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EN
The problem of the western and southern borders of the East European Platform is still subject to debate; different authors variously put this border on the geological maps of Europe. The deepness of the crystalline basement between the T–T zone and the Variscan orogen and within the so-called Scythian Platform makes recognizing the geotectonic structure of the area difficult. There are relatively few and small regions with rocks older than Mesozoic. There is no direct access to Precambrian strata over most of the area. Most structural information is provided by geophysical methods, but they do not allow to date the age of consolidated basement. The paleomagnetic studies of the area give equivocal results. Our analysis of available materials from between the T–T zone and the Variscan orogen and the Scythian Platform suggests that the Precambrian Platform has a larger extent than it was generally assumed. The platform extends westwards even as far as the front of the Variscan orogen, and to the SWand S it may reach the Alpine folded structures.
EN
. In this paper we describe relations between geological structure, shape and relief of the crystalline basement of the Precambrian cratons, and between rigid elements in Variscan orogens and the width of the younger fold belts in their foreland. The relations can be seen between the Baltic shield and Alpine belts. In places, where the fold belt is thrust over uplifted part of the craton's fundament, the fold belt and its marginal foredeep are tight and the fold belt is very high. In places, where the fold belt is thrust over deep part of the fundament, the fold belt and its marginal foredeep are broad. Similar relations can be seen between the East European craton and Variscan fold belts.
EN
Studies of magmatic rocks of the Triassic–Lower Cretaceous ophiolite association are of great significance for geodynamic reconstructions of the evolution of the Ukrainian Carpathians. These are almond-stone basalts, clasto-lavas of basalts, and dykes of trachytes in the complex of volcanic rocks of the Trostyanets Stream. Rocks are allochthonous and hence studies of their petrochemical and geochemical properties are of great importance. Volcanites belong to the K-Na series of rocks poor in ferrimagnesian and rich in lithophylic elements; they developed on the ensialic substratum. Results of studies of two-phase fluid inclusions in calcite indicate that the gas phase constitutes 10 to 25 vol. % and is represented by CH4 and its homologues – C2H6, C3H8 and C4H10. These data may indicate a possible formation of carbon and hydrocarbons by means of the Fischer-Tropsch reaction of hydrocarbon synthesis.
PL
Badania skał magmowych asocjacji ofiolitowej triasu–kredy dolnej mają duże znaczenie dla geodynamicznej rekonstrukcji ewolucji ukraińskich Karpat. Dotyczy to bazaltów migdałowcowych, law z klastami i dajek trachitowych w kompleksie skał wulkanicznych potoku Trostyanets. Skały są allochtoniczne, toteż bardzo ważne jest badanie ich właściwości petrochemicznych i geochemicznych. Wulkanity należą do serii skał K-Na ubogich w pierwiastki żelazo-magnezowe i litofilne; tworzyły się w podwarstwie ensialicznej. Badania dwufazowych inkluzji w kalcycie pokazały, że faza gazowa zajmuje od 10 do 25% obj. i jest reprezentowana przez CH4 i jego homologi – C2H6, C3H8 oraz C4H10. Dane te mogą wskazywać na możliwość tworzenia węgla i węglowodorów na drodze reakcji Fischer-Tropscha syntezy węglowodorów.
EN
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.
7
51%
EN
Since the beginning of the introduction of the concept of the East European branch of the Caledonides by Limanowski (1922), there has been much discussion on the trend of this branch towards the southwest of the East European craton. The extreme interpretations were given by Stille (1950), and later by Dadlez (1994). According to those authors, the East European branch of the Caledonides could trend along the entire course of the south-eastern boundary of the East European craton, from the western Baltic Sea to Ukraine. Analysis of existing geological data, in relation to the current geotectonic theories, puts in doubt the existence of this branch. The proved Caledonian structures, which could be considered as orogenic, are located exclusively in the West Pomeranian segment of the East European craton foreland. The other parts of the foreland should be considered either a lowered marginal edge of the craton or blocks of Avalonian origin.
PL
Od początku wprowadzenia pojęcia wschodnioeuropejskiej gałęzi kaledonidów przez Limanowskiego (1922) trwa dyskusja dotycząca przebiegu tej gałęzi na południowy zachód od kratonu wschodnioeuropejskiego. W skrajny sposób przedstawiał go Stille (1950), a później Dadlez (1994). Według nich wschodnioeuropejska gałąź kaledonidów przebiegałaby wzdłuż całej południowo-wschodniej granicy kratonu wschodnioeuropejskiego, od zachodniego Bałtyku po Ukrainę. Analiza istniejących danych geologicznych, w nawiązaniu do obowiązujących dzisiaj teorii geotektonicznych, stawia w wątpliwość istnienie tej gałęzi. Udokumentowane struktury kaledońskie, które można by uznać za orogeniczne, znajdują się wyłącznie w zachodniopomorskim segmencie przedpola kratonu wschodnioeuropejskiego. Pozostałe fragmenty tego przedpola trzeba uznać bądź za obniżoną, brzeżną krawędź kratonu, bądź za bloki pochodzenia awalońskiego.
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