Petrography, geochemistry and geochronology of the potassic granitoids of the Rio Itacambiruçu Supersuite : implications for the Meso- to Neoarchean evolution of the Itacambira-Monte Azul block.

Bersan, Samuel MoreiraDanderfer Filho, AndréAbreu, Francisco Robério deLana, Cristiano de Carvalho2018-09-102018-09-102018BERSAN, S. M. et al. Petrography, geochemistry and geochronology of the potassic granitoids of the Rio Itacambiruçu Supersuite : implications for the Meso- to Neoarchean evolution of the Itacambira-Monte Azul block. Brazilian Journal of Geology, v. 48, n. 1, p. 1-24, 2018. Disponível em: <http://www.scielo.br/scielo.php?pid=S2317-48892018000100001&script=sci_abstract&tlng=en>. Acesso em: 03 mai. 2018.23174692http://www.repositorio.ufop.br/handle/123456789/10149In the Itacambira-Monte Azul block (BIMA) the Archean rocks are represented by tonalite-trondhjemite-granodiorite (TTGs) of the Porteirinha Complex and by potassic granitoids of the Rio Itacambiruçu Suite that crop out at the Pedra do Urubu (PUp), Rio Gorutuba (RGp), Barrocão (BAp) and Lagoa Nova (LNp) plutons. This work presents new data for the PUp, RGp and BAp. The petrographic and lithochemical analyses allowed the subdivision of the Rio Itacambiruçu Suite in two groups of granitoids: a medium potassium group, represented by the PUp and RGp, and a high potassium group, in which the BAp rocks are inserted. The geochronological data showed different ages for the medium and high potassium groups, with crystallization ages at ca. 2.92 Ga and 2.65 Ga, respectively. Despite the differences observed between these two groups, the chemical signatures of these rocks are compatible with the signature of biotite-granites generated by the reworking of ancient continental crust. Thereby, the data obtained in this work, added to some previously published results, allowed to the identification of two Archean crustal stabilization events recorded in BIMA, one of Mesoarchean age and the other of Neoarchean age. In addition, we propose the lithodemic reclassification of the Rio Itacambiruçu Suite to Rio Itacambiruçu Supersuite.en-USabertoHigh-K granitoidsSão-Francisco paleocontinentArcheanBasementPetrography, geochemistry and geochronology of the potassic granitoids of the Rio Itacambiruçu Supersuite : implications for the Meso- to Neoarchean evolution of the Itacambira-Monte Azul block.Artigo publicado em periodicoTodo o conteúdo do periódico Revista Brasileira de Geociências, exceto onde identificado, está licenciado sob uma licença Creative Commons 4.0 que permite copiar, distribuir e transmitir o trabalho em qualquer suporte ou formato desde que sejam citados o autor e o licenciante. Fonte: Revista Brasileira de Geociências <http://www.scielo.br/revistas/bjgeo/iinstruc.htm>. Acesso em: 12 jan. 2017.