Structure of the Prague Basin:: The deformation diversity and its causes (the Czech Republic)

The paper deals with the diversity of deformations, esp. faults, in the Ordovician to the Devonian deposits of the Prague Basin, their relations to the Proterozoic basement, and draws some conclusions about causes of this diversity. Attention is paid to the eastern, deeper downfolded part of the Basin (Prague Synclinorium). Some longitudinal faults (Liben Thrusts, Tetin Thrust) are confined to the basin filling and are apparently due to the release of stresses generated during folding. Most of faults, however, are rooted in the Proterozoic basement and some of them were connected with Early Palaeozoic synsedimentary movements and/or volcanism (Prague Fault, Tachlovice Fault, Tobolka Fault, etc.). Some transverse faults separate segments having structures incompatible to one another. This testifies to the transverse faulting simultaneous with the folding and to the basement fractures influencing the deformation of the basin filling. The distinct SE vergency of folds in the Silurian-Devonian of the synclinorium can be explained by the underthrusting of a basement block towards NW. Otherwise, the tectonic transport in the synclinorium was bilateral and the vertical component of displacements prevailed. The general tectonic character of the Prague Synclinorium testifies to its fully autochthonous relation to the Proterozoic basement.