Early Pleistocene Variability of SST Record by Foraminifera shell Mg/Ca ratio at IODP Site U1313, North Atlantic

摘要

In this paper, we measured Mg/Ca ratio in planktonic foraminifera shell of Globigerinoides ruber (white) from early Pleistocene (2414.2～2253.77ka) North Atlantic deep sea sediment drilled at Site U1313, IODP Expedition 306, and tested 6 transform functions that used to reconstruct sea surface temperature(SST) with foraminifera shell Mg/Ca ratio, the result showed that the theoretical equation of Elderfield and Ganssen (2000) and the equation of Anand (2003) both are appropriate, but there is big difference between their results, so we use their average value as the final results to reflect SST in the North Atlantic area in early Pleistocene. The fluctuation of the SST we reconstructed and that of the benthic foraminifera oxygen isotopic are basically same, but in the stages of MIS 87 to 95, there exist 2.71ka to 19.54ka error, probably it was caused by the difference of the response to changes in water temperature between the planktonic foraminifera and the benthic foraminifera.