Planktonic foraminifera and sea surface temperature (SST) of the Xisha Trough, South China Sea since Last Glaciation

The high-resolution analysis on the carbon and oxygen isotopes and planktonic fo-raminifera of core SA12-19 dated with 14C approach in the Xisha Trough of South China Sea indi-cates that sediments are attributed to oxygen isotope stages 1—3 (stage 3 is not included com-pletely), during the late-glacial to post-glacial periods. The sea surface temperature (SST) of each sample is calculated based on palaeoecological transfer functions (FP-12E). The results reveal a gradual thermocline increase in this area during oxygen isotope stages 1—3 e.g. a temporal thermocline deepening in the middle Holocene. During the Holocene, the SST was 23.3—27.2℃ in winter, 28.8—29.8℃ in summer. During oxygen isotope stage 2, the SST was 21.4—24.4℃ in winter, 28.1—29.0℃ in summer; and 21.9—25.2℃ in winter, 28.5—29.3℃ in summer during oxygen isotope stage 3. The SST in winter during oxygen isotope stage 2 was 2—6℃ lower than that of stage 3. During the transitional period, a Younger Dryas Event, standing for a rapid cli-mate return, occurred obviously.