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Ore characterization and textural relationships among gold, selenides, platinum-group minerals and uraninite at the granite-related Buraco do Ouro gold mine, Cavalcante, Central Brazil

Published online by Cambridge University Press:  02 January 2018

J. Menez  and
N. F. Botelho
J. Menez*
Affiliation:
Instituto de Geociências, Universidade de Brasília, Brasília, DF 70910-900, Brazil
N. F. Botelho
Affiliation:
Instituto de Geociências, Universidade de Brasília, Brasília, DF 70910-900, Brazil
*
*E-mail: [email protected]
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Abstract

Gold occurrences have been reported in the northeastern part of Goiás State since the beginning of the 18th Century. The main mineralization is associated with Paleoproterozoic peraluminous, syntectonic granites of the Aurumina Suite and associated metasedimentary,graphite-bearing country rocks of the Ticunzal Formation. In the Buraco do Ouro gold mine, the mineralization is hosted in muscovite-quartz mylonite in a silicified shear zone near the contact between biotite-muscovite granite and paragneiss of the Ticunzal Formation. The ore mineralogy consistsof gold, paraguanajuatite (Bi2Se3), kalungaite (PdAsSe), isomertieite [Pd11Sb2As2], mertieite II [Pd8(Sb,As)3], sperrylite (PtAs2), padmaite (PdBiSe), bohdanowiczite (AgBiSe2), clausthalite (PbSe),krutaite (CuSe2), ferroselite (FeSe2), uraninite (UO2) and unnamed Ag-Pb-Bi-Se minerals. Local magnetite concentrations and rare chalcopyrite and pyrite are also associated with both mineralized and barren mylonites in a gangue consisting of muscovite, quartzand rare tourmaline. High TiO2 muscovite clasts in the ore are interpreted as the magmatic muscovite of the original granite, and the mineralization is considered to be synchronous with the syntectonic granite intrusion during syn-emplacement shearing and alteration. The associationbetween granitic rocks and platinum-group element (PGE)-bearing gold mineralization observed in the Buraco do Ouro mine is uncommon and unique in the context of the Aurumina Suite and the Ticunzal Formation, where gold deposits and occurrences are gold-only. The chemical data suggest the possibilityof a solid solution between paraguanajuatite and bohdanowiczite. In addition, a complex intergrowth occurs between paraguanajuatite, clausthalite and Ag-Pb-Bi-Se phases, one of which, a Pb-Bi-Se phase could represent a new mineral. Uraninite is identified for the first time in this mineralassemblage and its concentration in the ore seems important, as revealed by high gamma spectrometric measurements in the samples collected in the mine. The association between gold and uranium constitutes a regional signature, observed in both gold and uranium deposits in the Cavalcante region.

Keywords

Buraco do Ouro gold mineselenidesgoldplatinum-group element
Type
Research Article
Information
Mineralogical Magazine , Volume 81 , Issue 3 , June 2017 , pp. 463 - 475
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2017

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References

Alvarenga, C.J.S., Dardenne, M.A., Botelho, N.F., Machado, M.A., Lima, O.N.B. and Almeida, T. (2007) Relatório final das folhas Monte Alegre de Goiás, Cavalcante e Nova Roma: Programa Geologia do Brasil (PGB/CGB). UnB/CPRM, Companhia de Pesquisa de Recursos Minerais, Brasilia.Google Scholar
Bogossian, J. (2012) Mineralizações primárias e supergênicas de urânio do nordeste de Goiás e sudeste do Tocantins: Contexto geológico, miner-alogia e implicações metalogenéticas. Unpublished MSc thesis, Brasília University, Brasília, Brazil, 54 pp.Google Scholar
Botelho, N.F. and Moura, M.A. (1998) Granite-ore deposit relationships in Central Brazil. Journal of South American Earth Sciences, 11, 427–438.CrossRefGoogle Scholar
Botelho, N.F. and Silva, D.V. (2005) Mineralizações de Au e PGE hospedadas em rochas graníticas peralumi-nosas do nordeste de Goiás: Discussão sobre depósitos não convencionais de platinóides. Abstracts of the I Simpósio Brasileiro de Metalogenia [CD Rom].Google Scholar
Botelho, N.F., Fuck, R.A., Dantas, E.L., Laux, J.H. and Junges, S.L. (2006a) The Paleoproterozoic peralumin-ous Aurumina granite suite, Goiás and Tocantins, Brazil: Geological, whole rock geochemistry and U-Pb and Sm-Nd isotopic constraints. P. 92 in: The Paleoproterozoic Record of the São Francisco Craton, Brazil, Field Guide and Abstracts of the International Geological Correlation Programme (IGCP), 509: Paleoproterozoic Supercontinents & Global Evolution.Google Scholar
Botelho, N.F., Moura, M.A., Peterson, R.C., Stanley, C.J. and Silva, D.V. (2006b) Kalungaite, PdAsSe, a new platinum group mineral from Buraco do Ouro gold mine, Cavalcante, Goiás State, Brazil. Mineralogical Magazine, 70, 123–130.CrossRefGoogle Scholar
Cabral, A.R. and Lehmann, B. (2007) Seleniferous minerals of palladium and platinum from Ouro Preto-bearing mineralization in Brazil. Ore Geology Reviews, 32, 681–688.CrossRefGoogle Scholar
Cabral, A.R., Lehmann, B., Kwitko, R. and Costa, C.H.C. (2002a) The Serra Pelada Au-Pd-Pt deposit, Carajás Mineral Province, Northern Brazil: Reconnaissance mineralogy and chemistry of very high grade palladian gold mineralization. Economic Geology, 97, 1127–1138.Google Scholar
Cabral, A.R., Lehmann, B., Kwitko, R. and Costa, C.H.C. (2002b) Palladium and platinum minerals from the Serra Pelada Au-Pd-Pt deposit, Carajás Mineral Province, Northern Brazil. The Canadian Mineralogist, 40, 1451–1463.CrossRefGoogle Scholar
Cabri, L.J. (2002) The platinum-group minerals. Pp. 13–129 in: The Geology, Geochemistry, Mineralogy and Mineral Beneficiation of Platinum-group Elements (L.J. Cabri, editor). Canadian Institute of Mining, Metallurgy and Petroleum, Special Volume 54. CIM, Québec, Canada.Google Scholar
Cunha, L.M. (2006) Gênese e controle da mineralização de Au e Ag associada a granitos peraluminosos na mina de Aurumina, Goiás. Unpublished MSc thesis, Brasília University, Brasília, Brazil, 103 pp.Google Scholar
Damian, G., Ciobanu, C.L., Cook, N.J. and Damian, F. (2008) Bismuth sulphosalts from the galena-matildite series in the Cremenea vein, Suior, Baia Mare district, Romania. Neues Jahrbuch Für Mineralogie, 185, 199–213.CrossRefGoogle Scholar
D'el Rey Silva, L.J.H. and Senna Filho, V (1998) Ouro em sericita-quartzo hidrotermalitos controlados por cisalhamentos conjugados brasilianos, na região de Cavalcante (GO). Revista Brasileira de Geociências, 28, 405–408.CrossRefGoogle Scholar
Grainger, C.J., Groves, D.I. and Costa, C.H.C. (2002) The epigenetic sediment-hosted Serra Pelada Au-PGE deposit and its potential genetic association with Fe oxide Cu-Au mineralization within the Carajás Mineral Province, Amazon Craton, Brazil. Economic Geology, Special Publication, 9, 47–64.Google Scholar
Hippertt, J.F.M. and Massucatto, A.J. (1998) Phyllonitization and development of kilometer-scale extension gashes in a continental-scale strike-slip shear zone, north-Goiás, Central Brazil. Journal of Structural Geology, 20, 433–445.CrossRefGoogle Scholar
Holtstam, D. and Söderhielm, J. (1999) The discreditation of platynite. The Canadian Mineralogist, 37, 1313–1315.Google Scholar
Marchetto, C.M.L., Larson, L.T and Figueiredo, A.N. (1993) Platinum group minerals and gold in acid rocks, Cavalcante, Brazil. Pp. 47–51 in: Extended Abstracts of the I Brazilian Meeting on Platinum Group Elements. Google Scholar
Menez, I (2008) Depósito de Au-Pd-Pt associado a granito, mina Buraco do Ouro, Cavalcante, Goiás: Caracterização e modelo da mineralização. Unpublished MSc thesis, Brasília University, Brasília, Brazil, 88 pp.Google Scholar
Menez, I (2013) Mineralização não-convencional de Au-EGP-U relacionada a granitos peraluminosos da mina Buraco do Ouro, Cavalcante, Goiás, e relações texturais dos minerais de minério. Unpublished PhD thesis, Brasília University, Brasília, Brazil, 166 pp.Google Scholar
Mernagh, T.P., Heinrich, C.A., Leckie, IE, Carville, D.P., Gilbert, D.J., Valenta, R.K. and Wyborn, L.A.I. (1994) Chemistry of low-temperature hydrothermal gold, platinum, and palladium (± uranium) mineralization at Coronation Hill, Northern Territory, Australia. Economic Geology, 89, 1053–1073.CrossRefGoogle Scholar
Miller, C.F., Stoddard, E.F., Bradfish, L.J. and Dollase, W. A. (1981) Composition of plutonic muscovite: Genetic implications. The Canadian Mineralogist, 19, 25–34.Google Scholar
Monier, G. and Robert, J.L. (1986) Titanium in muscovites from two mica granites: Substitutional mechanisms and partition with coexisting biotites. Neues Jahrbuch für Mineralogie Abhandlungen, 153, 147–161.Google Scholar
Pimentel, M.M., Ferreira Filho, C.F. and Armele, A. (2006) Neoproterozoic age of the Niquelândia Complex, central Brazil: Further ID-TIMS U-Pb and Sm-Nd isotopic evidence. Journal of South American Earth Sciences, 21, 228–238.CrossRefGoogle Scholar
Sener, A., Grainger, C. and Groves, D. (2002) Epigenetic gold-platinum-group element deposits: Examples from Brazil and Australia. Mining and Metallurgy, 111, B65–B73.Google Scholar
Stanley, C.J., Criddle, A.J. and Lloyd, D. (1990) Precious and base metal selenide mineralization at Hope's Nose, Torquay, Devon. Mineralogical Magazine, 54, 485–93.CrossRefGoogle Scholar