Syn-collisional peraluminous magmatism in the Rio Doce region : mineralogy, geochemistry and isotopic data of the Urucum suite (eastern Minas Gerais state, Brazil).

Nalini Júnior, Hermínio AriasBilal, EssaidNeves, José Marques Correia2015-01-222015-01-222000NALINI JÚNIOR, H. A.; BILAL, E.; NEVES, J. M. C. Syn-collisional peraluminous magmatism in the Rio Doce region: mineralogy, geochemistry and isotopic data of the Urucum suite (eastern Minas Gerais state, Brazil). Revista Brasileira de Geociências, v. 30, n.1, p. 120-125, 2000. Disponível em: <http://www.sbgeo.org.br/pub_sbg/rbg/vol30_down/3001/3001120.pdf>. Acesso em: 24 set. 2014.2317-4692http://www.repositorio.ufop.br/handle/123456789/4347The Urucum Suite granitoids (Rio Doce region, southeastern Brazil) contains four main facies: megafeldspar granites, deformed medium- to coarse-grained granites, tourmaline, and pegmatitic facies. They intrude both the staurolite-garnet-muscovite-biotite schist of the São Tomé Formation (Rio Doce Group) and the Galiléia metaluminous suite (596 ±4 Ma). Detailed structural studies suggest that the Urucum Suite emplaced during an important dextral strike-slip movement (Dl phase) of the Brasiliano orogeny (650-450Ma). Modal and chemical mineralogical variations suggest an evolution from the megafeldspar facies to the pegmatitic facies. Whole-rock geochemistry indicates the peraluminous character of the Urucum Suite granitoids, the evolution from the megafeldspar facies granites to pegmatitic facies granites and suggests the syn-collisional character of this suite. U-Pb zircon (582 ± 2 Ma) and monazite (576-573 ± 4Ma) data indicate that the Urucum Suite emplaced during the Brasiliano orogeny. The peraluminous nature of the Suite and isotopic-rich character in the Rb-Sr (87Sr/86Sr = 0.7114 to 0.7165) and Sm-Nd (eNd = -7.4 and -8.2) systems indicate that it formed by partial melting of older intermediate to felsic crustal sources. Based on early Proterozoic model-ages (2.3 to 1.8 Ga) and on 2.0 Ga U-Pb inherited signature, granitoids of the Suite are probably derived from a rocks with a long crustal residence (Transamazonian basement), without extensive mantle contribution.en-USGranitoidsPeraluminousGeochemistryIsotopic dataNeoproterozoicSyn-collisional peraluminous magmatism in the Rio Doce region : mineralogy, geochemistry and isotopic data of the Urucum suite (eastern Minas Gerais state, Brazil).Artigo publicado em periodicoOs trabalhos publicados na Revista Brasileira de Geociências são de uso gratuito, com atribuições próprias, para aplicações cientifico-educacionais e não-comerciais. Fonte: Revista Brasileira de Geociências <http://www.ppegeo.igc.usp.br/index.php/rbg/about/submissions#copyrightNotice>. Acesso em: 08 mar. 2017.