Hostname: page-component-76fb5796d-25wd4 Total loading time: 0 Render date: 2024-04-25T08:55:29.262Z Has data issue: false hasContentIssue false
  • English
  • Français

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

Published online by Cambridge University Press:  05 July 2018

G. R. Olivo ,
M. Gauthier  and
M. Bardoux
G. R. Olivo
Affiliation:
Université du Québec à Montréal, Département des sciences de la terre, case postale 8888, succ. A, Montréal, PQ, Canada, H3C 3P8
M. Gauthier
Affiliation:
Université du Québec à Montréal, Département des sciences de la terre, case postale 8888, succ. A, Montréal, PQ, Canada, H3C 3P8
M. Bardoux
Affiliation:
Université du Québec à Montréal, Département des sciences de la terre, case postale 8888, succ. A, Montréal, PQ, Canada, H3C 3P8
Get access Rights & Permissions [Opens in a new window]

Abstract

Palladian 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.

Keywords

goldpalladiumItabira, Braziliron-formationjacutinga
Type
Mineralogy
Information
Mineralogical Magazine , Volume 58 , Issue 393 , December 1994 , pp. 579 - 587
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1994

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Bensusan, A. J. (1929) Auriferous jacutinga deposits. Inst. Mining. Metall. Bull, 8, 300, 1–25.Google Scholar
Cabri, L. J. (1981) Analyses of Minerals containing platinum-group elements. In Platinum-Group Elements: Mineralogy, Geology, Recovery (Cabri, L J., ed.). Canad. Inst. Mining. Metall. Spec. Vol. 23, 151–73.Google Scholar
Cabri, L. J. and Laflamme, J. H. G. (1974) Rhodium, platinum, and gold alloys from the Stillwater complex. Canad. Mineral, 12, 399–403.Google Scholar
Cabri, L. J. and Lafiamme, J. H. G. (1979) Mineralogy of samples from the Lac-des-Iles area, Ontario. Canada Centre for Mineral and Energy Technology, report, 79—27, 20 pp.Google Scholar
Clark, A. M. and Criddle, A. J. (1982) Palladium minerals from Hope's Nose, Torquay, Devon. Mineral. Mag., 46, 371–77.CrossRefGoogle Scholar
Dorr, J. V. N., and Barbosa, A. L. M. (1963) Geology and ore deposits of the Itabira district, Minas Gerais, Brazil. U. S. Geol. Surv. prof, pap., 341C, 110pp.Google Scholar
Gammons, C. H., Bloom, M. S. and Yu, Y. (1992) Experimental investigations of the hydrothermal geochemistry of platinum and palladium: I. Solubility of platinum and palladium sulfide minerals in NaCl/H2SO4 solutions at 300°C. Geochim. Cosmochim. Ada, 56, 3881–94.CrossRefGoogle Scholar
Henley, R. W. (1973) Solubility of gold in hydro-thermal chloride solutions. Chem. Geol, 11, 73–87.CrossRefGoogle Scholar
Hoefs, J., Muller, G., and Schuster, A. K. (1982) Polymetamorphic relations in iron ores from Iron Quadrangle, Brazil: the correlation of oxygen isotope variations with deformation history. Contrib. Mineral. Petrol, 79, 241–51.CrossRefGoogle Scholar
Ineson, P. R. (1989) Introduction to practical ore microscopy. Longman Earth Science Series, John Wiley & Sons, Inc., New York, 181 pp.Google Scholar
Ladeira, E. A. (1991) Genesis of gold in Quadrilatero Ferrifero: a remarkable case of permanency, recycling and inheritance-a tribute to Djalma Guimaraes, Pierre Routhier and Hans Ramberg. In Proceedings of Brazil Gold ‘91: an international symposium on the geology of gold (Ladeira, E. A., ed.), A. A. Balkema, Rotterdam, 11-30.Google Scholar
Leao de Sa, E. and Borges, N. R. A. (1991) Gold mineralization in Caue and Conceicao iron ore mines, Itabira-MG. Field guide book of Brazil Gold ‘91: An international symposium on the geology of gold. (Fleisher, R., Grossi Sad, J. H., Fuzikawa, K., Ladeira, E. A., eds.), 74-85.Google Scholar
Lindsley, D. H. (1976) Experimental studies of oxide minerals. In Mineralogical Society of America short course notes (Rumble, D., Ill, ed.), 3, L61-L88.Google Scholar
Meireles, E. M. and Silva, A. R. B. (1988) Deposito de ouro de Serra Pelada, Maraba, Para. In Depositos Minerais do Brasil (Schobbenhaus, C. and Coelho, C. E. S., eds.), 3, 547–57.Google Scholar
Mountain, B. W. and Wood, S. A. (1988) Chemical controls on the solubility, transport, and deposition of platinum and palladium in hydrothermal solutions: a thermodynamic approach. Econ. Geol, 83, 492–510.CrossRefGoogle Scholar
Olivo, G. R. and Gauthier, M. (1993) Mineralogy of the palladium-bearing gold deposit hosted by a Lake Superior type iron-formation, Caue Mine, Sao Francisco Craton, Brazil. In Geological Society of America Annual Meeting. Boston. MA. October 25-28-Abstracts with Programs, A-276.Google Scholar
Olivo, G. R., Gauthier, M., Bardoux, M., Leao de Sa, L., Borges, N., and Santana, F. C. (1993) Palladium-bearing gold deposits hosted by a Proterozoic Lake Superior-type iron-formation, Itabira Iron District, Minas Gerais, southeast Brazil. Geological Association of Canada and Mineralogical Association of Canada Joint Annual Meeting. May 17—19. Edmonton. Program and Abstracts, A-79.Google Scholar
Polonia, J. C. and Souza, A. M. S. (1988) 0 comportamento em microescala do ouro no minerio de ferro de Itabira, Minas Gerais. In Anais do Congresso Brasileiro de Geologia, 35, 58–69.Google Scholar
Seward, T. M. (1984) The transport and deposition of gold in hydrothermal systems. In Proceedings of the Symposium Gold'82: the geology, geochemistry and genesis of gold deposits. (Foster, R. P., ed.). A. A. Balkema, Rotterdam, 165-81.Google Scholar
Wilde, A. R., Bloom, A. S. and Wall, V. J. (1989) Transport and deposition of gold, uranium and platinum-group elements in unconformity-related uranium deposits. Econ. Geol. Monogr., 6, 637–60.Google Scholar
Wood, S. A. and Mountain, B. W. (1991) Hydro-thermal solubility of palladium in chloride solutions from 300°C to 700°C: preliminary experimental results-a discussion. Econ. Geol, 86, 1562–3.CrossRefGoogle Scholar