Objective There has been considerable debate about the definition of the lower boundary of Nanhua System by far.One definition is based on sedimentary sequence of different stages of basin evolution,focusing on whether deposits of the Banxi Period should be classified as Nanhua System.Another is the onset time of Nanhua glacial period. Objective There has has been debate about the definition of the lower boundary of Nanhua System by far. One definition is based on sedimentary sequence of different stages of basin evolution, focusing on whether deposits of the Banxi Period should be classified as Nanhua System. Another is is the onset time of Nanhua glacial period.