INVESTIGATIONS IN SUBROSION DEPRESSIONS IN THE MIDDLE VALLEY OF THE RIVER WERRA (GERMANY)

In subrosion depressions of the middle Werra valley, high-resolution sedimentological and palynological investigations were executed. In all depressions of this area an almost even sedimentation sequence, which is dividable in different temporal phases of deposition, is visible. Depending on the sedimentation conditions the layers are fluvial or limnic modified. According to the palynological results the area was already settled since neolithic times. An increase of human influences can be recognized for Bronze Age and Iron Age, but is not shown in the sedimentological results. Intensive land use of the area since the 6th century is recorded in the sedimentological and palynological sequence. The formation of massive alluvial clay layers reflect a drastic increase in erosion resulting from the deforestation of the whole region and in particular the floodplain forest. The development of these layers represent a fixed temporal marker in the middle Werra valley especially in the subrosion depressions. Based on the results a spatial process of hollow development in northeast direction can be derived in this area.