES FAZENDA BRASILEIRO UNIT WHICH IS UNDERLAIN BY FAZENDA CANTO UNIT. THREE DEFORMATION EVENTS: D1, INTENSE DUCTILE SHEARING; D2, NORTHWARD VERGING ASSYMETRIC FOLDS AND DUCTILE-BRITTLE SHEAR ZONES; D3, LOCALIZED CREMULATIONS WITH AXES PLUNGING 60 TO 120 DEGREES E. THREE PHASES OF FOLDING: FIRST SCHISTOSITY E-W, 5OS; SECOND S85E, 11SE AXES OF FOLDS, AND THIRD FOLD AXES OF FOLDS S38W, 54SW.

Economic information

Economic information about the deposit and operations

Development status Producer
Commodity type Metallic
Deposit size Large
Significant No
Discovery year 1976
Discoverer Rio Doce Geologia E Mineracao S.A. (Docegeo)
Year of first production 1984

Ownership information

  • Type Operator
    Owner Rio Doce Geologia E Mineracao (Docegeo) ; Paulo Abib Engenharia S. A.
    First year 1976
    Last year 1982

Reserves and resources

  • Type In-situ
    Estimate year 1988
    Total resources 647,949,000mt ore
    Commodity Subtype Grade units Group Importance Year
    Gold Au 2.35 g/mt Gold Major 1988

Comments on the reserve resource information

  • (1) = MEASURED, OXIDIZED ORE; (2) = MEASURED SULFIDE ORE; (3) = INDICATED SULFIDE ORE; (4) = INFERRED SULFIDE ORE; (5) = (1) + (2) + (3); ORE (6) = OXIDIZED RESERVE LEFT IN 1988; T = TOTAL; OTHER SYMBOLS FOR INDIVIDUAL ORE BODIES: VQ = QUARTZ VEIN. OXIDIZED ORE CUTOFF GRADE = 0.7 G/MT AU. SULFIDE CUTOFF GRADE = 2.0 G/MT AU.

Comments on the workings information

  • STARTED AS OPEN PIT, HEAP-LEACHING OPERATION OF WEATHERED ORE AND IN 1990 WAS IN TRANSITION FROM OPEN-PIT MINING TO UNDERGROUND MINING OF A SELECTED BLOCK. MINED UNDERGROUND BY SUBLEVEL SHRINKAGE-CAVING, WITH CAPACITY TO PRODUCE 252000 MT/YR. OPEN-PIT HAS 5 M LEVELS AND HAS CAPACITY TO PRODUCE 200000 MT/YR. RECOVERY BY CARBON-PULP METHOD.

Comments on development

  • TOTAL$: 66.7 ; ECON.COM: 400 PERSONS WILL BE EMPLOYED AT FULL PRODUCTION. HEAP LEACHING OPERATION COSTS $212 PER OZ. ; MILL.CAP : 2500 MT/D

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS TC00087

Bibliographic references

  • Deposit

    SKILLINGS, D.N., JR., 1988, CVRD EXPANDING ANNUAL PRODUCTION OF FAZENDA BRASILEIRO GOLD MINE IN BAHIA TO 6 METRIC TONS: SKILLINGS' MINING REVIEW, AUGUST 20, 1988, P. 4-7.

  • Deposit

    TEIXEIRA, J.B.G., KISHIDA, A., MARIMON, M.P.C., XAVIER, R.P., AND MCTEATH, I., 1990, THE FAZENDA BRASILEIRO GOLD DEPOSIT, BAHIA, GEOLOGY, HYDROTHERMAL ALTERATION, AND FLUID INCLUSIONS: ECONOMIC GEOLOGY, V. 85, NO. 5, P. 990-1009.

  • Deposit

    REINHARDT, M.C., AND DAVISON, I., 1990, STRUCTURAL AND LITHOLOGIC CONTROLS ON GOLD DEPOSITION IN THE SHEAR-ZONE-HOSTED FAZENDA BRASILEIRO MINE, BAHIA STATE, NORTHEAST BRASIL: ECONOMIC GEOLOGY, V. 85, NO. 5, P. 952-967.

  • Deposit

    DE MIRANDA SANTOS, O., VICTORASSO, E.C.L., DA SILVA, R.M., GUERRA, H.R.M., CHAVES, J.L., MANTOVANI, T.J., E SILVA, R.A., KALIL, A.R., JR., SANTOS, V.A.M., NAVARRO, L.A.G., AND PENA, L.S.T., 1988, MINA OURO DE FAZENDA BRASILEIRO, BAHIA, IN PRINCIPAIS DEPOSITOS MINERAIS DO BRASIL, EDS., C. SCHOBBENHAUS AND C.E.S. COELHO: MINISTERIO DAS MINAS E ENERGIA, BRASILIA, V. III, P. 431-

  • Production

    TEIXEIRA, J.B.G. AND OTHERS (1990); DE MIRANDA SANTOS AND OTHERS (1988).

  • Reserve-Resource

    SKILLINGS, 1988, P. 6-7.

General comments

Subject category Comment text
Deposit THE ZONE OF LOW GRADE OXIDIZED ORE FOR HEAP LEACHING EXTENDS TO THE OXIDATION LIMIT OF 15 METERS DEEP, WITH THE CUTOFF RECENTLY INCREASED FROM 0.7 TO 0.9 GRAMS OF GOLD PER TON. SULFIDE ORE TO BE MINED BY UNDERGROUND METHODS IS CONTAINED WITHIN OREBODIES PLUNGING 12 DEGREES FROM SURFACE. THREE TYPES OF VEINS: (1) QUARTZ VEINS, UP TO 2% CALCITE, ALTERATION HALOS OF SERICITE, CHLORITE, BIOTITE, UP TO A FEW CM'S THICK; (2) QUARTZ-CARBONATE-BIOTITE VEINS; CARBONATE CORES WITH BIOTITE MARGINS; (3) QUARTZ-ALBITE-SULFIDE VEINS, RELATED TO HIGH GRADE ORE, CONTAIN GOLD, PYRITE, ARSENOPYRITE. MINERALIZED VENS POSTDATE DI. REINHARD AND DAVISON (1990) DISCUSS VEINS IN DETAIL. DEPOSIT CONSISTS OF ORE BODIES IN A ZONA STRIKING E-W AND DIPPING 30-50S. THE BODIES PLUNGE 11 DEGREES S85E. THEY ARE EXPLORED TO AT LEAST 240 M BELOW THE SURFACE. ORE BODIES HAVE COMPLICATED SHAPES AND IN CROSS-SECTIONS AND LONG-SECTIONS, THEIR SHAPE, IN PART, IS RELATED TO FOLDING. GOLD IS ERRATICALLY DISTRIBUTED
Deposit OCCURRING IN MICROFRACTURES IN QUARTZ, INCLUSIONS IN ARSENOPYRITE, AND MICROFRACTURES IN PYRITE AND ARSENOPYRITE WITH SIZES BETWEEN 1-200 MICRONS.

Reporter information

Type Date Name Affiliation Comment
Reporter 01-DEC-1989 Bolm, Karen S. U.S. Geological Survey
Updater 01-DEC-1993 Page, Norman J. U.S. Geological Survey
Updater 15-JUL-1994 Page, Norman J. U.S. Geological Survey