Relations between sedimentary sequence and paleoclimatic changes during last 200 ka in the southern South China Sea

Abstract

Core NS-93-5 was taken from the mild slope terrace of the southern South China Sea (SCS), which has preserved the steadiness depositional record of the normal marine environment since late Quaternary. Sedimentary sequence and oxygen isotopic stratigraphy of high resolution in the near 200 ka of the southern SCS has been established. By the comparative analysis with GISP2's ice core, the depositional record of D/O's events 1-21 and Heinrich's events H1-H6 in the southern SCS that reflected the quick climate change in short time scale since the last interglacial stage is revealed, which indicates that in the last 200 ka in the southern SCS and the Arctic area there was tele-connection of paleoclimate and the unstability of the Western Pacific Warm Pool. This note shows that the sedimentary layers order of this sea area classified by color identification and by oxygen isotope stratum has the very good corresponding relation. The color feature of sediment changes along with the climate and the former arranges a stagnant time of 1-1.5 ka generally. It was suggested that the paleoclimatic changes resulted in the rise and fall of sea level, the open and close of strait thoroughfare and the upwelling activity, which causes the changes of the oxidation-reduction condition of deep water along with the dynamic environment in this sea area, thus producing the different sediment features of sea bed. In addition, a volcanic ash layer, about 17 cm thick, has been found in the transition of oxygen isotope 4/5 stage, which is related wit the Toba's volcanic eruption.