Palladium-bearing gold deposit hosted by Proterozoic lake superior-type iron-formation at the Caue iron mine, Itabira District, southern Sao Francisco Craton, Brazil; geologic and structural controls; reply

1995 ◽  
Vol 90 (8) ◽  
pp. 2372-2374
Author(s):  
Gema Ribeiro Olivo ◽  
Michel Gauthier ◽  
Marc Bardoux ◽  
Euripides Leao de Sa ◽  
Jose Teotonio F. Fonseca ◽  
...  
Keyword(s):  
Gold Deposit ◽  
Lake Superior ◽  
Iron Formation ◽  
Structural Controls ◽  
Iron Mine ◽  
Superior Type

Palladium-bearing gold deposit hosted by Proterozoic lake superior-type iron-formation at the Caue iron mine, Itabira District, southern Sao Francisco Craton, Brazil; geologic and structural controls

1995 ◽  
Vol 90 (1) ◽  
pp. 118-134 ◽  
Author(s):  
Gema Ribeiro Olivo ◽  
Michel Gauthier ◽  
Marc Bardoux ◽  
Euripedes Leao de Sa ◽  
Jose Teotonio F. Fonseca ◽  
...  
Keyword(s):  
Gold Deposit ◽  
Lake Superior ◽  
Iron Formation ◽  
Structural Controls ◽  
Iron Mine ◽  
Superior Type

Palladium minerals from the Cauê iron mine, Itabira District, Minas Gerais, Brazil

1995 ◽  
Vol 59 (396) ◽  
pp. 455-463 ◽  
Author(s):  
Gema Ribeiro Olivo ◽  
Michel Gauthier
Keyword(s):  
Copper Oxide ◽  
Lake Superior ◽  
Minas Gerais ◽  
Iron Formation ◽  
Chloride Complexes ◽  
Mylonitic Foliation ◽  
The Core ◽  
Physico Chemical ◽  
Iron Mine ◽  
Chemical Conditions

AbstractPalladium-bearing minerals from the Cauê iron mine, Itabira District, Minas Gerais, Brazil, are found in gold-rich jacutinga, a hydrothermally-altered Lake Superior-type carbonate-bearing oxide facies iron-formation. Palladium occurs as: native palladium with trace contents of Au, Fe and Cu; palladseite ((Pd,Cu,Hg)17Se15), which was found in the core of a grain of palladium; palladium–copper oxide ((Pd,Cu)O); and arsenopalladinite (Pd8(As,Sb)3), with inclusions of palladium–copper oxide. The palladium and palladium–copper oxide grains are coated with films of gold and commonly do not exceed 100 µm in width. These palladium minerals occur in hematite bands and in boudinaged bands of quartz and white phyllosilicate parallel to the S1 mylonitic foliation. Palladium-copper oxide also occurs as inclusions in gold grains which are strongly to weakly stretched parallel to S1.Palladium mineralization is interpreted as synchronous with intense D1 shearing and contemporaneous with the peak of thermal metamorphism. At high oxygen fugacities and high temperatures (up to 600°C), Pd may have been transported as chloride complexes and deposited following changes in pH caused by mineralizing fluids reacting with jacutinga. Deposition may also have been prompted by the formation of insoluble selenide and arsenide–antimonide minerals and by the dilution of C1 concentrations in the mineralizing fluid. Textural studies, and the zonation observed in palladium and other hydrothermal minerals, suggest that oscillations in the physico-chemical conditions of hydrothermal fluids occurred during the mineralizing event.

scholarly journals Lake Superior-type iron-formation

1995 ◽  
Author(s):  
G A Gross
Keyword(s):  
Lake Superior ◽  
Iron Formation ◽  
Superior Type

Palladian gold from the cauê iron mine, Itabira District, Minas Gerais, Brazil

1994 ◽  
Vol 58 (393) ◽  
pp. 579-587 ◽  
Author(s):  
G. R. Olivo ◽  
M. Gauthier ◽  
M. Bardoux
Keyword(s):  
Gold Mineralization ◽  
Lake Superior ◽  
Minas Gerais ◽  
Iron Formation ◽  
Stability Field ◽  
Progressive Deformation ◽  
Chloride Complexes ◽  
Mylonitic Foliation ◽  
Iron Mine ◽  
Palladium Content

AbstractPalladian gold from the Cauê iron mine, Itabira District, Minas Gerais, Brazil is found in horizons of hydrothermally-altered Lake Superior-type oxide-facies iron-formation locally called jacutinga. Palladium content of the gold grains varies from 1% to 20%, high palladium values being associated with palladium-copper-oxide inclusions and showing island-mainland and replacement (relict) textures in the Corpo Y and Corpo X orebodies. In the Aba Leste orebody, palladium is homogeneously distributed throughout the gold grains.Palladium and gold mineralization was synchronous with intense D1 shearing. Palladium was deposited early during the generation of S1-mylonitic foliation, and was replaced by gold during progressive deformation.At high oxygen fugacities (hematite stability field) and high temperatures (up to 600°C) Pd and Au may have been transported as chloride complexes, and their deposition may have occurred mainly as a result of changes in pH, but dilution of Cl concentrations may have also caused Pd and Au precipitation. Deposition of Pd as selenide may have taken place early during the creation of S1-fabrics.

Structural controls on the Cowarra gold deposit near Bredbo, southeastern New South Wales

1996 ◽  
Vol 43 (2) ◽  
pp. 201-215 ◽  
Author(s):  
M. J. Rickard ◽  
K. G. McQueen ◽  
P. Hayden
Keyword(s):  
Gold Deposit ◽  
New South ◽  
New South Wales ◽  
Structural Controls ◽  
South Wales
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