Terrestrial-marine sedimentary cycles in the South Yellow Sea, China: implications for paleoenvironmental reconstruction since MIS 5

Abstract

Sedimentary records of the continental shelves since Marine Isotope Stage (MIS) 5 are valuable for paleoenvironmentalreconstruction and decipherment of land sea interactions. Since the 1990s, different perspectives on global glacioclimate magnitudesand the associated evolution of major sedimentary environments during the Late Pleistocene have caused a distinctive understanding ofmarine transgressions and coastal deposits during MIS 3 and MIS 5. Moreover, the chronology of sediment sequences from this regionwas primarily determined based on radiocarbon dating, which might be problematic for deposits of 40 50 ka BP or older. In this study,we used both a 150-m-long sedimentary core (YZ07) as a typical record and 12 collected regional boreholes as a synthesis to resolve theissues. On the basis of an age model of accelerator mass spectrometry (AMS) radiocarbon and optically stimulated luminescence (OSL)dating, the sedimentary sequences during the period from MIS 5 up to MIS 1 were documented by Core YZ07 drilled from the westerncoast of the South Yellow Sea (SYS), and the marine sediments were recognized by the paleontological fossils. The results indicate threeterrestrial-marine sedimentary cycles since MIS 5, including the MIS 5, MIS 3, and MIS 1 marine transgressions as well as the MIS 2and MIS 4 marine regressions in the coastal plain and offshore area of the SYS. Meanwhile, there was a major sedimentary hiatus duringMIS 2 and MIS 4 due to strong erosions. Different dating methods on these regional cores, including AMS14 C and OSL, have confirmedthe existence of the MIS 3 marine transgression in the SYS. The intensity of marine transgression and the height of sea levels during MIS3 and MIS 5 recorded in sediments were dominated by the changes of global climate-driven glaciers and regional tectonic movement.