Sortable silt analyses on IODP Expedition 382 Scotia Sea sites

斯科舍海的沉积记录保存了南极冰盖的主要振荡、南大洋海洋格局的变化和主要区域构造事件的信息。在国际大洋钻探计划第382次考察期间，在斯科舍海钻探了三个地点。IODP第382次考察站在位于南极绕极海流锋南部和北部的斯科舍海两个著名盆地中恢复了从中新世晚期到今天的几乎连续的记录。在这段时间内，全球气候变化和南极冰盖的振荡引发了海洋格局的重大变化。因此，底流速度的变化将反映环境条件的变化，对全球温盐环流并进而对地球气候系统产生重大影响。我建议对从斯科舍海回收的IODP考察382站点的离散沉积物样品进行系统的可分选淤泥分析。从可分选粉砂分析中得到的细粒度分布已被广泛用于推断沉积时的古低速。将可分类的淤泥结果与区域地震地层学研究相结合，将重建斯科舍海的底流路径和速度及其随时间的变化。这将允许重建的海洋学模式的斯科舍海和德雷克海峡，以及其变化如何与南极冰盖的演变。总体而言，拟议的研究将允许底流分选，冰筏沉积和冰盖动态行为之间的比较。拟议研究的结果将揭示海洋格局的演变及其与南极冰盖演变的联系，涉及全球气候影响。

The sedimentary record of the Scotia Sea keeps the information of the major Antarctic Ice Sheet oscillations, variability in the oceanographic pattern of the Southern Ocean and main regional tectonic events. Three sites were drilled in the Scotia Sea during the International Ocean Drilling Program (IODP) Expedition 382. IODP Expedition 382 sites recovered an almost continuous record between late Miocene and present day, in two distinguished basins of the Scotia Sea located to the south and to the north of the South Antarctic Circumpolar Current Front. In this time frame, major changes in the oceanographic pattern were triggered by the global climatic variability and the oscillation of the Antarctic Ice Sheet. Thus, the changes on the speed of bottom flows would reflect changes in the environmental conditions with major impacts on the Global Thermohaline Circulation and by extension on the Earth climatic system. I propose to perform systematic sortable silt analyses on discrete sediment samples from the IODP Expedition 382 sites recovered in the Scotia Sea. Fine grain-size distributions derived from sortable silt analyses have been widely used to infer palaeoflow speeds at the time of sedimentation. Combination of the sortable silt results with regional seismo-stratigraphic studies will provide the reconstruction of bottom current paths and velocities in the Scotia Sea and their variability through time. This will allow the reconstruction of the oceanographic pattern of the Scotia Sea and the Drake Passage, and how its variability relates to the Antarctic Ice Sheet evolution. Overall the proposed research will allow comparison between bottom-current sorting, ice-rafted sedimentation and ice sheet dynamic behaviour. Results of the proposed study would reveal the evolution of the oceanographic pattern and its link to the Antarctic Ice Sheet evolution, involving global climatic implications.