Jednostki geologiczne Polski i ich stanowisko w tektonice Europy

Abstract

GEOLOGICAL UNITS OF POLAND AND THEIR SITUATION IN THE TECTONICS OF EUROPESummaryThe present paper refers to the tectonic subdivisions published in the Polish geological literature. The author explains the fundamental tectonic terms applied for fold areas (geosynclinal areas) and for platform ones, and stresses genetical differences in tectonic nomenclature used. When analysing the tectonics of the area of Poland the author also refers to the works of the Subcommision of Tectonic Map of the World, presented on the tectonic map of Europe and in the materials of the symposium on this map (Tectonique de l’Europe, Moscou, 1964). A subdivision of the area of Poland into tectonic units has been shown in the light of two different conceptions of the extent of the pre-Cambrian platform (Figs. 1 and 2). The data obtained so far allow to accept the opinion by M. Limanowski (1922), D. N. Sobolev (1926), A. D. Arkhangyelsky (l932), H. Stille (1924, 1950) and the first opinion presented by N. S. Shatsky (1946). It appears that the presence of the Circum-Fennosarmatian Caledonids is real. The area of Poland belongs to the following tectonical units (Fig. 3): pre-Cambrian platform of Eastern Europe, Palaeozoic orogens (Caledonids, Variscids), Palaeozoic platform of Middle and West Europe and Alpine orogen. The following are units distinguished within the pre-Cambrian platform; near-Baltic trough (peribaltic trough), Łeba elevation, Mazury-Suwałki elevation (hump), Podlasie lowering (graben), Siemiatycze elevation (horst), Bug lowering (trough). Folded substratum of the distinguished units has been characterized and stratigraphical situation and thickness of sedimentary cover have been discussed. Palaeozoic mountain belts crop out in Sudetes, in the Święty Krzyż Mts., and partly in the eastern and north-eastern margin of the Silesian-Cracow Coal Basin. Caledonids are represented by the southern part of the Święy Krzyż Mts. (Kielcides) in the miogeosynclinal development (externides). In the area of the Kielcides two phases of Caledonian foldings are distinctly marked. To the Variscids belong West Sudetes developed in the eugeosynclinal facies (externides) and East Sudetes (Moravosilesides) divided into two zones. The internal zone is crystalline and represents internides, the external in turn is developed in Culm facies and represents externides. The vergence of the (West Sudetes is different from that of the East Sudetes. The Silesian-Cracow Coal Basin represents an intermount basin filled up with the coal-bearing formation and molasse. From the north and northeast it is limited by the Variscian chain of Cracowides hidden under the sedimentary cover. The Łysogóry constitute the eastern part of the sub-Variscian zone. In their foreland an underdeveloped fore-deep occurs that must be connected with the fore-deep of Westphalia, Belgium and South England. The Palaeozoic platform occupies a considerable part of the country. Caledonian substratum has been ascertained in the Lublin region (Lublinides), between the Vistula and San Rivers, in the Upper Silesia, and also under the Miocene of the Carpathian fore-deep and under the Carpathian flysch (Vistulides). Caledonian substratum probably occurs also in the southern area of Mazowsze, in the area of Kujawy and in West Pomerania. Variscian substratum, in turn, has been encountered in bore holes situated within the Fore-Sudetic monocline, Silesian-Cracow monocline and in the Miechów trough (Cracovides). In all probability, the same substratum may be found also in the area of Wielkopolska. Old- and young-Alpine synorogenic movements are responsible for the following tectonical units within the Permo-Mesozoic platform cover: Pomeranian-Kujavian swell, Szczecin trough, Mogilno-Łódź trough, Miechów trough, marginal trough, Fore-Sudetic monocline and Silesian-Cracow monocline (Fig. 3). In Poland, Alpides are represented by Tatras (internides), Pieniny Klippen Belt, and flysch Carpathians (externides). In the flysch Carpathians are distinguished several tectonical zones that correspond to nappe units. These are: Magura zone, Fore-Magura zone, Dukla zone, Krosno zone (= Silesian, SubSilesian and Skole nappes). At the Neogene time, in the forefield of the flysch Carpathians a fore-deep was formed on various members of Caledonian and Variscian substratum, partly also on the platform cover of this substratum.