Provenance and sedimentary environments of the Proterozoic São Roque Group, SE-Brazil: Contributions from petrography, geochemistry and Sm–Nd isotopic systematics of metasedimentary rocks

The Proterozoic metasedimentary sequences exposed in the São Roque Domain (Apiaí Terrane, Ribeira Belt, southeast Brazil) consist of metasandstones and meta-felspathic wackes with some volcanic layers of within-plate geochemical signature (Boturuna Formation), a passive margin turbidite sequence of metawackes and metamudstones (Piragibu Formation), and volcano-sedimentary sequences with MORB-like basalts (Serra do Itaberaba Group; Pirapora do Bom Jesus Formation). A combination of zircon provenance studies in metasandstones, whole-rock geochemistry and Sm–Nd isotopic systematics in metamudstones was used to understand the provenance and tectonic significance of these sequences, and their implications to the evolution of the Precambrian crust in the region.