Deep reflection seismic experiments in western Poland

Abstract

The Upper Cretaceous sequence in the area located between Uniejów, Kłodawa and Ozorków, Central Poland, is dominated by carbonate and carbonate-siliceous deposits. They are represented by limestones, marly limestones, marls and opokas with local gaize intercalations in the uppermost part of the sequence. There is also a complex of Santonian-Campanian clastics immediately adjoining the present-day Mid-Polish Swell near the Kłodawa Salt Diapir. The clastics may represent gravity flow deposits associated with a strong uplift of the Izbica-Kłodawa-Lęczyca Zone due to salt movements during inversion of this structure related to the incipient phase of the Late Cretaceous inversion of the whole Mid-Polish Swell. These processes caused increasing morphological gradients when passing south-westwards to the neighbouring subsiding trough. Detailed sedimentological studies of the clastic series cannot be made due to insufficient material and poor core condition. Investigations of the regional facies distribution and sedimentation, performed both along the areas adjoining the present-day Mid-Polish Swell and in local inversion structures, may help in the elucidation of timing of the incipient tectonic inversion phase of the Mid-Polish Trough which was ultimately transformed into the Mid-Polish Swell during the Early Tertiary.