Eastern European craton

EASTERN EUROPEAN CRATON (RU: Восточно-Европейская платформа), Russian craton, European craton, is one of the largest, relatively stable places of the continental Earth's crust, which is belonging to the series of the ancient (pre-Riphean) cratons. The craton occupies the significant part of the eastern and northern Europe, from the Scandinavian mountains to the Ural mountains, and from the Barents sea to the Black and Caspian seas. The boundary of the craton passes at the north-east and at the north along the Timan ridge, and along the coast of the Kola peninsula, while at the south-west, the boundary passes along the line, which is transversing the Central European plain near the Warsaw city, and which then goes to the north-west across the Baltic sea, and across the southern part of the Jutland peninsula.

Within the structure of the Eastern European craton, there are distinguished the ancient pre-Riphean (mostly Karelian, more than 1600 million years) folded crystalline basement, and the sedimentary (epi-Karelian) cover, which is calmly embedded above this basement. There form the basement of the Eastern European craton the strongly metamorphosed sedimentary and magmatic rocks, which have been crumpled into the folds, and which have been transformed within the large regions into the gneisses and crystalline schists. There are distinguished the areas, within the limits of which these rocks have the very ancient Archean age, namely, older than 2500 million years (the Kola, White sea, Kursk, Bug-Podolsk, Dnepr, and other massifs). There are situated between these massifs the Karelian folded systems, which have been formed of the rocks of the Lower Proterozoic age (2600-1600 million years). Within the Finland and Sweden countries, there correspond to these folded systems the Svecofennian folded systems; the Early pre-Cambrian formations within the limits of the south-western Sweden, southern Norway, and also Denmark and Poland countries, have been subjected to the deep re-working during the Gothian epoch (approximately 1350 million years), and during the Dalslandian epoch (1000 million years). The basement outcrops only at the north-west of the craton (the Baltic shield), and at the south-west of the craton (the Ukrainian crystalline shield). On the remaining area, which is greater in terms of the sizes, and which is distinguished under the name of the Russian platform, the basement is covered with the cover of the sedimentary depositions.

Within the western and central parts of the Russian platform, which is lying between the Baltic and Ukrainian shields, the basement is relatively uplifted, is embedded shallowly, above the level of the ocean within the certain places, and is forming the Belarus anteclise and the Voronezh anteclise. The Baltic syneclise (which is stretching from the Riga city into the south-western direction) separates these anteclises from the Baltic shield, and the system of the graben-shaped depressions of the Pripyat-Dnepr-Donets aulacogene, which is ending at the east as the Donets folded structure, separates these anteclises from the Ukrainian shield. To the south-west of the Belarus anteclise, and to the west of the Ukrainian shield, along the south-western boundary of the craton, there is extended the Vistula-Dnestr zone of the peripheral (pericratonal) subsidences. The eastern part of the Russian platform is characterized by the deeper embedment of the basement, and by the existence of the thick sedimentary cover. Here are distinguished the two syneclises, namely, the Moscow syneclise, which is extended to the north-east almost to the Timan ridge, and the Caspian syneclise (at the south-east), which is bounded by the tectonic faults. There separates these syneclises the Volga-Ural buried anteclise, which has been constructed complicatedly. The basement of this anteclise has been dismembered into the protrusions (Tokmovskiy, Tatarskiy, and others), which are separated by the grabens-aulacogens (Kazanskiy-Sergievskiy, Upper Kama river). At the east, the Volga-Ural anteclise is framed by the deep peripheral Kama-Ufa depression. Between the Volga-Ural and Voronezh anteclises, there is extended the deep Pachelma Riphean aulacogene, which is merging with the Moscow syneclise at the north. Within the limits of the latter syneclise, there has been identified at the depth the whole system of the Riphean graben-shaped depression s, which have the north-eastern and north-western strike. The largest of these depressions are the Middle Russian and Moscow aulacogens. Here the basement of the Russian platform is submerged to the depth of 3-5 kilometres, while within the Caspian depression, the basement has the deepest embedment (more than 20 kilometres).

Within the structure of the sedimentary cover of the Eastern European craton, there participate the depositions since the Upper Proterozoic (Riphean) till the Quaternary. The most ancient rocks of the cover (the Lower and Middle Riphean), which are represented by the compacted clays and quartzites, exist within the peripheral depressions, and also on the territory of Finland, Sweden (the Iotnian stage), within Karelia, and other regions. Within the majority of the deep depressions and aulacogens, the sedimentary strata start with the Middle or Upper Riphean depositions (clays, sandstones, basalt lavas, tuffs). The sedimentary strata of the cover have been disturbed within the certain places by the gentle curves, dome-shaped uplifts (vaults) and elongated uplifts (embankments), and also by the dip-slip tectonic faults. Within the Pripyat-Dnepr-Donets aulacogene, there are well developed the Devonian and Permian salt-bearing strata, while within the Caspian depression, there are well developed the Permian salt-bearing strata, and these strata within both places have been disturbed by the numerous salt domes.

With the rocks of the basement, there are associated the iron ores (Krivoi Rog iron ore basin, Kursk magnetic anomaly, Kostomuksha within Karelia, "Kiruna" within Sweden, and others), the ores of nickel, copper, titanium, the micas, pegmatites, depositions of the apatite (the Khibiny deposits), and so on. The sedimentary cover contains the reservoirs of the natural combustible gas and petroleum (the Volga-Ural petroliferous province, the Pripyat and Dnepr-Donets depressions, the Caspian syneclise), the deposits of the rock salts and potassium salts (the Upper Kama salt-bearing basin, the Pripyat potassium-bearing basin, and others), of the mineral coal (the Lvov-Volyn coal basin, the Donetsk coal basin, the Moscow region coal basin), of the phosphorites (the Egoryevskoe deposit, the Vyatsko-Kamskoe deposit), of the bauxites, the deposits of the building raw materials (limestones, dolomites, clays, and others), and also the reservoirs of the fresh and mineralized waters.