Mezozoiczne i trzeciorzędowe rowy obszaru monokliny przedsudeckiej

Abstract

MESOZOIC AND TERTIARY TROUGHS IN THE FORE-SUDETIC MONOCLINE Summary The paper presents an outline of geological structure of regional dislocation systems of the Fore-Sudetic Monocline (Poznań - Kalisz and Poznan - Oleśnica systems), within which Keuper-Rhaetian-Lias and Tertiary troughs have developed. Other major trough structures of this region are also discussed. The borehole and geophysical, especially reflection seismics data made it possible to reconstruct spatial relations between the troughs and their evolution. It was found that Mesozoic troughs were forming in the area of the Fore-Sudetic Monocline from the end of sedimentation of the Gypsum Beds (Upper Keuper) till the end of the Lias. The next phase of formation of troughs followed tectonic movements from the turn of the Cretaceous and Tertiary. The movements resulted in uplift of this area and its subsequent erosion in the Paleogene. The studies showed that the troughs occurring east of the Poznań - Oleśnica dislocation system began to originate at the begining of the Miocene whereas those belonging to the Poznań - Oleśnica system as well as Chruścian - Nowa Wieś and Chrobnień - Rawicz troughs presumably began to originate as early as the Late Eocene.