Long-term evolution of late Pliocene to mid-Pleistocene bottom current regime in response to intermediate water circulation in the NE-Atlantic

拟议的项目将详细阐述上新世-更新世古水流强度的长期历史，以响应北大西洋漂流沉积物产生NADW的主要地点之一附近的深水和中水形成。从底流输送的细沉积物中解开粉砂大小的浮冰碎屑的最新进展将用于建立可靠的古海流记录，从而在重大环境变化时期建立海流强度的变异和进化。细砂和粉砂组分的详细粒度分析将为端元模型提供基础，端元模型是一种数学统计方法，用于分解不同粒度组分但来源不同的沉积物。通过区分泥沙大小的冰筏漂移和底流沉积物输运，我们将能够整合上新世/更新世深水地层和温盐环流环下游古流强度重建区域的高纬度海洋结果，从而更好地了解这一全球系统的物理流动机制。

The proposed project will elaborate a long-term history of Pliocene-Pleistocene palaeocurrent strength in response to deep and intermediate water formation close to one of the main locations of NADW production from drift sediments in the North Atlantic. Recent progress in unravelling ice-rafted debris of silt size from bottom current transported fine sediments will be used to establish a reliable palaeocurrent record, and thus the variability and evolution in current strength during times of significant environmental changes. Detailed grain-size analysis of the fine sand and silt fraction will provide the base for the end-member modelling, a mathematical-statistical approach to unmix sediments of distinct size fractions but different in their origin. By the differentiation of silt-sized ice-rafted bias from bottom current sediment transport, we will be able to integrate the results from the high-latitude oceans in Pliocene/Pleistocene deep-water formation and palaeocurrent strength reconstructions regions further downstream in the thermohaline circulation loop for a better insight into the physical flow regime of this global system.