Research advances, a subdivision and correlation of the Meso-Neoproterozoic stratigraphy in China

This paper systematically sorts out the Meso-Neoproterozoic stratigraphic problems on the Stratigraphic Chart of China (2014), based on the achievements of relevant experts and the author's team in stratigraphic chronology in the past 10 years. By combining the results with the spatio-temporal development and correlation relationship of geological events, the study focuses on studying the definition of the bottom boundary of the Mesoproterozoic and the Mesoproterozoic Undefined System, the stratigraphic relationship in the Meso-Neoproterozoic transition period, and the division of the lower boundary of the Cryogenian, as well as the timing of the Tonian Luoquan glaciation. On this basis a subdivision and correlation framework of the Meso-Neoproterozoic strata of China are presented and the similarities and differences among the North China, Yangtze, and Tarim block discussed. The research indicates that it is more reasonable to set 1800 Ma (or 1780 Ma) as the lower boundary of the Mesoproterozoic than 1600 Ma. Although the Mesoproterozoic Undefined System is developed in both the northern and southern margins of North China and South China block, the Shennongjia Group in the northern margin of the Yangtze block is more favorable than others and as a result, suggested as the temporary stratotype of the Undefined System in China for focused research. The proto-Qingbaikou System in Jiao-Liao-Xuhuai-Ji-Yu of the North China block, is probably older than 1000 similar to 820 Ma), i. e., parts of it belong to the Mesoproterozoic. We propose that the proto-Nanhuan System corresponds to the international Cryogenian (720 similar to 635 Ma). The Qingbaikou System is bounded by a tectonic plane dated to 820 Ma-its lower part is named as the Lower Series of the Qingbaikou System (1000-820 Ma), and the upper part is named as the Upper Series of the Qingbaikou System (820 similar to 20 Ma). The decision on whether to divide these into two systems will be made when more evidence becomes available. The Luoquan Formation and coeval strata in the southern margin of North China block probably belong to the upper Sinian (Ediacaran). Our research provide data, evidence and the reference subdivision, to revise and improve for "the Meso-Neoproterozoic" division and correlation in the Stratigraphic Chart of China.