Please use this identifier to cite or link to this item: http://www.repositorio.ufop.br/handle/123456789/3999
Title: Pb/Pb single-zircon dating of paleoproterozoic calc-alkaline/alkaline magmatism in the southeastern São Franciso Craton region, Brazil.
Authors: Evangelista, Hanna Jordt
Peres, Guilherme Gravina
Macambira, Moacir Jose Buenano
Keywords: Geochronology
Transamazonian
Trondhjemite
Quadrilátero Ferrífero
São Francisco craton
Issue Date: 2000
Citation: EVANGELISTA, H. J.; PERES, G. G.; MACAMBIRA, M. J. B. Pb/Pb single-zircon dating of paleoproterozoic calc-alkaline/alkaline magmatism in the southeastern São Franciso Craton region, Brazil. Revista Brasileira de Geociências, São Paulo, v. 30, n.1, p. 174-176, 2000. Disponível em: <http://www.ppegeo.igc.usp.br/index.php/rbg/article/view/10969>. Acesso em: 24 set. 2014.
Abstract: Two chemically and petrographically distinct intrusive bodies (a calc-alkaline trondhjemite and an alkaline quartz-syenite cut by granitic aplites) occur in the vicinity of Piranga (Minas Gerais State), near the southeastern border of the São Francisco craton, Brazil. They intrude the Rio das Velhas greenstone belt and the Mantiqueira complex, both of Archean age. Both intrusive bodies are variably deformed and mylonitized. Age determinations using the Pb/Pb single-zircon evaporation method yielded Paleoproterozoic ages for the emplacement/crystallization of the trondhjemite (2058 ± lOMa), quartz-syenite (2036 ± 4Ma), as well as the younger aplites (2012 ± 8Ma). These ages allow us to interpret the calc-alkaline as well as the alkaline magmatism as manifestations of the Transamazonian event in the southeastern São Francisco craton region. Furthermore, the calc-alkaline trondhjemite is interpreted to have intruded during compressional deformation, while the alkaline quartz-syenite and its aplitic differentiates are post-orogenic, possibly extension-related. In terms of the Rb vs. (Y +Nb) contents, the trondhjemite plots in the field of volcanic arc granites, whereas the syenite and the aplites plot in the field of post-collision granites. The mylonitic overprinting of the syenite and the trondhjemite is also Paleoproterozoic, as deduced from the 2012 ± 8Ma age of the undeformed younger aplitic dykes which cut the syenite. It is likely that this alkaline magmatism correlates with a Paleoproterozoic post-collisional magmatic event well documented in the Transamazonian mobile belts of the northern São Francisco craton.
URI: http://www.repositorio.ufop.br/handle/123456789/3999
ISSN: 2317-4692
metadata.dc.rights.license: Os 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.
Appears in Collections:DEGEO - Artigos de periódicos

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