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 paleoenvironmental reconstruction and decipherment of land-sea interactions. Since the 1990s, different perspectives on global glacioclimate magnitudes and the associated evolution of major sedimentary environments during the Late Pleistocene have caused a distinctive understanding of marine transgressions and coastal deposits during MIS 3 and MIS 5. Moreover, the chronology of sediment sequences from this region was 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 the issues. 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 western coast of the South Yellow Sea (SYS), and the marine sediments were recognized by the paleontological fossils. The results indicate three terrestrial-marine sedimentary cycles since MIS 5, including the MIS 5, MIS 3, and MIS 1 marine transgressions as well as the MIS 2 and MIS 4 marine regressions in the coastal plain and offshore area of the SYS. Meanwhile, there was a major sedimentary hiatus during MIS 2 and MIS 4 due to strong erosions. Different dating methods on these regional cores, including AMS 14 C and OSL, have confirmed the existence of the MIS 3 marine transgression in the SYS. The intensity of marine transgression and the height of sea levels during MIS 3 and MIS 5 recorded in sediments were dominated by the changes of global climate-driven glaciers and regional tectonic movement.

Chronology of a Holocene Core From the Pearl River Delta in Southern China

“…Previous studies compared ages by both radiocarbon and OSL dating methods on delta deposits. In studies of transgression events during the last glacial-interglacial period in coastal areas of eastern China, most 14 C dating ages fell into MIS 3 (e.g., Huang et al, 1982;Lin et al, 1989;Yim et al, 1990;Liu et al, 2009;Yin et al, 2016;Ye et al, 2017). These dating results could be problematic due to the limits of 14 C dating (Yim et al, 1990;Yi et al, 2013;Lai et al, 2014;Song et al, 2015;Yu et al, 2019), including the "reservoir effects" in coastal deposits (Stanley and Chen, 2000;Alves et al, 2015), the "new" carbon introduction during exposure (Yim et al, 1990), and the restricted theoretic upper limit to 50 ka (Reimer et al, 2013) or pracitcal upper limit to only 25-30 ka (Lai et al, 2014;Song et al, 2015;Yu et al, 2019).…”