Dynamics of biogenic silica sedimentation in the NE Atlantic during the late Pliocene - Pleistocene

北大西洋在过去20年里推动了古海洋学领域的发展，这在很大程度上是因为使用传统的活塞芯记录了上一个冰川周期中千年和米兰科维奇以下尺度的气候变化。我们在这里建议利用IODP第303次北大西洋航段获得的材料，将这一记录进一步向前推，这将延长对过去约4 Ma气候变异性的研究。我们提出了一种基于地球化学和微古生物学指标的多参数方法来重建东北大西洋晚更新世-晚更新世生物成因硅沉积历史。特别是，我们将讨论与海洋环流变化、全球气候历史以及硅质和钙质生物生产之间的转变有关的蛋白石生产的变化。由于硅藻实际上是最重要的硅质生产者，我们还将探索硅藻群落的短期和长期变化，作为水体质量、养分有效性和保存性变化的指标。此外，我们打算确定与东北大西洋快速气候事件和长期气候模式相关的硅藻瓣膜溶解的变化。

The North Atlantic has driven the field of paleoceanography over the last 20 years, in large part because of progress in documenting millennial - and sub-Milankovitch-scale climate variability over the last glacial cycle using conventional piston cores. We propose here to push the record further back in time utilizing the material gained during IODP Leg 303 North Atlantic I which will extend the study of climate variability over the last ca. 4 Ma. We propose here a multiparameter approach based on geochemistry and micropaleontology proxies to reconstruct the late Plio-Pleistocene history of biogenic silica sedimentation in the NE Atlantic... In particular, we will address the variations of opal production related with ocean circulation changes, global climatic history, and the shift between production of siliceous and calcareous organisms. Since diatoms are actually the most important siliceous producers, we will also explore the short and long-term variations in the diatom community as proxy for changes in water masses, nutrient availabilty and preservation. In addition, we intend to determine the variations of diatom valve dissolution associated with rapid climate events and long-time climate patterns in the NE Atlantic.