Integrated tectonic-geophysical modelling to unravel the structural transition from the eastern Subhercynian Basin to the Flechtingen Basement High

The Flechtingen Basement High (FBH) is one of the most striking basement uplifts formed due to the late Cretaceous contraction of Central Europe. It represents the separating element of two realms of Mesozoic strata deposited in the former Central European Basin, the Altmark region in the north and the Subhercynian Basin in the south. In its central part, which is our area of interest, the internal structure of the FBH comprises Paleozoic rocks of Carboniferous and Devonian age, which were deformed during the Variscan Orogeny. In Late Cretaceous times these rocks were uplifted in the backlimb of a large thrust-bounded basement anticline showing a continuous transition from Paleozoic to Mesozoic strata of the Subhercynian Basin in the south. In the eastern part additional backthrusts occur where Devonian strata is overthrust on Triassic sediments. Due to a thick Cenozoic cover investigating the structural style of these thrusts by means of classical geometrical modelling is hampered by missing detailed geological and geophysical data. Therefore, we use an integrated tectonic-geophysical modelling approach by combining classical tectonic concepts of cross-section balancing, 3D geological modeling and an in-detail analysis of gravity data including gradient calculations as well as Euler deconvolution to gain additional information on the fault network and hidden, deep-seated structures. First results show that this approach significantly enhances our understanding on the distribution of Permocarboniferous basins and on the dip and subsurface expression of large thrust faults.