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Monika Jachowicz, Polish Geological Institute (Poland)
Monika Jachowicz, Polish Geological Institute (Poland)
Adam Tomas, Polish Geological Institute (Poland)
Anna Tomas, Polish Geological Institute (Poland)
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In the basement of the Carpathians occur two old tectonic units - blocks, which origin is connected with Precambrian sedimentary and tectono-thermal processes. These are Upper Silesian (USB) and Malopolska (MB) Blocks. They differ from each other general structure of the Precambrian basement and the Lower Paleozoic sedimentary covers occurring on them. The blocks are separated by the Krakow-Lubliniec Fault Zone, which was active many times. It is a part of the Elbe lineament and it continues probably to Dobrogea region in Romania. The USB which basement consists of the Precambrian crystalline and the anchimetamorphic rocks, together with Brno Block in the Czech Republic, form the greater tectonic unit named Brunovistilicum. Paleozoic sedimentary cover rests on this basement. This cover is comprises different lithological and facial deposits, of the Cambrian, Ordovician, Devonian and Carboniferous with the Coal-Bearing Carboniferous sediments.
The MB is a tectonic unit for which a consolidation age as well as the northern and north-eastern boundaries have not been determited yet. The Vendian anchimetamorphic clastic rocks are the oldest well-known rocks forming the MB. They occur to the south and south-west of the Holy Cross Mountains. The Precambrian and Paleozoic rocks of the MB are represented by the different lithological and facial complex of rocks from the Vendian to the Upper Carboniferous (flysch). The Proterozoic-Paleozoic deposits were subjected to remodeling during Alpine orogeny.
In the tectonics of the consolidated basement of the Carpathians in the territory of Poland three major elements influencing its structure are distinguished. These are two transverse fault zones ( A-A, B-B), generally SW-NE oriented, where the basement is dipping eastward. The third element of a comparable meaning to the other two is a longitudinal zone of the basement dipping southward-"regional basement slope". The transverse dislocations zones (A-A, B-B) divide the consolidated basement of the Polish Carpathians into three sectors. The western sector, located west of A-A zone, the central sector between A-A and B-B zones, and eastern sector located east of the last zone (B-B). In the basement of the Carpathians three longitudinal blocks of the crust separated by deep lineaments. These are (starting from the south) Inner Carpathian Block (BKW), Outer Carpathian Block (BKZ) and Carpathian Foredeep Block (BZPK). All these three blocks (BKW, BKZ, BZPK) are dissected by two, transverse NE-SW oriented dislocations zones (deep lineaments) of an oblique slip character. These are formerly distinguished A-A and B-B zones.
The presented outline of tectonics of the consolidated basement of the Polish Carpathians is the present-day status that had finally developed in three stages in the Neogene during the Late Alpine collision, i.e. in the Lower Miocene (Ottangian), Middle Miocene (Lower Badenian) and Upper Miocene (Late Sarmatian) stages.
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