GEOLOGICAL RECORDS OF LATE CENOZOIC TECTONO-SEDIMENTARY-PALEOCLIMATIC EVENTS IN CHINA

The focus of China's regional geological survey is being shifted to the largely overburden areas such as plains, basins, grasslands and deserts, and to the deep three-dimensional survey as well. The regional geological survey in Quaternary loose sediment covered area aims to reveal the surface process and the relationship between different spheres in late Cenozoic, and to explore the relationship between man and nature. However, a great difficulty in geological mapping in the covered area is that the lateral extension of Quaternary loose sediments is commonly unstable. Special attention should be paid to significant tectonic, sedimentary, paleoclimatic and paleoenvironmental events, such as unconformities, erosion surfaces, volcanic rocks, lacustrine deposits, transgressive layers, paleoclimatic deposits(loess, laterite, black soil, etc.) and paleocultural layers. They are often isochronous and can serve as important signs of lateral correlation of Quaternary loose sediments. The tectono-geomorphic evolution of East Asian continent are mainly controlled by two geodynamic systems: the Indian-Eurasian plate collision in the west, making rapid uplift and northeastward extension of the plateau, and the subduction of the eastern Pacific plate towards the Eurasian continent, forming a complex trench-arc-basin system on the eastern edge of the East Asian continent. The two tectonic systems have established the geological background of China since late Cenozoic, resulting in significant changes in the earth's deep process and surface environment. The overall performance is the uplift of the Qinghai-Tibet Plateau and the extension and thinning of eastern lithosphere, which finally shaped the current landform and water system pattern. According to these characteristics of Quaternary loose sediment cover, this paper analyzes the important tectono-sedimentary-paleoclimatic events since late Cenozoic in China, and summarizes the geological records of these events, especially the important sedimentary layer, erosion surface, unconformities, transgressive layers, etc., so as to make a regional comparison of Quaternary loose sediment in the regional geological survey of the covered area.