Bündelantrag PASADO-Support 2: Qualitative environmental and climatic reconstruction for the last glacial interglacial cycles in southern Patagonia - the stable isotope record of the ICDP site Laguna Potrok Aike, Argentina (PASADO-Isotope)

本项目的总体目标是研究南半球中纬度（52°S）的末次冰期-间冰期旋回。在阿根廷南部巴塔哥尼亚干草原上的一个770年前的马尔湖——拉古纳波托克湖的沉积物记录钻探，提供了环境和气候变化的独特记录。结果将与海洋南大洋和南极冰芯数据以及模型结果进行比较，并有助于了解全球气候如何相互作用。沉积有机质和湖相碳酸盐的稳定同位素研究将集中在岩心捕集器样品和中部盆地的完整复合剖面上。有机碳和氮同位素将有助于了解湖泊初级生产和有机质来源。湖泊碳酸盐、植物大残骸和沉积纤维素的氧碳同位素组成将有助于评估南巴塔哥尼亚水循环的变化。在与国家和国际科学小组的合作下，这些调查将以几千年至几十年的分辨率提供定性的气候和环境重建。研究结果将揭示与南极绕极流相互作用的南半球西风带的强度和纬向位置在半球和全球水分和能量分布中的时间变化。总之，这些结果提供了与生态过程和气候强迫直接或间接相关的湖泊生产力、有机质来源、异域沉积物供应和水文变化的信息。

As the overall aim, this project focuses on studying the last glacial-interglacial cycle of the Southern Hemispheric mid-latitudes (52°S). Drilling of the sediment record of Laguna Potrok Aike, a 770 ka old maar lake in the dry steppe of southern Patagonia (Argentina), provides a unique record of environmental and climate variations. Results will be compared with marine Southern Ocean and Antarctic ice core data as well as with modelling results and help to understand how climate interacts globally. Stable isotope investigations of sedimentary organic matter and lacustrine carbonates will focus on core catcher samples and the complete composite profile from the central basin. Organic carbon and nitrogen isotopes will give insights into lacustrine primary production and organic matter sources. Oxygen and carbon isotope composition of lacustrine carbonates, plant macroremains and sedimentary cellulose will allow evaluating changes in the hydrological cycle of southern Patagonia. In collaboration with national and international science teams these investigations will make available qualitative climate and environmental reconstructions at multi-millennial to multi-decadal resolution. The results will give insights into temporal changes of intensity and latitudinal position of the Southern Hemisphere Westerlies interacting with the Antarctic Circumpolar Current in the hemispheric and global distribution of moisture and energy. Altogether, these results provide information on lacustrine productivity, origin of organic matter, allochthonous sediment supply and hydrological variations that are directly and indirectly related to ecological processes and climatic forcing.