Correlation of tectonic blocks in the foreland of the East European Craton in Poland with those in Ukraine

Abstract

According to common interpretations, two narrow crustal blocks are supposed to occur on the south-western edge or in the foreland of the East European Craton. The first one, bounded on the NE by the Nowe Miasto-Radom-Rava Ruska fault system, and on the SW by the Holy Cross Fault, stretches NW-SE from the Łysogóry-Radom region in Poland to the Rava Ruska Zone in Ukraine. The second one, bounded on the NE by the Holy Cross Fault, and from the SW by the Chmielnik-Ryszkowa Wola–Krakovets fault zone, is thought to tie together the Kielce area of the Holy Cross region with the Kokhanivka Zone in Ukraine. Both these blocks may have formed in connection with the development of regional listric faults during Precambrian asymmetric stretching of the Baltica continent, and were part of the marginal zone of the East European Craton. The sedimentary development of the blocks can be comparable to the Blake Plateau off the Florida coast. Both the Paleozoic sections and tectonic deformation styles in the Polish and Ukrainian segments of these blocks are different. Paleozoic tectonic structures of the Holy Cross region have a southern vergence, while the Paleozoic rocks of the Rava Ruska and Kokhanivka regions in western Ukraine are thrust towards the NE. This demonstrates the different tectonic evolution of the Paleozoic succession between the Holy Cross region and western Ukraine, and makes questionable the genetic relationships between these two regions. In this situation, the tectonic blocks of the foreland should be considered heterogeneous. Structural-facies evidence suggests that the SW boundary of the East European Craton should be moved at least to the Chmielnik–Ryszkowa Wola-Krakovets fault.