EGU Stephan Mueller Special Publication Series, 1, 151–165, 2002 c European Geosciences Union 2002 Mid-Polish Trough inversion – seismic examples, main mechanisms, and its relationship to the Alpine-Carpathian collision P. Krzywiec Polish Geological Institute, ul. Rakowiecka 4, 00-975 Warszawa, Poland (Email:
[email protected]) Received: 8 December 2000 – Accepted: 16 March 2001 Abstract. Numerous brittle deformations related to the Late Cooper and Williams, 1989; Coward, 1994). Numerous pro- Cretaceous inversion of the Mid-Polish Trough (MPT) have cesses could cause basin inversion, i.e. inversion of subsi- been identified in its various parts using seismic data. The dence trends. It is often related to compressional stresses role of Zechstein evaporitic deposits during basin evolution transferred from zones of continental collision or active sea- and inversion is also described. A model for the Pomera- floor spreading. For example, Late Cretaceous-Tertiary in- nian segment of the MPT has been constructed that includes version in Europe has been often attributed to Alpine col- significant decoupling between pre-Zechstein basement and lision and Atlantic spreading (Dadlez, 1980a; Dronkers Mesozoic sedimentary infill. In areas without significant in- and Mrozek, 1991; Erlstrom et al., 1997; Roure and Col- fluence of Zechstein deposits on tectonic processes, classical letta, 1996; Stackenbrandt and Franzke, 1989; Schroder,¨ inversion structures have been interpreted like reverse faults 1987; Ziegler, 1989, 1990). Studies of inversion pro- and uplifted basement blocks. Thickness reductions and lo- cesses resulted in development of numerous models linking cal angular unconformities pointing to syn-tectonic sedimen- deep (lower crustal-mantle) ductile deformations with up- tation often accompany these inversion structures.