Distribution and Dimension of Young Tectonics in the Neuwied Basin and the Lower Middle Rhine

Abstract

In the Neuwied Basin the displacement of the oldest Tertiary sediments is widespread, whereas in the Lower Middle Rhine area this occurred locally along a structurally weak line (Ahr Valley-Laacher Lake). This displacement continued during the Pliocene period in the latter area with the result that the Pliocene siliceous oolite gravels overlay the Oligocene sediments or they are to be found close together. On the edge of and outside the Neuwied Basin the displacement of the Tertiary sediments lies between 20 and 130 m. In the case of the old Pleistocene terraces in the Neuwied Basin, the displacement values are considerable, whereas one is confronted with an unimportant single-block tectonic process in the Lower Middle Rhine area. In contrast to the older main terraces (t_R1-t_R4) with their constant altitude, the younger main terrace (t_R5) in the Lower Middle Rhine area is characterised by a very large falling gradient which can be traced back to tectonic processes. Proof of displacements belonging to the Middle or Young Pleistocene period can only be found on the northern edge of the Rhenish Massif and in parts of the Neuwied Basin.