Lower Triassic Conodont Zonations of Chaohu Area, Anhui Province and Their Global Correlation

The paleogeographical setting of Chaohu during the Early Triassic was in the deep part of the Yangtze platform and the Lower Triassic sequence is complete throughout with rich and various fossils, especially distinct ammonoid and conodont biostratigraphic sequences, and it is one of the most typical sections of Early Triassic chronostratigraphy in the world. Lower Triassic conodont fossils were systematically collected from continuous sections of West Pingdingshan, North Pingdingshan and South Majiashan, Chaohu, Anhui Province on a sample-by-sample basis. Detailed zonations are made in each section. Eight conodont stratigraphic zones have been distinguished. They are, in ascending order, Hindeodus typicalis Zone, Neogondolella krystyni-Neogondolella planata Zone, Neospathodus kummeli Zone, and Neospathodus dieneri Zone, Neospathodus waageni Zone, Neospathodus pingdingshanensis Zone, Neospathodus homeri Zone, and Neospathodus anhuinensis Zone. They may be precisely correlated with contemporaneous ones in North America and other areas. These data are reliable evidence for erecting the global stratotype of the Induan-Olenekian boundary (GSSP).