Subsydencja bruzdy śródpolskiej w permie i mezozoiku

Ryszard Dadlez, Marek Narkiewicz, RandelI A. Stephenson, Martin T.M. Visser

Abstrakt


SUBSIDENCE OF THE MID-POLISH TROUGH IN THE PERMIAN AND MESOZOIC

Summary

The Mid-Polish Trough evolved during the Permian and Mesozoic along the Trans-European Suture Zone separating two distinct crustal domains: pre-Cambrian crystalline basement of the East European Platform and thinner west European crust of the Palaeozoic age. Tectonic subsidence analysis of the Trough revealed three distinct events: (1) initial extensional phase (syn-rift) during the late Permian (Saxonian) through early Triassic, (2) less pronounced extensional event spanning the Oxfordian-Kimmeridgian, and (3) irregularly distributed subsidence pulse starting in the Cenomanian. The second event may be related to rifting or back-arc spreading in the northern Tethyan area while the third one is probably related to the basin inversion starting in the late Cretaceous (Coniacian-Santonian). The forward modeling results indicate a pre-inversion thinning of the crust. In the light of these results the "transitional crustal layer" [8] underlying the basin depocentre would be interpreted as an uppermost mantle layer rather than "crustal keel".