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The northern part of the Northeast German Basin contains a large number of Late Permian (Zechstein) salt pillows, whereas diapiric structures are almost completely absent. This lack of diapirs facilitated the study of early stages of salt movement in the basin. Salt pillows and related structures were investigated in terms of distribution, geometry and time of initiation of salt flow within the regional geological context. The primary Zechstein thickness in the study area was reconstructed to gain more insight into the relationship between the geometry of the salt layer and the style of the salt-related structures. In this study, no clear spatial relationship between the salt structures and basement faults has been found and the location of the salt structures in this area appears to be highly independent of the underlying structural grain. The overburden is affected by minor faulting. We propose that buckling of the overburden due to regional compression significantly contributed to the initiation of the Late Jurassic to Early Cretaceous salt structures in the basin. Reverse faulting of the Gardelegen and Haldensleben Faults is related to inversion tectonics and exerted a compression on the basin fill. During the deformation, the Late Permian salt layer acted as an efficient detachment and led to a marked decoupling of the Mesozoic overburden from the underlying pre-Zechstein rocks.

Fig. 9 Time-migrated seismic section of the Grimmen High from DEKORP-line BASIN 9601 (DEKORP-BASIN Research Group 1999). The structure is interpreted as a drag-related anticline at the basin margin due to compression from the SE. The increasing resistance against the deformation propagation at the salt pinch-out produced this anticline with associated thrusts and backthrusts. The Upper Keuper unconformity is well imaged indicating Triassic tectonic activity

The tectono-sedimentary evolution of the Rotliegend deposits of the northernmost margin of NE German Basin (NEGB) has been analysed on the basis of detailed sedimentary logs of 300 m of core material together with the re-evaluation of 600 km of seismic lines. Three distinct phases were recognized. During the initial Phase I, basin geometry was largely controlled by normal faulting related to deep-seated ductile shearing leading to a strong asymmetric shape, with a steep fault-controlled eastern margin and a gently, dipping western margin. The results of forward modelling along a cross-section ®t the basin geometry in width and depth and reveal a footwall uplift of c. 1000 m. Adjacent to the steep faults, local sedimentation of Lithofacies Type I was con®ned to non-cohesive debris¯ow-dominated alluvial fans, whereas the gently dipping western margin was dominated by alluvial-cone sedimentation.During the post-extensional period (Phase II), cooling of the lithosphere generated additional accommodation space. The sediments of Lithofacies Type II, comprising mainly clast-supported conglomerates, are interpreted as braided ephemeral stream¯ow-surge deposits. Tectonic quiescence and an increase in¯ood events resulting from wetter climate led to progradation of this facies over the entire region. At the end of this period, the accommodation space was almost completely ®lled resulting in a level topography.Phase III was controlled by the thermal-induced subsidence of the southerly located NEGB in post-Illawarra times. The formerly isolated region tilted towards the SW, thus forming the northern margin of the NEGB during uppermost Havel and Elbe Subgroup times. The sediments of Lithofacies Type III were divided into a marginal sandstone-dominated environment and a ®ner-grained facies towards the SW. The former consists of poorly-sorted coarse-grained sandstones of a proximal and medial ephemeral stream oodplain facies. The latter comprise mud¯at ®nes and ®ne-grained distal ephemeral stream deposits. The end of the tectonosedimentary evolution is marked by the basinwide Zechstein transgression.

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