The position of the Rupelian/Chattian boundary in the southern Upper Rhine Graben based on new records of microfossils

摘要: This study analyses the regressive phase of marine Froidefontaine Subgroup and subsequent fluvio-lacustrine Niederroedern formation in southern Upper Rhine Graben during Late Rupelian position Rupelian/Chattian boundary. The is based on sedimentary record several microfossil groups from two boreholes, with a focus new records fish otoliths, Bolboforma Charophyta. biostratigraphic evaluation these provides evidence for boundary within upper Formation. contrary to results previous sedimentological approach, which places at base fauna indicates biogeographic relation France, Molasse Basin Switzerland Germany.