The stratigraphy and depositional environments of China' s sea shelves since MIS5(74-128)ka

Based on the comprehensive analysis of 28 boreholes of late Quaternary sedimentation and the high-resolution seismic profiles, the authors studied the stratigraphic characteristics identification and sedimentary environment rebuilding by comparing the results of other 46 boreholes as references in China's sea shelves. Three distinct transgression processes were discovered in the shelves of China's sea areas, with 3 marine strata well preserved. The strata of MIS1 and MIS3 are relatively thin in the Bohai Sea and the East China Sea, but thick in the Yellow Sea. There exists little sedimentation of Last Glacial period in the Bohai Sea and the Yellow Sea, but there have been quite integrated sedimentation units without obvious hiatus in the East China Sea since 100 ka B.P.. There were coastal and continental deposits in the inner shelf and nearshore and neritic deposition in the outer shelf of the South China Sea during late Pleistocene, with neritic sedimentation in Holocene. As a whole, the sedimentary environment changes of China's sea shelves since MIS5 in turn primarily were neritic and offshore deposits in MIS5 (74-128 ka), continental sedimentation of lagoon-fuvial-coast in MIS4 (60-74 ka), neritic and tidal flat deposits in MIS3 (24-60 ka), terrestrial or fluvial sedimentation in MIS2 (12-24 ka), and tidal sand ridge and neritic deposition in Holocene. Furthermore; the neotectonic movement and regional subsidence also influenced the late Quaternary stratigraphic development and their preservation in China seas. The results will provide direct evidence for the study of China's Quaternary sedimentation and global climate changes