Discordances of the top surface of carboniferous deposits of the Upper Silesian Coal Basin

Geological boundaries of the structural stages between Late Variscan Moravian-Silesian-Cracow orogene and Saalian Sławków Graben taphrogene, Early and Late Kimmerian epeirogene, Middle Alpine Silesian-Cracow Monocline, and Late Alpine Carpathian Foredeep are defined as discordances. These structural surfaces of different age, present in the top surface of Carboniferous deposits of the Upper Silesian Coal Basin, were investigated in morphotectonic research. Discordances in the morphotectonical record separate older faulted and folded Carboniferous deposits from younger, nearly subhorizontal rocks of epi-Variscan cover. This polychronic and polygenetic geological heterochronous boundary of the top surface of Carboniferous deposit consists of the following coeval discordances: sub-Permian, sub-Triassic, sub-Jurassic, sub-Cretaceous, sub-Miocene and sub-Quaternary. Those buried erosional surfaces with ancient landforms were some formed by terrestrial, others by marine planation. The repeated erosion of Carboniferous deposits and sedimentation of covers as well as fault, monocline and fold-flexure deformations are reflected in differentiated configuration of discordances in the height range from about 400 m a.s.l. to 6000 m b.s.l.