Evolução geológica dos batólitos granitóides neoproterozóicos do sudeste do estado de são paulo

• Autor(a) principal: Godoy, Antonio Misson [UNESP]
• Data de Publicação: 2010
• Outros Autores: Hackspacher, Peter Christian [UNESP], de Oliveira, Marcos Aurèlio Farias [UNESP], de Araújo, Larissa Marques Barbosa
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://www.periodicos.rc.biblioteca.unesp.br/index.php/geociencias/article/view/3992; http://hdl.handle.net/11449/71883
• topic: Geochemistry; Granitoid batholiths; Neoproterozoic; accretion; batholith; crystallization; emplacement; facies; granitoid; igneous geochemistry; magmatism; pegmatite; Proterozoic; shear zone; Brazil; Sao Paulo [Brazil]

The Neoproterozoic granitogenesis related to the Central Mantiqueira Province comprise the calc alkaline to alkaline granitoid complexes of Sorocaba, San Francisco, São Roque, Ibiúna and Piedade. These complexes occur in a ruptil tectonic to tardi (Sn+3) event. The emplacement of the different facies in transtractives structures of the pull-apart type are characterized in the area by the main transcurrent shear zones of Taxaquara-Pirapora, Itu-Jundiuvira, Moreiras, Cangüera and Caucáia of ENE-WSW general direction. The massifs present complex internal architecture characterized by intrusions in restrict initial phase of intermediate equigranular nature. Also present a main phase of porfiroid monzo and sienogranite that fragments the previous phase, followed by lateral accretion of equi to inequigranular material, and in some cases by the accretion of late phases of circular bodies of porfiroid rapakivi granites, and a late to final phase of aplitic to pegmatitic composition. This magmatism grew with the intrusions of successive magmatic pulses, partially controlled by many reactivations of the shear zones. The REE also suggest that the magmatic phases are similar, synchronous and repetitive in four of the complexes in both domains, present in the São Francisco Complex. The crystallization starts from accretion processes, but compositionally quite different from the others. The variation in compositions and ages (TDM) for these granites reflect the derivation from different sources developed under different magmatic conditions, followed by processes of contamination that frequently occur in the crust.