Where is the Russian platform. East European Platform: landform

East European platform, Russian platform

East European Platform

East European Platform, Russian platform, European platform, one of the largest relatively stable areas earth's crust, belonging to the number of ancient (pre-Riphean) platforms. It occupies a significant part of the Eastern and Northern Europe, from the Scandinavian mountains to the Urals and from the Barents to the Black and Caspian Seas. The border of the platform on the N.-E. and S. runs along the Timan Ridge and along the coast of the Kola Peninsula, and in the southwest. - along the line crossing the Central European Plain near Warsaw and then going to S.-3. across the Baltic Sea and the northern part of the Jutland peninsula.

Until the last decade, to V. p. in the north-east. attributed the area of the Pechora lowland, the Timan ridge, the Kanin and Rybachy peninsulas, as well as the adjacent part of the bottom Barents Sea; on S.-Z. the platform included the northern part of Central Europe (the Central European Plain, the territory of Denmark, the eastern part of Great Britain and the bottom of the North Sea). AT last years The interpretation of the tectonic nature of these areas has changed due to the fact that the age of the basement within them was determined as Late Proterozoic. Some researchers (M.V. Muratov and others) began to attribute these areas to the area of the Baikal folding of the adjacent folded belts and thereby exclude them from the boundaries of the ancient (pre-Riphean) platform. According to another opinion (A. A. Bogdanov and others), the same pre-Riphean foundation of the platform was only partially reworked by the Baikal folding, and on this basis, the named areas continue to be considered as part of the V. p.

The ancient, pre-Riphean (Karelian, more than 1600 million years) folded crystalline basement and the sedimentary (Epikarelian) cover quietly overlying it stand out in the structure of the V. p. The foundation protrudes only on the northwest. ( Baltic shield) and Yu.-Z. (Ukrainian shield) platforms. On the rest of the larger area, allocated under the name of the Russian Plate, the foundation is covered with a cover of sedimentary deposits.

In the western and central parts of the Russian plate, lying between the Baltic and Ukrainian shields, the basement is relatively elevated and shallow, forming the Belorussian and Voronezh anteclises. They are separated from the Baltic Shield by the Baltic syneclise (stretching from Riga to southwest direction), and from the Ukrainian shield - a system of graben-shaped depressions of the Dnieper-Donetsk aulacogen, including the Pripyat and Dnieper grabens and ending in the V. Donetsk folded structure. To the southwest of the Belorussian anteclise and to the west of the Ukrainian Shield, along the southwestern boundary of the platform, the marginal Bug-Podolsk depression extends.

The eastern part of the Russian Plate is characterized by a deeper basement and a thick sedimentary cover. Here stand out two syneclises - Moscow, stretching to the north-east. almost to Timan, and the Caspian Sea bordered by faults (in the southeast). They are separated by the complexly constructed Volga-Ural anteclise. Its foundation is divided into ledges (Tokmovsky, Tatarsky, etc.), separated by aulacogene grabens (Kazan-Sergievsky, Verkhnekamsky). From the east, the Volga-Ural anteclise is framed by the marginal deep Kama-Ufimskaya depression. Between the Volga-Ural and Voronezh anteclises is the large and deep Pachelma aulacogen, which merges with the Moscow syneclise in the north. Within the latter, at a depth, a whole system of graben-like depressions was found, with a northeast and northwest strike. The largest of them are the Central Russian and Moscow aulacogenes. Here, the foundation of the Russian plate is submerged to a depth of 3-4 km, and in the Caspian depression, the foundation has the deepest occurrence (16-18 km).

The structure of the basement of the V. p. includes highly metamorphosed sedimentary and igneous rocks crumpled into folds, which in large areas have been transformed into gneisses and crystalline schists. Areas are distinguished within which these rocks are of very ancient Archean age, older than 2500 million years (massifs of the Belomorsky, Ukrainian-Voronezh, southwestern Sweden, etc.). Between them are the Karelian fold systems, composed of rocks of the Lower and Middle Proterozoic age (2600-1600 Ma). In Finland and Sweden, they correspond to the Svecofennian fold systems, and in western Sweden and southern Norway, a slightly younger one, the Dalslandian. On the whole, the foundation of the platform, with the exception of the western margin (the Dalslandian and Gothic fold systems), was formed by the beginning of the Late Proterozoic (previously 1600 Ma).

The sedimentary cover includes sediments from the Upper Proterozoic (Riphean) to Anthropogenic. The oldest rocks of the cover (Lower and Middle Riphean), represented by compacted clays and sandy quartzites, are present in the Bug-Podolsky and Kama-Ufimsky depressions, as well as in Finland (Iotnium), Sweden and Norway (sparagmite) and other areas. In most deep depressions and aulacogenes, sedimentary strata begin with Middle or Upper Riphean deposits (clays, sandstones, diabase lavas, tuffs), in the Dnieper-Donetsk aulacogen - with Middle Devonian rocks (clays, sandstones, lavas, rock salt), in the Caspian syneclise, the age of the lower parts sedimentary cover is unknown. The sedimentary strata of the cover are disturbed in places by gentle bends, dome-shaped (vaults) and elongated (swells) uplifts, as well as normal faults.

In the history of V. p., two major period. During the first of them, which covered the entire Archean, Early and Middle Proterozoic (3500-1600 Ma), the formation of a crystalline basement took place, during the second - the actual platform development, the formation of a sedimentary cover and modern structure (from the beginning of the Late Proterozoic to the Anthropogen) .

Basement minerals: iron ores (Krivoy Rog basin, Kursk magnetic anomaly, Kiruna), nickel, copper, titanium, mica, pegmatites, apatite, etc. The sedimentary cover contains deposits of combustible gas and oil (Volga-Ural anteclise, Pripyat depression, Caspian syneclise), deposits of rock and potassium salts (Kama Cis-Urals, Pripyat depression, etc.), fossil coal (Lviv, Donetsk, Moscow region basin), phosphorites, bauxites, deposits of building materials (limestone, dolomite, clay, etc.), as well as deposits of fresh and mineral waters.

Lit.: Shatsky N.S., The main features of the structure and development of the East European platform, “Izv. Academy of Sciences of the USSR. Geological Series, 1946, No. 1; European tectonics. Explanatory note to the International tectonic map of Europe, M., 1964; Tectonics of Eurasia. (Explanatory note to the tectonic map of Eurasia, scale 1:5000000), M., 1966; Bogdanov A. A., Tectonic history of the territory of the USSR and neighboring countries, “Bulletin of Moscow State University. Series IV. Geology, 1968, No. 1; Nalivkin D.V., Geology of the USSR, M., 1962.

M. V. Muratov.

East European platform. Tectonic scheme.

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5.1. general characteristics

Geographically, it occupies the territories of the Central Russian and Central European Plains, covering a vast territory from the Urals in the east and almost to the coast of the Atlantic Ocean in the west. The basins of the Volga, Don, Dnieper, Dniester, Neman, Pechora, Vistula, Oder, Rhine, Elbe, Danube, Daugava and other rivers are located on this territory.

On the territory of Russia, the EEP occupies the Central Russian Upland, characterized by a predominantly flat relief, with absolute elevations up to 500 m. Only on the Kola Peninsula and in Karelia is it manifested mountainous relief with absolute marks up to 1200 m.

The boundaries of the EEP are: in the east - the Ural folded region, in the south - the structures of the Mediterranean folded belt, in the north and northwest - the structures of the Scandinavian Caledonides.

5.2. Basic structural elements

Like any platform, WEP has a two-tiered structure.

The lower tier is the Archean-Early Proterozoic basement, the upper tier is the Riphean-Cenozoic cover.

The foundation on the EEP lies at depths from 0 to (according to geophysical data) 20 km.

The foundation comes to the surface in two regions: 1) in Karelia and on the Kola Peninsula, where it is represented Baltic shield, which also occupies the territory of Finland, Sweden and parts of Norway; 2) in central Ukraine, where it is represented Ukrainian shield. The area of the foundation at depths up to 500 m in the region of Voronezh is called Voronezh crystalline massif.

The area of distribution of the platform cover of the Riphean-Cenozoic age is called Russian stove.

The main structures of the Russian Plate are as follows (Fig. 4).

Rice. 4. Main structures of the East European Platform

1. Platform border. 2. Boundaries of the main structures. 3. Southern boundary of the Scythian plate. 4. Precambrian aulacogens. 5. Paleozoic aulacogenes. The numbers in the circles indicate the names of the structures not labeled on the scheme: 1-9 - aulacogenes (1 - Belomorsky, 2 - Leshukonsky, 3 - Vozhzhe-Lachsky, 4 - Central Russian, 5 - Kazhimsky, 6 - Kaltasinskiy, 7 - Sernovodsko-Abdulinsky, 8 - Pachelma, 9 - Pechoro-Kolvinsky); 10 – Moscow graben; 11 - Izhma-Pechora depression; 12 - Khoreyver depression; 13 – Ciscaucasian foredeep; 14-16 - saddles (14 - Latvian, 15 - Zhlobin, 16 - Polissya).

Areas of relatively deep (more than 2 km) occurrence of the basement correspond to gently sloping negative structures - syneclises.

Moscow occupying the central part of the plate; 2) Timano-Pechora (Pechora), located in the northeast of the plate, between the structures of the Urals and the Timan Ridge; 3) Caspian, located in the southeast of the plate, occupying the interfluve of the Volga and Emba, on the slopes of the Volga-Ural and Voronezh anteclise.

Areas with respect to the elevated position of the foundation correspond to gently sloping positive structures - anteclises.

The most important of them are: 1) Voronezh, located above the crystalline massif of the same name; 2) Volga-Ural, located in the eastern part of the plate, bounded from the east by the structures of the Urals, from the north by the Timan Ridge, from the south by the Caspian syneclise, from the southwest by the Voronezh anteclise, from the west by the Moscow syneclise.

Within syneclises and anteclises, structures of higher orders are distinguished, such as ramparts, vaults, depressions, and troughs.

The Timan-Pechora, Caspian syneclises and the Volga-Ural anteclise correspond to oil and gas bearing provinces of the same name.

Between the Ukrainian shield and the Voronezh crystalline massif (and the anteclise of the same name) is located Dnieper-Donetsk (Pripyat-Donetsk) aulacogen - this is a narrow structure of a graben-like basement subsidence and an increased (up to 10-12 km) thickness of the cover rocks, which strikes west-northwest.

5.3. Foundation structure

The foundation of the platform is formed by Archean and Lower Proterozoic complexes of deeply metamorphosed rocks. Their primary composition is not always deciphered unambiguously. The age of the rocks is determined according to absolute geochronology.

Baltic Shield. It occupies the northwestern part of the platform, and borders on the folded structures of the Scandinavian Caledonides along faults. deep having a thrust nature. To the south and southeast, the foundation plunges stepwise under the Riphean-Cenozoic cover of the Russian Plate.

complexes lower archaean (AR1) in different blocks of the Baltic Shield are represented by various gneisses, crystalline schists, ferruginous (magnetite) quartzites, amphibolites, marbles, migmatites. Among the gneisses, the following varieties are distinguished: amphibole, biotite, high-alumina (with kyanite, andalusite, sillimanite). The probable protolith of amphibolites and amphibole gneisses are rocks of the mafic type (basaltoids and gabbroids), high-alumina gneisses are sedimentary rocks of the type of clay sediments, magnetite quartzites are ferruginous-siliceous deposits (of the jasperoid type), marbles are carbonate deposits (limestones, dolomites). The thickness of AR 1 formations is not less than 10-12 km.

The AR 1 formations form structures of the gneiss dome type, in the central parts of which there are large massifs of oligoclase and microcline granites, with which pegmatite fields are associated.

complexes upper archaean(AR2) form narrow synclinor zones in the AR 1 formations. They are represented by high-alumina gneisses and shales, conglomerates, amphibolites, carbonate rocks, and magnetite-bearing quartzites. The thickness of the AR 2 formations is at least 5-6 km.

education Lower Proterozoic(PR 1) with a thickness of at least 10 km are narrow graben-synclinal structures incised into the Archean substrate. They are represented by conglomerates, sandstones, siltstones, mudstones, metamorphosed subalkaline basaltoids, quartzite-sandstones, gravelstones, locally dolomites, and also shungites (high-carbon metamorphosed rocks such as shales).

The PR 1 formations are intruded by coeval intrusions of gabbronorites with copper-nickel mineralization, alkaline ultramafic rocks with carbonatites containing apatite-magnetite ores with phlogopite, as well as younger (Riphean) rapakivi granites (Vyborg massif) and Devonian nepheline syenites. The latter are represented by layered concentrically zoned massifs: the Khibiny with deposits of apatite-nepheline ores and the Lovozero with deposits of tantalum-niobates.

The deepest in the world was drilled on the Baltic Shield Kola ultradeep well(SG-3) with a depth of 12,261 m (the design depth of the well is 15,000 m). The well was drilled in the northwestern part of the Kola Peninsula, 10 km south of the city of Zapolyarny (Murmansk region), near the Russian-Norwegian border. Well drilling started in 1970 and completed in 1991.

The well was drilled under the program of deep and ultra-deep drilling carried out in the USSR by the decisions of the Government.

The purpose of drilling SG-3 was to study the deep structure of the Precambrian structures of the Baltic Shield, typical of the foundations of ancient platforms, and to assess their ore content.

The tasks of drilling the well were:

1. Study of the deep structure of the Proterozoic nickel-bearing Pechenga complex and the Archean crystalline base of the Baltic Shield, elucidation of the features of the manifestation of geological processes at great depths, including the processes of ore formation.

2. Elucidation of the geological nature of seismic boundaries in the continental crust and obtaining new data on the thermal regime of the interior, deep water solutions and gases.

3. Getting the most complete information about the material composition rocks and their physical condition, opening and studying the boundary zone between the "granite" and "basalt" layers of the earth's crust.

4. Improvement of existing and creation of new technologies and technical means for drilling and integrated geophysical surveys of ultra-deep wells.

The well was drilled with full core sampling, the recovery of which was 3,591.9 m (29.3%).

The main drilling results are as follows.

1. In the interval 0 – 6842 m, metamorphic formations PR 1 were uncovered, the composition of which is approximately the same as that discussed above. At depths of 1,540-1,810 m, ultramafic bodies with sulfide copper-nickel ores were unearthed, which refuted the notion of pinching out of the ore-bearing Pechenga complex and expanded the prospects for the Pechenga ore field.

2. In the interval 6,842–12,261 m, metamorphic formations AR were uncovered, the composition and structure of which are approximately the same as those discussed above. At depths of more than 7 km, several horizons of magnetite-amphibole rocks, analogues of ferruginous quartzites of the Olenegorsk and Kostomuksha deposits, were discovered in Archean gneisses. Gabbroids with titanomagnetite mineralization were discovered at a depth of about 8.7 km. In the interval of 9.5 - 10.6 km, an 800-meter interval with high (up to 7.4 g / t) contents of gold, as well as silver, molybdenum, bismuth, arsenic and some other elements associated with hydrogenation processes, was established in the Archean formations. -geochemical deconsolidation of Archean rocks.

3. The geophysical boundary (surface) of Konrad (the boundary of the “granite” and “basalt” layers) assumed at depths of about 7.5 km was not confirmed. The seismic boundary at these depths corresponds to the zone of deconsolidation of rocks in the Archean formations and near the Archean-Lower Proterozoic boundary.

4. Throughout the well section, inflows of water and gases containing helium, hydrogen, nitrogen, methane, heavy hydrocarbons are established. Studies of the isotopic composition of carbon have shown that in the Archean strata the gases are of a mantle nature, while in the Proterozoic they are of a biogenic nature. The latter may indicate possible origin biological processes that later led to the emergence of life on Earth, already in the early Proterozoic.

5. Data on changes in the temperature gradient are among the fundamentally new ones. Down to a depth of 3,000 m, the temperature gradient is 0.9-1 o /100 m. Deeper, this gradient increased to 2-2.5 o / 100 m. As a result, at a depth of 12 km, the temperature was 220 o instead of the expected 120-130 o.

Currently, the Kola well operates in the geolaboratory mode, being a testing ground for testing equipment and technology for deep and ultra-deep drilling and geophysical exploration of wells.

Ukrainian shield. It is a large ledge of the foundation, having the shape of an irregular oval. From the north, it is limited by faults, along which it contacts with the Dnieper-Donetsk alagogen, and in southbound immersed under the deposits of the platform cover.

Metamorphic rocks AR 1 , AR 2 and PR 1 take part in the structure of the shield.

complexes lower archaean(AR1) are represented by plagiogneisses, biotite-plagioclase, amphibole-plagioclase, high-alumina (sillimanite and corundum) gneisses, crystalline schists, amphibolites, migmatites, and quartzites.

In the structure of complexes upper archaean(AR2) involved a variety of gneisses, amphibolites, chlorite schists, ferruginous quartzites and hornfelses. These formations form narrow synclinor zones incised into the Early Archean substrate. The thickness of the AR formations is at least 5-7 km.

To formations Lower Proterozoic(PR 1) refers Krivoy Rog series, containing iron ore deposits of the Krivoy Rog basin.

This series has a three-membered structure. In its lower part, arkosic metasandstones, quartzites, and phyllites occur. The middle part of the series is mainly composed of interbedded jaspilites, cummingtonite, sericite, and chlorite schists. This part of the series contains the main industrial iron ore deposits of the Krivoy Rog basin; number of ore layers in different parts basin ranges from 2 to 7. The upper part of the series is composed of quartzite-sandstones with sedimentary metamorphosed iron ores, quartz-carbonaceous, micaceous, biotite-quartz and two-mica shales, carbonate rocks, metasandstones. The total thickness of the formations of the Krivoy Rog series is at least 5-5.5 km.

Among the AR and PR complexes there are large massifs of Archean and Early Proterozoic age: granites (Umansky, Krivorozhsky, etc.), complex multiphase plutons, the composition of which varies from gabbro-anorthosites, labradorites to rapakivi granites (Korostensky, etc.), as well as massifs nepheline syenites (Mariupol) with tantalum-niobium mineralization.

Located at depths up to 500 m. Studied in connection with geological exploration and exploitation of iron ores of the Kursk Magnetic Anomaly (KMA).

Archean(AR) formations are represented here by various gneisses, amphibolites, ferruginous hornfelses, and crystalline schists.

education Lower Proterozoic(PR 1) are highlighted as Kursk and Oskol series. As part of Kursk series are represented: in the lower part, alternating metasandstones, quartzites, gravelites, in the upper part, alternating phyllites, two-mica, biotite schists, horizons of ferruginous quartzites, to which the KMA deposits are confined. The thickness of the formations of the Kursk series is at least 1 km. Overlying oskol series 3.5-4 km thick is formed by carbonaceous shales, metasandstones, metabasalts.

Among the AR and PR sequences there are massifs of coeval intrusive rocks represented by granites, gabbronorites with copper-nickel mineralization, and granosyenites.

5.4. Case structure

In the structure of the cover of the Russian Plate, 5 structural-stratigraphic complexes are distinguished (from bottom to top): Riphean, Vendian-Cambrian, Lower Paleozoic (Ordovician-Lower Devonian), Middle-Upper Paleozoic (Middle Devonian-Permian), Mesozoic-Cenozoic (Triassic-Cenozoic).

Riphean complex.

The Riphean sequences are distributed in the central and marginal parts of the platform. The most complete sections of the Riphean are located in the western Urals, which will be discussed when considering this region. The Riphean of the central part of the platform is represented by all three divisions.

Lower Riphean(R1). In its lower part, red-colored quartz and quartz-feldspar sandstones occur with horizons of trap-type basalts. Up the section, they are replaced by dark mudstones with interlayers of marls, dolomites, and siltstones. Even higher lies a thick stratum of dolomites with interlayers of mudstones. Thickness is about 3.5 km.

Middle Riphean(R2). It is represented mainly by gray-colored sandstones with interlayers of dolomites and trap-type basalts with a total thickness of about 2.5 km. In the stratified section, bedded bodies of dolerites and gabbrodolerites occur.

Upper Riphean(R3). At its base lie quartz and quartz-feldspar sandstones, above - red mudstones and siltstones with interlayers of dolomites, even higher - alternation of mudstones, siltstones, sandstones and dolomites; the section ends with dolomites. The total thickness is about 2 km.

Vendian-Cambrian complex.

Wend(V). It is represented mainly by terrigenous and volcanogenic formations.

The lower part is dominated by red-colored sandstones, siltstones, banded clays, and tillites. [ Tillites are metamorphosed moraine deposits.]. The presence of tillites is the most feature lower parts of the section of the Vendian deposits. This, in turn, testifies to the manifestation of intense glaciation in the Vendian time (Valdai glaciation), which in its distribution and intensity is comparable to the Quaternary glaciation.

The middle part of the Vendian is represented by sandstones, siltstones with horizons of basalts, trachybasalts and their tuffs.

The upper part of the Vendian section is represented by members of alternating sandstones, siltstones, mudstones, including red-colored ones, containing nodular phosphorites. The total thickness of the Vendian formations is about 1.5 km.

Cambrian (Є ). Cambrian deposits with a total thickness of about 600-700 m are distributed mainly in the Baltic on the southern slope of the Baltic Shield. They are represented by terrigenous deposits, including clays, quartz sandstones with glauconite, and small nodules of phosphorites.

Lower Paleozoic (Ordovician-Lower Devonian complex).

Ordovician(O). Ordovician deposits with a total thickness of no more than 500 m are distributed mainly in the western parts of the platform. 9

deposits About 1– glauconite sandstones with abundant phosphatized brachiopod shells; in some places they form a shell conglomerate, in which the content of P 2 O 5 reaches 30%, and they acquire industrial importance as a phosphate raw material. The upper part of section O 1 is represented by limestones, dolomites, and marls.

deposits About 2-3 formed by carbonate deposits (limestones, dolomites, marls), among which there are layers and horizons of oil shale (kukersites) up to 5 m thick, which Leningrad region and Estonia are of industrial importance and are being worked out (Estonian or Leningrad shale basin).

Silurus(S). Lower and Upper Silurian deposits of normal thickness no more than 250 m (with local increases up to 900 m) are predominantly carbonate deposits forming large reef masses. Organogenic limestones predominate among carbonate deposits; dolomites and marls are also present. In some places, at the very tops of the Silurian section, bentonite clays are present.

Lower Devonian(D1). Lower Devonian deposits with a total thickness of up to 1.6 km are represented by alternating units of sandstones, siltstones, argillaceous dolomitic limestones, mudstones.

Middle-Upper Paleozoic (Middle Devonian-Permian) complex.

Middle and Upper Devonian(D2-D3). Deposits D 2 and D 3 are widespread on the platform. They come to the surface in the Baltic, where they form the Main Devonian field, and in the Voronezh anteclise - the Central Devonian field. On the rest of the Russian plate, they are discovered by numerous wells drilled in connection with the exploration of oil and gas.

In the Central Devonian field, D 2 deposits in the volume of the Eifelian and Givetian stages are represented by variegated sandstones in the lower part of the section (the so-called “ancient red sandstones”), which are overlain by members of interbedded marls, clays, dolomites, gypsum, and sandstones. Deposits D 3 (Fransian and Famennian stages) are represented by limestones and dolomites with interlayers of variegated clays. The total thickness of the Middle and Upper Devonian deposits does not exceed 150–200 m.

In the Main Devonian field, the D 2 deposits are predominantly sandstones interbedded with limestones and dolomites, while the D 3 deposits are predominantly carbonate (limestone-dolomite) composition. The total thickness of these deposits is not more than 450 m.

In the Dnieper-Donetsk aulacogen, Middle-Upper Devonian formations reach a thickness of 3.3 km. They are represented here by a complex alternation with facies replacements by sandstones, siltstones, mudstones, limestones, dolomites, anhydrites, gypsum, rock salt beds. This section contains beds, covers, and flows of trap-type basalts, trachybasalts, and their tuffs.

The formation of massifs of nepheline syenites (Khibiny and Lovozero) on the Baltic Shield belongs to the Middle-Late Devonian. In addition, the level D 3 -C 1 includes the formation of kimberlites of the southern coast of the White Sea, belonging to the Arkhangelsk diamondiferous province.

Carbon(C). Carboniferous deposits are widespread on the platform.

Two types of the section of Carboniferous deposits can be distinguished: 1) terrigenous-carbonate (Moscow region) and 2) terrigenous coal-bearing (Donetsk).

The first type of the section belongs to the Moscow syneclise, the second - to the Dnieper-Donetsk aulacogene.

Carboniferous deposits of the Moscow syneclise are arranged as follows.

Tournaisian Stage C 1 t It is represented by limestones alternating with interlayers and packs of variegated clays and calcareous conglomerates.

Visean Stage C 1 v. In its lower part there are quartz sands, interbedded with refractory clays enriched in alumina, brown coal seams. The thickness of the coal-bearing strata is usually 20-30 m, in some places increasing up to 70 m. Coals are of industrial importance and are mined in mines in the Tula, Kaluga and Moscow regions. In the northwest of the Moscow syneclise (Leningrad region), the Tikhvin bauxite deposit is located at this level.

The upper part of the Visean stage is composed of light sands with interlayers of clays containing rare nodules of phosphorites, thin (up to 1 m) interlayers of brown coals and limestones. The section of the Visean stage ends with limestones.

Serpukhovian C 1 s represented mainly by limestone.

The total thickness of the Lower Carboniferous deposits is about 300 m.

Medium carbon C 2. At its base lie red-colored cross-bedded sands, which are replaced up the section by limestones, dolomites, and marls. Thickness 100-150 m.

Upper carbon C 3 also formed by limestones, dolomites, marls. The thickness is about 150 m.

The Carboniferous deposits of the Dnieper-Donetsk aulacogen have a fundamentally different structure. They are represented exclusively by terrigenous coal-bearing deposits with a total thickness of 10-11 km. The section distinguishes 15 regional suites, of which 5 suites belong to the Lower Carboniferous, 7 to the middle, and 3 to the upper. These deposits are represented by intricately rhythmically interbedded sandstones, mudstones, siltstones, coal beds and lenses. The rocks are usually dark gray or black in color. This section also contains thin (a few cm, up to 1 m) limestone interbeds. In total, about 300 coal layers and interlayers have been identified in the Donbas section, of which half is of industrial importance. The usual working thickness of coal seams is 1-1.2 m. Donbass coals are of high quality; from top to bottom they change from gas to anthracites. The formations of the upper part of the Middle Carboniferous and the lower part of the Upper Carboniferous are the most carbon-saturated.

Perm (R). Permian deposits are distributed mainly on the eastern margin of the platform, in the Cis-Urals, where they are most fully studied.

The Permian deposits are also characterized by two types of section, which are separated by the Timan Ridge.

To the north of the Timan Ridge, Permian deposits are essentially terrigenous continental, coal-bearing. Their thickness ranges from 1 to 7 km. The Pechora (Vorkuta) coal basin is confined to these deposits. Coal-bearing strata are represented by a complex alternation of sandstones, mudstones, siltstones, a small amount of limestones, coal seams. There are up to 150-250 coal seams and interlayers in the coal-bearing strata. The grade composition of coal ranges from brown to anthracite. The usual working thickness of the seams is 1.5-3.5 m, sometimes reaching 30 m. The deposits of the Lower Permian and the lower part of the Upper Permian are the most coal-saturated.

To the south of the Timan Ridge, the section of Permian deposits is more diverse and is represented as follows. At the base of the Lower Permian lies a sequence of variegated conglomerates, sandstones, siltstones, mudstones, and limestones. The clastic material consists of rocks that make up the mountainous Urals. The thickness of this stratum is at least 500-600 m.

Parallel and somewhat higher in the section, there is a thick layer of limestones that make up large carbonate reef massifs. The thickness of limestones in reef massifs reaches 1 km.

The boundary of the Lower and Upper Permian is met by variegated evaporite-bearing deposits, represented by a complex alternation of sandstones, dolomites, limestones, marls, gypsum, anhydrites, potassium, magnesium and rock salts. All these rocks are in close interbedding and facies mutual transitions. The thickness of these deposits reaches 5 km. At this age level, the Verkhnekamsk and Pechora salt-bearing basins are located.

The upper part of the Upper Permian is composed of copper-bearing variegated carbonate-clayey-sand deposits, represented by alternating sandstones, marls, limestones, clays, siltstones, mudstones, and conglomerates. In this stratum there are a large number of manifestations and small deposits of cuprous sandstones, on the basis of which the copper industry of the Urals was born back in the 17th century. The thickness of copper deposits reaches 1 km.

All deposits of the Permian age are characterized by shallow coastal-marine, lagoonal, deltaic, coastal-continental conditions of accumulation.

Mesozoic-Cenozoic (Triassic-Cenozoic) complex.

Triassic(T). Triassic deposits are widespread on the platform and are represented by all three divisions.

The Lower and Middle Triassic deposits have a certain duality in their position. On the one hand, they complete the previous complex, and on the other hand, they begin the Mesozoic-Cenozoic complex. Some researchers consider the Lower and Middle Triassic deposits as part of the Middle-Upper Paleozoic structural-stratigraphic complex.

deposits lower triassic (T1) are represented mainly by continental deposits, composed of variegated coarse cross-bedded sandstones with interlayers of conglomerates, siltstones, clays, marls; clays and siltstones sometimes contain siderite concretions. The thickness of deposits T 1 in different places of the platform ranges from 200 to 850-900 m.

deposits middle triassic (T2) are also represented by continental variegated sandy-argillaceous deposits up to 800 m thick.

For Upper Triassic (T3) are also characterized by variegated and gray-colored sandy-argillaceous deposits, sometimes containing interlayers of brown coal, up to 1,000 m thick.

The predominantly continental character of the Triassic deposits reflects the general feature of the Earth's development at that time, which was characterized by a geocratic regime.

Yura(J). Jurassic deposits are represented by all three divisions. The most common are deposits of the upper section, less - the middle and very limited - the lower. Jurassic deposits are characterized by both marine and continental accumulation conditions.

Lower Jurassic (J1) deposits in their lower part are composed of continental sandy-clayey strata, and in the upper part - marine clays, limestones, sandstones containing interlayers of oolitic leptochlorite-hydrogoethite iron ores. The thickness is about 250 m.

Middle Jurassic (J2) deposits in the central parts of the platform are predominantly marine, and they are formed by sandstones with limestone interlayers, clays containing numerous ammonite fauna, which are most common in the Volga region. Here, the thickness of the Middle Jurassic deposits does not exceed 220-250 m. In the western part of the Caspian syneclise, the deposits of this time are predominantly continental - these are sandy-argillaceous strata with layers of brown coal, sometimes of industrial importance. The thickness of these deposits is increased here up to 500 m.

Upper Jurassic (J3) deposits of normal thickness up to 300 m are composed mainly of marine clays containing interlayers of glauconite sands, phosphorite nodules, marcasite concretions, and oil shale horizons; the latter are of industrial importance in a number of regions and are being developed.

Chalk(K). Cretaceous deposits are predominantly marine formations.

Lower Cretaceous (K1) deposits are represented mainly by sandy-argillaceous rocks with glauconite and nodules and layers of phosphorites. The thickness of the deposits in different parts of the platform ranges from 100-120 to 500 m.

Upper Cretaceous (K2) deposits are predominantly carbonate - these are marls, limestones, writing chalk. Among the carbonate rocks there are horizons of glauconite sands, flasks, tripoli, siliceous clays and phosphorites. The thickness is not more than 500 m.

Paleogene(P). Paleogene deposits are distributed only in the southern part of the platform, in the northern Black Sea region, where they are represented by both marine and continental deposits.

Lower Paleogene – Paleocene (P1) is formed by an 80-meter stratum of sands with interlayers of clays, flasks, and siliceous glauconite sands.

Middle Paleogene – Eocene (P2) with a total thickness of up to 100 m is composed of marine sediments in the lower and upper parts, consisting of glauconite sands, sandstones, clays, and in the middle part - coalified quartz sands with brown coal interlayers.

Upper Paleogene – Oligocene(P3) up to 200 m thick is represented by sandy-argillaceous strata containing industrial deposits of manganese ores (South Ukrainian manganese basin).

Neogene(N). Neogene deposits are also distributed mainly in the southern part of the platform.

deposits Lower Neogene – Miocene (N 1) is set certain sequence in the change from bottom to top along the section of continental deposits by lagoonal, and then by marine ones. In the lower part of the Miocene, continental coal-bearing terrigenous deposits occur, in the middle part there are variegated lagoon clays with gypsum layers, and in the upper part there are limestones forming large reef massifs. The total thickness of the Miocene deposits approaches 500 m.

Upper Neogene – Pliocene(N 2) is represented mainly by marine sandy-clayey deposits 200-400 m thick, containing layers of oolitic sedimentary iron ores (Kerch iron ore basin).

Quaternary deposits(Q) are ubiquitous and are represented by various genetic types: glacial, fluvioglacial, alluvial, eluvial, deluvial, etc. Glacial and fluvioglacial deposits predominate in the northern parts of the platform - these are boulders, sands, and moraine loams. Loess strata predominate in the southern parts of the platform. Alluvial deposits are confined to river valleys, where they form terraces of different ages, eluvium is developed on watershed areas, and deluvium is developed on their slopes. On the coast of the Baltic and Black Seas, sea terraces are known, composed mainly of sands. Sea placers of amber are associated with them (the coast of the Baltic Sea, Kaliningrad region), as well as ilmenite-zircon placers of the Black Sea region (Southern Ukraine).

5.5. Minerals

Various and numerous mineral deposits are distributed on the East European Platform. Among them are hydrocarbon raw materials (oil, natural gas, condensate), solid fuels (brown, hard coal, oil shale), ferrous, non-ferrous, rare metals, non-metallic minerals. They are located both in the foundation and in the platform cover.

Minerals in the foundation.

Black metals. The most significant are the iron ore deposits of the ferruginous quartzite formation, localized in the Archean and Lower Proterozoic complexes of the Baltic, Ukrainian shields and the Voronezh crystalline massif.

Baltic Shield

On the Kola Peninsula, in the metamorphic formations AR 1 (Kola series), Olenegorsk deposit with ore reserves of 450 million tons and an average iron content of 31%.

In the Republic of Karelia, in AR 2 metamorphic formations, Kostomuksha deposit with ore reserves of 1.4 billion tons and an average iron grade of 32%.

On the Kola Peninsula, in Early Proterozoic alkaline ultrabasic rocks with carbonatites, Kovdorskoe deposit of apatite-magnetite ores with phlogopite. The reserves of the deposit are 770 million tons of ore containing 28% iron and 7-7.5% P 2 O 5 .

Ukrainian shield

In the Lower Proterozoic metamorphic complexes (Krivoy Rog series) is located Krivoy Rog iron ore basin (Ukraine) with iron ore formations of ferruginous quartzites. The explored ore reserves of this basin are estimated at 18 billion tons with an iron content of 34-56%.

Voronezh crystalline massif

The Lower Proterozoic metamorphic complexes (Kursk Group) host Russia's largest iron ore basin – Kursk magnetic anomaly(KMA), located on the territory of the Kursk, Belgorod and Oryol regions. The KMA is a giant oval with a length of 600 km from NW to SE, a width of 150-200 km and an area of about 120 thousand sq. km. The total explored reserves of iron ores are 66.7 billion tons with iron content from 32-37 to 50-60%.

[Common to all deposits of the formation of ferruginous quartzites is: 1) large thickness of ore bodies, defined as 10-100 m; 2) a large extent of ore bodies - hundreds of meters, a few kilometers; 3) their approximately homogeneous mineral composition is magnetite, hematite, martite].

Non-ferrous metals. The most significant are Pechenga and Monchegorsk groups of sulfide copper-nickel deposits associated with gabbronorite bodies of the early Proterozoic. It is located on the Baltic Shield (Kola Peninsula). The main ore minerals are pentlandite, chalcopyrite, pyrrhotite, and pyrite. Solid and disseminated ores are distinguished at the deposits. Copper content fluctuates within 0.5-1.5%, nickel - 0.5-5%, ores contain platinum group metals.

rare metals. Place of Birth ( Lovozerskaya Group) rare metals(tantalo-niobates) are confined to the zonal concentrically layered massif of nepheline syenites of the same name on the Kola Peninsula. The average content of Ta 2 O 5 is 0.15%, Nb 2 O 5 0.2%. The main ore mineral is loparite, which contains up to 10% Nb 2 O 5 , 0.6-0.7% Ta 2 O 5 and up to 30% rare earths of the cerium group.

non-metals. Khibiny group of deposits (Yukspor, Kukisvumchorr, Koashva etc.) of apatite-nepheline ores is confined to the massif of nepheline syenites of the same name on the Kola Peninsula (Baltic Shield). Ore deposits have a sheet and lenticular form with a length of 2-3 to 6 km and a thickness of up to 80 m. The content of apatite in the ore is from 10 to 80%, nepheline - from 20 to 65%. Explored reserves of apatite-nepheline ores are about 4 billion tons with a content of P 2 O 5 from 7.5 to 17.5%. These ores are the main source of raw materials for the production of phosphate fertilizers. The deposits are of a complex nature. Mineral composition ores - apatite, nepheline, sphene, titanomagnetite. Apatite also contains Sr, TR, F, nepheline - Al, K, Na, Ga, Rb, Cs, sphene - Ti, Sr, Nb, titanomagnetite - Fe, Ti, V. All these components in one or another least extracted during the technological redistribution of apatite-nepheline ores.

Of the other non-metallic minerals, the following should be noted: rapakivi granites of the Vyborg (Baltic Shield) and Korosten (Ukrainian Shield) massifs, labradorites (Korosten massif), used as a facing material; decorative quartzite (Shokshinsky deposit on the Baltic Shield); deposits of noble topazes, morions and citrines in pegmatite fields associated with Early Proterozoic granites in Volhynia (Ukrainian shield), etc.

Minerals in a case.

Hydrocarbon raw materials. There are 3 large oil and gas provinces (OPPs) on the East European Platform: Timan-Pechora, confined to the syneclise of the same name, Volga-Urals (anteclise of the same name), Caspian Sea (syneclise of the same name).

Timan-Pechora Oil and Gas Province area of 350 thousand square meters. km has about 80 oil, natural gas and condensate fields. They are confined to 8 oil and gas bearing complexes (OGK): terrigenous red V-O, carbonate S-D 1 , terrigenous D 2 -D 3 f, carbonate D 3 , terrigenous C 1 , carbonate C 1 v 2 -P 1 , terrigenous-carbonate-halogen P 1 -P 2 , terrigenous T. The depths of occurrence of oil and gas deposits range from 500-600 m to 2.5-3 km. The most famous deposits are Yaregskoe oil-titanium and Vuktylskoe gas condensate.

Volga-Ural oil and gas field with an area of 700 thousand sq. km, there are about 1,000 deposits. They are confined to the following five oil and gas complexes: terrigenous-carbonate D 2 , carbonate D 3 -C 1 , terrigenous C 1 , carbonate C 2 -P 1 , carbonate-clay-sulphate-saline C 3 -P 2 . Productive horizons lie at depths from 500 to 5,000 m. 920 different-scale deposits have been discovered within the province, the most famous of which are Romashkinskoe, Bavlinskoe, Orenburg and etc.

Caspian OGP area of 500 thousand square meters. km has about 100 deposits. It distinguishes two groups of OGKs: subsalt-bearing and suprasalt-bearing. The subsalt-bearing group is represented by 4 NGCs: terrigenous D-C 1 , carbonate D 3 -C 1 , carbonate C 1 -C 2 , terrigenous C 2 -P; The suprasalt-bearing group contains two oil and gas condensates: terrigenous P 2 -T and carbonate-terrigenous J-K. The depths of productive formations vary from 300 to 3,300 m. The most famous field is Astrakhan.

solid fuel. On the territory of the East European Platform there are three large coal-bearing basins (Moscow, Donetsk and Pechora), and two shale basins (Baltic and Timan-Pechora).

Podmoskovny brown coal basin. total area development of coal-bearing deposits to a depth of 200 m is 120 thousand sq. km. Coal-bearing are sandy-argillaceous deposits of the Visean stage C 1 . General geological resources - 11 billion tons, balance reserves in the sum of categories A + B + C 1 - 4.1 billion tons, C 2 - 1 billion tons, off-balance - 1.8 billion tons.

Donetsk coalfield (Donbass). It is confined to the Dnieper-Donetsk aulacogen. It occupies an area of 60 thousand sq. km. C 1 terrigenous deposits are coal-bearing. The basin has been explored to a depth of 1,800 m. Up to this depth, the total reserves of conditioned coals are estimated at 109 billion tons. The reserves of industrial categories amount to 57.5 billion tons, of which anthracite accounts for 24%, gas coal - 48%, coking coal - 17%, lean coal - 11%

Pechorsky (Vorkuta) coal basin. The area is about 300 thousand sq. km. It is located in the polar and subpolar parts of the Cis-Ural trough. The terrigenous deposits of the Lower and Upper Permian are coal-bearing. The grade composition of coal ranges from brown to anthracite. Total geological reserves and resources are estimated at 265 billion tons, of which explored reserves are 23.9 billion tons

Baltic slate pool. The area of development of industrial shale potential is about 5.5 thousand sq. km. It is located on the southern slope of the Baltic Shield, mainly on the territory of the Leningrad Region and Estonia. The Middle Ordovician carbonate deposits are productive, among which there are horizons of combustible shale (kukersites) up to 9 m thick, which are of industrial importance. The total explored reserves of kukersites are estimated at 9.3 billion tons.

Timano-Pechora slate pool. It is located within the syneclise of the same name (Republic of Komi). It is confined to marine sandy-argillaceous sediments of the Upper Jurassic, containing 3 horizons of combustible shale with a thickness of 0.5-3.7 m. Ayuvinsky field, forecast resources of the entire basin are estimated at 29 billion tons.

Black metals. Ferrous metals are represented by deposits of sedimentary iron and manganese ores, which form large ore basins, in marine terrigenous sediments of the Paleogene and Neogene.

Kerch (Kerch-Taman) iron ore pool. It occupies an area of 250-300 sq. km on the Kerch Peninsula of Ukraine and partly on Taman Peninsula Russia (districts of the Black Sea). Ore-bearing are marine Pliocene (N 2) sandy-clayey strata containing layers of brown iron ore up to 25-40 m thick. The predominant part of the ores has an oolitic composition. The main ore minerals are hydrogoethite and leptochlorite. Explored reserves of iron ores amount to 1.84 billion tons with an average iron content of 37.5%.

South Ukrainian (Nikopol) manganese ore basin. It is located on the southern slope of the Ukrainian shield and covers an area of about 5 thousand sq. km. The most famous deposits are Nikopol, Big Tokmak. Oligocene marine sandy-silty-clayey deposits are productive, in which 2-3-meter layers of sedimentary manganese ores occur. The following types of ores are distinguished: oxide (average manganese content 27.9%), oxide-carbonate (average manganese content 25.0%) and carbonate (average manganese content 22.0%). The main ore minerals of oxide ores are pyrolusite, psilomelane, manganite, of carbonate ores - calcium rhodochrosite, manganese calcite. The reserves of manganese ores in this basin amount to 2.5 billion tons.

Non-ferrous metals. Non-ferrous metal deposits in the platform cover are represented by bauxites.

Bauxites are presented in Tikhvin deposits and(Leningrad region), North Onega bauxite-bearing region ( Arhangelsk region) and in Timanskaya bauxite province (Republic of Komi).

The Tikhvin and North Onega bauxites are confined to C 1 terrigenous deposits.

In the Timan bauxite ore province, 400 km long and up to 100 km wide, Middle Timan and South Timan boxite regions. The bauxites of the Srednetimansky region are D 3 aged, they are associated with multi-colored silty and sandy hydromicaceous and kaolinite-hydromicaceous clays, which are weathering crust on dolomitic limestones R 3 . The main ore minerals are boehmite, diaspore, minor ones are chamosite, goethite, hematite. The chemical composition of bauxite is as follows: Al 2 O 3 - 36.5-55.2%, SiO 2 - 2.7-12.3%, Fe 2 O 3 - 20.2-35%, silicon module (Al 2 O 3 : SiO 2), which determines the amount of free alumina, ranges from 3.5-4 to 20. The bauxite-bearing member of the Yuzhno-Timansky region has an Early Carboniferous age and is represented by kaolin clays with layers of allites and bauxites of various varieties. Bauxites have kaolinite-gibbsite-boehmite, kaolinite-boehmite composition. The chemical composition of bauxites: Al 2 O 3 - 40-70%, SiO 2 - 12-28%, Fe 2 O 3 - 3.6-12.6%, the flint module ranges from 1.5-5.5.

non-metals. Of the non-metallic minerals of great industrial importance, phosphorites, salts, precious and ornamental stones should be noted.

Baltic The phosphorite-bearing basin is located in the northwestern part of the Moscow syneclise, on the southern slope of the Baltic Shield, on the territory of the Leningrad Region and Estonia. The area is 15 thousand sq. km. Lower Ordovician sediments are phosphate-bearing, represented by a shell rock conglomerate of variable thickness - from 1-2 to 8-10 m. In some places it is overlapped by a horizon of oil shale. The balance reserves of phosphorites are 1.3 billion tons with an average content of P 2 O 5 12%.

Vyatsko-Kama the phosphorite-bearing basin is located in the central part of the Russian plate (Kirov region). It occupies an area of 1.9 thousand sq. km. Phosphate-bearing sediments are the Lower Cretaceous, represented by quartz-glauconite sand, in which phosphorite nodules ranging in size from 10 to 20-30 cm are loaded. Phosphorite reserves are 2.1 billion tons with a P 2 O 5 content of 11-15%.

Verkhnekamsky the salt-bearing basin is located in the Cis-Ural foredeep, it occupies an area of 6.5 thousand sq. km. Boundary deposits P 1 and P 2 are productive, represented by a variegated evaporite-bearing carbonate-sandy-argillaceous formation. Stone, potassium and magnesium salts are released in the pool. The main minerals of the salts are halite (NaCl), sylvin (KCl) and carnallite (MgCl 2 ·KCl 6H 2 O). Salt industrial reserves amount to 3.8 billion tons, prospective - 15.7 billion tons.

Caspian the saline basin occupies an area of about 600 thousand sq. km, coinciding, in essence, with the Caspian oil and gas province. About 1,200 salt domes (diapirs) are known here, in which the thickness of salt-bearing deposits reaches 8-11 km, decreasing to 1.5-2 km or until they are completely wedged out in the inter-dome spaces. The deposits of the Kungurian stage P 1 are predominantly salt-bearing. The composition of salts, along with halite and carnallite, also contains polyhalite K 2 MgCa 2 4 2H 2 O and bischofite MgCl 2 6H 2 O. On the territory of this basin, the waters (brine) of lakes Elton and Baskunchak are also saline. The total salt reserves are approaching 3 billion tons.

Arkhangelsk the diamond-bearing province is located in the north of the platform, on the southern coast of the White Sea (Arkhangelsk region). Alazoniferous are kimberlite pipes having age D 3 -C 1 . The most famous deposits them. Karpinsky, Lomonosovskoe and others. The reserves of the latter are approaching 230 million carats.

Kaliningradsky The amber-bearing region is located on the southern coast of the Baltic Sea. Industrial amber-bearing is associated with secondary placers formed during the washing of glauconite-quartz sands and siltstones of the upper Eocene (Middle Paleogene) with a thickness of 0.5-20 m, which are considered as deltaic deposits.

The groundwater. Groundwater deposits are located within a number of large artesian basins - Caspian, Baltic, Pechora, Moscow, Volga-Kama and etc.

In addition, a large number of common minerals (sand and gravel mixtures, pebbles, limestones, marls, chalk, crushed stone) are known in the platform cover, used as building materials in industrial, civil and road construction, cement production and other purposes.

East European Platform

Russian platform, European platform, one of the largest relatively stable areas of the earth's crust, one of the ancient (pre-Riphean) platforms. It occupies a significant part of Eastern and Northern Europe, from the Scandinavian mountains to the Urals and from the Barents to the Black and Caspian Seas. The border of the platform on the N.-E. and S. runs along the Timan Ridge and along the coast of the Kola Peninsula, and in the southwest. - along the line crossing the Central European Plain near Warsaw and then going to S.-3. across the Baltic Sea and the northern part of the Jutland peninsula.

Until the last decade, to V. p. in the north-east. attributed the area of the Pechora lowland, the Timan ridge, the Kanin and Rybachy peninsulas, as well as the adjacent part of the bottom of the Barents Sea; on S.-Z. the platform included the northern part of Central Europe (the Central European Plain, the territory of Denmark, the eastern part of Great Britain and the bottom of the North Sea). In recent years, the interpretation of the tectonic nature of these areas has changed due to the fact that the age of the basement within them was determined as Late Proterozoic. Some researchers (M.V. Muratov and others) began to attribute these areas to the area of the Baikal folding of the adjacent folded belts and thereby exclude them from the boundaries of the ancient (pre-Riphean) platform. According to another opinion (A. A. Bogdanov and others), the same pre-Riphean foundation of the platform was only partially reworked by the Baikal folding, and on this basis, the named areas continue to be considered as part of the V. p.

The ancient, pre-Riphean (Karelian, more than 1600 million years) folded crystalline basement and the sedimentary (Epikarelian) cover quietly overlying it stand out in the structure of the V. p. The foundation protrudes only on the northwest. (Baltic Shield) and Yu.-Z. (Ukrainian shield) platforms. On the rest of the larger area, allocated under the name of the Russian Plate, the foundation is covered with a cover of sedimentary deposits.

In the western and central parts of the Russian plate, lying between the Baltic and Ukrainian shields, the basement is relatively elevated and shallow, forming the Belorussian and Voronezh anteclises. They are separated from the Baltic Shield by the Baltic Syneclise (stretching from Riga in a southwestern direction), and from the Ukrainian Shield by a system of graben-like depressions of the Dnieper-Donetsk Avlakogenea, including the Pripyat and Dnieper grabens and ending in the V. Donetsk folded structure. To the southwest of the Belorussian anteclise and to the west of the Ukrainian Shield, along the southwestern boundary of the platform, the marginal Bug-Podolsk depression extends.

The eastern part of the Russian Plate is characterized by a deeper basement and a thick sedimentary cover. Two syneclises stand out here (See Syneclise) - Moscow, stretching to the north-east. almost to Timan, and the Caspian Sea bordered by faults (in the southeast). They are separated by the complexly constructed Volga-Ural anteclise. Its foundation is divided into ledges (Tokmovsky, Tatarsky, etc.), separated by aulacogene grabens (Kazan-Sergievsky, Verkhnekamsky). From the east, the Volga-Ural anteclise is framed by the marginal deep Kama-Ufimskaya depression. Between the Volga-Ural and Voronezh anteclises is the large and deep Pachelma aulacogen, which merges with the Moscow syneclise in the north. Within the latter, at a depth, a whole system of graben-like depressions was found, with a northeast and northwest strike. The largest of them are the Central Russian and Moscow aulacogenes. Here, the foundation of the Russian plate is submerged to a depth of 3-4 km, and in the Caspian depression, the foundation has the deepest occurrence (16-18 km).

There are two major periods in the history of VP. During the first of them, which covered the entire Archean, Early and Middle Proterozoic (3500-1600 Ma), the formation of a crystalline basement took place, during the second - the actual platform development, the formation of a sedimentary cover and modern structure (from the beginning of the Late Proterozoic to the Anthropogen) .

M. V. Muratov.

East European platform. Tectonic scheme.

Great Soviet Encyclopedia. - M.: Soviet Encyclopedia. 1969-1978 .

See what the "East European Platform" is in other dictionaries:

- (Russian platform) Precambrian platform, occupying most of the East. and part of the Zap. Europe. The foundation protrudes to the surface on the Baltic Shield and the Ukrainian massif; the most important structures are also anteclises (Belarusian, Voronezh ... Big Encyclopedic Dictionary

- (Russian platform), pre-Cambrian platform, occupying b. h. Eastern and parts of Northern and Western Europe. The foundation protrudes to the surface on the Baltic Shield and the Ukrainian massif; the most important structures are also anteclises (Belarusian ... Russian history

The Russian platform, the European platform, is one of the largest, relatively stable sections of the continental crust, one of the ancient (pre-Riphean) platforms. Takes means. part of the East. and Sev. Europe, from Scandinavian ... ... Geological Encyclopedia

- (Russian platform) one of the largest relatively stable areas of the earth's crust. It occupies the territory of Eastern Europe between the Caledonian folded structures of Norway in the northwest, the Hercynian folds of the Urals in the east and the Alpine ones ... ... Wikipedia - see East European platform. Mountain Encyclopedia. Moscow: Soviet Encyclopedia. Edited by E. A. Kozlovsky. 1984 1991 ... Geological Encyclopedia

The Russian Plain, one of the largest plains in the world, is located in the greater, eastern part of Europe. In the north it is washed by the waters of the White and Barents Seas, and in the south by the Black, Azov, and Caspian Seas. In the northwest it is bounded by the Scandinavian mountains ... Great Soviet Encyclopedia

- (Russian Plain), one of the largest plains in the world, occupying most of Eastern Europe. In the north it is washed by the waters of the White and Barents Seas, in the south by the Black, Azov and Caspian Seas. On the southwest bounded by the Carpathians, in the south ... ... encyclopedic Dictionary

- (geological), a large structure of the earth's crust, with low mobility, flat or plateau-like relief. The structure is two-tiered: at the base lies an intensely deformed, crystalline foundation, overlapped by sedimentary ... ... Modern Encyclopedia

Foundation. Archean and partially Lower Proterozoic deposits that form the foundation of the East European Platform are strata of primary sedimentary, volcanic-sedimentary and volcanic rocks metamorphosed into varying degrees. Archean formations are characterized by very energetic and specific folding associated with the plastic flow of the material during high pressures and temperatures.

characteristic feature foundation is the submeridional orientation of the main structural elements and their mostly symmetrical arrangement: the most ancient granulite and gneiss-amphibolite complexes prevail in the western Baltic-Belarusian-Western Ukrainian geostructural region and in the eastern Volga-Urals. They are separated by the younger Late Archean Early Proterozoic granite-greenstone Karelian-Kursk-Krivoy Rog superbelt.

The foundation of the platform is exposed only on the Baltic and Ukrainian shields, while in the rest of the space, especially within large anteclises, it has been exposed by boreholes and has been well studied geophysically.

Within the East European Platform, the oldest rocks are known with an age of up to 3.5 billion years or more, which form large blocks in the basement, which are framed by younger folded zones of Late Archean and Early Proterozoic age.

Archean formations. On the Baltic Shield in Karelia and on the Kola Peninsula, the oldest deposits, represented by gneisses and granulites with an age of 2.8-3.14 billion years, come to the surface.

On the Ukrainian Shield, the most ancient Archean rock complexes are widespread, represented by two complexes: the first is amphibolites, metabasite, jaspilites, i.e., rocks of primary basic composition, metamorphosed under conditions of amphibolite, sometimes granulite facies. The second - granite-gneisses, granites, migmatites, gneisses, anatectites * - in general, acidic rocks, in some places with relics of an ancient foundation.

On the Voronezh anteclise, the oldest rocks are gneisses and granite-gneisses. They are overlain by metabasites.

The oldest Archean formations have been traced under the cover of the Russian plate. They are metamorphosed in granulite and amphibolite facies, compose large massifs and blocks, and are characterized by widely developed granite-gneiss domes.

Lower Proterozoic formations relatively weakly developed in the foundation of the platform, including on the shields. They sharply differ from the most ancient Archean strata, composing linear folded zones or isometric troughs.

On the Baltic Shield above the Archean complexes with a clear unconformity lies the Lower Proterozoic essentially volcanic sequence with conglomerates in the upper part, up to 2.5 km thick.

On the Ukrainian Shield, the Lower Proterozoic is represented by the Krivoy Rog series, which forms narrow synclinoria superimposed on the Archean complexes, 10–50 km wide. The Krivoy Rog series is subdivided into the lower terrigenous sequence (quartzite-sandstones, conglomerates, phyllites, graphite schists); the middle one is iron ore, consisting of rhythmically alternating jaspilites and flysch-like schists*; the upper one is mostly terrigenous (conglomerates, gravelstones, quartzites). The total thickness of the series is up to 7-8 km, its deposits are intruded by granites with an age of 2.1-1.8 billion years.

The analogues of the described formations on the Voronezh anteclise are also deposits of the three-membered Kursk series with an iron ore sequence in the middle part, forming narrow synclinor zones oriented in the meridional direction.

The formation of the Upper Archean and Lower Proterozoic sequences discussed above was everywhere accompanied by repeated emplacement of complex multiphase intrusions from ultrabasic to acidic. In many places, they occupy almost the entire space, so that the host rocks remain only in the form of relics of the top of the intrusions.

Minerals associated with the foundation, are best studied within shields or anteclises, where they are covered only by a thin sediment cover or directly exposed on the surface.

Iron. The Kursk metamorphogenic iron ore basin is located on the southwestern slope of the Voronezh anteclise and is associated with the Lower Proterozoic jaspilites of the Kursk Group. The richest ores (Fe 60%) are the weathering crust of ferruginous quartzites and are composed of hematite and martite. The ferruginous quartzites themselves with a Fe content of 25 - 40% can be traced for hundreds of kilometers in the form of layers up to 1.0-0.5 km thick. The colossal reserves of rich and poor ores make the group of these deposits the largest in the world.

The Krivoy Rog iron ore basin, which began to be mined as early as the 19th century, is similar in type to the Kursk one and is associated with deposits of nine horizons of Lower Proterozoic ferruginous quartzites that have undergone weathering or hydrothermal processing to form rich hematite-martite ores (Fe up to 65%). However, the Krivoy Rog deposits are dozens of times inferior to the Kursk ones in terms of reserves.

The same type of Proterozoic deposits are known on the Kola Peninsula (Olenegorsk, Kostamuksha). Magmatic iron ore deposits - Enskoe, Kovdorskoe, Afrikanda (Kola Peninsula) - supply the Cherepovets Metallurgical Plant with raw materials. In recent years, ferruginous quartzites have also been discovered on the Belarusian anteclise.

Copper and nickel. A number of sulfide copper-nickel deposits (Pechenga, Monchegorsk and others) are associated with the Lower Proterozoic basic and ultrabasic bodies on the Kola Peninsula. Nickel deposits are also associated with the weathering crust of hypermafic rocks on the Ukrainian Shield.

Tin and molybdenum . The Proterozoic granites on the Kola Peninsula and on the Ukrainian Shield are associated with hydrothermal and contact-metasomatic deposits of tin and molybdenum, the largest of which is Pitkyaranta (Karelia).

Mica. On the Baltic Shield, mica deposits are known, which are located in Proterozoic pegmatites.

Graphite. A number of graphite deposits are being developed on the Ukrainian Shield in the Archean graphite gneisses near the town of Osipenko.

Conclusions. A review of the structure of the basement of the East European Platform shows the complexity of its internal structure, which is determined by the "skeleton" of Early Archean heterogeneous blocks, enveloped by relatively narrow and extended zones, mainly Late Archean and much less often Early Proterozoic folding. These zones, forming folded systems, although they differ from each other in a number of features, they have much in common in the nature of development, in the type of volcanogenic and sedimentary strata, and in structures. The processes that “soldered” all the Archean massifs caused the latter to be reworked, producing polymetamorphic complexes and diaphtorites* in them. At the turn of the Early and Late Proterozoic, the western regions of the Russian Plate underwent crushing and intrusion of rapakivi granites, while powerful acid ignimbrite* volcanism manifested itself in the northwest of the Baltic Shield, in Sweden.

Platform cover. The real (orthoplatform) cover of the East European Platform begins from the Upper Proterozoic - Riphean and is subdivided into two stages. The lower floor is composed of Riphean and Lower Vendian deposits, the upper one is composed of Vendian-Cenozoic deposits.

Lower floor (Riphean - Lower Vendian)

In the Riphean time, to the northeast of the formed part of the Russian platform (Pechora syneclise), as well as to the southeast (Caspian syneclise and to the west (Polish-German syneclise) of it, new geosynclinal regions were laid. They accumulated clastic deposits, siderite oolitic and carbonate rocks of algal origin, spilto-keratophyric * and flysch-like * strata. All these deposits in the Baikal epoch of folding were strongly crushed and cut through by numerous intrusions of granitoid rocks. The Baikalides, joining the epikarelian part of the Russian platform, finally formed its foundation.

Simultaneously with the formation of the Riphean geosynclinal regions in the epikarelian part of the Russian platform, the Palchemsky, Polessky (Volyn-Orsha) and other aulacogens actively formed. large plot, which gave rise to the Moscow and Baltic syneclises. These areas of subsidence are places of accumulation of various effusive-sedimentary formations of continental and marine origin. Already in the Riphean, transgression develops on the Russian platform.

Riphean complex. Riphean deposits are widely developed on the East European platform and are associated with numerous and diverse aulacogens (Fig. 1.5).

Figure 1.5 Riphean aulacogenes of the East European Platform (according to R.N. Valeev): 1 - areas of uplifts; 2 - aulacogenes: 3 - manifestations of trap magmatism; 4 - Hercynian aulacogenes; 5 - framing geosynclines. Numbers in circles denote aulacogenes. 1 - Ladoga, 2 - Kandalaksha-Dvinsky, 3 - Keretsko-Leshukovsky. 4 - Pre-Timansky. 5 - Vyatsky, 6 - Kamsko-Belsky, 7 - Sernovodsko-Abdulinsky, 8 - Buzuluksky, 9 - Central Russian, 10 - Moscow, 11 - Pachelmsky, 12 - Dono-Medveditsky, 13 - Volyn-Polessky, 14 - Botnica-Baltic, 15 - Pripyat-Dneprovsko-Donetsk, 16 - Kolvo-Denisovsky

Lower Riphean deposits are common in the east of the platform (for example, in the Pachelma aulacogen), as well as in the Volyn–Orsha and in the extreme west of the platform.

The lower parts of the sections of the Lower Riphean strata are composed of coarse terrigenous red-colored deposits accumulated under continental conditions. They are represented by conglomerates, gravelstones, inequigranular sandstones, siltstones and mudstones. At the tops of the sections quite often there are members of thinner rocks, mainly glauconite sandstones, mudstones, interlayers of dolomites, limestones and marls. The presence of stromatolites and glauconite indicates the shallow marine nature of the accumulation of these deposits. Volcanic rocks are known in places in the Lower Riphean: horizons of basaltic ash, tuffs and basalt covers, and gabbro-diabase intrusions were intruded in the western areas of the platform at that time. The thickness of the Lower Riphean deposits is hundreds of meters, often a kilometer.

The Middle Riphean deposits are rather arbitrarily distinguished in the sections and are present in the east of the platform (in the Pachelma and other aulacogenes) and in the Volyn-Orsha aulacogen. The deposits of the Middle Riphean are represented by terrigenous red-colored rocks: red, pink, purple, brown sandstones, siltstones, mudstones with limestone and dolomite interbeds.

The thickness of the Middle Riphean deposits reaches 1.4 km in the Moscow aulacogene, and in other places it does not exceed 0.5-0.7 km. In the western regions of the platform in the Middle Riphean, outpourings of basaltic and alkaline-basaltic lavas and explosive eruptions occurred, as evidenced by interlayers of tuffs and tuff breccias. Volcanic activity was accompanied by the intrusion of bedded intrusions of gabbro-diabases.

Upper Riphean deposits are widely developed in the eastern and central regions of the platform (in the Pachelma and other aulacogenes) and in the southwest of the platform. The bottoms of the sections are represented by red-colored and variegated terrigenous rocks - sandstones, siltstones, mudstones, formed in a continental setting. The middle and upper parts of the sections of the Upper Riphean strata are usually composed of green, gray, in some places almost black sandstones, often glauconite, siltstones, mudstones. In some places, for example, in the Pachelma aulacogen, members of dolomites and limestones appear. The main part of the Upper Riphean deposits accumulated in a very shallow marine basin. The thickness of the deposits of the Upper Riphean reaches 0.6-0.7 km, but more often it is a few hundred meters.

Conclusions. Thus, in the Riphean time, there were aulacogenes on the East European platform that cut through the elevated basement of the platform and were filled with strata of red-colored, continental, shallow-marine, and lagoonal variegated deposits. In the Early Riphean, aulacogenes developed near the Ural geosyncline. Continental deposits dominated in the first half of the Riphean. The formation of aulacogens in the Riphean time was accompanied by trap and alkaline magmatism. Areas with the most intense intrusive, effusive, and explosive * magmatism gravitated towards the eastern and western margins of the platform, which were distinguished by the greatest fragmentation of the basement. The Riphean deposits are characterized by a general complication of the set of facies over time, but at the beginning of the Early, Middle, and Late Riphean, coarser continental sequences accumulated. During the early and middle Riphean, uniform sediments formed, with a wide distribution of oligomictic sands and sandstones. Only in the Late Riphean deposits more differentiated in composition began to be deposited, among which polymictic sandstones, siltstones, and less often dolomites and marls are developed. In the shallow waters of the Riphean time there was abundant vegetation. During the Riphean time, the climate changed from hot, arid to cold. The platform as a whole was highly elevated, its contours were stable, as were the geosynclinal troughs framing it, fed by erosion of the platform rocks. Such a stable elevated position was broken only in the Vendian time, when the nature of tectonic movements changed and cooling set in.

The upper floor of the platform cover (Vendian - Cenozoic)

In the first half of the Vendian, a structural restructuring took place, which was expressed in the death of aulacogenes, their deformation in places and the appearance of extensive gentle depressions - the first syneclises. In the history of the formation of the upper stage of the platform cover, several milestones are outlined, which were characterized by a change in the structural plan and the set of formations. There are three main complexes:

1) Vendian-Lower Devonian;

2) Middle Devonian-Upper Triassic;

3) Lower Jurassic - Cenozoic.

The time of formation of these complexes generally corresponds to the Caledonian, Hercynian and Alpine stages of development, and the boundaries between them, during which a change in the structural plan occurred, correspond to the corresponding epochs of folding.

Vendian-Lower Devonian complex.

The events that developed on the Russian Platform in the first half of the Paleozoic were largely due to the processes that took place in the Rügen-Pomeranian geosynclinal region of the Grampian geosyncline (Caledonides). The subsidence of the latter was accompanied by the subsidence of a significant northwestern part of the platform, where transgressions developed in the Cambrian, Ordovician, and Silurian, coming from the Grampian area. When, by the end of the Silurian period, folded mountain structures rose in the Grampian region, the Russian platform also experienced a general uplift, and its northwestern part was completely freed from the sea. Subsequently, this was an area of stable uplifts, and if sedimentation occurred here, then, as a rule, in continental or lagoonal conditions. In the Early Devonian, in the west of the platform, the Lvov-Ljubljana trough and the Baltic syneclise began to descend. The bowing did not spread to the territory of Belarus.

The Baltic-Pridnestrovian zone of pericratonic * subsidence of the Caledonian stage will include the following structures of the second order: the Baltic syneclise, the Masurian ledge of the Belarusian anteclise, the Podlasie-Brest depression, the Lukovsky-Ratnovsky horst, the Volyn depression, etc.

Vendian deposits widespread on the East European platform. The Vendian deposits on the Russian Plate are represented by terrigenous rocks: conglomerates, gritstones, sandstones, siltstones, and mudstones. Less common are carbonate rocks: marls, limestones and dolomites. Sandstones and siltstones are colored green, greenish-gray, black, red-brown, pink.

In the first half of the Early Vendian, the structural plan of the plate resembled that of the Late Riphean, and deposits accumulated within the aulacogenes, occupying only a slightly larger area and composing elongated or isometric troughs. In the middle of the Early Vendian, the sedimentation conditions and the structural plan began to change. Narrow troughs began to widen, deposits seemed to “splash out” beyond their limits, and in the second half of the Early Vendian, extensive depressions were predominantly developed. In the northwest of the platform, a sublatitudinal Baltic trough appears, bounded from the east by the Latvian saddle. In the western and southwestern regions of the platform, an extensive trough formed, consisting of a number of depressions separated by uplifts. The eastern areas of the platform, adjacent to the Urals, experienced subsidence. The rest of the platform was raised. In the north there was the Baltic Shield, which at that time extended far to the south, to Belarus. In the south was the Ukrainian-Voronezh shield. In the second half of the Early Vendian, there was cold snap climate, as evidenced by tillites in the Vendian deposits of a number of areas, which were then replaced by variegated and red-colored carbonate-terrigenous sediments.

In the late Vendian, the areas of sedimentation expanded even more, and the deposits already cover large areas of the platform as a continuous cover (Fig. 1.6). Huge gentle troughs - syneclises - begin to form. The upper part of the Vendian deposits is represented mainly by terrigenous gray-colored rocks: sandstones, siltstones, clays, mudstones, etc., up to tens of meters thick. All these deposits are closely related to the sediments of the Lower Cambrian.

An important feature of the Vendian deposits is the presence of volcanic rocks in them. In the Brest and Lvov depressions and in Volyn, basalt covers are widely developed, and less often, layers of basalt tuffs. The Upper Vendian sediments in many places contain mature horizons of basalt tuffs and ash, which testify to explosive volcanic activity.

The thickness of the Vendian deposits is usually a few hundred meters, and only in the eastern areas of the platform does it reach 400-500 m.

Deposits of the Cambrian system represented mainly by the lower division.

Lower Cambrian deposits are common in the Baltic syneclise, which opened far to the west in the Early Cambrian, separating the structures of the Baltic Shield from the structures of the Belarusian uplift. Cambrian outcrops are found only in the region of the so-called glint 6 (cliff of the southern coast of the Gulf of Finland), but under the cover of younger formations they have been traced by drilling further east, up to Timan. Other area of development Cambrian deposits on the surface - the region of the Dniester trough (Fig. 1.6).

Lower Cambrian deposits are represented by marine facies of a shallow epicontinental sea of normal salinity. The most characteristic section of the Cambrian is exposed in the steep cliff of the southern coast of the Gulf of Finland, where above the laminaritic layers of the Upper Vendian there are conformably supralaminarite sandstones dating back to the Cambrian. They are according to

Figure 1.6 The main structures of the East European Platform at the Caledonian stage of development (according to M. V. Muratov): 1 - areas of stable uplifts. Deflections: 2 - in the Late Vendian; 3 - in the Cambrian period; 4 - in the Ordovician period; 5 - in the Silurian period; 6 - geosynclines surrounding the platform; 7 - manifestations of basaltic volcanism in the Vendian time; 8 - total thickness of deposits, km; 9 - grabens; 10 - weak folded deformations. I - Baltic trough; II - Dniester trough

are replaced by a thickness of the so-called "blue clays". Eophyton sands, sandstones, and layered clays with remains of Eophyton algae lie above.

The Lower Cambrian section ends with gray cross-bedded sands and sandstones with clay interbeds. The thickness of the Lower Cambrian deposits penetrated by boreholes in the Baltic trough does not exceed 500 m.

Thus, in the Cambrian period, a shallow sea existed only in the west of the platform, and then mainly in the early epoch of this period. But the Baltic trough expanded westward towards Lithuania, Kaliningrad and the Baltic Sea, where the thickness of the Cambrian

deposits increases. Marine conditions also existed in the Dniester trough, while the rest of the platform was uplifted land. Consequently, there was a sharp reduction in the marine basin by the end of the Early - beginning of the Middle Cambrian and a break in sedimentation, which falls on the Middle and partly on the Late Cambrian. Despite the uplifts that took place in the Late Cambrian, in the Ordovician and Silurian periods, the structural plan remained almost unchanged.

Early Ordovician period within the latitudinal Baltic trough, subsidence occurs again and from the west the sea transgresses to the east, spreading approximately to the meridian of Yaroslavl, and in the south - to the latitude of Vilnius. Marine conditions also existed in the Dniester trough. In the Baltic, the Ordovician is represented by marine terrigenous deposits in the lower part, terrigenous-carbonate in the middle, and carbonate in the upper. They contain an exceptionally rich and diverse fauna of trilobites, graptolites, corals, tabulates, brachiopods, bryozoans and other organisms that existed in warm, shallow seas. The most complete sections of the Ordovician are described in the northern flank of the Baltic Foredeep in Estonia, where all the stages of this system are distinguished. The thickness of the Ordovician deposits does not exceed 0.3 km.

In the southwest, in the Dniester trough, the Ordovician section is represented by a thin (a few tens of meters) sequence of glauconite sandstones and limestones. The rest of the platform was uplifted during the Ordovician period.

During the Silurian period in the west of the platform, the Baltic trough continued to exist, which was even more reduced in size (Fig. 5). To the east of the transverse uplift (Latvian saddle), the sea did not penetrate. In the southwest, Silurian deposits are also known in Transnistria. They are represented exclusively by carbonate and carbonate-argillaceous rocks: limestones of various colors, thin-layered marls, less often clays, in which an abundant and diverse fauna is found. The thickness of the Silurian deposits in Estonia does not exceed 0.1 km, but increases to the west (in Northern Poland - more than 2.5 km). In Podolia and in the region of Lviv, the thickness of the Silurian reaches 0.5-0.7 km. Judging by the similar nature of the fauna in the Baltic and Dniester troughs, these sea basins were connected somewhere to the northwest, on the territory of Poland.

The Silurian is dominated by deposits of the open shallow sea, and coastal facies were developed only along the eastern margins of the sea basin. In the course of time, the area of uplifts, which covered most of the platform, expanded, and the sea, retreating to the west in the Late Silurian, almost completely left its limits.

During the early Devonian The Russian plate was characterized by high standing, only its extreme western and eastern regions, where thin deposits of this age are found, slightly sagged.

Conclusions. Thus, during the Vendian, Cambrian, Ordovician, Silurian, and Early Devonian, the East European Platform as a whole was dominated by uplifts, which, starting from the Cambrian, gradually covered an increasing area. The subsidence was most stable in the western part of the platform, in the Baltic and Pridnestrovian troughs. In the late Silurian - early Devonian in the Baltic region, the formation of reverse faults, grabens in some places, and platform inversion uplifts oriented in the sublatitudinal direction arose. At this time, which corresponds to the Caledonian era of the development of the geosynclinal regions surrounding the platform, the climate was hot or warm, which, along with shallow sea basins, contributed to the development of an abundant and diverse fauna.

Middle Devonian-Upper Triassic complex.

During the Middle Devonian a new structural plan begins to form, which was preserved in general terms almost until the end of the Paleozoic and characterized the Hercynian stage of the development of the platform, during which subsidence prevailed, especially in its eastern half.

In the late Paleozoic, the Russian Platform developed into close connection with the Ural geosynclinal region. The subsidence of the latter was accompanied by a significant subsidence, primarily of the eastern part of the platform, and here, earlier than in other areas of the platform, wide transgressions developed and intensive sedimentation took place (Fig. 1.7; 1.8). When, at the end of the Paleozoic, mountain folded structures rose in the Ural geosynclinal region, the Russian platform also experienced uplift.

In the early Devonian, the platform that was uplifted at the end of the Caledonian tectogenesis is still a continent. The clearly expressed lowering of the platform begins from the Eifelian. It covers the eastern half of the platform, a large transgression is developing here. This sea left oil-producing strata of the Volga-Ural oil-bearing province in the east of the platform. In the central parts, it was shallower; not carbonate, but clastic deposits are widespread here. In the west, predominantly continental red-colored and lagoonal gypsum deposits are developed. At the end of the Devonian, the sea remained only in the southeast of the platform (Fig. 1.8).

Tectonic movements at that time were distinguished by significant differentiation (Fig. 1.7). The Baltic Shield experienced upward movements. In the south of the platform, in the Middle Devonian, the Dnieper-Donetsk aulacogen formed, dividing the Sarmatian shield into a southwestern half (Ukrainian shield) and a northeastern half (Voronezh anteclise). The Caspian syneclise, the Dnieper-Donetsk, Pripyat and Dniester troughs experienced the maximum subsidence. The northeastern part of the Sarmatian shield - in the outlines of the modern Volga-Ural anteclise together with the Moscow syneclise - was also covered by subsidence. The western part of the platform also sagged vigorously.

Devonian deposits are very widespread on the Russian Plate, exposed on the surface in the Baltic and Belarus (Main Devonian field), on the northern slopes of the Voronezh anteclise (Central Devonian field), along the southeastern margin of the Baltic Shield, in Transnistria and along the southern margins of the Donbass. In other places, the Devonian, under the cover of younger deposits, fills the Dnieper-Donetsk trough, the Moscow syneclise, and depressions western regions plate, is developed everywhere within the Volga-Ural anteclise. The Devonian is extremely diverse in terms of facies, and the maximum thickness of the deposits exceeds 2 km.

Starting from the Eifelian and especially the Givetian Ages of the Middle Devonian, the paleogeographic situation changed dramatically, significant areas of the Russian Plate began to experience subsidence. Since transgressions mainly spread from east to west, facies of the open sea prevail in the eastern regions, while lagoonal and lagoonal-continental facies prevail in the western regions (Fig. 1.8).

In the area of the Main Devonian field, deposits of the Eifelian, Givetian, Frasnian, and Famennian stages are present. The sediments of the Eifelian and Givetian stages with erosion lie on older rocks and are represented by a red-colored stratum of sandstones and clays, and in the middle part - marls and limestones with salt lenses. Most of the Frasnian stage is composed of limestones, dolomites and marls. The tops of the Frasnian and the entire Famennian are represented by sandy-argillaceous, in some places variegated deposits.

In the Central Devonian field, Eifel sandy-clayey-carbonate deposits lie directly on the basement rocks. Above are thin clay-carbonate deposits of the Givetian

tiers, replaced by Frasnian variegated pebbles, sandstones, clays. The upper part of the Frasnian and the entire Famennian are represented by carbonate limestones, more rarely marls with thin clay interbeds. The total thickness of the Devonian in the Central field reaches 0.5 km.

To the east, in the Volga-Ural region, the section of the Middle-Upper Devonian deposits as a whole differs from those described above in deeper, purely marine facies. Deposits of the Givetian stage, which are eroded on thin Eifelian deposits, are represented mainly by

Figure 17 The main structures of the East European Platform at the Hercynian stage of development (according to M.V. Muratov): 1 - areas of stable uplifts, 2 - areas of moderate and weak subsidence; 3 - areas of energetic subsidence; 4 - geosynclines; 5 - Caledonides; 6 - manifestations of Devonian volcanism; 7 - total thickness of deposits, km; 8 - grabens; 9 - weak folded deformations. I - Polish-Lithuanian syneclise; II - Lvov depression; III - Dnieper-Donetsk trough; IV - Moscow syneclise; V - East Russian depression; VI - Caspian syneclise

dark bituminous clayey limestones. The overlying Frasnian deposits in the lower parts are composed of sands, clays and sandstones, often saturated with oil. The Famennian Stage is composed of dolomites, less often marls and limestones.

Figure 1.8 Stratigraphic columns reflecting the features of sedimentation on the East European Platform in the Devonian period (according to V.M. Podobina)

Of particular interest are the Devonian deposits of the revived Dnieper-Donetsk aulacogen, where they form a thick sequence in its central part, rapidly wedging out to the sides. The Middle Devonian (beginning with the Givetian) and the lower parts of the Upper Devonian are represented by a salt-bearing stratum more than 1 km thick. In addition to rock salts, it contains interlayers of anhydrites, gypsum, and clays. The Famennian stage is composed of very variegated and facially variable deposits: carbonate-sulfate clays, marls, sandstones, etc. In the extreme west, in the Pripyat graben in the Famennian stage, there are lenses and sequences of potassium salts. Oil deposits have been found in intersalt deposits of the Devonian. The total thickness of the Devonian deposits exceeds 2 km.

The formation of the Dnieper-Donetsk aulacogen was accompanied by volcanism. So, in the region of the Braginsko-Loevskaya saddle, boreholes uncovered olivine and alkaline basalts, trachytes and their tuffs, about 1.8 km thick. Manifestation of alkaline basalt volcanism also took place in the northeastern part of the Pripyat trough. The Frasnian age is the time of fragmentation of the foundation of the aulacogen.

Upper Devonian volcanics are also known from the southern outskirts of the Donbass. Boreholes also uncovered Upper Devonian basalts in the Volga-Ural anteclise.

In the Late Devonian on the Kola Peninsula, ring intrusions of alkaline rocks were introduced (Lovozero, Khibiny and other massifs).

Conclusions. The Devonian period on the East European platform was marked by a significant restructuring of the structural plan, the fragmentation of its eastern part and the initiation of a number of aulacogenes. The Early Devonian era was a time of almost universal uplifts. During the Eifelian, local subsidence occurred. The transgression that began in the Givetian reached its maximum in the Early Famennian, after which the sea basin contracted, became shallow, and a complex pattern of facies distribution was created with a predominance of lagoons. Differentiated tectonic movements were accompanied by alkaline, basic, alkaline-ultrabasic and trap magmatism. At the beginning of the Late Devonian, narrow (1–5 km) but extended (100–200 km) grabens formed in the Cis-Urals, indicating the fragmentation of the crust.

During the Carboniferous approximately the same structural plan was preserved, which had developed by the end of the Devonian time. The areas of maximum deflection were located within the East Russian Basin, gravitating towards the Ural geosyncline. Carboniferous deposits are very widespread on the plate, being absent only on the Baltic and Ukrainian shields, in the Baltic, on the Voronezh and Belorussian anteclises. In many places where these deposits are overlain by younger rocks, they have been penetrated by boreholes. Among the largest negative structures of the Carboniferous period, one can name the Dnieper-Donetsk trough; in the west of the platform, the Polish-Lithuanian depression was formed, and in the east, the East Russian depression. Timan experienced a relative uplift. In the southeast of the platform, the Caspian depression continued to sag.

The Carboniferous deposits of the central regions of the Russian Plate are characterized mainly by carbonate rocks, only in the lower visa are coal-bearing, and in the lower part of the Moscow stage - sandy-argillaceous strata, fixing erosion. The maximum carboniferous thickness reaches 0.4 km in the Moscow syneclise, and in the east and southeast the plates exceed 1.5 km.

The section of the Carboniferous in the west of the plate, in the Lvov-Volynsk coal-bearing basin, differs from the one described above in that limestones are common in the lower visa, and coals appear in the upper visa and in the Bashkirian stage of the Middle Carboniferous, with the coal-bearing stratum reaching 0.4 km, and the total thickness Carboniferous - 1 km.

Conclusions. For the Carboniferous, it is necessary to emphasize the clearly expressed meridional orientation of the main troughs. The eastern regions of the Russian Plate sank much more intensively than the western and central ones, and the conditions of an open, albeit shallow, sea basin prevailed there. The waves of uplifts that took place in the late tour - early visa, late visa, in the early Bashkirian and early Moscow time only briefly interrupted the steady subsidence of the plate. The Late Carboniferous era was characterized by slow uplifts, as a result of which the sea became shallow and dolomites, gypsum and anhydrites accumulated in a hot dry climate. But the Early Visean time was most distinctive, during which there was a rather dissected relief, an extremely complex facies setting, and a humid climate that contributed to the accumulation of coal and bauxite in the north.

During the Permian period the structural plan of the platform as a whole inherits that of the Carboniferous period. In the second half of the Permian, uplifts occur on the platform, induced by orogenic movements in the closing Ural geosyncline. The area of precipitation accumulation acquires an even clearer meridional orientation, clearly gravitating towards the Urals. Along the eastern border of the platform with the growing mountain structures of the Urals, in the Permian, the Cis-Ural marginal trough was laid, in the process of its development, as it were, “rolled” onto the platform. As in the Carboniferous, the maximum thickness of Permian deposits is observed in the east. Permian marine sediments are characterized by a rather poor fauna, which is due to the increased or decreased salinity of the basins of that time. Permian deposits are widespread within the platform and are exposed in the east, southeast, and northeast. In the Caspian basin, Permian deposits are known in salt domes. In the west of the Russian Plate, Permian is known in the Polish-Lithuanian and Dnieper-Donets depressions.

The Permian period on the East European platform was characterized by a complex paleogeographic setting, frequent migration of shallow sea basins first, normal salinity, then brackish water, and, finally, the predominance of continental conditions at the end of the Late Permian, when almost the entire platform came out of the sea level and sedimentation continued only in the east and southeast. The Permian, especially the Upper Permian, deposits are closely related to the molasses of the * Cis-Ural marginal foredeep.

The lower section of the Permian system lithologically differs sharply from the upper one and is represented mainly by carbonate rocks, strongly gypsum-bearing at the top of the section. The thickness of the Lower Permian deposits does not go beyond a few hundred meters and increases only to the east.

The Upper Permian is everywhere composed of terrigenous rocks, only in the northeastern regions the Kazanian stage is represented by limestones and dolomites. The thickness of the Upper Permian deposits also amounts to a few hundreds of meters, but increases sharply in the east and in the Caspian depression.

The climate of the Permian period was hot, at times subtropical, but generally characterized by considerable dryness. In the north, conditions of a humid climate of temperate latitudes prevailed.

In the Permian, there was a manifestation of magmatism on the Kola Peninsula, where complex massifs of nepheline syenites were formed - Khibiny and Lovozero.

Triassic deposits are closely related to the deposits of the Tatarian stage of the Upper Permian. Uplifts at the end of the Permian were again replaced by subsidences, but sedimentation in the Early Triassic took place over a much smaller area. The East Russian depression broke up into several isolated depressions. The Volga-Ural anteclise began to take shape. The deposits of the Lower Triassic lie in places with erosion on older rocks; they are most widely distributed on the surface in the northeastern part of the Moscow syneclise. They are developed in the Caspian, Dnieper-Donetsk and Polish-Lithuanian depressions. Everywhere, except for the Caspian Sea, the Lower Triassic is represented by variegated continental sediments composed of sandstones, clays, marls, and rarely lacustrine limestones. The clastic material was brought from the east, from the collapsing Paleo-Ural mountains, as well as from the Baltic and Ukrainian shields and the growing Voronezh, Volga-Ural and Belorussian anteclises. The thickness of variegated flowers in the northeast is 0.15 km, and in the Dnieper-Donetsk depression it increases to 0.6 km.

In the Middle Triassic, almost the entire territory of the platform was covered by uplifts, except for the Caspian Basin. There is evidence of the presence of Middle Triassic deposits in the Dnieper-Donetsk depression.

The Upper Triassic in the form of thin argillaceous deposits with interlayers of sandstones is known in the Dnieper-Donetsk depression and in the Baltic.

Conclusions. The main features of the Hercynian stage in the development of the East European Platform are as follows.

1. The duration of the Hercynian stage is approximately 150 million years and covers the time from the Middle Devonian to the Late Triassic inclusive.

2. The total thickness of deposits ranges from 0.2-0.3 to 10 km

and more (in the Caspian basin).

3. The beginning of the stage was accompanied by a restructuring of the structural plan, vigorous tectonic movements, crushing of the basement and a wide manifestation of alkaline-basalt ultrabasic - alkaline and trap volcanism.

4. The structural plan changed little during the Hercynian stage, and the areas of uplifts gradually grew by the end of the stage. In general, dives prevailed on the platform, especially at the beginning of the stage, which sharply distinguishes it from the Caledonian.

5. From the middle of the stage, the orientation of the troughs was meridional and the areas of troughs were pushed to the east, which is due to the influence of the Hercynian geosyncline of the Urals.

6. At the end of the stage, the Russian plate was formed within the boundaries close to modern ones, and the main structures were formed.

7. The lower parts of the section of the Hercynian complex are composed mainly of terrigenous deposits, sometimes saline. In the middle of the section, carbonate strata are widespread, at the top they are again replaced by terrigenous, red-colored, less often saline deposits. At the end of the Hercynian stage, the growth of salt domes began in the Ukrainian and Caspian depressions.

8. During the entire stage, the climate remained hot, sometimes humid, sometimes more arid.

The East European Platform corresponds to one of the largest continental blocks of Eurasia and belongs to the belt of ancient Laurasian platforms, which also includes the Siberian and North American platform. It is a diamond-shaped continental block about 3000 km across, the base of which was formed about 1.6 billion years ago.

Two main types can be distinguished in relations with the uneven-aged fold-and-thrust structures surrounding the platform. So the Urals and the Carpathians are separated from the platform by their forward troughs superimposed on the lowered edges of the platform, and the Scandinavian Caledonides and the Baikal folded structures of the Timan directly overlap the autochthonous complexes of the platform along the thrust system, and the ridges can reach more than 200 km. However, traditionally, in both cases, it is customary to consider the front of the thrusts beyond the boundaries of the platform. In the remaining parts of its perimeter, the East European Platform borders on young plates - the Central European in the west, the Scythian-Turan in the south, and these limits are also represented by faults, partly subvertical, partly thrust. The southeastern corner of the platform is occupied by the Caspian Basin with a suboceanic type of crust, which is traditionally included in the platform. The boundary in this section of the platform is usually drawn along the buried South Emben dislocation zone. The depression is a relic oceanic basin filled with sediments up to 20 km thick. and its inclusion in the East European Platform, in this case, is very conditional. West south modern border platform acquires a clearer character - it runs along the Paleozoic thrust of the Donets-Caspian folded zone, goes around the Donets Ridge and, turning to the west, crosses the Sea of Azov and the Black Sea and docks with the Teyser-Tornquist strike-slip zone.

The Precambrian crystalline basement is exposed mainly along the northwestern periphery of the East European Platform - the Baltic Shield, and also in the south - within the Ukrainian Shield. In addition, the structures of the crystalline basement of the platform include submerged massifs - the Voronezh and Volga-Urals, most of which are covered by platform sediments up to 1.5 km thick. These tectonic units have a pronounced large-block structure. So in the structure of the Ukrainian shield, five are distinguished, and the Baltic - six blocks, separated by deep faults or seams along which they were soldered. Each of the blocks has an individual internal structure, and often a material composition that is disharmonious with adjacent tectonic units. On the Baltic Shield stand out: Murmansk, Kola, Belomorsky, Karelian, Svekofensky and Svekonorwegian blocks. The Ukrainian shield is also formed by several blocks: Volyn-Podolsky, Odessa-Belotserkovsky, Kirovograd, Prydniprovsky, Pryazovsky. It can be assumed that similar blocks form the structure of the Voronezh and Volga-Ural massifs.

The oldest (AR 1) basement formations are granulite-gneiss areas composed mainly of rocks of the granulite facies of metamorphism. Apparently, among them there are protocontinental massifs formed on the original crust of the oceanic type, the relics of which are tonalites, ultramafic rocks and other rocks with an isotopic age of 3700 to 3100 Ma. The Murmansk and White Sea blocks of the Baltic Shield should be included in the group of essentially granulite blocks. The most typical rocks of their constituents are high-alumina biotite gneisses; metamorphosed "mature" sedimentary rocks, and metamorphosed volcanics of mafic composition, including amphibolites and charnockites (hypersthenic gneisses). The development fields of the described metamorphites are characterized by large granite-gneiss domes. They are rounded or elongated in one direction, tens of kilometers in diameter. Plagiogranite-gneisses and migmatites are exposed in the cores of the domes.

On the territory of the Kola and Karelian blocks of the Baltic Shield, as well as on most of the Ukrainian Shield, greenstone belts are "squeezed" between similar granite-gneiss domes. The composition of greenstone belts is fairly similar for most ancient platforms. The lower parts, as a rule, are composed of strata of basic effusives of spilite-diabase composition, sometimes significantly metamorphosed. The pillow structure indicates the outpouring of these mafic rocks under underwater conditions. The upper parts of the section are often represented by acid effusives - keratophyres, felsite, with interlayers of quartzite sandstones and gravelstones. According to the petrochemical characteristics, these metavolcanites in most cases correspond to MOR basalts and basaltic komatiites, however, sometimes metamorphosed calc-alkaline volcanic rocks of basalt-andesite-dacite composition are widely found in the greenstone belts. The structural position of the greenstone belts unequivocally testifies in favor of the fact that they are nothing more than the seams of the collision of various blocks of the most ancient crust. Stratigraphic contacts with the surrounding granulite-gneiss complexes are not observed anywhere, they are either shaded during later joint metamorphism, granitization and deformation of both complexes, or tectonic. AT last case greenstone belts are either narrow, highly compressed synclines bounded by faults, or rather isometric remnants of tectonic covers thrust over the granulite-gneiss base, which are preserved in the spaces between the domes. Isotope-geochronological dating allows us to consider that the formation of granite-greenstone areas on the territory of the East European platform occurred in the interval of 3100 - 2600 million years. There is no unambiguous point of view on the geodynamic nature of greenstone belts. They are associated with the subsidence and reworking of the primary sialic crust above the rising mantle diapira, or they see an analogy with modern rifts that "cracked" the protocontinental granulite-gneiss crust, or they are compared with the modern system of island arcs and marginal seas.

The Svecofennian block has absolutely individual structural features in the composite structure of the Baltic Shield. It is a typical representative of gneiss-shale areas. The most significant distinguishing features are: the absence of an Archean foundation; wide development of shale and gneiss-shale strata of the Early Proterozoic age, as well as large granitoid plutons, intruded in the range of 1850-1700 million years ago. essential role in shale sections, it belongs to metavolcanics of both basic and felsic composition. In their structure, the complexes that make up the Svecofennian block are similar to the gravuaco-volcanic series of Phanerozoic folded belts that formed in marginal seas separated by island arcs. Thus, the Svecofennian block can be interpreted as being formed as a result of accretionary tectonics. Granites, ubiquitous in the territory of the block, are an indicator of collisional processes, as a result of which the svecophenides were obducted and thrust onto the Karelian basement with the formation of an extended (almost 1500 km long) West Karelian thrust zone, "cutting off" the contours of the Kola-Karelian Archean-Proterozoic superterrane. The outcrops of the Lower Proterozoic (1.9 Ga) ophiolite complex gravitate to the zone of this thrust, indicating the formation of the Svecofennian belt on the oceanic-type crust. On the western periphery of the Svecofennian block, the Gotha (Trans-Scandinavian) volcano-plutonic belt is developed, composed of magmatites of mantle origin. Most notable in the belt are terrestrial felsic lavas, including rhyolites, dacites, ignimbrites, as well as lavas of increased alkalinity interspersed with agglomerates and arkoses. The effusives are associated with granite batholiths. The age of lavas and granites breaking through them is estimated at 1750-1540 million years. The composition and structure of this Proterozoic volcanic-plutonic belt is very similar to the continental marginal belts of the Andean type. Taking into account this analogy, it can be assumed that the Gothic belt in the Proterozoic occupied a marginal position and was formed above the subduction zone.

The composition and structure of the westernmost tectonic unit of the Baltic Shield, the Svekonorwegian block, is also highly individual. In terms of its structure, history of development, and time of final cratonization, this tectonic element is close to the Grenville orogenic belt of North America and is considered as its eastern extension. The time of formation of the most ancient rocks of the Svekonorwegian zone corresponds to the interval of 1.75-1.9 billion years. They underwent significant reworking during the epoch of the Gothic (at the level of 1.7-1.6 billion years) and Dalsladian - Sveconovergian (1.2-0.9 billion years) orogeny. The internal structure of the block is notable for its considerable complexity and actually represents a collage of cratonic, island-arc, etc. terranes. The metamorphosed volcanic-sedimentary and terrigenous sequences of the Early-Middle Proterozoic are most widely developed in varying degrees.

In general, the outcrops of the Early Proterozoic complexes of the Baltic and Ukrainian shields gravitate towards the suture zones delimiting the Archean blocks and, in contrast to the latter, have a more diverse composition and structure.

In the east of the Kola block, near the suture zone, the Lower Proterozoic deposits fill the Keivsky synclinorium and are represented by a series of the same name, unconformably overlying Archean gneisses. The Keivy Group is filled with sediments typical of a passive continental margin: at the base there are conglomerates with fragments of Archean rocks, then a thick sequence of high clayey shales and paragneisses, and at the top - arkose sandstones, as well as interlayers of dolomites, including stramotalites. The age of the granites breaking through the series is 1900-2000 million years.

The Proterozoic of the suture zone of the Kola and White Sea blocks (Pechenga and Imadra-Varzug zones) is similar in structure and composition to the Phanerozoic ophiolite belts. The bulk of the section is made up of effusives of basic, to a lesser extent intermediate and ultrabasic compositions. Many lavas have a cushion structure. Among the lavas there are horizons of conglomerates, arkoses, and quartzites containing fragments of Archean gneisses and granites. The section is saturated with ultramafic, gabbro, gabbronorite, and anorthosite bodies. The probable age of the rocks is 1900-1800 million years, the age of metamorphism is 1800-1700 million years.

The Early Proterozoic complexes of the East Karelian suture zone located between the Karelian and White Sea blocks are geodynamically associated with subduction processes. These formations are described as part of the Sumian complex. The age of the deposits is 2400 million years. In general, the complex is formed by two types of deposits - volcanogenic (Tungut series), which are characterized by continuous series from basalts through andesites to rhyolites, and detrital (Sariolian series). The Sumium of the Karelian Block was subject to folding, metamorphism, and was intruded by plagiogranites with an age of ~2000 Ma.

In internal parts Archean blocks from the turn of ~ 2.3 billion years (Seletska folding), the appearance of essentially terrigenous sediments of the protoplatform cover is noted. The section of this complex is represented by three strata: jatulium - quartz conglomerates, gravelstones, sandstones interbedded with rare covers of basalts; suisariy - clay shales, phyllites, dolomites with interlayers of tholeiitic basalts; Vepsian - conglomerates and sandstones with gabbro-diabase sills.

On the Ukrainian Shield, the famous Krivoy Rog series, containing rich deposits of jespelite ores, belongs to the Early Proterozoic. It is localized mainly along the Krivoy Rog zone on the border between the Dnieper and Kirovograd blocks, as well as along the Orekhovo-Pavlograd zone, which limits the Dnieper and Azov blocks, forming narrow fault synclinoria. A complete analogue of the Krivoi Rog series is the well-known Kursk series of the Voronezh massif. The absolute age of these deposits falls within the range of 2500-1880 Ma. The section is represented by three strata from bottom to top: essentially detrital (quartzite-sandstone, conglomerate, phyllite, graphite schist); flysch-like (rhythmic alternation of jespelites and cherts); terrigenous (conglomerates, gravelstones, quartzites). The total thickness is 7-8 km, all deposits are intruded by granites with an age of 2.1 - 1.8 billion years

The foundation of the East European Platform is broken by narrow, deep (up to 3 km or more) graben-like troughs (aulacogens) - dead rays of ancient rift systems. In the history of the development of the platform, three main epochs of graben-formation are outlined: Riphean, Devonian and Permian (Oslo graben).

Riphean aulacogens are the most numerous. They form an almost rectangular network of northeast and northwest directions and break the foundation of the platform into a series of blocks roughly corresponding to shields and submerged massifs. The longest (at least 2000 km) is a system of northeastern grabens, extending from the western end of the Ukrainian shield to the junction of the Timan with the Urals and consists of two independent aulacogens: Orsha-Volyn-Kresttsovsky in the west and Sredne-Russian in the east. From the place of their junction to the southeast, the Pachelma paleorift departs, and to the northwest, less clearly defined, the Ladoga. The Kandalaksha and Mezen grabens approach the Middle Russian aulacogen almost at a right angle from the north. In the very east of the platform, on the Volga-Ural arch, there is the Kaltasinsky aulacogen. The grabens-filling complexes are dominated by Middle Riphean red-colored coarse clastic strata formed due to erosion of nearby uplifts. Often, thick (up to 400 m) lava covers of basalts, tuffs, volcanic breccias, and dolerite sills appear at the base of the section. Of the igneous complexes, bimodal alkaline-ultrabasic series with carbonatites are characteristic. Higher in the section, the Riphean volcanic-terrigenous formations are replaced by Vendian shallow-marine sediments, the strata of which pass from the grabens to the adjacent basement blocks, which indicates that large areas of the platform were involved in the subsidence, the formation of sedimentary basins, and, as a result, the beginning of the accumulation of the platform cover.

The second epoch of continental rifting is associated with the emergence of the Pripyat-Dnieper-Donetsk aulacogen, as well as a series of grabens along the eastern margin of the platform. The formation of the Dnieper-Donetsk rift separating the Ukrainian and Voronezh massifs occurred at the end of the Middle - Late Devonian and was accompanied by intense magmatism: outpourings of alkaline basalts, the intrusion of alkaline-ultrabasic intrusions. The Upper Devonian is characterized by evaporites, which mark the subsidence of the paleorift and its connection with the sea basin. In the Carboniferous, this region was a place of accumulation of thick strata of parallic coals (Donbass), and at the end of the Permian, its eastern part underwent intense deformations as a result of the convergence of the Ukrainian and Voronezh shields. Terrigenous sedimentation within the aulacogen continued throughout the Late Paleozoic and into the Mesozoic.

Most of the platform, with the exception of the shields, is covered by the Phanerozoic sedimentary cover. Its formation took place in three stages, directly related to the stretching of the basement and the development of the surrounding oceans.

The Vendian-Lower Paleozoic complex composes: a strip that crosses but diagonally the East European Platform and separates the Baltic Shield from the southern crystalline massifs (Moscow syneclise); a strip along the Teiseira-Tornquist line (Baltic syneclise) and a strip stretching along the Timan (Mezen syneclise). Sedimentary basins of this time formed either above the Riphean aulacogenes or along the passive margins of the East European continent. The composition of the Vendian-Lower Paleozoic platform complex is represented by shallow sandy-clayey, and in the upper (Ordovician-Silurian) - carbonate sediments with evaporites. Of no small importance is the wide development of tillites, characteristic of the early Vendian, which indicates a sheet glaciation.

The Middle-Upper Paleozoic complex in places inherits earlier depressions, as in the Moscow syneclise, but the main volume of the cover is concentrated on the eastern and southeastern margins of the platform and in the region of the Dnieper-Donetsk aulacogen. In the south and southeast of the platform, the complex mostly begins with the Middle Devonian. FROM initial periods its formation is associated with the formation of extension structures - Devonian grabens. The most complete section (from the middle Ordovician to the Lower Carboniferous) is characteristic of the eastern margin of the platform, where it is involved in the nappe-thrust dislocations of the western slope of the Urals. In its composition, it can be confidently compared with the sediments of passive continental margins. Most notable for the complex under consideration are carbonate sediments, including reef facies, numerous in the Early and Late Devonian, Carboniferous, and Early Permian. The Late Devonian is characterized by the distribution of clay facies saturated with organic carbon. Their accumulation is associated with stagnant waters. In the Permian, due to the growth of the Urals and the thrusting of the ridges onto the platform, the sedimentary basin gradually dried up and salt-bearing strata formed. The result of this process was the formation of the Cis-Ural marginal foredeep, filled with a powerful red-colored molasse, a product of the destruction of the Ural Mountains.

The Meso-Cenozoic complex is developed only along the southern periphery of the platform: in the Caspian basin, in the Pripyat-Dnieper trough and the Black Sea basin. The sea penetrated beyond this strip only in narrow tongues in the Late Jurassic and Early Cretaceous, forming thin strata of sediments. The complex is dominated by terrigenous strata; writing chalk accumulated only during the period of maximum transgression in the Late Cretaceous. The thickness of the complex is small, only occasionally exceeding 500 m.

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