Zircon U-Pb ages and Hf isotopes tracking the origin of Permian Paraná Basin ash-fall layers: are they coming from Choiyoi formation? - Marques dos Santos, M. M.; Passarelli, Claudia Regina; Basei, Miguel Angelo Stipp; Saad, Antonio Roberto; Santos, Paulo Roberto dos; Siga Júnior, Oswaldo (South American Symposium on Isotope Geology, 2022)