Holocene Sediment Dynamics in the Vicinity of a Roman battlefield near Osnabrück (NW-Germany)

Abstract

The interpretation of the Holocene sediment dynamics at Mount Kalkriese in the Wiehengebirge mountains (northwestern Germany) shows that the onset and the extent of human land use corresponds well with most colluvial archives in Central European loess regions: The onset of soil erosion in the Wiehengebirge mountains started during the Early Neolithic period. For the Bronze Age, erosion and colluviation are documented as well. A considerable increase of soil erosion with correlated reworking of colluvial sediments was found since Roman times, indicated by the burial of Germanic artifacts of Roman Age at the toe-slopes. Unfortunately, no absolute ages exist for the post roman period. However, in analogy to other sites it can be assumed that highest erosion rates occurred during the Middle Ages. This study also shows typical problems when using the soilscape model for calculating the sediment budget: since truncated soil profifi les are used to model eroded volumes, only minimum soil erosion is mapped. This can lead to a considerable discrepancy between eroded and accumulated volumes. Therefore, we have to assume that soil erosion at the plateau and in upslope areas at Mount Kalkriese was much higher than predicted by the soilscape model. In addition, extensive anthropogenic accumulation soils (Plaggen soils) were deposited in the downslope areas, thereby increasing the discrepancy between erosion and accumulation volumes. The combination of mapping erosion and accumulation with augerings and trenches, calculation of the mass balance by GIS, relative and absolute dating and geophysical evidence provides a powerful tool in landscape interpretation. Due to the small number of numerical ages, the landscape model at Mount Kalkriese has to be considered preliminary.