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

在过去的20年里，北大西洋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岩心记录了末次冰期周期千年和次米兰科维奇尺度的气候变化。我们建议利用IODP第303航次北大西洋I期间获得的材料将记录进一步推回到过去，这将扩展对过去气候变率的研究。四马。我们在这里提出了一个多参数的方法，地球化学和微体古生物代理重建晚上新世更新世的历史，生物硅沉积在东北大西洋...特别是，我们将解决蛋白石生产的变化与海洋环流的变化，全球气候的历史，以及生产硅质和钙质生物之间的转变。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，作为水团，营养物质可用性和保存变化的代理。此外，我们打算确定硅藻阀溶解的变化与快速的气候事件和长期的气候模式在东北大西洋。

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.