The Wiek Fault System east of Rügen Island: origin, tectonic phases and its relationship to the Trans-European Suture Zone

Abstract

AbstractThe Tornquist Fan, reflecting the northern part of the Trans-European Suture Zone, comprises a series of fault zones and major single faults, striking mainly subparallel to the SW margin of the Fennoscandian Shield. The deep-seated faults of Wiek, Nord Jasmund and Schaabe, which cross the northern part of Rügen Island and areas of the adjacent Baltic Sea from NW to SE, originated in the late Paleozoic. They are accompanied by younger faults, especially in the Pomeranian Bay, that were formed by Mesozoic tectonic processes. Based on reprocessed offshore seismic lines east of Rügen, a polyphase evolution for the Wiek Fault System is proposed. It implies changes in the stress field since the Caledonian Orogeny. Crustal extension in the Middle Devonian led to the formation of basins along the SW margin of Laurussia. Subsequent compressional movements, induced by the distant Variscan Orogeny, resulted in segmentation and block faulting of the Rügen Basin prior to the late Carboniferous. These Paleozoic faults were reactivated by Mesozoic extensional stress regimes. In addition, new en echelon faults were generated, contemporaneously with the formation of the Western Pomeranian Fault System. Since the Late Cretaceous (Africa–Iberia–Europe convergence), selected major normal faults have been reactivated as reverse faults.