Abstract:

In Europe, few studies are available that deal with the long-term propagation of climate change and associated terrestrial system response at the interface of the Atlantic and Mediterranean system. The existing work does not predate the Last Interglacial which strongly limits our understanding of how both systems contracted and expanded during glacial-interglacial cycles. A better understanding of the interaction of the Atlantic and Mediterranean systems converging along the Rhône-Rhine axis may be achieved, if loess-palaeosol-sequences (LPS) from the Upper Rhine Graben are integrated that are most likely to comprise much of the last million years. Thick LPS of the Kaiserstuhl area (southern Upper Rhine Graben) are suited best to hinge archives along the Rhine River (dominated by Atlantic marine-temperate climate) with those found along the Saône-Rhône axis (rather Mediterranean influence). For this the most favorably complete record is the 30 m thick Riegel LPS that will be subject to detailed investigations in the coming years in the framework of the international KaiserLink project (funder: DFG).
While this master-record will serve as a most valuable reference profile and dating-based correlation target, previous work has highlighted the enormous potential of other LPS in the surroundings which are likely to cover specific time intervals in a higher resolution. Here we present a field- and literature-review based assessment of the potentials of LPS in the Southern Upper Rhine Graben for this task. We critically assess and re-calibrate existing dating results and process geochemical and geophysical data (mostly obtained in the 1980s) using state of the art quality criteria and multivariate statistics. Together with the outcomes of the crucial KaiserLink project, this will provide a valuable framework towards the acquisition of a million years record at the interface of the Atlantic and Mediterranean climate systems.