Suborbital-scale climate variability of the last three glacial/interglacial cycles – high-resolution environmental reconstructions from sediments of the Rodderberg crater (Germany)

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The main objective of this proposal will be to test if suborbital-scale northern hemispheric climatic variabilities are the trigger for environmental changes recorded in the sedimentary archive of the Rodderberg crater (south of the city of Bonn, western Germany). As rapid variability of the Earth’s system is increasingly relevant for ongoing debates about climate change and little is known about the responses of environmental systems to such modifications from Central Europe, it is important to study continental records that provide comparable information especially from previous interglacials. The proposed research focuses on the geochemical characterisation of such a sedimentary record by high-resolution XRF core-scanning together with bulk geochemistry. Additionally, quantitative reconstructions of temperature and other environmental parameters will become available based on the study of chironomids, diatoms, pollen and stable isotopes to identify millennial- to centennial-scale environmental variability. Time control for this Middle to Late Pleistocene record will be achieved by radiocarbon and luminescence dating supported by tephrochronology. This approach will lead to an age/depth model for the last three glacial/interglacial cycles. Rigorous statistical evaluation of the entire dataset on timescale will generate a chemostratigraphy for the identification of indicators with environmental and palaeoclimatic significance. The proposed study will eventually provide deep and high-resolution insights into climatically forced environmental conditions for the last ~320 ka with a strong focus on the oldest and most pronounced of the three interglacials in superposition. This interglacial, most likely equivalent to the Holsteinian, is representative for the current interglacial – the Holocene – and thus might give hints for the natural baseline of future climate trends.