Some Remarks on the Position of the Rhenish Massif Between the Variscides and the Caledonides

On the background of the repeated discussion on the mid-European Caledonides, their relations to the Variscides and the present plate-tectonic models a simplified synopsis of selected geological facts is presented including the Proterozoic-Palaeozoic development in a section from the Bohemian massif/Upper Rhine region through the Rhenohercynian zone to the Brabant massif. An attempt is made to demonstrate that the polarity within the Variscan zones involves subsidence, magmatism and deformation processes of the Cadomian, Caledonian and Variscan stages of development, thus showing the intimate relations between them. More or less limited pre-Carboniferous molassoid sedimentation, indicating the beginning cratonization and marking the following transition to the Variscan stage, are decreasing in age from the internides (Cambrian — Tremadocian, concluding a restricted Cadomian development) to the externides and the foreland (Old red, concluding the Caledonian development). With increasing duration and importance of the Caledonian cycle, the Variscan development is diminishing in time and intensity from south to north. The Variscan externides developed, in this view, in a rather mobile area without a coherent or widespread Cadomian or Caledonian basement. Processes in the internides synchronous to the Caledonian development in the north should be considered as belonging to the Variscan cycle.