U-Pb dating of granites in the Neoproterozoic Sergipano Belt, NE-Brazil: Implications for the timing and duration of continental collision and extrusion tectonics in the Borborema Province

Autor(es)

Bueno, Juliana Finoto ^[1] ; Oliveira, Elson Paiva ^[1] ; McNaughton, Neal J. ^[2] ; Laux, Jorge Henrique ^[3]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, Inst Geosci, BR-13083970 Campinas, SP - Brazil

^[2] Curtin Univ Technol, John Laeter Ctr Mass Spectrometry, Sch Appl Phys, Perth, WA 6845 - Australia

^[3] DGM Sureg Pa, Companhia Pesquisa Recursos Minerais, BR-90840030 Porto Alegre, RS - Brazil

• Tipo de documento: Artigo Científico
• Fonte: GONDWANA RESEARCH; v. 15, n. 1, p. 86-97, FEB 2009.
• Citações Web of Science: 38

Resumo

The Sergipano Belt is the outcome of collision between the Pernambuco-Alagoas Massif and the Sao Francisco Craton during Neoproterozoic assembly of West Gondwana. Field relationships and U-Pb geochronology of granites intruded in garnet micaschists of the Macurure Domain are used to constrain the main collisional event (D(2)) in the belt. The granites are divided into two groups, the pre-collisional granites (pre- to early-D(2)) and the syn-collisional granites (syn- to tardi-D(2)), the latter were emplaced as sheets along the S(2) axial plane foliation or they were collected at the hinge zones of F(2) folds. A U-Pb SHRIMP zircon age of 628 +/- 12 Ma was obtained for the pre-collisional Camara tonalite. Two U-Pb TIMS titanite ages were obtained for the syn-collisional granites, 584 10 Ma for the Angico granite and 571 +/- 9 Ma for the Pedra Furada granite, and these ages are close to the garnet-whole rock Sm-Nd isochron of 570 Ma found for the peak of metamorphism in the Sergipano Belt. The ages of the Camara tonalite (628 Ma) and the Pedra Furada granite (571 Ma) mark respectively the maximum age for beginning of the D(2) event and minimum age for the end in the Macurure Domain. Using these ages, the main Neoproterozoic D(2) collisional event has been in operation in the Sergipano Belt for at least 57 million years. Correlation with coeval granitoids farther north in the Borborema Province indicate that while in the Sergipano Belt the syn-D(2) granites (ca. 590-570 Ma) were emplaced under compression, in the Borborema Province they emplaced under extensional conditions related to regional strike-slip shear zones. These contrasting emplacement settings for contemporaneous Neoproterozoic granitoids are explained by a combination of continent-continent collision and extrusion tectonics. (C) 2008 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 04/05054-2 - Cronologia de colocacao de granitos no dominio macurure e implicacoes para a evolucao crustal na faixa sergipana, nordeste do brasil.
• Beneficiário: Juliana Finoto Bueno
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 02/03085-2 - Geocronologia u-pb shrimp e isotopos de nd na faixa sergipana nordeste do brasil: implicacoes para a evolucao tectonica e proveniencia de sedimentos.
• Beneficiário: Elson Paiva de Oliveira
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 05/60119-5 - Petrogênese e cronologia de alojamento nde granitos colisionais na Faixa Sergipana, Nordeste do Brasil
• Beneficiário: Juliana Finoto Bueno
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto
• Processo FAPESP: 02/07536-9 - Cinematica e cronologia da deformacao em limites de terrenos da faixa sergipana e do bloco serrinha nordeste do brasil.
• Beneficiário: Elson Paiva de Oliveira
• Modalidade de apoio: Auxílio à Pesquisa - Regular