Analysis of Sediment Areal Distribution in Laguna Potrok Aike (ASADO)

点击翻译按钮获取中文摘要

We propose to carry out a mapping of surficial sediments in Laguna Potrok Aike, southern Patagonia (Argentina). This will bring forward our understanding of processes controlling the spatial sediment distribution, geochemical sediment characteristics and nutrient availability in a modern maar lake. In view of the approaching ICDP deep drilling “Potrok Aike Maar Lake Sediment Archive Drilling Program” (PASADO) this knowledge is vital for a thorough understanding of the long sediment record to be drilled from the deep central lake basin. With the proposed mapping project five aspects of spatial sediment variability will be covered. (1) Which depositional processes are important and is it possible to distinguish particles that have experienced long eolian transport? (2) Changes in redox conditions reflected by the Fe/Mn-ratio occur in the sediment profile. Can these be used as a proxy for palaeo lake level variations? (3) Changes in phosphorus concentration probably vary with water depth. Where is the origin of the high phosphorous concentration and how do these changes influence lake biota and carbonate precipitation? (4) The validity of stable isotope values (13C) as a proxy for palaeo-shoreline proximity will be tested. (5) It will be checked whether pollen are evenly distributed across the lake and provide a comparable signal for all investigated core positions.