Tectono-metamorphic evolution of the Central Ribeira Belt, Brazil : a case of late neoproterozoic intracontinental orogeny and flow of partially molten deep crust during the assembly of West Gondwana

Autor: Meira, Vinicius Tieppo, 1983
Přispěvatelé: UNIVERSIDADE ESTADUAL DE CAMPINAS
Rok vydání: 2019
Předmět:
Zdroj: Repositório da Produção Científica e Intelectual da Unicamp
Universidade Estadual de Campinas (UNICAMP)
instacron:UNICAMP
Popis: Agradecimentos: The first author is thankful to CAPES and CNPq for the PhD scholarships and CAPES for postdoctoral fellowship. T. Hyppolito acknowledges São Paulo Research Foundation for a postdoctoral fellowship (FAPESP Grant 2014/23422-0). Fernando Bea and Pilar Montero are thanked for their help with SHRIMP analysis and data treatment. Lucas Schiavetti and Glaucia Barreto are thanked for field assistance. Haakon Fossen is fully acknowledged for his comments and suggestions on the first version of this manuscript. Aitor Cambeses is acknowledged for fruitful discussions and help with the illustrations. Thanks are due to the COTEC-IF and workers of the Parque Estadual da Serra do Mar and Parque Estadual de Ilhabela for allowing access and sampling in the conservation area. This research was financially supported by São Paulo Research Foundation (FAPESP Grants 2012/15462-7 and 2016/06114-6), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq Grant 404767/2016-8), and CIC (University of Granada). The data used are listed in the references, tables, and supporting information. This is the IBERSIMS Publication 20 Abstract: Recent advances in understanding the plate tectonics, intracontinental deformation, and flow of partially molten crust have significantly improved our knowledge of collisional tectonics and the way in which we understand complex ancient orogens. The Central Ribeira Belt represents a Neoproterozoic fold-and-thrust belt formed in the Brasiliano Orogenic Cycle associated with the assembly of West Gondwana. This fold-and-thrust belt is currently interpreted as a result of recurrent collisions and amalgamation of terranes against large cratons. Based on an integrated structural, petrological, and geochronological study in two metamorphic complexes of the Central Ribeira Belt (Embu and Costeiro complexes), we challenge the current model that involves multiple terrane collisions. Our data show for the first time metamorphic ages older than 600 Ma for samples from Costeiro and Embu complexes and suggest that both geological units experienced an intermediate-P metamorphism (M1) at circa 620 Ma and a low-P metamorphism (M2) at circa 575 Ma. Our proposed tectonic model is consistent with an M1 event related to an intracontinental orogeny, formed in response to the collision between the São Francisco Craton and the Paranapanema Block. On the other hand, the later M2 metamorphism records extensional and wrench tectonics associated with orogenic collapse, constrained by the decompression paths of the metasedimentary sequences and M2-related S3 mylonitic foliation. The M2 metamorphism is associated with wide, right-lateral strike-slip shear zones and voluminous peraluminous magmatism in the Embu Domain and widespread partial melting of the middle crust forming migmatitic rocks and peraluminous leucogranites in the Costeiro Domain COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPES CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP Fechado
Databáze: OpenAIRE
Externí odkaz: