https://repositorio.ufba.br/handle/ri/5266
Tipo: | Artigo de Periódico |
Título: | Sediment hosted lead–zinc deposits of the Neoproterozoic Bambuı´ Group and correlative sequences, São Francisco Craton, Brazil: A review and a possible metallogenic evolution model |
Título(s) alternativo(s): | Ore Geology Reviews |
Autor(es): | Misi, Aroldo Iyer, Sundaram Sankara Subba Coelho, Carlos Eduardo Silva Tassinari, Colombo Celso Gaeta Rocha, Washington J. S. Franca Cunha, Ioná de Abreu Gomes, Adriana S. Rocha Oliveira, Tolentino Flávio de Teixeira, João Batista Guimarães Conceição Filho, Valter Mônaco |
Autor(es): | Misi, Aroldo Iyer, Sundaram Sankara Subba Coelho, Carlos Eduardo Silva Tassinari, Colombo Celso Gaeta Rocha, Washington J. S. Franca Cunha, Ioná de Abreu Gomes, Adriana S. Rocha Oliveira, Tolentino Flávio de Teixeira, João Batista Guimarães Conceição Filho, Valter Mônaco |
Abstract: | The Proterozoic sediment-hosted Zn–(Pb) sulfide and non-sulfide deposits of the São Francisco Craton, Brazil, are partially syn-diagenetic and epigenetic and were probably formed during extensional events. The majority of the deposits occur within shallow water dolomites. The Pb isotopic data of sulfides are relatively homogeneous for individual deposits and plot above the upper crust evolution curve of the Plumbotectonic model. Some of the deposits are characterized by highly radiogenic lead (206Pb/204Pb ≥ 21) originating from the highly radioactive crust of the São Francisco Craton. Pb and S isotopic data suggest the sources of metal and sulfur for the deposits to be the basement rocks and seawater sulfates in the sediments, respectively. The relatively high temperatures of formation (100 to 250 °C) and moderate salinity (3% to 20% NaCl equiv.) of the primary fluid inclusions in the sphalerite crystals suggest the participation of basinal mineralizing fluids in ore formation. The steep paleo-geothermal gradient generated by the radioactively enriched basement rocks probably assisted in heating up the circulating mineralizing fluids. |
Palavras-chave: | Proterozoic Pb–Zn deposits São Francisco Craton Isotopes Fluid inclusions Metallogeny |
URI: | http://www.repositorio.ufba.br/ri/handle/ri/5266 |
Data do documento: | 2005 |
Aparece nas coleções: | Artigo Publicado em Periódico (IGEO) |
Arquivo | Descrição | Tamanho | Formato | |
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S016913680500020X-main.pdf | 2,04 MB | Adobe PDF | Visualizar/Abrir |
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