Calcareous plankton response to early Paleogene climate change

在拟议的研究中，将在第401站调查从最晚的古新世到中期始新世的地表水状况所反映的长期气候变异性。该遗址位于比斯开湾，是提供古近纪碳酸盐的最北部的遗址之一。第401号站位由整个研究区间的连续沉积记录组成，包含保存完好的钙质超微化石和浮游有孔虫。在全球范围内，研究间隔的特点是始新世早期气候最佳，随后逐渐冷却，最终导致渐新世冰库，如底栖有孔虫三角洲818O所示。对这段时间内的地表水状况知之甚少，因为关于钙质超微化石和浮游有孔虫的研究很少，而在这项研究中，旨在破译浮游生物对古近纪长期气候变化的反应。为了实现这一目标，将在401号站点汇编多物种浮游有孔虫同位素记录，这将为我们提供有关水文情况的信息，并与钙质浮游生物群落的变化进行比较。这些数据将使我们能够更好地理解环境变化、生态和钙质浮游生物在这一关键时期的演变之间的相互作用。

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.