The Campanian - Maastrichtian (Late Cretaceous) climate transition: the history of palaeoceanographic changes

白垩纪晚期的特征是地球系统从白垩纪温室过渡到较冷的新生代气候，其中包括全球碳循环中的几次扰动。该项目的目的是研究热带太平洋（沙茨基隆起1210B地点）海洋环流和深水形成的历史变化与最新坎帕尼亚至早期马斯特里希特碳同位素事件（CMBE和MME）的关系。利用高分辨率底栖生物和浮游有孔虫稳定同位素分析，在碳同位素事件过程中重建了表层和深水温度的变化历史。利用放射性成因同位素（Nd）对海洋环流和不同深、中层水团源区的变化进行解读。对来自热带太平洋、南大西洋和南大洋的大块沉积物的氧化铁涂层进行Nd同位素分析，将有助于重建深水同位素特征。通过对热带太平洋不同位置水团流量的比较，重建其与碳循环扰动的关系。因此，在不同海洋和陆架海剖面之间发展的年龄模型比较提供了独特的机会来识别碳循环和海洋环流之间的领先和滞后。

The latest Cretaceous was characterised by the transition of the Earth´s system from the Cretaceous greenhouse to the cooler Cenozoic climate that includes several perturbations in the global carbon cycle. The aim of this project is to investigate the history of changes in ocean circulation and deepwater formation in the tropical Pacific (Site 1210B, Shatsky Rise) relative to the latest Campanian to early Maastrichtian carbon isotope events (CMBE and MME). The history of changes in surface- and deep-water temperature will be reconstructed in the course of the carbon isotope events using highresolution benthic and planktic foraminiferal stable isotope analyses. Changes in ocean circulation and the source regions of different deep and intermediate water masses will be deciphered by using radiogenic isotopes (Nd). Nd isotope analyses of ferromanganese oxide coatings of bulk sediments from the tropical Pacific, the South Atlantic and the Southern Ocean will allow the reconstruction of deep-water isotope signatures. By comparison of different locations past water mass flow in the tropical Pacific and its relationship to carbon cycle perturbations will be reconstructed. Thereby, the developed age-model comparison between various ocean and shelf-sea sections provides the unique opportunity to recognize leads and lags between the carbon cycle and ocean circulation.