Cretaceous Continental Sedimentology And Paleogeography In China

Continent is an important part of earth surface system. Some important event happened in Cretaceous occurred on continent too. Scientists had realized that it is impossible to research the characteristic and mechanism of earth surface system changing in Cretaceous. East Asia is the largest continent in Cretaceous. China lies in its east margin. It is important to research Cretaceous stratum in China. They contain information of tectonic system change, basin-mountain coupling, and climate change.Continental stratigraphic framework in China is the base of this paper. Basis in the former study, a new stratigraphic framework which includes many new data of lava ages, biostratigraphy and magnetostratigraphy is established. Cretaceous stratums only occur in western China in early Early Cretaceous and they grow all over China in late Early Cretaceous, In early Late Cretaceous, northwestern China and northeastern China except Songliao basin are lack of Cretaceous stratum. Cretaceous stratums occur locally in North China and southeastern China but they extensively occur in southwestern and central South China through early Late Cretaceous. In late Late Cretaceous, southeastern China and North China are lack of Cretaceous stratum and Cretaceous stratums occur locally in northwestern and northeastern China but they extensively occur in southwestern and central South China.Based on the study of lithofacies, filling sequence, basin type and sedimentary facies from many typical profiles in different basins, Cretaceous continental stratums are divided into six types which are named Northeast area, Northwest area, North China area, Southwest area, Central South area and Southeast area. It is considered that basins in Southwest area and Northwest area are flexural basins. They are filled by red bed which is formed in river and lake system under arid to semi-arid climate. Northeast area, North China area, Central South area and Southeast area lied in a huge rift basin system. The differences between these basins in filling sequence are controlled by both tectonic activity and climate.Reconstruction of the paleogeography of China in Cretaceous is the most important matter. Under the help of continental Cretaceous stratum data-base, Cretaceous dinosaurs and'special deposition'in China are checked. And the boundary of the land in China has been suggested. A chart named'Data chart of Cretaceous paleography in China'has been finished. And Cretaceous paleogeography in China has been reconstructed. A huge plateau named'East plateau'lied across the east margin of China, and basins lied in western China in early Early Cretaceous. In late Early Cretaceous, eastern China is under extension condition. Sediment basins are exist all over China. The Da Hinggan-Taihang mountain-Huaying mountain and Qilian mountain-Qinling-Dabie mountain have existed and they are the boundary of western-eastern China and North-South China. There is a huge plateau in central Asian, which is named Ancient Asian plateau. North area and Northeast area (except Songliao basin) lifted in early Late Cretaceous. In late Late Cretaceous, North China plateau and east range exist. Northeast area and Northwest area are locally filled by clastic rock formed in river and lake. Central South area and Southeast area are the main depositional location through Late Cretaceous.