Calcareous plankton response to early Paleogene climate change

在提出的研究中，将研究DSDP 401站点从最新古新世到中始新世的长期气候变率，以地表水条件为反映。该遗址位于比斯开湾，是提供古近纪碳酸盐的最北部遗址之一。DSDP 401遗址是一个连续的沉积记录，包括保存完好的钙质纳米化石和浮游有孔虫。在全球范围内，研究区间以早始新世气候最佳期为特征，随后逐渐冷却，最终导致渐新世冰窖，底栖有孔虫三角洲818O表明了这一点。由于对钙质纳米化石和浮游有孔虫的研究很少，因此对这段时间的地表水条件了解较少，本研究旨在破译浮游生物对长期古近纪气候变化的响应。为实现这一目标，将编制401站点的多物种浮游有孔虫同位素记录，为我们提供水文情况信息，并与钙质浮游生物群落的变化进行比较。这些数据将使我们对这一关键时期的环境变化、生态和钙质浮游生物进化之间的相互作用有更深入的了解。

In the proposed study long-term climate variability as reflected by surface water conditions will be investigated from the latest Paleocene to the Middle Eocene at DSDP Site 401. This site is situated in the Bay of Biscay and represents one of the most northern sites which provide Paleogene carbonates. DSDP Site 401 consists of a continuous sedimentary record through the study interval and contains well preserved calcareous nannofossils and planktic foraminifera. Globally, the study interval is characterized by the Early Eocene Climatic Optimum and the subsequent gradual cooling finally leading to the Oligocene icehouse as indicated by benthic foraminiferal Delta 818O. Less is known about the surface water conditions during this interval, because only few sites have been studied with respect to calcareous nannofossils and planktic foraminifera yet In this study it is intended to decipher the response of planktic organisms to the longterm Paleogene climate changes. In order to achieve this goal multi-species planktic foraminiferal isotope records will be compiled for Site 401, which will supply us with information on the hydrographical situation, and compared to changes in the calcareous plankton communities. These data will allow us to improve our understanding on the interplay between environmental change, ecology and evolution of calcareous plankton during this crucial interval.