Senckenberg Research

Tipping points in the hydrological evolution of lake systems
The aim of the work package is the detection of tipping points over time, during which permanent lake systems could be established in large sedimentation basins or their disappearance was initiated. Therefore, drilling cores from the two basins of Qaidam (China) and Gaxun Nur (Inner Mongolia) can be used, which cover nearly complete records of the sedimentary processes of the last 2 to 3 million years. By applying a multiproxy approach with high resolution sample series from the two long sediment cores changes in the lake systems can be identified. Thereby, the focus is on the question whether the tipping points are controlled by external cyclic climate drivers on glacial-interglacial to stadial-interstadial time scales or whether there is an interplay with non-climatic impulses such as tectonic and orographic influences. For this purpose, sedimentological, geochemical, mineralogical and micropaleontological methods such as the measurement of the total organic carbon (TOC) content, grain size analysis, X-ray fluorescence (XRF) scanning, X-Ray diffraction (XRD) of minerals, ICP (mass spectrometer) element analysis, quantitative analysis of pollen and spores, and the measurement of stable isotopes in ostracods (δ18O, δ13C) are applied.