Third-Order Sequence Division of Yunmengshan and Baicaoping Formation of Proterozoic in Yuxi District of China: an Example from Xiatang Profile in Lushan

There are controversies on the Proterozoic stratigraphic genesis, division, correlation and palaeogeographical evolution of western Henan in China. Based on the basic description of sedimentary facies, Yunmengshan and Baicaoping formation of Proterozoic typical section in western Henan is divided into 4 third-order sequences. Sequence stratigraphy framework which reflects sedimentary and overlap is established with basis of two kinds of facies-change surface and two kinds of diachrononism in stratigraphical records. Although chronostratigraphic belonging of Precambrian strata is controversial and Precambrian sequential stratigraphic study is tremendously challenging, the establishment of sequence stratigraphy framework of proterozoic Yunmengshan and Baicaoping formation in western Henan provides actual data to reshape palaeogeographic pattern of Palaeoproterozoic North China craton. What is more, it becomes a typical example of characteristics and exploration of stratigraphic accumulation under the background of tidal action.