Stress field evolution at the northern part of the South German Block

This paper deals with results of an investigation of the paleo stress field evolution in the overburden of the Werra potash deposit and adjoining areas. By means of microtectonical methods we investigated the fault activities and deduced a sequence of correlated stress fields during the Mesozoic and Cenozoic up to nearly present time. The incomplete stratigraphie record has hindered sufficiently exact datings for most of the determined deformation stages. The investigations allowed to describe 2 pre-basaltic, 2 synbasaltic and 2 post-basaltic stress field patterns in the Werra region. When we include adjacent areas we may determine further stress stages. Normal faulting is widespread and dominant, interrupted by three compressional impulses in the Late Cretaceous, Miocene and the near present time. The underlying ductile salt beds of Zechstein cause the high mobility of the overburden reacting during the tensional phases of stress field evolution in bookshelf or domino style.