The planets are closely related to each other, because the geology of the Earth begins with the formation of the crust. The age of the earth's lithosphere, as evidenced by the most ancient rocks, is more than $3.5 billion years. On land, two main types of tectonic structures are distinguished - platforms and geosynclines, which differ significantly from each other.

Definition 1

Platforms- these are stable, vast areas of the earth's crust, consisting of a crystalline basement and a sedimentary cover of younger rocks

On the platforms, as a rule, there are no rock formations, vertical movements have a very low speed, there are no modern active volcanoes, and earthquakes are very rare. The formation of the crystalline basement of the Russian Platform dates back to the Archean and Proterozoic eras, which is about $2 billion years ago. At this time, powerful mountain-building processes took place on the earth.

The result of these processes were mountains, composed of ancient rocks crumpled into folds such as gneisses, quartzites, crystalline schists. By the beginning of the Paleozoic, these mountain formations leveled off, and their surface experienced slow fluctuations. If the surface fell below the level of the ancient ocean, a marine transgression began with the accumulation of marine sediments. There was a formation of sedimentary rocks - limestones, marls, dark-colored clays, salts. On land, when it rose and was freed from water, there was an accumulation of red sands and sandstones. With the accumulation of sedimentary material in shallow lagoons and lakes, brown coals and salts accumulated. In the Paleozoic and Mesozoic eras, ancient crystalline rocks turned out to be overlain by a sedimentary cover of a fairly large thickness. To determine the composition, thickness, properties of these rocks, geologists drill wells in order to get a certain amount of core from it. Experts can explore the geological structure by studying the natural outcrop of rocks.

Today, along with traditional geological methods, geophysical and aerospace research methods are used. The rise and fall of the territory of Russia, the formation of continental conditions are due to tectonic movements, the causes of which are not yet completely clear. The only thing that is indisputable is that they are connected with the processes that take place in the bowels of the Earth.

Geologists distinguish the following tectonic processes:

1. Ancient - the movements of the earth's crust occurred in the Paleozoic;
2. New - movements of the earth's crust occurred in the Mesozoic and early Cenozoic;
3. The latest are tectonic processes characteristic of the last few million years. They played a particularly important role in the creation of modern relief.

General features of the relief of Russia

Definition 2

Relief- this is a set of irregularities on the surface of the Earth, including oceans, seas.

The relief has a great influence on the formation of climate, the distribution of plants and animals, and on the economic life of man. Relief, as geographers say, is the framework of nature, so its study usually begins with the study of relief. The relief of Russia is surprisingly diverse and quite complex. Majestic mountain ranges, ancient ridges, cones of volcanoes, intermountain basins are replacing the endless plain expanses. The physical map of Russia and images taken from space show well the general patterns of the country's orographic pattern.

Definition 3

Orography- the relative position of the relief relative to each other.

Orography of Russia:

1. The territory of Russia is $60% occupied by plains;
2. Lower are the western and central parts of Russia. A clear boundary between these parts runs along the Yenisei River;
3. Mountains on the territory of Russia are located on its outskirts;
4. In general, the territory of the country has an inclination towards the Arctic Ocean. Proof of this is the flow of large rivers - the Northern Dvina, Pechora, Lena, Yenisei, Ob, etc.

On the territory of Russia there are two largest plains in the world - East European or Russian and West Siberian.

Relief of the Russian Plain hilly, with alternating high and low areas. The northeast of the Russian Plain is higher - more than $400 m above the level of the World Ocean. The Caspian lowland, located in its southern part, is the lowest part - $ 28 $ m below the level of the World Ocean. The average heights of the Russian Plain reach about $170$ m.

Relief of the West Siberian Lowland does not differ in variety. The lowlands lie mostly $100$ m below the level of the World Ocean. Its average height is $120$ m, and only in the northwest the height rises to $200$ m. The North Sosvinskaya Upland is located here.

The watershed between the plains is Ural ridge The ridge itself does not have great heights, and its width reaches $150$ km. The top of the Urals is the town of Narodnaya, with a height of $1895$ m. The Ural Mountains stretch from north to south for $2000$ km.

The third largest plain in Russia is located between the Lena and the Yenisei - this high plain is called Central Siberian Plateau. The average height of the plateau above the ocean level is $480$ m. Its maximum height is located in the area of ​​the Putorana plateau - $1700$ m. Central Yakutsk plain, and in the north it descends as a step into North Siberian lowland.

The mountainous regions of Russia occupy the southeastern outskirts of the country.

To the south-west of the Russian Plain, between the Black and Caspian Seas, the highest mountains of Russia are located - caucasian. Here is the highest point of the country - Elbrus, the height of which is $5642$ m.

From west to east along the southern outskirts of Russia, they go further Altai Mountains and Sayans. The tops of which, respectively, are the cities of Belukha and Munku-Sardyk. Gradually, these mountains pass into the ranges of Cisbaikalia and Transbaikalia.

Stanovoy Ridge connects them with the ranges of the northeast and east of Russia. Here are located medium-high and low ranges - Chersky, Verkhoyansky, Suntar-Khayata, Dzhugdzhur. In addition to them, there are numerous highlands here - Yano-Oymyakonskoe, Kolyma, Koryakskoe, Chukchi.

In the southern part of the Far East of the country, they are connected with low and medium-altitude ridges. Amur and Primorye, for example, Sikhote-Alin.

Mountains in the extreme east of the country Kamchatka and the Kuriles. All the active volcanoes of the country are located here, and the highest of the active volcanoes is Klyuchevskaya Sopka. Mountains occupy $10$% of the territory of Russia.

Minerals of Russia

Russia, in terms of mineral reserves, occupies a leading position in the world. Today, more than $200$ of deposits are known, the total value of which is estimated at $300 trillion. dollars.

Certain types of Russian minerals in world reserves are:

1. Oil reserves - $12$%;
2. Natural gas reserves - $32$%;
3. Coal reserves - $30$%;
4. Reserves of potash salts - $31$%;
5. Cobalt - $21$%;
6. Iron ore reserves - $25$%;
7. Nickel reserves - $15$%.

In the bowels of Russia there are combustible, ore, non-metallic minerals.

Fuels include:

1. Coal. The largest deposits of which are Kuznetsk, Pechora, Tungusskoe;
2. Oil of Western Siberia, the North Caucasus and the Volga region;
3. Natural gas, as a rule, accompanies oil fields. But, in Russia there are purely gas fields on the Yamal Peninsula;
4. Peat, the largest deposit of which is the Vasyugan deposit in Western Siberia;
5. Burning shale. During their distillation, a resin is obtained, in composition and properties, close to oil. The Baltic shale region is the largest.

Ore minerals are represented by a variety of ores.

Among them:

1. Iron ore, in terms of the reserves of which Russia ranks first in the world. Known deposits are KMA, Kola Peninsula, Gornaya Shoria;
2. manganese ores. There are 14 known deposits in the Urals, Siberia and the Far East. The largest deposits of manganese are concentrated in the Yurkinsky, Berezovsky, Polunochnoye deposits;
3. aluminum ores. The extraction of aluminum for the country is quite costly, because the ore is of poor quality. The Ural and West Siberian reserves of nephelines and bauxites are quite large. A more promising region includes the North Ural region;
4. Russia ranks first in the world in terms of non-ferrous metal ores. The most significant deposits are located in Eastern Siberia and on the Taimyr Peninsula.

By production diamonds in world volume, Russia accounts for $25$% and only South Africa produces more than Russia.

From non-metallic Minerals Russia produces precious stones of both organic and mineral origin, and a wide range of building minerals.

Ukraine

Geological structure of Ukraine.

The earth's crust within the territory of Ukraine is of continental type and has a thickness of 25-25 km. It consists of basalt, granite and sedimentary layers. The greatest thickness in Ukraine the earth's crust reaches on the Ukrainian shield and in the Carpathians, and the smallest - in Transcarpathia and under the Black Sea.

Earth's crust

Between the earth's crust and upper mantle is Mohorovichic surface , where the speed of passage of seismic waves changes rapidly. In 1909, its existence was established by the Yugoslav geophysicist Andrei Mohorovichich (1857-1936). In Ukraine, the surface of Mohorovichich lies mainly at a depth of 40-50 km with fluctuations from 30 to 60 km.

The formation of the earth's crust took place over a long geological history - the basalt layer was formed 3.8-4.2 billion years ago. The oldest rocks in Ukraine were found on the Ukrainian Shield (near the city of Zaporozhye) - they are represented by Archean crystalline rocks, whose age is estimated at 3.7 billion years. The age of the Precambrian rocks of the Krivoy Rog ore-bearing series is 2-2.5 billion years, and that of the Kirovograd and Zhitomir granites is 1.9 billion years. The Paleozoic deposits of the Donbass were formed 250-440 million years ago, the Mesozoic deposits of the Crimean mountains - 70-240 million years, and the Cenozoic (Paleogene and Neogene) of the Ukrainian Carpathians - 10-65 million years.

Scheme of tectonic zoning of the territory of Ukraine.

1 - Ukrainian shield; 2 – slopes of the Ukrainian shield and the Voronezh massif; 3 - shield framing: Volyn-Podolsk and Scythian plates, Dnieper-Donetsk depression and Pripyat trough; 4 – southeastern margin of the West European Platform; 5 - Black Sea depression; 6 - Donetsk folded area; 7 - fold systems of the Carpathians, Dobruja and Crimea; 8 - Carpathian and Predobrudzha troughs.

The Earth's crust and mantle surface together make up the Earth's lithosphere. Due to the interaction of the lithosphere, hydrosphere, atmosphere and biosphere, modern landscapes of the earth's surface were formed. An important role in their formation belongs to rocks and the nature of their occurrence.

Ukraine has a number of tectonic regions of different ages, with redi which are the Precambrian East European, Paleozoic Scythian and West European platforms, Cimmerian and Alpine folded structures with a complex geological history and structure.

Ukrainian shield - one of the oldest geological structures of the Earth. It stretches across the entire territory of the country from the northwest (the village of Klyosov, Rivne region) to the southeast almost to the Sea of ​​Azov. The area of ​​the shield is about 180,000 km 2 , the length is more than 1000 km, and the maximum width is 250 km.

Ukrainian shield

The East European platform enters Ukraine with its southwestern and southern parts and occupies a significant area of ​​flat Ukraine. Depending on the depth of the sedimentary strata, crystalline shields and massifs, plateaus, depressions and troughs are distinguished within the platform.

The foundation of the Ukrainian part of the East European Platform is formed by the Ukrainian shield, consisting of solid crystalline Precambrian rocks - granites, gneisses, labradorites, amphibolites, etc. They come to the surface in river valleys on the territory of Rivne, Zhytomyr, Cherkasy, Dnepropetrovsk, Zaporozhye and some other regions .

In the western direction, the rocks of the Ukrainian Shield submerge to a depth of 4-6 km. Here they are covered with a thick layer of Paleozoic, Mesozoic and Cenozoic deposits that form the Volyn-Podolsk plate.

Volyn-Podolsk plate

Stratigraphic scale of Ukraine
Akrotema	Eonoteme			Age of the lower boundary (million years)	Duration (million years)
Phanerozoic	Cenozoic	Quaternary
		Neogene
		Paleogene
	Mesozoic
		Triassic
	Paleozoic	Perm
		Carbonic
		Devonian
		Silurian
		Ordovician
		Cambrian
Proterozoic

The Volyn-Podolsk plate is a marginal structure bounded in the southwest by the Carpathian foredeep. The Precambrian basement within the Volyn-Podolsk plate is located at a depth of 2000-2500 m. On its uneven surface, disturbed by tectonic faults, Paleozoic deposits occur. Cambrian rocks are exposed in the river valley. Goryn and Mogilev Transnistria. Deposits of the Ordovician and Silurian systems (represented by carbonate sandstones and limestones) are most common near the city of Kamenetz-Podolsky, where they form the slopes of the Dniester valley and its tributaries (Smotrych, Zbruch and Zhvanchik). Devonian deposits (shales, sandstones and dolomites) are exposed in the Dniester valley near the town of Zalishchyky.

Jurassic deposits and Cretaceous deposits unconformably overlie the uneven surface of Paleozoic rocks. They are represented mainly by chalk and marl, the total thickness of Mesozoic rocks increases from the east (20-30 m) to the west (600-800 m).

Paleogene sands, clays and sandstones are exposed only in the northeast of Volyn Polesye. Significant areas (mainly in the south) are occupied by Neogene limestones, sands, clays and gypsums. Anthropogenic deposits have an almost continuous distribution and are represented mainly by loess-like loams, and in Volyn Polissya - glacial, water-glacial, alluvial and lacustrine deposits.

Slopes of the Voronezh massif

The northeastern part of Ukraine is occupied by the southwestern slope of the Voronezh crystalline massif. Precambrian rocks occur here at a depth of 150 m (Znob-Novgorodskoye) to 970 m (Putivl) and are overlain by sedimentary Meso-Cenozoic deposits of Permian, Jurassic, Cretaceous and Paleogene age. Marls, limestones, chalk, glauconite sands, sandstones and clays are exposed in many places in the Sumy, Kharkiv and Luhansk regions (especially on the slopes of river valleys). Anthropogenic deposits take part in the structure of the modern relief.

Dnieper-Donetsk depression

Between the Ukrainian shield and the Voronezh crystalline massif is located Dnieper-Donetsk depression - one of the deepest depressions on the East European platform. In its axial part, the Precambrian basement is located at a depth of 12-20 km.

The Dnieper-Donetsk depression is filled mainly with Devonian (over 4000 m thick) sedimentary deposits, Carboniferous (3700 m), Permian (1900 m), Triassic (450 m), Jurassic (650 m), Cretaceous (650 m), Paleogene (250 m ) and Neogene (30 m) rocks. Oil and gas fields are associated with Devonian and Carboniferous rocks in the Dnieper-Donetsk depression. Permian deposits are represented by variegated clays, limestones, dolomites and gypsums. Part of the gas fields are located in the thickness of the Triassic rocks (clays, sands, sandstones and marls). From the Meso-Cenozoic deposits within the Dnieper-Donetsk depression, Jurassic (on the southwestern slope), Cretaceous, Paleogene and Neogene rocks are exposed. The most common Paleogene sands, sandstones, marls and clays. Paleogene and Neogene deposits are overlain by Anthropogenic alluvial and fluvioglacial sands, moraine clays, and loess-like loams.

Donetsk folded region

Dislocated Devonian, Carboniferous and Permian deposits take part in the geological structure of the Donetsk folded region. The most ancient, Devonian, deposits are common in the river basin. Wet Volnovakha and are represented by limestones, shales, sandstones, basalts and tuffs. Particularly important is the carbon deposits, the thickness of which is 10-12 km. These are shales, limestones, sandstones, among which there are numerous (more than 200) layers of coal - for more than two centuries the main mineral resource of Donbass. Permian, Triassic, and Jurassic sandy-argillaceous rocks occur in the northwestern part of the Donets Basin. Cretaceous deposits (marls, chalk) are exposed on the slopes of the hills, and Paleogene clays, sands, marls are found on the periphery of the Donbass, and Neogene sands and clays are found in the southeast.

GEOLOGICAL STRUCTURE AND HISTORY OF THE DEVELOPMENT OF THE TERRITORY

The Omsk Region is located within the young West Siberian Platform* (Hercynian Plate). In the geological structure of its territory, a folded basement composed of Paleozoic and pre-Paleozoic rocks and a platform cover with gently sloping Mesozoic and Cenozoic deposits are clearly distinguished.

The foundation has a complex structure and consists of igneous formations (granites, diabases, etc.), volcanic tuffs, and metamorphosed rocks (gneisses, shales) to varying degrees. The basement rocks are folded into complex folds and crossed by faults of northeast and northwest strike. Along these faults, some sections-blocks of the foundation fell, others rose. As a result of tectonic movements of the foundation blocks, deflections and protrusions were formed on its surface.

As scientists have established with the help of the latest geophysical data and satellite images, there are peculiar “basalt windows” in the foundation - blocks made up of oceanic crust, and ring structures.

The surface of the foundation plunges from south to north. So, in the south of the region, the foundation is opened by wells at a depth of several hundred meters, in Omsk - 2936 m, in the Kormilovsky district (state farm "Novo-Alekseevsky") - 4373 m.

The platform sedimentary cover in the lower part of the section repeats the basement topography in its occurrence. Its upper horizons practically do not reflect the surface of the foundation.

The sedimentary rocks of the cover are represented by sands, sandstones, clays, mudstones, etc. A thick sedimentary cover was formed over tens of millions of years over six geological periods (240 million years).

During this time, the earth's crust experienced slow vertical oscillations. When lowering its sea waters flooded vast territories. In the warm seas formed, a rich organic world developed, contributing to the formation of marine sedimentary strata. Then the lowering of the earth's crust was replaced by an uplift, the sea became shallow and gradually disappeared, the territory of the region became flat land with numerous lakes and rivers. Terrestrial vegetation was widely developed. These events were repeated many times.

Over the entire geological history of the formation of the West Siberian Plate, a sedimentary cover was formed here, the thickness of which varies from 3000-3500 m in the north to 500-1000 m - at the southern border of the region. The upper part of the cover (250-300 m) is composed of continental Upper Paleogene-Neogene clays, loams and sands. Outcrops of these rocks are exposed along the banks of the river. Irtysh and its tributaries (Fig. 3.), as well as in large lake basins. Most often, these deposits are overlain by thin Quaternary deposits.

Each geological period in the history of the region is marked by characteristic natural conditions and geological processes. To answer the question of what happened in the distant past, it is necessary to travel through the geochronological table (Table 1).

Table 1

GEOCHRONOLOGICAL TABLE

eras	Periods (duration, million years)	Major geological events	natural conditions	organic world	Rock formation
KAYNOZOYSKAYA	Quaternary (anthropogen) 1.8	Repeated glaciations in the north of the West Siberian Plain, which influenced the natural conditions of the Omsk region.	Repeated flooding, formation of glacial lakes. At the maximum glaciation in the north of the region there was tundra, to the south of it - forest-tundra, then forest-steppe.	Of the animals lived mammoth, woolly rhinoceros, bison, giant deer. The vegetation is close to modern.	Covering loams, sands, sandy loams, loams. Peat, lake sapropel.
Neogene (Neogene) 22.8	Slow vertical movements of the earth's crust - uplifts. Intensive development of rivers.	At the beginning of the Neogene, the plain is covered with coniferous-deciduous forests. The climate is moderately warm and humid. By the end of the period, temperature and humidity decrease. Forest-steppe and steppe appear.	Small-leaved tree species are widely used. Animal world – mastodons, proboscis, ancient horses, rhinos, hippos, saber-toothed tiger, etc. The emergence of man.	Sands, sandy loams, loams, clays, concretions, and lignites formed in lakes, swamps, and rivers. Neogene rocks are found in the bluffs of the Irtysh, Om, Tara, and other rivers.
KAYNOZOYSKAYA	Paleogene (Paleogene) 40.4	At the beginning of the Paleogene, a short uplift of the earth's crust, and then a long subsidence and the advance of the sea on land. At the end of the period, the subsidence was replaced by the rise and retreat of the sea.	For almost 30 million years, the Paleogene Sea existed in the region. At the end of the Paleogene, the mora becomes shallow and breaks up into lake basins. The resulting land was covered with coniferous-deciduous forests with an admixture of heat-loving plants. The climate is warm and humid.	Marine fauna predominates; the Paleogene sea is inhabited by mollusks, fish, and protozoa - radiolarians, diatoms, and others. On land, the flowering of ungulates and predators.	Clays with interlayers of sand accumulated at the bottom of the sea. On land, in lakes - clays, silts, sands, brown coals
Mesozoic	Cretaceous (chalk) 79.0	With the onset of the Cretaceous period, the slow uplift of the earth's crust began, the retreat of the sea. In the second half of the Cretaceous, the earth's crust subsides and the entire area is flooded by the sea.	In the first half of the Cretaceous, the region was flat land covered with coniferous forests. In the forests grew: pine, spruce, cedar and heat-loving tropical plants. The climate is subtropical, humid. In the future, a warm sea existed on the territory of the region, the water temperature was 20 ° C. From time to time, a cold current penetrated from the north and the water temperature dropped.	The sea was inhabited by cephalopods, fish and other animals, and various algae.	In lakes and rivers, thick strata of predominantly sands and sandstones were formed, to which underground thermal waters are confined. Various clays were formed in the sea - siliceous, calcareous.
Jurassic (Jurassic) 69.0	There was a slow subsidence of the earth's crust, which reached a maximum in the Late Jurassic. This sinking caused the advance of the sea.	In the first epochs of the Jurassic period, the region was represented by a low-lying plain with numerous lakes and rivers. The climate is warm and humid. In the late Jurassic, the entire region was occupied by the sea, which existed for 25 million years.	The sea was inhabited by numerous cephalopods - ammonites, belemnites, fish, algae. Coniferous, ginkgo, and other plants are widespread on land.	Sedimentary rocks accumulated in lakes and rivers - clays and sands, which later turned into mudstones and sandstones. The rocks contain many plant remains and a layer of coals. Clays deposited in the sea contain a large amount of organic substances, from which hydrocarbons (oil and gas) can be formed.
Triassic (Triassic) 35.0	Slow vertical uplifts of the earth's crust. Intensive destruction and erosion of rocks. Locally volcanic.	Raised plain. There were extensive forests. The climate is hot, arid.	The forests are dominated by gymnosperms.	Deposits are rare. Mudstones, siltstones, sandstones. Volcanic rocks - diabases.
Paleozoic	Perm (Permian) 38.0	General uplift of the region. The entire territory is a single stable paraplatform linking the Siberian and Russian platforms.	Area of ​​plateaus and uplands with developed erosion processes. The climate is hot and dry.	On land, the development of terrestrial reptiles, conifers, the appearance of ginkgo. At the end of the period, the extinction of trilobites, four-pointed corals. some molluscs and brachiopods.	Clastic material supplied from surrounding mountain structures.
Hard coal (carbon) 74.0	A time of relatively calm tectonic activity. Deflection of the territory and transgression of the sea. At the end of the period, the general uplift of the earth's crust. Sea regression. Volcanic activity is not observed.	The sea is shallow, open, warm with a normal hydrochemical regime. At the end of the period, a large area was drained, a low plain.	The first reptiles. Tree ferns, horsetails and club mosses, the first gymnosperms. Widespread distribution of large insects. In the seas there are bony and cartilaginous fish, invertebrates.	Volcanogenic and normal sedimentary marine rocks of all types.
Devonian (Devonian) 48.0	The regional uplift of the territory caused cracking of the earth's crust, the revival of deep faults, and an outbreak of volcanism.	The land is a desert, on the southern outskirts of which volcanoes were located.	Wide distribution of bony and cartilaginous fish. On land, there are tree-like ferns, horsetails and club mosses. Appearance of the first amphibians and insects.	Volcanogenic sedimentary rocks. clay, sand, limestone.
Silurian (Silur) 30.0	The West Siberian Platform is a continuation of the Siberian Platform. It shows active tectonic processes.	Noticeable restructuring of paleolandscapes. At the beginning of the period, the territory is dominated by mountainous land, at the end by a flat desert plain.	The first land plants (psilophytes). In the seas there are graptolites, corals, brachiopods, trilobites.	Terrigenous sediments, saline and gypsum-bearing, are probable.
Ordovician (Ordovician) 67.0	Deflection of the earth's crust.	The seas are warm and normally salty with numerous islands and underwater volcanoes.	Appearance of the first fish. The flourishing of trilobites, corals. There are bryozoans and graptolites on the seabed.	Effusive and terrigenous formations.
Cambrian (Cambrian) 65.0	Most of the territory of Western Siberia has lost the features of the geosyncline. A para-platform was formed.	Bring the transgression of the sea! to the dismemberment of land. Widespread areas of underwater volcanism. The sea is shallow water with high salinity.	Wide distribution of marine invertebrates: trilobites, archaeocyaths, four-beam corals. Active development of blue-green algae.	Effusive and terrigenous formations.
Proterozoic	>2000	The Ural-Siberian geosynclinal belt occupies the entire space between the Siberian and Russian platforms. Active tectonic processes and volcanism.	Sharply dissected relief.	The appearance of the first plants - algae and invertebrates, sponges, radiolarians, brachiopods, arthropods. worms.	Clayey and carbonate sediments and effusive rocks predominate.

Questions and tasks.

Geologically, the territory of Russia consists of a complex mosaic of blocks formed by various rocks that arose over 3.5–4 billion years.

There are large lithospheric plates 100–200 km thick, which experience slow horizontal movements at a rate of about 1 cm/year due to convection (substance flow) in the deep layers of the Earth's mantle. Deep cracks - rifts - are formed during the spreading, and later, during spreading, oceanic depressions appear. The heavy oceanic lithosphere, when changing the movement of plates, sinks under the continental plates in subduction zones, along which oceanic trenches and island volcanic arcs or volcanic belts form at the edges of the continents. When continental plates collide, a collision occurs with the formation of folded belts. In the collision of oceanic and continental plates, an important role is played by accretion - the attachment of alien blocks of the crust, which can be brought thousands of kilometers away when immersed and absorbed by the oceanic in the process of subduction.

At present, most of the territory of Russia is located within the Eurasian lithospheric plate. Only the folded region of the Caucasus is part of the Alpine-Himalayan collision belt. In the extreme east is the Pacific Oceanic Plate. It plunges under the Eurasian Plate along the subduction zone expressed by the Kuril-Kamchatka deep-water trench and the volcanic arcs of the Kuril Islands and Kamchatka. Within the Eurasian Plate, splits along the Baikal and Momsky rifts are manifested, expressed by the depression of the lake. Baikal and large fault zones in . The boundaries of the plates are highlighted with increased .

In the geological past, as a result of displacement, the East European and Siberian platforms were formed. The East European Platform includes the Baltic Shield, where Precambrian metamorphic and igneous rocks are developed on the surface, and the Russian Plate, where the crystalline basement is covered by a sedimentary cover. Accordingly, the Aldan and Anabar shields, formed in the Early Precambrian, are distinguished within the Siberian Platforms, as well as vast spaces overlain by sedimentary and volcanic rocks, which are considered as the Central Siberian Plate.

Between the East European and Siberian platforms stretches the Ural-Mongolian collision belt, within which folded systems of a complex structure have arisen. A significant part of the belt is overlain by the sedimentary cover of the West Siberian Plate, the formation of which began at the beginning of the Mesozoic. From the east, the Siberian Platform is adjoined by heterogeneous folded structures, which arose largely as a result of accretion.

Archaeus. Archean formations come to the surface on the Aldan and Anabar shields and participate in the structure of the foundation of the platforms. They are represented mainly by gneisses and crystalline schists. The Archean rocks are highly metamorphosed, up to the granulite facies, and the processes of magmatization and granitization are intensively manifested. For Archean rocks, there are radiological datings in the range of 3.6–2.5 Ga. Archean rocks are intensively dislocated everywhere.

Proterozoic

The lower and upper Proterozoic are distinguished, sharply differing in the degree of metamorphism and dislocation.

The Lower Proterozoic participates in the structure of the shields along with the Archaean. It includes: gneisses, crystalline schists, amphibolites, metavolcanic rocks and marbles in some places.

The Upper Proterozoic in many regions is subdivided into Riphean and Vendian. Compared with the Lower Proterozoic, these rocks are characterized by significantly less metamorphism and dislocation. They form the base of the cover of the platform areas. On the Russian Plate in the Riphean, basic volcanic rocks are widely developed in places, while sandstones, gravelstones, siltstones, and clays predominate in the Vendian. On the Siberian Platform, the Upper Proterozoic is represented by almost non-metamorphosed sandy-clayey and carbonate rocks. In the Urals, the Upper Proterozoic section has been studied in the most detail. The Lower Riphean is composed of shales, quartzite-like sandstones, and carbonate rocks. In the Middle Riphean, along with terrigenous and carbonate rocks, basic and felsic volcanic rocks are widespread. The Upper Riphean is composed of various terrigenous rocks, limestones and dolomites. At the very top of the Riphean, there are basic effusives and tillite-like conglomerates. The Vendian is composed of sandstones, siltstones, and flyschoid mudstones. In the folded areas framing the Siberian Platform, the Upper Proterozoic has a similar structure.

Paleozoic

The Paleozoic includes the Cambrian, Ordovician, Silurian, Devonian, Carboniferous and Permian systems.

On the Russian plate in the Cambrian system, characteristic "blue clays" are developed, giving way to siltstones and fine-grained sandstones. On the Siberian Platform in the Lower and Middle Cambrian, dolomites with layers of anhydrites and rock salt are common. In the east, they are facially replaced by bituminous carbonate rocks with interlayers of combustible shale, as well as with reef bodies of algal limestones. The Upper Cambrian is formed by red-colored sandy-clayey rocks, in places carbonates. In folded areas, the Cambrian is characterized by a variety of composition, great thickness, and high dislocation. In the Urals, in the Lower Cambrian, basic and felsic volcanics, as well as sandstones and siltstones with reef limestones, are common. The Middle Cambrian falls out of the section. The Upper Cambrian is formed by conglomerates, glauconite sandstones, siltstones and mudstones with siliceous shales and limestones in the form of separate layers.

The Ordovician system on the Russian Plate is composed of limestone, dolomite, and carbonate clays with phosphorite nodules and oil shale. A variety of carbonate rocks are developed on the Siberian Platform in the Lower Ordovician. The Middle Ordovician is composed of calcareous sandstones with interlayers of shell limestones, sometimes with phosphorites. The Upper Ordovician contains sandstones and mudstones with siltstone interbeds. In the Urals, the Lower Ordovician is represented by phyllite-like shales, quartzite-like sandstones, gravelstones, and conglomerates with limestone interlayers and locally with basic volcanic rocks. The Middle and Upper Ordovician are composed mainly of terrigenous rocks in the lower part, and limestones and dolomites with interlayers of marls, mudstones and siltstones in the upper part; basalts, siliceous tuffites and tuffs predominate to the east.

The Silurian system on the Russian Plate is composed of limestones, dolomites, marls and mudstones. On the Siberian platform in the Lower Silurian, organogenic clayey limestones are common with interlayers of marls, dolomites, and mudstones. The Upper Silurian contains red-colored rocks, including dolomites, marls, clays, and gypsums. In the Western Urals, in the Silurian, dolomites and limestones are developed, in places clay shales. To the east, they are replaced by volcanic rocks, including basalts, albitophyres, and siliceous tuffites. Within the accretion belt in northeastern Russia, Silurian deposits are diverse in composition. Carbonate rocks are developed in the Upper Silurian: red-colored rocks and conglomerates appear in the center and east of the Urals. In the extreme east of the country (Koryak Autonomous Okrug), basalts and jaspers predominate with limestones in the upper part of the section.

The Devonian system on the Russian plate differs significantly in structure in its various parts. In the west, at the base of the Devonian, limestones, dolomites, marls, and small-pebble conglomerates are developed. In the Middle Devonian, rock salt appears together with red-colored terrigenous rocks. The upper part of the section is distinguished by the development of clays and marls with layers of dolomites, anhydrites and rock salt. In the central part of the plate, the volume of terrigenous rocks increases. In the east of the plate, together with red-colored rocks, bituminous limestones and shales are widespread, which stand out as a domanic formation. On the Siberian platform, the Devonian in its northwestern part is composed of evaporites, carbonate and clayey deposits, in the eastern part - volcanic-sedimentary rocks with layers of rock salt and evaporites. In some areas in the south of the platform, coarse-clastic red-colored strata with basalt covers are developed. In the west of the Urals, the Lower Devonian is dominated by limestones, along with sandstones, siltstones, and mudstones. In the Middle Devonian, limestones are also common with an admixture of sandstones, siltstones, argillaceous and siliceous shales. The Upper Devonian begins with a sandy-clayey stratum. Limestones with layers of marls, dolomites and bituminous shales lie above. In the eastern regions of the Urals, in the Lower and Middle Devonian, volcanic rocks of basic and acidic composition are developed, accompanied by jaspers, shales, sandstones and limestones. In some places in the Devonian deposits of the Urals, bauxites are noted. In the Verkhoyansk-Chukotka folded system, the Devonian is represented mainly by limestones, clay shales and siltstones. The section of the Kolyma-Omolon massif has significant differences, where volcanic rocks, including rhyolites and dacites, accompanied by tuffs, spread in the Devonian. In the more southern regions of the accretion belt in northeastern Russia, predominantly terrigenous rocks are distributed, in places reaching great thickness.

The Carboniferous system on the Russian Plate is formed mainly by limestones. Only at the southwestern limit of the Moscow syneclise do clays, siltstones, and sands with coal deposits come to the surface. On the Siberian platform, limestones are predominantly distributed in the lower part of the Carboniferous, and sandstones and siltstones are distributed above. In the west of the Urals, the Carboniferous is formed mainly by limestones, sometimes with layers of dolomites and siliceous rocks, while only in the Upper Carboniferous terrigenous rocks with massive bodies of reef limestones predominate. In the east of the Urals, flyschoid sequences are common, and in some places volcanic rocks of intermediate and basic composition are developed. In some areas, terrigenous coal-bearing strata are developed. Predominantly terrigenous rocks are involved in the structure of the folded belt in the northeast of Russia. Clayey and siliceous shales are common in the southern regions of this belt, often accompanied by volcanic rocks of intermediate and basic composition.

The Permian system on the Russian Plate in the lower part is represented by limestones, which are replaced up the section by evaporites, in places with rock salt. In the Upper Permian, in the east of the plate, sandy-argillaceous red-colored deposits arose. In the more western regions, deposits of mixed composition are common, including sandstones, siltstones, clays, marls, limestones, and dolomites. In the upper part of the section, among the terrigenous rocks, there are variegated marls and red-colored clays. On the Siberian platform, the Permian is composed mainly of terrigenous rocks, in places with coal beds, and also with interbeds of argillaceous limestones. In the folded systems of the Far East in the Permian, along with terrigenous rocks, siliceous schists and limestones, as well as volcanic rocks of various compositions, are developed.

Mesozoic

The Mesozoic includes deposits of the Triassic, Jurassic and Cretaceous systems.

The Triassic system on the Russian Plate is composed of sandstones, coglomerates, clays and marls in the lower part. The upper part of the section is dominated by variegated clays with brown coal seams and kaolin sands. On the Siberian platform, the Tunguska syneclise was formed by Triassic rocks. Here, in the Triassic, lavas and tuffs of basalts of great thickness were formed, attributable to the trap formation. Sandstones, siltstones and mudstones of great thickness are developed in the Verkhoyansk folded system. Within the accretion belt in the Far East, limestones, siliceous rocks, and volcanic rocks of intermediate composition are manifested.

The Jurassic system on the Russian Plate is represented in the lower part by sandy-argillaceous rocks. In the middle part of the section, along with clays, sandstones and marls, limestones and brown coals appear. The Upper Jurassic is dominated by clays, sandstones and marls, in many areas with nodules of phosphorites, sometimes with oil shale. On the Siberian platform, Jurassic deposits fill individual depressions. In the Lena-Anabar depression, thick strata of conglomerates, sandstones, siltstones, and mudstones are developed. In the extreme south of the platform, terrigenous deposits with coal seams occur in depressions. The folded systems of the Far East in the Jurassic are dominated by terrigenous rocks, accompanied by siliceous shales and volcanic rocks of intermediate and felsic composition.

The Cretaceous system on the Russian Plate is composed of terrigenous and rocks with nodules of phosphorites and glauconite. The upper part of the section is distinguished by the appearance of limestones, as well as marls and writing chalk, flasks and tripoli, in places with abundant flint concretions. On the Siberian platform, various terrigenous rocks are widespread, in some areas containing layers of coals and lignites. In the folded systems of the Far East, predominantly thick terrigenous rocks are distributed, sometimes with siliceous shales and volcanics, as well as with coal seams. In the Cretaceous in the Far East, extended volcanic belts formed on the active margins of the continent. Volcanogenic rocks of various compositions are developed within the Okhotsk-Chukotka and Sikhote-Alin belts. On and chalk is composed of terrigenous rocks of great thickness, along with siliceous rocks and volcanic rocks.

Cenozoic

The Paleogene system on the Russian Plate is composed of flasks, sandstones and siltstones, in some areas marls and phosphorite-bearing sands. On the West Siberian Plate, the Paleogene is formed by flasks, diatomites, mudstones, and sands. In places there are interlayers of iron and manganese ores. Lenses of brown coals and lignites are present in some areas. In the Far East, individual depressions are filled with terrigenous strata of great thickness. In volcanogenic belts they are accompanied by basalts. Andesites and rhyolites are developed in Kamchatka.

The Neogene system on the Russian Plate is composed of sands and clays of the Miocene, and above - Pliocene limestones. On the West Siberian Plate, the Neogene is represented mainly by clays. Pebbles, sands and clays are widespread in the Far East in the Neogene. A significant role belongs to volcanic rocks, which are especially common in Kamchatka and the Kuril Islands.

The Quaternary system (quaternary) is manifested almost everywhere, but the thickness of the deposits rarely exceeds a few tens of meters. A significant role is played by boulder loams, traces of ancient ice sheets.

Intrusive formations of various ages and compositions are widespread on shields and in folded belts. The most ancient Archean complexes on the shields are represented by orthoamphibolites and other ultrabasic and basic rocks. Younger Archean granitoids compose complexes with an age of 3.2–2.6 Ga. Large massifs form alkaline granites and syenites of the Proterozoic with a radiological age of 2.6–1.9 Ga. In the marginal part of the Baltic Shield, rapakivi granites with an age of 1.7–1.6 Ga are common. Intrusions of alkaline syenites of Carboniferous age - 290 Ma are distinguished in the northern part of the shield. In the Tunguska syneclise, along with volcanics, bedded intrusions - dolerite sills - are widespread. In the volcanic belts of the Far East, large intrusions of granitoids are developed, which together with volcanic rocks form volcano-plutonic complexes.

In recent decades, extensive work has been carried out to study the adjacent water areas, including offshore geophysical work and well drilling. They were sent to search for hydrocarbon deposits on the shelf, which led to the discovery of a number of unique fields. As a result, it became possible to show the structure of water areas on a geological map, although in the eastern seas of the Russian sector of the Arctic, the map remains largely schematic. Due to insufficient study, it was necessary to show undivided deposits in some places. The marine basins are filled with thick Mesozoic and Cenozoic sedimentary rocks with separate outcrops of Paleozoic and granitoids of different ages on uplifts.

In the basin, on the Precambrian basement, a cover of sedimentary rocks is developed with outcrops of the Triassic and Jurassic along its sides, and in the center - with a wide distribution of the Upper Cretaceous - Paleocene. Under the bottom, a continuation of the West Siberian plate with a Cretaceous and Paleogene cover is traced. In the eastern sector of the Arctic, significant parts of the water area are covered by Neogene sediments. Volcanic rocks are developed in the Gakkel mid-ocean ridge and near the De Long Islands. Near the islands, continuations of outcrops of Mesozoic and Paleozoic rocks can be traced.

In Okhotsk, and from under a continuous cover of Neogene deposits, older sedimentary rocks, volcanics and granitoids, forming relics of microcontinents, protrude in places.

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FEDERAL AGENCY FOR EDUCATION AND SCIENCE OF THE RUSSIAN FEDERATION

STATE EDUCATIONAL INSTITUTION

HIGHER PROFESSIONAL EDUCATION

BASHKIR STATE UNIVERSITY

Faculty of Geography

Department of Geology and Geomorphology

geological structure of the TERRITORY

Coursework by discipline

"Structural geology and geomapping"

Compiled by: student of group 2.5

Rakhimov I. R.

Head: Associate Professor

Larionov Nikolai Nikolaevich

Ufa 2009

Introduction

1. Physical-geographical sketch

2. Stratigraphy and lithology

3. Tectonics

4. History of geological development

5. Minerals

6. Spec (Sedimentary rocks)

Conclusion

INTRODUCTION

This course work sums up the study of the course of structural geology and geomapping.

The main goal of the course work is to consolidate the material in the course of Structural Geology and Geomapping and gain experience in analyzing a geological map, which is an image on a topographic basis using conventional signs, the distribution and condition of the occurrence of rocks on the earth's surface, divided by age, composition and origin.

The objectives of the course work are:

Detailed description of the geological structure of the region of the given area: compilation of a physical and geographical characteristic; study of stratigraphy, tectonics and lithology of the area

Drawing up a geological section

Drawing up an orohydrographic scheme

Drawing up a structural-tectonic scheme

Reconstruction of the history of geological development based on geological materials, section, stratigraphic column

Description of minerals that may be found in the proposed area.

To solve the above problems, an educational geological map No. 1, made on a scale of 1:50000, is analyzed. The relief is depicted by solid horizontal lines drawn every 10 m. Map compiled by D.N. Utekhin, editors: Yu.A. Year of publication - 1984.

The large stratigraphic units of this region are the Carboniferous, Jurassic and Cretaceous systems. The general character of the occurrence of the strata is horizontal.

1. PHYSICAL AND GEOGRAPHICAL OUTLINE

1) Orography

The relief of the described territory is mostly the valley of the Myshega River with its tributaries. The river is undergoing a stage of maturity, as evidenced by the relative flatness of this land area, as well as the widespread occurrence of alluvial deposits that form the river floodplain. Small hills can act as watersheds between the rivers Para and Olkhovka, Olkhovka and Severka, as well as Yagodnaya and Snezhet. The maximum absolute heights do not exceed 201 m. The minimum level is the floodplain in the lower reaches of the river. Myshegi - 115 m. The maximum relative height of 95 m characterizes the relief of a land area with an approximate area of ​​310 km 2 as flat. The highest mark of this area is a hill to the east of the source of the river. Severki - 200.5 m.

The hills mostly have gentle slopes. Composed of clays, sands and sandstones, they cannot have large values ​​of absolute elevations.

2) Hydrography

The Myshega River is the main one and is a drainage basin for a number of tributaries. Geographically, the riverbed Myshega stretches from west to east. Right tributaries: r. Yagodnaya and r. Snow. Left tributaries: r. Vozha and R. Olkhovka and r. Severka. Also, the left tributaries include three small rivers that do not have a name. The Para River is a tributary of the second order in relation to the river. Myshege.

For this area, the density of the river network is quite high. The Myshega River has low and high floodplains, as well as at least one terrace above the floodplain. Judging by the fact that the river flows through a flat area, it can be judged with accuracy that lateral erosion prevails over bottom erosion. This allows the growth of large numbers of meanders and, given this, the river can be described as meandering.

3) Geographic and economic characteristics of the region

Within the map, we have the opportunity to observe several small settlements - villages. Listing these settlements from north to south, the following sequence will be established: Koty, Dubki, Rozhki, Shukhovo, Koptevo, Kalinovka, Ivanovka, Popovka, Petrovka, Uzkoye, Podlipki, Nelidovo, Petushki, Kolki, Rye, Zlobino, Zhdanovka, Kryukovo, Ermolino , Kuzmino, Olkhovka, Long, Steep, Spawning, Koltsovo, Desired, Berry.

If we talk about the patterns of distribution of these villages, then all of them are located along the banks of the above rivers. The highest density of settlements is observed along the banks of the Myshega. As for the distribution of houses and other buildings in the settlements themselves, their shapes are elongated, apparently along two or three parallel streets.

Two country roads stretch in the meridional direction. The western road passes near the village of Rozhki, through the village of Popovka, the village of Kuzmino, the village of Dolgoe and between the village of Zhelannoye and the village of Yagodnoye. Through the river Myshega passes a wooden bridge connecting Kuzmino and Dolgoye.

The eastern road passes near the village of Ivanovka, then through the river. Myshega on a wooden bridge and through the village of Koltsovo.

There is a railroad in the north-east of the map, and Koty station is located to the south of the village of Koty.

2. STRATIGRAPHY AND LITHOLOGY

The geological structure of this territory involves deposits of the Quaternary, Cretaceous, Jurassic and Carboniferous systems. A characteristic fact for these systems is that they are composed only of sedimentary rocks. The total thickness of the rocks that make up the territory is more than 160 m.

COAL SYSTEM

The deposits of this system are the oldest in the structure of the territory we are describing. The Carboniferous system has outlets in the northwestern and northeastern parts of the map. In addition, deposits of Carboniferous age are exposed in the banks of the Myshega River, as well as in all incised side valleys. The Carboniferous system is represented by the lower section, which includes 2 tiers: Visean and Serpukhovian.

The system is represented by limestones, clays, limestones with layers of dolomite.

Visean stage

The rocks that make up the Visean Stage are represented by dark gray, gray, massive and layered, organogenic-detrital limestones, limestones with interlayers of greenish-gray calcareous clays. Since they are the oldest in this area, the relationship with the underlying rocks has not been established. The total thickness of the stage exceeds 80 m. The stage is subdivided into 5 horizons: Aleksinsky, Mikhailovsky, Venevsky, Tarussky and Steshevsky.

The Aleksinsky Horizon (C1al) of the Visean Stage is represented by gray and dark gray limestones, massive and layered, organogenic-detrital. The total thickness of the deposits of the Aleksinsky horizon is more than 15 m.

The Mikhailovsky Horizon (C1mh) of the Visean Stage is represented by gray microgranular, organogenic-detrital limestones with interlayers of greenish-gray calcareous clays. The thickness of the Mikhailovsky horizon is 20 m.

The Venev Horizon (C1vn) of the Visean Stage is represented by massive light gray limestones with purple and brown spots. The thickness of this horizon is about 15 m.

The Tarusa Horizon (C1tr) of the Visean Stage is represented by light gray layered, microgranular, organogenic-detrital limestones. The thickness of this horizon is 10 m.

The Steshevsky Horizon (C1st) of the Visean Stage is represented by gray shale clays with interlayers of dolomite. Below - fat gray, cherry-red and green clays. The thickness of this layer is 20 m.

Namurian

The Namurian stage is represented by only one horizon, the Protvinsky horizon.

The Protvinsky Horizon (C1pr) of the Namurian Stage is represented by white massive, recrystallized, cavernous limestones. The thickness of the horizon is 15 m.

JURASSIC SYSTEM

The deposits of the Lower Carboniferous system unconformably overlie rocks of the Upper Jurassic system. The Jurassic system is represented by the upper section, which includes three stages: Callovian, Oxfordian, Kimmeridgian. Rock outcrops of this system are located throughout the map. The rocks of this system are represented by gray, silty and sandy clays. The total thickness is 30 m.

Callovian Stage (J3cl). The deposits of the Callovian stage unconformably lie on the Protvinsky horizon of the Serpukhovian stage of the lower part of the Carboniferous system. Gray silty and sandy, calcareous clays compose the Callovian Stage, which is 15 m thick.

Oxfordian Stage (J3ox). This stage is composed of gray, silty and sandy clays, calcareous in places. The layer thickness is 10 m.

Kimmeridgian Stage (J3km). This stage is composed of gray clays, which are about 5 m thick.

CHALK SYSTEM

The Lower Cretaceous deposits unconformably overlie the deposits of the Upper Jurassic system, since the Tithonian stage of the Upper Jura and the Berriasian stage of the Lower Cretaceous fall out of the chronological sequence. Cretaceous deposits have exits on the tops of hills or on their slopes. Only two tiers are presented - Valanginian and Aptian. The described system is composed of green, glauconite sands, quartz and white sandstones, and gray clays. The total thickness is 35 m.

Aptian Stage (K1ap). The deposits of the Aptian Stage unconformably overlie the deposits of the Valanginian Stage with azimuthal unconformity, because deposits of the Hauterivian, Barremian, and Aptian centuries of the late Cretaceous period fall out of the section. This stage unconformably overlies the previous one. It is composed of sands and white quartz sandstones, the thickness of which is 20 m.

3. TECTONICS

The tectonic setting of this region is calm. There are no discontinuous violations, faults. The absence of folding and the horizontal occurrence of sedimentary rocks indicate that this area belongs to the platform cover.

Only by restoring the history of the development of the area, by the presence of stratigraphic unconformities, one can say that the territory was uplifted at certain intervals of time. Namely, the absence of rocks of the middle and upper Carboniferous system and rocks of the Permian and Triassic systems in the section. Also, the Jurassic system is represented only by the upper section, and the Cretaceous only by the lower one. All these conditions characterize positive tectonic movements.

In the Quaternary, there was a decrease in the base of erosion of the main river of the described area.

In this area, 3 main structural stages can be distinguished, which are indicated by the surfaces of stratigraphic unconformities: Lower Carboniferous, Upper Jurassic and Lower Cretaceous.

Lower Carboniferous Floor

The deposits of this structural stage in the analyzed area are represented by only two tiers of the lower section of the Carboniferous system. The rocks of this structural stage come to the surface mainly in the northwestern and northeastern parts of the map; in addition, Carboniferous deposits are exposed in the banks of the Myshega River, as well as in all incised lateral river valleys. The floor is represented by sedimentary deposits - limestones and clays.

Upper Jurassic floor

The deposits of this structural stage in the analyzed area are represented only by the upper section. Outcrops are scattered throughout the map. The floor is represented by clays.

lower chalk floor

This structural stage has become widespread in the southwestern, southeastern, and central parts of the described map. The Lower Cretaceous stage has exits on the tops of hills or on their slopes. The floor is represented by sands, sandstones and clays.

4. HISTORY OF GEOLOGICAL DEVELOPMENT

The history of the geological development of this area can begin to be described from the Carboniferous period. In addition to this period, two more periods of sedimentation are distinguished: Jurassic and Cretaceous. The oldest rocks distributed on the territory of this map are deposits of the Visean Age of the Carboniferous period. Carbonate rocks indicate that this area was in marine conditions. In the Namurian, marine conditions of sedimentation persisted.

Subsequently, deposits of the Early Jurassic period with stratigraphic unconformity accumulated on the rocks of the Carboniferous age. This can be explained by the fact that the transgression of the sea occurred in the Permian period, as evidenced by sandstones in the deposits of the Callovian stage. During the Jurassic, the transgression of the sea continued, as the Kimmeridgian deposits are thinner than the Callovian deposits.

After the Jurassic, there was a break in sedimentation, as evidenced by the stratigraphic unconformity between the Jurassic and Cretaceous systems. This period is represented by sands and clays, which indicates further transgression of the sea. The area was uplifted. Also, after the Valangian age of the Cretaceous period, there was a break in sedimentation, as evidenced by the stratigraphic unconformity between the Valangian and Aptian stages. The sediments of the Aptian Stage are represented by white quartz sands, which suggest that sedimentation took place in the coastal zone.

In general, the sedimentation environment was stable, the tectonic regime was calm.

5.MINERAL RESOURCES

Sedimentary rocks of this territory can theoretically be minerals. Minerals include limestones of the Carboniferous period, which can be used for liming acidic soils in agriculture, and can also be used in the production of building materials. This natural material is also used to produce lime, cement; in metallurgy - as fluxes. Besides, limestone is applied in decorative registration of an external and internal interior of walls of rooms.

Plastic gray clays of the Kimeridge stage of the Upper Jurassic, which can be used in sculpture, can also be attributed to minerals. Sandy clays of the Callovian stage can be widely used in the production of bricks.

The white sand of the Aptian stage of the Cretaceous system can be used in decorative plasters and roofing materials. Quartz sands are suitable for construction purposes, roads, and this rock can also be used for glass production.

Phosphorite pebbles are used in chemical raw materials.

Glauconite grains of the Valanginian stage of the Cretaceous system can be used to clean soil and hard surfaces (asphalt, concrete) from oil products, because glauconite has sorption properties.

6. SEDIMENTARY ROCKS

Sedimentary rocks are formed as a result of the redeposition of weathering products and the destruction of various rocks, chemical and mechanical precipitation from water, the vital activity of organisms, or all three processes simultaneously.

Classification of sedimentary rocks

Various geological factors are involved in the formation of sedimentary rocks: the destruction and redeposition of the destruction products of pre-existing rocks, mechanical and chemical precipitation from water, and the vital activity of organisms. It happens that several factors take part in the formation of a particular breed at once. However, some rocks can be formed in different ways. So, limestones can be of chemical, biogenic or detrital origin. This circumstance causes significant difficulties in the systematization of sedimentary rocks. There is no single scheme for their classification yet.

Various classifications of sedimentary rocks were proposed by J. Lapparan (1923), V. P. Baturin (1932), M. S. Shvetsov (1934), L. V. Pustovalov (1940), V. I. Luchitsky (1948), G. I. Teodorovich (1948), V. M. Strakhov (1960), and other researchers.

However, for ease of study, a relatively simple classification is used, which is based on the genesis (mechanism and conditions of formation) of sedimentary rocks. According to it, sedimentary rocks are subdivided into detrital, chemogenic, organogenic, and mixed.

Genesis of sedimentary rocks

"Sedimentary rocks" combine three fundamentally different groups of surface (exogenous) formations, between which there are practically no significant common properties. Actually, chemogenic (salts) and mechanogenic (detrital, partly terrigenous) sedimentary rocks are formed from sediments. Precipitation occurs on the surface of the earth, in its near-surface part and in water basins. But in relation to organogenic rocks, the term "sediment" is often not applicable. So if the sedimentation of the skeletons of planktonic organisms can still be attributed to sediments, then where to attribute the skeletons of benthic, and there more colonial, for example, corals, organisms is not clear. This suggests that the very term "Sedimentary rocks" is artificial, far-fetched, it is archaism. As a result, V. T. Frolov tries to replace it with the term "exolith". Therefore, the analysis of the formation conditions of these rocks should be carried out separately.

In the class of mechanogenic rocks, the first two concepts are equivalent and characterize different properties of this class: mechanogenic - reflects the mechanism of formation and transfer, clastic - composition (consists practically of fragments (the concept is not strictly defined)). The term "terrigenous" reflects the source of the material, although significant masses of detrital material formed under underwater conditions are also mechanogenic.

Mechanogenic sedimentary rocks

This group of rocks includes two main subgroups - clays and clastic rocks. Clays are specific rocks composed of various clay minerals: kaolinite, hydromicas, montmorillonite, etc. Clays released from suspension are called sedimentary clays, in contrast to the residual clays present in the preserved weathering crusts.

General properties of clastic rocks

Clastic rocks are the main part of mechanogenic rocks. Among sedimentary rocks, "clastic rocks" are one of the most common classes of rocks. The scope of this concept corresponds to the ideas of the early periods of the formation of lithology. Initially, they included rocks containing the actual fragments of rocks and minerals, on the one hand, and the products of their mechanical (physical) transformation - rounded grains of rocks and minerals - on the other. But the definition of "fragment" is missing. The situation is the same with the antagonist of "breccia" - pebbles: what is a pebble? There is a narrow definition of the concept of "pebbles", according to which pebbles are limited in linear dimensions. However, in lithology there are also objects that are similar in meaning to pebbles, but of different sizes: boulders, gravel, etc. In a broad sense, "pebbles" (or pellets according to L.V. Pustovalov) - "these are fragments of rocks rolled with water." There is a significant genetic difference between clasts and pellets. "Clastic rocks" - rocks composed only of fragments of parent rocks (minerals). Pellets are not fragments in the literal sense and therefore cannot be included in the group of "detrital rocks". They constitute an independent, very common group of sedimentary formations (conglomeroids), composed entirely or mainly of pellets of various sizes (pebbles, gravel, conglomerates, pebbles, gravelstones, etc.)

The main structures of sedimentary rocks are:

clastic - the rock consists of fragments of particles larger than 0.01 mm, pre-existing rocks;

fine-grained (clay or pelitic) - the rock consists of particles smaller than 0.01 mm in size (clay, marl);

crystalline inequigranular - crystals of minerals (rock salt, gypsum) are visually visible in the rock;

cryptocrystalline (afonite) - minerals in the rock are visible only under a microscope (chalk);

detrital - the rock is composed of fragments of shells or fragments of plants.

In sedimentary rocks, primary textures are distinguished - arising during the period of sedimentation (for example, layered) or in not yet hardened, plastic sediment (for example, underwater landslide) and secondary textures - formed at the stage of transformation of sediment into rock, as well as during its further changes (diagenesis, catagenesis, the initial stages of metamorphism).

CONCLUSION

In the course of the course work, the following goals and objectives were achieved:

1) We learned how to analyze geological maps

2) Described in detail the geological structure of the area, compiled a physical and geographical essay. The relief of this territory is generally flat, there are several hills. The main river of the described region is the Myshega River.

3) We found out the stratigraphy, tectonics and lithology of the area. Three systems are distinguished in this area: Carboniferous, Jurassic and Cretaceous, which are represented by sedimentary rocks: limestones, clays, sands, quartz sandstones. The total thickness is over 160 m.

4) This area can be attributed to the platform cover; there are no folds, faults, or faults.

5) There are three main structural stages: Lower Carboniferous, Upper Jurassic, Lower Cretaceous.

6) Based on the information received about the stratigraphy, tectonics of the occupied territory, we have restored the history of geological development. The sedimentation environment is calm.

A geological profile of the map was drawn along the highlighted line.