Depositional age and provenance of the Itajaí Basin, Santa Catarina State, Brazil: Implications for SW Gondwana correlation

The Itajaí Basin is a fault-bounded late- to post-orogenic basin deposited adjacent to the Dom Feliciano Belt in the state of Santa Catarina, Brazil. The basin is composed of alluvial-deltaic and platformal successions followed by a turbiditic complex and fan-delta deposits. U-Pb zircon dating of a tuff and five sandstone samples indicates a maximum depositional age of 563 ± 3 Ma for the intermediate and upper sections of the Itajaí Basin, and zircon dating of a rhyolite stock indicates a minimum depositional age of 549 ± 4 Ma. These dates are compatible with the previous assignment of an Ediacaran age to the sediments based on the discovery of Ediacara-type fossils such as Parvancorina, Charniodiscus, Cyclomedusa, and Aspidella. The U-Pb detrital zircon ages show a change in the sedimentary input from the base to the top. At the base, zircon grains from the Transamazonian and Brasiliano/Pan-African orogenic cycles occur as major sources with some Archean contribution. The upper section is dominated by Brasiliano/Pan-African zircon grains, most of which range in age from 824 to 770 Ma and 656 to 563 Ma. Pb and Sm-Nd whole rock isotope data suggest that the main source area for the basin infill was a reworked crust such as the Dom Feliciano Belt. We also present the regional correlation of the Itajaí Basin with the basins formed during the late stages of the SW Gondwana.