The Quaternary sediment record of the Upper Rhine Graben

The Upper Rhine Graben (URG) is the central part of the European Cenozoic Rift System, and has repeatedly been subsiding since ca. 50 ka. Consequently, it has been filled by a kilometre-thick sediment sequence including several hundred metres of Quarternary strata. Fed by the Rhine and its tributaries, the URG collects deposits derived from the Alps as well as from the graben shoulders and their hinterlands – deposits that have built up a significant stratigraphic archive that links the Alpine realm with the Central European lowlands.

The work summarised here is based mainly on drill cores that recovered diverse successions and illustrate the Quaternary infill of the URG along a transect from south to north. It begins with (glacio-)fluvial gravels and sands as a distal signal of the Pleistocene glaciations of the Alps. Towards the north, these interfinger, among others, with palustrine and lacustrine deposits that contain abundant biological remains that are indicative of climatic conditions and the general environmental setting. The architecture of the deposits is determined by patterns of differential subsidence that is still ongoing, as indicated by neotectonic dislocations. Even in the Heidelberg area, the depocentre affected by highest subsidence and deposition rates, unconformities can be observed.

Overall, the URG is one of Europe's longest-reaching, best-resolved and thus most significant Quaternary archives. Although its infill allows inferences on a variety of processes acting on and below surface, such as sediment dynamics, development of palaeoenvironments, and neotectonic activity, it is still largely untapped and further investigation is warranted.