Contrasting tectonic and sedimentary history of the central and eastern parts of the Polish Carpathian foredeep basin-results of seismic data interpretation

摘要

Polish Carpathian foredeep basin (PCFB) is located at the junction between Western and Eastern European Platforms. Such location caused different evolution of various parts of this basin. In the central part of the PCFB growth fault-propagation folds related to latest (Badenian) stages of thrusting in this segment of the Carpathians developed. Only minor normal faulting related to Miocene reactivation of older basement faults was detected. Paleovalleys mapped within the Mesozoic basement were interpreted as Palaeogene tectonically controlled erosional features developed after inversion of the Polish Trough. In the central PCFB post-evaporitic sediments were supplied into the foredeep basin from south. from the eroded Carpathians. In the eastern part of the PCFB, a system of large normal faults related to Miocene fiexure-induced reactivation of inherited Mesozoic faults was identified. Within the hangingwall of this system, reverse faults, rotated blocks and basement pop-up structures were described. Their formation was related to combined effect of compressional stresses transferred from the Carpathian collision zone and reactivation of older large-scale fault caused by both flexural extension and strike-slip movements. During deposition of the Miocene foredeep sediments differential compaction also played an important role. Gentle onlap of the Middle Badenian evaporites by post-evaporitic sediments towards the NW was interpreted as a result of tectonically driven relative sea-level rise and re-establishment of marine connections with eastern Paratethys.