Eiszeitfenster Oberrheingraben

Climate and Environment in the Upper and Middle Pleistocene of Southwest Germany

Gaining insights into past climate change and illuminating its effects on flora and fauna is currently the subject of a project supported by the Klaus Tschira Foundation. The Reiss-Engelhorn-Museen, CEZA and the University of Potsdam are working together to reconstruct the climate in the Upper Rhine Graben over the last few thousand years, which stretches up to 30 km wide and 300 km long from Basel to Frankfurt/Main and Mainz. Its sedimentary layers include the Quaternary cold and warm periods up to the present day and are thus an important continental climate and environmental archive for Central Europe. The gravel and sand deposits have long been mined for economic purposes. Fossil remains of fauna and flora have also come to light. Remains of large mammals such as cave lion, leopard, cave and brown bear, forest elephant, mammoth, aurochs, water buffalo, various species of deer, the steppe and forest rhinoceros as well as hippopotami can be found as well as remains of the flora in the form of tree trunks.

Most of the sample material for the project comes from the Klaus Reis Collection from Deidesheim, which, with over 15,000 individual objects (cranial and postcranial skeletal elements, mainly from the “Upper Rhine Graben” find area), is one of the most extensive quaternary palaeontological private collections in Europe. Through its donation to the Curt-Engelhorn-Foundation an extremely important addition to the existing Quaternary Palaeontological Collection of the Reiss-Engelhorn-Museen was made.

Report

The sample material at our disposal is not assignable to specific sediment layers and thus cannot be classified according to stratigraphic age. Dating is therefore only possible through chemical-physical analyses, e.g. with the help of the ¹⁴C-method on individual finds. However, since this method only goes back to a maximum of 50,000 years, age and environmental statements of older finds are only possible in combination with further investigations, such as analyses of the stable isotope ratios of the elements nitrogen, carbon and oxygen (δ15N, δ13C, δ18O) and the paleogenetics of the temporal calculations of the gene sequence changes of selected species.

The reconstruction of the climate history and its effects on flora and fauna is done by identifying animals that lived at times of similar or different climatic conditions. If an assignment to certain cold or warm phases is successful, detailed knowledge about the climatic conditions and changes within or between these phases can be gained. C- and N-isotope ratios of bone collagen and C-isotope ratios at the structural carbonate of samples from the same species reflect long-term changes in nutritional behaviour in response to changing climatic and environmental conditions that controlled the animals’ food supply. For animal species living at the same time, these data can reveal predator-prey relationships and help to reconstruct food chains and food webs.

Methods for fossil DNA analysis such as DNA extraction and sequencing have been continuously improved over the last 5-10 years. However, there are still only a few palaeogenetic studies on non-human glacial faunal elements with a time depth of more than 50,000 years. The existing collection material will be used to conduct a large-scale population genomic study in this new field of research. In the first phase of the project, the screening of samples with ¹⁴C was started in order to get a rough overview of the existing age ranges. In particular, ¹⁴C ages in the range of 30,000 cal BC – 48,000 cal BC are obtained. Some samples analysed so far are, as expected, older than 50,000 years or cannot be dated with ¹⁴C. First interesting results of the stable isotope analyses and DNA investigations are also available and provide remarkable statements.