Basement structure below the West-Carpathian-East Carpathian Orogen junction (eastern Poland, north-eastern Slovakia and western Ukraine)

The morphology and tectonics of the consolidated basement of the Carpathians has been analysed using magnetotelluric and deep seismic sounding. The results of these two methods allow for reconstruction of the depth of the consolidated basement in a similar manner. The magnetotelluric sounding has mainly been applied for the area of Poland and deep seismic sounding for the area of Slovakia and Ukraine. The products of the research are: the map of the depths of the consolidated basement, sketch of the main tectonic elements layout and numerous deep cross-sections. It has been stated that the morphology of the consolidated basement of the Carpathians is very variable. The depth of the top of the consolidated basement ranges from a few kilometers to ca. 24 km. The top surface of the basement dips from the northwest towards the east. It has the shape of a trough with the Tarnow-Putila axis. North and south of the trough axis the surface of the consolidated basement rises from a few to several kilometers at the Carpathian overthrust and the Pieniny Klippen Belt, respectively. The greatest drops are observed in eastern part of the studied region, in Ukraine, where the surface of the consolidated basement is at depths below 22 km. The axis of the largest depths of the consolidated basement from Rahiv to Krosno is regular and has a SE-NW orientation. Near Krosno, it bends southward to the Krynica region where it again reverts to the SE-NW orientation. The consolidated basement between the Dunajec and Tisa rivers has a blocky pattern and is dissected by numerous longitudinal and transverse dislocations. Along the transverse dislocation, this surface is systematically thrown in a south-eastern direction. The basement surface between the "regional basement slope" and the peri-Pieninian dislocation has a form of the trough with the axis Rahiv-Krynica. This graben is likely filled up with Paleozoic and Mesozoic deposits. It is believed that flysch units are rooted in this graben.