Calymmian (1.50-1.45 Ga) magmatic records in Votuverava and Perau sequences, south-southeastern Brazil: Zircon ages and Nd-Sr isotopic geochemistry

Author(s)

Siga, Oswaldo, Jr. ; Stipp Basei, Miguel Angelo ; Sato, Kei ; Passarelli, Claudia Regina ; Nutman, Allen ; McReath, Ian ; dos Prazeres Filho, Helcio Jose

• Document type: Journal article
• Source: Journal of South American Earth Sciences; v. 32, n. 4, p. 8-pg., 2011-12-01.

Abstract

The main aim of this work is to present and discuss the U-Pb zircon ages and Nd-Sr isotopic data from the metabasic rocks that occur within the metamorphosed Votuverava and Perau volcano sedimentary sequences, located in the Apiai Terrane, south-southeastern Brazil. The geochemical pattern of most of these metabasic rocks is similar to those of tholeiitic basalts, suggesting an extensional environment. The U-Pb zircon ages obtained around ca. 1480 Ma characterize an important basic magmatism during the Mesoproterozoic in south-southeastern Brazil. Nd model ages and epsilon(Nd)/epsilon(Sr) signatures suggest the Mesoproterozoic as the main period of mantle/crust differentiation for the crustal precursors of these metabasic rocks. It is quite possible that the Mesoproterozoic extentional events that caused the opening of large sedimentary basins in southern-southeastern Brazil have been underestimated. Possible regional correlations between the Votuverava-Perau basin (PR), the Betara and Agua Clara sequences (PR-SP) and the Serra do Itaberaba Group (SP) demonstrate the magnitude of the extensional process associated with the break-up of the preexisting continental masses. (C) 2011 Elsevier Ltd. All rights reserved. (AU)

• FAPESP's process: 05/58688-1 - South America in the context of supercontinents: fusion and fission
• Grantee: Miguel Angelo Stipp Basei
• Support Opportunities: Research Projects - Thematic Grants