Integrated stratigraphic regionalization of eastern China sea areas and adjacent land and their characteristics

The geology of Eastern China seas has been the interest of scholars for a long time because of its complicated tectonic patterns and stratigraphic frameworks. However, the research level of stratigraphy is quite different from the sea to the land. Enormous data is available in the land area so that the research degree is quite high, while the degree of research in the sea area is low because of the restriction of various conditions. In addition, the stratigraphic regionalization is mainly done for land areas, no any sea-land unified classification of stratigraphic regions has been reached so far, which restricts the deep understanding of the stratigraphic development characteristics in the east part of China. Using the geological mapping data on scale of 1∶1 million and larger carried out in recent years, this paper made an integrated stratigraphic regionalization for the eastern China seas and adjacent areas. Systematic studies of the stratigraphic development characteristics are made with focus on the stratigraphic characteristics and sedimentary evolutionary history for the region to the north of Taiwan since Mesozoic. The results show that the eastern China seas and adjacent areas belongs to a first order stratigraphic region (Eurasian), 5 second order and 13 third level stratigraphic subregions. For the major sea basins, the Bohai Sea area belongs to the North China Plain stratigraphic region, and the North Yellow Sea the Liaodong stratigraphic region. The South Yellow Sea is mainly located in the Lower Yangtze stratigraphic region, while the East China Sea and the Okinawa Trough mainly located in the East China Sea stratigraphic region. Since Mesozoic, the basins in the eastern China Seas have suffered complicated tectonic-sedimentary evolution, and the stratigraphic development characteristics are obviously different. The results of this paper extend the stratigraphic regionalization from the land to the sea and the understanding of the stratigraphic characteristics in the east part of China is deepened.