Latest Devonian–Early Mississippian conodont biostratigraphy in the Naqing section, Guizhou, South China

Abstract

The Naqing section in Luodian (Guizhou, South China) contains a deep-water carbonate-dominated succession of the Late Devonian through the Permian. In this study, 72 conodonts species/subspecies of 11 genera were obtained from the lower part of this section including. Seven middle to late Famennian and four early to late Tournaisian conodont biozones were recognized as, in ascending order, Palmatolepis marginifera marginifera Zone, Palmatolepis marginifera utahensis Zone, Polygnathus granulosus Zone, Palmatolepis rugosa trachytera Zone, Polygnathus styriacus Zone, Palmatolepis gracilis manca Zone, Palmatolepis rugosa rugosa Zone, Siphonodella isosticha Zone, Gnathodus punctatus Zone, Gnathodus typicus-Gnathodus cuneiformis Zone, and Gnathodus typicus-Protognathodus cordiformis Zone. Several key conodont biozones across the Devonian–Carboniferous Boundary (DCB) interval found elsewhere are not discovered in the Naqing section, likely due to a conodont-barren interval in the siliciclastic facies. The middle Famennian–late Tournaisian conodont biozones illustrated in this study provide a robust chronostratigraphic framework for further research on biotic and paleo-environmental events during the Late Devonian through Early Mississippian critical greenhouse-icehouse climate transition.