Paleomiąższości i litofacje wapienia muszlowego i kajpru dolnego oraz paleotektonika triasu środkowego na Niżu Polskim

Abstract

 Na podstawie map paleomiąższości i litofacji utworów górnego pstrego piaskowca, wapienia muszlowego i kajpru dolnego przeprowadzono analizę paleotektoniczną, z której wynika, że ruchy tektoniczne decydujące o paleotektonice triasu środkowego miały miejsce głównie w końcowym etapie rozwoju basenu - w wapieniu muszlowym górnym i kajprze dolnym.  PALAEOTHICKNESS AND LITHOFACIES OF THE MUSCHELKALK AND LOWER KEUPERAND THE MIDDLE TRIASSIC PALAEOTECTONICS IN POLISH LOWLANDTwo palaeothickness and lithofacies maps of the Muschelkalk and Lower Keuper have been elaborated (Figs 1, 2). In the Lower and Middle Muschelkalk the axis of the sedimentary basin was sub-parallel and lithofacies pointed to a shallow marine basin with the carbonate sediments predominating. Terrigenous material was transported to the basin from the north and north-east (Fig. 1). In the Upper Muschelkalk and Lower Keuper the axis of the basin changed its direction from parallel to NW-SE, and clastic material was shed mainly from the north and east (Fig. 2).As a result of the analysis of the above mentioned maps and the palaeothickness and lithofacies maps of the Upper Buntsandstein, the palaeotectonic map of the Middle Triassic (Fig. 3) has been made, comprising in a chronostratigraphic sense the Anisian and Ladinian (Tab. I). A series of structural positive and negative elements was distinguished in the map. It is concluded that the tectonic movements, influencing the Middle Triassic palaeotectonics, took place in the final stage of the evolution of the basin namely in the Upper Muschelkalk and Lower Keuper. It also seams that the connection between the Middle Triassic epicontinental basin in Poland and the Tethyan basins existed in the Kraków-Tarnow Depression area, and that the "Moravian Gate" was then only an embayment.