Impact of the Mid-Pleistocene Transition on Meuse River Terraces in the Southern Netherlands

River terrace deposits are excellent archives of paleoenvironmental conditions. For this reason, they have been broadly studied, especially the ones dating from the Late Pleistocene and Holocene. On the other hand, little is known about Early Pleistocene terraces due to their state of preservation, which is often not as good as younger terraces, and also due to complications in acquiring good age-dates. The Lower Meuse river, a major tributary of the Rhine river, located in the Southern Netherlands and the adjoining area in northeastern Belgium, exhibits a well preserved terrace staircase which, for decades, has been intensely investigated. The spatial configuration of the terraces is well known, and age constraints, mainly based on correlations made with paleo-climate data from the ODP 677, are also available, which allows for tracing the boundaries of the Early, Middle and Late Pleistocene terraces.

The existing spatial and temporal constraints of these terraces make the Lower Meuse river terrace staircase a suitable object of study for understanding the effects of the Mid-Pleistocene Transition (MPT; 1.2 – 0.8 Ma) in northwest European river systems. In order to achieve that, we aim to compare the different terrace levels according to their ages, and main sedimentary and morphological parameters. More specifically, a comparison will be drawn between pre-, syn and post-MPT terraces. Differences in sedimentary parameters and trends are expected as a result of the climatic deterioration and changes in the duration of climatic events amid the MPT, as well as due to local tectonics (uplift of the Ardennes region). By comparing pre-, syn- and post-MPT terraces, as examples, we expect to find evidences pointing to an acceleration of incision and erosion rates, decrease of terrace width, and increase in grain-size and gravel-accumulation thickness. The comparative assessment will help to clarify how the Meuse river system responded to the MPT, and to what extent these parameters and trends are a product of climate change and/or tectonic forcing.

To achieve the proposed goals, this study updates the Meuse terrace maps for the Netherlands and integrates it with maps of the adjacent regions in Germany and Belgium that also encompass remnants of the Meuse terraces. For that, this study relies on existing maps, a high resolution DEM, and a dense borehole database together with sediment core archives provided by the Geological Survey of the Netherlands (TNO). Concomitantly, we are building a new geochronological framework for the terrace staircase based on cosmogenic nuclides extracted from terraces sediment. We are using both burial isochron (three new age-dates) and simple burial dating methods (twelve new age-dates) in order to trace the MPT boundaries stored in the terraces and infer paleo-erosion and paleo-incision rates.