Geochemical and palynological evidence for the age determination of Permian coals, southern Brazil

A correlation between palynostratigraphic data and an absolute age determination of Permian of the Paranل Basin in southern Brazil are established for the first time, mainly through the study of coal-bearing strata of the Candiota Coalfield. Prior palynofloristic studies about these Permian coals and associated rocks assigned the microfloras identified in the coals to the Caheniasaccites ovatus subzone (Artinskian/Kungurian). The absolute age determination made on tonstein interbedded in the Candiota Upper Coal Seam, using U/Pb, indicates an age of 267.1±3.4 Ma. Palynological analyses performed on samples of this tonstein show the presence of a microfloristic association that can be included in the same biostratigraphic zone as the coals. Integration of the data obtained by these different methods and the available data on stratigraphy sequence studies of the southern portion of Paranل Basin show that the C. ovatus subzone related to coal-bearing strata must be restricted to the Kungurian until the base of the Roadian.