Evidence for paleoclimate changes from lignin records of sediment core A02 in the southern Yellow Sea since ~ 9.5 cal. kyr B.P.

Abstract

Sediment core A02 collected from the central Yellow Sea mud (CYSM) was analyzed for various lignin parameters to provide evidence for the paleoclimate changes in the southern Yellow Sea (SYS) area during the Holocene. The results showed that the variations of various lignin parameters were dominated by the hydrodynamic sorting process driven by climate factors, and in turn lignin records can well reflect paleoclimate changes during the Holocene. The paleovegetation of the Yellow River basin was dominated by nonwoody angiosperms, and the terrestrial organic matter in core A02 was highly degraded and mainly came from peat and surface soils. Compared with climate records in previous studies, we found that terrestrial organic matter indicator Ʃ8, marine organic matter indicator P phenols and vegetation parameters S/V, C/V ratios had the similar variation trends with the El Niño-Southern Oscillation (ENSO) on the millennial time scale and correlated well with the Bond events (0 to 6) and the East Asian Winter Monsoon (EAWM) on the multidecadal to centennial time scale. ENSO events dominated the long-term trends of the biomarkers in the SYS during the Holocene while EAWM for the shorter time scale. Lignin records of core A02 responded not only to the regional climatic factors such as the EAWM but also to the global climatic factors such as Bond events and ENSO. In addition to the global cold climate events, it also recorded other regional cold events (at around 3.7cal. kyrB.P., 6.5cal. kyrB.P. and 7.0cal. kyrB.P.) and coincided well with previous related records in the East Asian. These proved that the paleoclimate in SYS area was controlled by both regional and global climatic factors.