Rheology predictions across the western Carpathians, Bohemian massif, and the Pannonian basin: Implications for tectonic scenarios

On the basis of extrapolation of failure criteria, lithology, and temperature models, we predict the rheology of the lithosphere for several sections through the Carpathians and surrounding regions. Our models show significant lateral variations in rheology for the different tectonic units, with important implications for the tectonic evolution. The rheologically strong lithosphere of the Polish Platform area contrasts with the weak lithosphere of the Pannonian basin, indicating that the arcuate shape of the Carpathian orogen is primarily caused by an inherited curvature of an ancient embayment in the foreland, with the Pannonian units passively filling the space. The Polish Platform and the Moesian Platform exhibit a similar rheological anisotropy caused by NW-SE trending weakness zones paralleling the Tornquist - Teisseyre zone. This anisotropy was the main controlling factor on the behavior of the lithosphere in this area since Cadomian times, as documented by the geological evolution of the Sudety Mountains and the Mesozoic Polish Trough, including the Late Cretaceous Alpine inversion and the Neogene development of the Carpathian foreland. This rheological anisotropy appears to have a major controlling impact on the development of at least the eastern part of the European lithosphere. Rheology predictions for the Bohemian massif support the idea that the rigid lithosphere of the Bohemian massif governed the bending of the Alpine-Carpathian transition zone, expressed in the large-scale wrench movements opening the Vienna basin. In the foreland area, detachment levels are predicted for upper and lower crustal levels, leading to a decoupling of crustal and subcrustal flexure in most areas. Comparison with basin formation models indicates that our predictions for effective elastic thickness (EET) are similar to those derived from flexural models for the foreland area. Also, EET predictions from extensional basin models in the Pannonian region yield values close to our findings.