The legacy of the NE German Basin - Reactivation by compressional buckling

In contrast to previously published models for the area, the seismic reflection Moho is essentially flat beneath the NE German Basin along the DEKORP deep seismic profile Basin'96. This raises the question, whether the present structure of the crust and flat Moho reflect the initial formation of the basin or modification by more recent processes. A 2D flexural model, developed for a thin elastic plate, is presented together with lithospheric strength profiles calculated along the BASIN 9601 reflection seismic line. The analysis shows a southward decrease of lithospheric strength below the Basin, with a lithospheric decoupling between the crust and the mantle. The modelling supports the hypothesis that the present Moho topography is caused by flexural buckling which caused subsidence of the NE German Basin during the Upper Cretaceous-Early Cenozoic inversion event. This suggests that the basin is in isostatic disequilibrium, and that compressive stresses are required to keep the present basin geometry.