Structure and Miocene evolution of the Gdów tectonic “embayment” (Polish Carpathian Foredeep) : a new model based on reinterpreted seismic data

Analysis of previously available stratigraphic data coupled with the re-interpretation of seismic profiles calibrated by boreholes has allowed the construction of a new tectonic model of evolution of the Gdów “embayment” – a tectonic re-entrant located along the Carpathian front east of Kraków (southern Poland). This model shows that the main phase of localized fault-controlled subsidence took place in the Early Badenian and was associated with deposition of the locally overthickened Skawina Formation. Also, deposition of evaporites of the Wieliczka Formation seems to have been tectonically controlled by local basement faulting. Supra-evaporitic siliciclastic deposits have developed as a result of overall north-directed sediment progradation from the eroded Carpathian belt towards the Carpathian Foredeep. During the final stages of development of the Carpathian fold-and-thrust wedge the previously subsiding Gdów “embayment” area was uplifted and basement faults were reactivated either as reverse faults or as low angle thrust faults. Along the leading edge of this inverted structure a triangle zone developed, with backthrusting along the evaporitic level. As a result, overthickened evaporites, formed in local tectonically-controlled depressions within the area of the Gdów “embayment” area have been strongly folded and internally deformed.