Marine Isotope Stage 11 in the Pacific Southern Ocean; a coccolithosphore perspective

该项目旨在对南大洋太平洋海域的晚更新世间冰期海洋同位素阶段（MIS 11）有新的认识，目前该地区的资料很少。MIS 11（约424至374 kyr之间）是一个独特的异常漫长的间冰期，通常被认为是全新世在没有任何人为干扰的情况下的模拟。在这段时间内，在南方高纬度地区观测到碳酸盐含量高的白色厚层。本文拟对R/V Polarstern ANT XXVI/2南极南极考察中获得的MIS 11沉积物（PS75/091、PS75/079、PS75/076、PS75/059、PS75/047和PS75/046）的球粒石群数据进行综合、多参数记录。为了表征球砾石古生产力，将使用两个独立的指标：纳米化石堆积率（NAR）和不同粒级球砾石Sr/Ca比值。此外，还将评估主要物种Gephyrocapsa caribbeanica的碳酸盐对总上层碳酸盐产量的贡献，并对碳酸盐溶蚀进行量化。所有检索到的信息将使我们能够评估粒石藻是否在MIS 11期间改变了南大洋太平洋段无机碳系统的平衡。

This project aims to get new insights into the late Pleistocene interglacial Marine Isotope Stage (MIS 11) in the Pacific sector of the Southern Ocean, where little information is available. MIS 11 (between ca. 424 and 374 kyr) is a unique exceptionally long interglacial period often regarded as an analogue of what the Holocene would have been without any anthropogenic interference. Thick white layers with high carbonate content have been observed at high southern latitudes during this time interval. We intend to elaborate an integrated, multi-parameter record of coccolithophore data on MIS 11 sediments retrieved during R/V Polarstern ANT XXVI/2 expedition in the polar South Pacific (cores PS75/091, PS75/079, PS75/076, PS75/059, PS75/047 and PS75/046). In order to characterize the coccolithophore palaeoproductivity two independent proxies will be used: the Nannofossil Accumulation Rate (NAR) and the coccolith Sr/Ca ratio measured in different coccolith size fractions. In addition, the carbonate contribution of the main species Gephyrocapsa caribbeanica to the total pelagic carbonate production will be assessed and the carbonate dissolution quantified. All the information retrieved will allow us to evaluate if the coccolithophores modified the equilibrium of the inorganic carbon system during MIS 11 in the Pacific sector Southern Ocean.