Lower and Upper Neoproterozoic magmatic records in Itaiacoca Belt (Parana-Brazil): Zircon ages and lithostratigraphy studies

Autor(es)

Siga, Jr., O. ^[1] ; Basei, M. A. S. ^[1] ; Passarelli, C. R. ^[1] ; Sato, K. ^[1] ; Cury, L. F. ^[1] ; McReath, I. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Geociencias, BR-05508080 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: GONDWANA RESEARCH; v. 15, n. 2, p. 197-208, APR 2009.
• Citações Web of Science: 24

Resumo

The Itaiacoca Belt is a sequence of metavolcanic and metasedimentary rocks that crop out east of Parana and southeast of Sao Paulo states, in southern Brazil. This geologic-geochronologic study supports division of the Itaiacoca Belt into two major lithologic sequences. The older is a carbonate platform sequence (dolomitic meta-limestones/metamarls/calc-phyllites/ carbonate phyllites) with minimum deposition ages related to the end of the Mesoproterozoic/beginning of the Neoproterozoic (1030-908 Ma:U-Pb, zircon of metabasic rocks). The younger sequence contains mainly clastics deposits (meta-arkoses/metavolcanics/metaconglomerates/metapelites) with deposition ages related to the Neoproterozoic (645-628 Ma:U-Pb,zircon of metavolcanic rocks). These ages are quite close to K-Ar ages (fine fraction) of the 628-610 Ma interval, associated with metamorphism and cooling of the Itaiacoca Belt. The contact between the dolomitic meta-limestones and meta-arkoses is marked by intense stretching and high-angle foliation, suggesting that the discontinuity between these associations resulted from shearing. It is proposed here that the term Itaiacoca Sequence, should represent the dolomitic meta-limestones, and the term Abapa Sequence represents the meta-arkoses/metavolcanics/phyllites. in a major tectonic context, these periods are related to the break-up of Rodinia Supercontinent (1030-908 Ma) and the amalgamation of the Gondwana Supercontinent (645-628 Ma). (C) 2008 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 06/03608-6 - Estudo geocronológico e litogeoquimico do domínio Paranaguá (Iguape/ SP - São Francisco do Sul/ SC): implicações tectônicas
• Beneficiário: Oswaldo Siga Junior
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 05/58688-1 - A América do Sul no contexto dos supercontinentes: fusão e fissão
• Beneficiário: Miguel Angelo Stipp Basei
• Modalidade de apoio: Auxílio à Pesquisa - Temático