https://repositorio.ufba.br/handle/ri/2571
Tipo: | Artigo de Periódico |
Título: | Geochronology (U-PB/PB-PB) and isotopic signature (RB-SR/SM-ND) of the paleoproterozoic guanambi batholith, Southwest Bahia State (ne Brazil) |
Título(s) alternativo(s): | Revista Brasileira de Geociências |
Autor(es): | Conceicao, Herbet Oberli, Felix Meier, Martin Martin, Hervé Macambira, Moacir José Buenano Santos, Emerson Barreto dos Paim, Marcio Mattos Leahy, Geraldo Augusto da Silva Leal, Luiz Rogerio Bastos |
Autor(es): | Conceicao, Herbet Oberli, Felix Meier, Martin Martin, Hervé Macambira, Moacir José Buenano Santos, Emerson Barreto dos Paim, Marcio Mattos Leahy, Geraldo Augusto da Silva Leal, Luiz Rogerio Bastos |
Abstract: | The Guanambi batholith (GB) is located in south-western Bahia, Brazil, where it forms part of the Urandi-Paratinga mobile belt. The batholith extends over an area of almost 6,000 km2 and is mainly composed of syenites and monzonites, with subordinate granites, mafic syenites and lamprophyric dykes. Two main units can be recognized: the multiple intrusions, being divided into four regions (Paratinga, Laguna, Igapora and Guanambi) and the so-called late-intrusions forming the Cara Suja, Cerafma and Estreito massifs. U-Pb and Pb-Pb isotopic data demonstrate that the batholith was emplaced 2.05 Ga ago. GB has (i) highly negative initial εNd (-7.4 to -10.6), pointing to an enriched source, and (ii) Sr initial ratios between 0.704 and 0.707. Both chemical and isotopic signatures suggest that GB formed by fractional crystallization of a lamprophyric magma derived from a Paleoproterozoic enriched mantle source. |
Palavras-chave: | Guanambi batholith. Geochronology. Enriched mantle. Syenites |
URI: | http://www.repositorio.ufba.br/ri/handle/ri/2571 |
Data do documento: | 2000 |
Aparece nas coleções: | Artigo Publicado em Periódico (IGEO) |
Arquivo | Descrição | Tamanho | Formato | |
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10573-35524-1-PB.pdf | 234,95 kB | Adobe PDF | Visualizar/Abrir |
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