Allochthone Triasschollen am Unterwerrasattel als Schlüssel zum Verständnis saxonischer Grabentektonik

The analyse of the tectonic structures of the allochthonous triassic clods of the Unterwerrasattel results in three storeys: at the bottom a brittle graywacke storey (pre-salinar), at the top a brittle triassic storey (post-salinar) with intramesozoic evaporite layers and in the middle a ductile Zechstein layer (salinar), mostly anhydrite and gypsum. Typical structures of the postsalinar storey are extensional forms like normal faults, rollovers and gliding and allochthonous clods. The salinar shows both extensional and compressional structures, like detachments, folds, thrusts and a hinterland dipping duplex. In the pre-salinar strike slip faults are expected. A palinspastic was reconstructed with results from analogous transtensive sandbox experiments. For the Hessian Grabens the model of a multiple decoupling in the ductile salinar and also in the intramesozoic evaporite layers was developed. Rhenish grabens form over NNE-SSW en echelon strike slip faults; hercynian grabens form over WNW-ESE en echelon strike slip faults. The Hessian Grabens were built at the jurassic / cretacious boundary. The Unterwerrasattel is a push-up structure of cretacious and tertiary time.