Restudy of the Llandovery conodont biostratigraphy in the Xiushan area, Chongqing City, China

摘要

Previous studies of conodonts suggested that the upper member of the Xiushan Formation (late Llandovery) corresponds to the Pterospathodus eopennatus Superbiozone, but no data were obtained from the lower member in the Xiushan area. In this study, the entire Xiushan Formation was resampled from the Datianba section in the Xiushan area of Chongqing City on the Yangtze Platform in South China. In total, 40 samples were collected and processed. Fifteen of these samples contained identifiable conodont specimens. The present study indicates that the lower member and main part of the upper member of the Xiushan Formation correspond to the Pterospathodus eopennatus Superbiozone, while the top of the upper member probably correlates with the Pterospathodus celloni Superbiozone.