• What is the structure of the lithosphere?
• What phenomena occur at the boundaries of its plates?
• How are seismic belts located on Earth?

The structure of the earth's crust. The largest features of the country's relief are determined by the peculiarities of the geological structure and tectonic structures. The territory of Russia, like the whole of Eurasia, was formed as a result of the gradual convergence and collision of individual large lithospheric plates and their fragments.

The structure of lithospheric plates is heterogeneous. Within their limits there are relatively stable areas - platforms and mobile folded belts. The location of the largest forms of land relief - plains and mountains - depends on the structure of lithospheric plates. Plains are located on platforms.

Tectonic structures and the time of their formation are shown on tectonic maps, without which it is impossible to explain the patterns of distribution of the main landforms.

Mountains formed in mobile folded belts. These belts arose at different times in the marginal parts of the lithospheric plates when they collided with each other. Sometimes fold belts are found in the inner parts of the lithospheric plate. Such, for example, is the Ural Range. This suggests that once there was a boundary between two plates, which later turned into a single, larger plate.

The geological history of the Earth begins with the formation of the earth's crust. The oldest rocks indicate that the age of the lithosphere is more than 3.5 billion years.

The period of time corresponding to the longest (longest) stage in the development of the earth's crust and the organic world is commonly called the geological era. The entire history of the Earth is divided into five eras: Archean (ancient), Proterozoic (the era of early life), Paleozoic (the era of ancient life), Mesozoic (the era of middle life), Cenozoic (the era of new life). Eras are subdivided into geological periods. The names of the periods most often come from the localities where the corresponding deposits were first found.

Geological reckoning, or geochronology, is a branch of geology that studies the age, duration and sequence of formation of rocks that make up the earth's crust.

Sciences that study the earth's crust

The diversity of modern relief is the result of a long geological development and the impact of modern relief-forming factors, including human activity. Geology deals with the study of the structure and history of the development of the Earth. Modern geology is divided into a number of branches: historical geology studies the regularities in the structure of the earth's crust during geological time; geotectonics is the study of the structure of the earth's crust and the formation of tectonic structures (folds, cracks, shifts, faults, etc.). Paleontology is the science of extinct (fossil) organisms and the development of the organic world of the Earth. Mineralogy and petrography study minerals and other natural chemical compounds. If the occurrence of rocks is not disturbed by crushing, folds, ruptures, then each layer is younger than the one on which it lies, and the uppermost layer was formed later than all.

In addition, the relative age of rocks can be determined from the remains of extinct organisms.

It was only in the 20th century that they learned to determine the absolute age of rocks with sufficient accuracy. For these purposes, the process of decay of radioactive elements contained in the rock is used.

Geological table contains information about the successive change of eras and periods in the development of the Earth and their duration. Sometimes the table indicates the most important geological events, stages in the development of life, as well as the most typical minerals for a given period, etc.

The table is built from the most ancient stages of the development of the Earth to the modern one, so you need to study it from the bottom up. With the help of a geochronological table, one can obtain information about the duration and geological events in different eras and periods of the Earth's development.

Geological maps contain detailed information about what rocks are found in certain regions of the globe, what minerals lie in their bowels, etc.

Rice. 15. Geological chronology. The history of the development of the Earth

The geological map will allow you to get an idea of ​​the distribution of rocks of various ages throughout Russia. Please note that the most ancient rocks come to the surface in Karelia and Transbaikalia.

In the course of the geography of continents and oceans, you have already become acquainted with a map of the structure of the earth's surface, that is, with a tectonic map. By studying the tectonic map of Russia, you can get detailed information about the location and age of various tectonic structures within our country.

Rice. 16. Tectonic structures of the world

Compare the geological and tectonic maps and determine to which tectonic structures the outcrops of the most ancient rocks are confined.

Analysis of the tectonic map of Russia allows us to draw the following conclusions.

Areas with a flat relief are confined to platforms - stable areas of the earth's crust, where folding processes have long ended. The most ancient of the platforms are East European and Siberian. At the base of the platforms lies a rigid foundation composed of igneous and highly metamorphosed rocks of the Precambrian age (granites, gneisses, quartzites, crystalline schists). The foundation is usually covered with a cover of horizontal sedimentary rocks, and only on the Siberian Platform (Central Siberian Plateau) are significant areas occupied by volcanic rocks - Siberian traps.

On the map (Fig. 16), determine within which lithospheric plates the territory of Russia is located.

The outcrops of the foundation, composed of crystalline rocks, to the surface are called shields. In our country, the Baltic Shield on the Russian Platform and the Aldan Shield on the Siberian Platform are known.

Compare tectonic and physical-geographical maps and determine what relief forms are characteristic of shields.

Rice. 17. Platform structure

Mountainous regions are distinguished by a more complex geological structure. Mountains are formed in the most mobile parts of the earth's crust, where, as a result of tectonic processes, rocks are crushed into folds, broken by faults and faults. These tectonic structures arose at different times - in the eras of the Paleozoic, Mesozoic and Cenozoic folding. The youngest mountains of our country are located in the Far East, namely the Kuril Islands and Kamchatka. They are part of the vast Pacific volcanic belt, or the Pacific Ring of Fire, as it is called. They are distinguished by significant seismicity, frequent strong earthquakes, and the presence of active volcanoes.

Rice. 18. Structure of the folded area

The information of geological and tectonic maps is necessary not only for geologists and geographers, but also for builders, as well as representatives of other professions.

Table 2. Main active volcanoes in Russia

To successfully work with these rather complex maps, one must first carefully study their legends.

Questions and tasks

1. What sciences are engaged in the study of the history of the development of the Earth?
2. What information can be obtained from a geochronological table?
3. What is shown on a tectonic map?
4. Using a geochronological table, write a story about the formation of the main forms of the surface of our country.
5. Determine from the geochronological table in which era and period we live; what geological events are currently taking place; what minerals are formed.

1) What is the structure of the lithosphere?

The lithosphere consists of separate large blocks - lithospheric plates.

2) What phenomena occur at the boundaries of its plates?

The boundaries of lithospheric plates can diverge; can collide, then geosynclinal belts are formed.

3) How are seismic belts located on Earth?

There are two major seismic belts. They include one latitudinal, that is, located along the equator, and the second is the meridian, respectively, perpendicular to the previous one. The first is called the Mediterranean-Trans-Asian and it originates approximately in the Persian Gulf, and the extreme point reaches the middle of the Atlantic Ocean. The second is called the meridional Pacific, and it passes in full accordance with its name.

Questions in a paragraph

*Compare the geological and tectonic maps and determine which tectonic structures the outcrops of the most ancient rocks are confined to.

Shield areas on the Russian and Siberian platforms.

*Compare tectonic and physical-geographical maps and determine what relief forms are characteristic of shields.

Low mountains and plateaus.

Questions at the end of the paragraph

1. What sciences study the history of the development of the Earth?

Geology, geotectonics, paleontology, mineralogy, petrography.

2. What information can be obtained from a geochronological table?

Information about the change of eras and periods in the history of the development of the Earth and their duration, the most important geological events, the stages of life development, the most typical minerals for the period.

3. What is shown on the tectonic map?

Location and age of tectonic structures.

4. Using a geochronological table, make up a story about the formation of the main landforms of our country?

The largest flat relief forms are confined to ancient platforms, the formation of which has long been completed (Russian platform, Siberian platform, West Siberian plate). Mountain areas were formed in different epochs of folding. In the earliest Baikal folding, the Yenisei Ridge, the Eastern Sayan, the Baikal region and Transbaikalia were formed. In the Paleozoic, the Western Sayan and Eastern Altai formed into the Caledonian folding. The Urals and Western Altai are formed into the Hercynian folding. Verkhoyansky Range and Chersky Range, Sikhote-Alin - Mesozoic folding. The modern Cenozoic folding includes the Caucasus, the mountains of Kamchatka and the Kuril Islands.

5. Determine from the geochronological table in which era and period we live, what geological events are taking place now, what minerals are being formed.

We live in the Cenozoic era, the Quaternary period. Now there is mountain building in the Alpine-Himalayan fold belt, a general uplift of the territory, changes in sea levels. The flourishing of angiosperms and mammals is observed. Minerals are formed - peat, alluvial deposits of gold and diamonds, building materials.

Planet Earth. To find out the age of rocks, use them absolute and relative age.

The absolute age of rocks is determined by the ability of some radioactive elements to self-decompose in natural conditions. The relative age is determined by the conditions of occurrence of sedimentary rocks, the features of their composition, and the remains of organisms that lived in past eras. It is clear that the deeper layers reflect more ancient geological events.

The study of the age of rocks made it possible to compile geochronological table(table of geological chronology).

In geological history, large time intervals are distinguished - eras and periods.

In the geological past, the most ancient archean era followed by Proterozoic, Paleozoic, Mesozoic, Cai Nozoic. Each era is divided into periods. The earliest of these is Precambrian.

Pay attention to the fact that the geochronological table is built from the most ancient stages to the modern one and you need to read it from the bottom up. For each era, the corresponding stage in the development of climate, wildlife, the main geological events and the most characteristic minerals are shown.

Geological table (table of geological reckoning)

Era and its duration (million years)	Period		Major geological events		The evolution of nature and the organic world	Minerals
	Beginning (million years ago)	Duration (million years)	Warehouse era	Changes in the face of the Earth
Cenozoic (67)	(2) Quaternary (2)		Alpine	The general uplift of the territory, the increase in land. Accumulation of snow in the mountains and repeated glaciations. Formation of modern relief	The emergence of modern man. The emergence of humanoid ancestors	Building materials (clay, sand), alluvial deposits of gold, diamonds
	(25) Neogene (23.5)			Powerful volcanism, mountain building in the Alpine-Pacific mobile belt. On the territory of Russia - the formation of new mountain structures (Caucasus, Kamchatka). The emergence of the basins of the seas - Black, Caspian, Okhotsk, Japanese	The appearance of treeless landscapes - steppes, savannahs, as well as gallery tropical forests. Distribution of ungulates, rodents. The emergence of new insects (grasshoppers)	Brown coal, oil, rock salt, sedimentary iron ores, building materials (granite, marble)
	(67) Paleogene (42)			Destruction of the Mesozoic mountains. The advance of the seas. Accumulation of precipitation. Beginning of Alpine folding	dominance of mammals. The appearance of saber-toothed tigers and mammoths. Distribution of birds and bony fish	Brown coal, oil, oil shale
Mesozoic (163)	(137) Chalk (70)		Cimmerian (Mesozoic)	Formation of new mountain structures. On the territory of Russia - the mountains of North-Eastern Siberia (ridges Verkhoyansky, Chersky) and the Far East (Sikhote-Alin). Platform lifting	At the end of the period - the death of dinosaurs on land, sea lizards and ammonites in the Ocean. All groups of modern mammals arise. Angiosperms, flowering plants. Flora becomes similar to modern	Hard coal, oil, oil shale, phosphate rock, chalk, ores of tin, arsenic, antimony, gold, silver, copper, lead
	(195) Jurassic (58)			Sea inundation. Accumulation of precipitation. Powerful mountain building. Platform splits. Rise of the destroyed mountains of the Baikal folding	Hot and humid climate. The emergence of mammals. Kingdom of dinosaurs. Forest vegetation acquires a zonal character	Coal, oil shale, phosphorites
	(230) Triassic (35)			Sushi rise. The most extensive retreat of the sea. Destruction of pre-Mesozoic mountains. Formation of the sedimentary cover of platforms	Dry climate. The advent of dinosaurs (two-legged lizards). Coniferous forests. The first animal-like predators (beast-toothed) - the forerunners of mammals	Rock salt, oil, coal
Paleozoic	(285) Perm (55)		Hercynskaya	Completion of the Hercynian folding. Formation of new mountain structures. Raising ancient platforms. On the territory of Russia - the formation of the Ural Mountains, Altai. The emergence of the foundations of the West Siberian and Turan platforms, the Scythian platform	Dry climate. Gradual disappearance of fern and horsetail forests. Reptiles become oviparous	Rock and potash salts, gypsum, coal, oil, combustible gas
	(350) Carboniferous (75-65)			Dropping sushi. Flooding of ancient platforms. A new stage of city building. On the territory of Russia - the activation of tectonic movements in the Ural-Tien Shan mobile belt. Splits of the submerging Siberian platform and lava outpourings (formation of basalt covers - Siberian traps)	Increase in the area of ​​swampy lowlands. Hot and humid climate. The flowering of fern and horsetail forests. Appearance of gymnospermous coniferous plants. The rise of amphibians. The appearance of insects (dragonflies) and reptiles (reptiles)	Abundance of coal and oil. Copper, tin-tungsten, poly-metal ores
	(410) Devonian (60)		Caledonian	Retreat of the seas. Elevations, which were replaced by subsidence by the end of the period. Reducing the strength of tectonic movements. The destruction of the mountains. Terrain leveling	Strengthening the continentality of the climate, the appearance of the first deserts. Ancient amphibians. Widespread distribution of terrestrial plants. Exit of vertebrates to land. The great invasion of life on land	Oil, combustible gas, medicinal mineral waters
	(440) Silurian (30)			Mountain building between Precambrian structures. Rise of the ancient platforms. On the territory of Russia - the formation of the Sayans of the eastern part of Altai	Cross-finned fishes, bony fishes. Cartilaginous fish. Appearance of vertebrae. The first land plants - psilophytes	Iron, copper and other ores, gold, phosphorites, oil shale
	(500) Ordovician (60) material from the site			Decrease in the area of ​​the seas, volcanism. Beginning of the Caledonian folding	The appearance of armored fish
	(570) Cambrian (70)			The attenuation of mountain building, the slow sinking of the continents, the flooding of vast areas of land. Destruction and smoothing of mountains. Accumulation of sedimentary rocks	Corals, sponges, molluscs, arthropods (crayfish and trilobites)	Bauxites, phosphorites, sedimentary ores of manganese and iron, rock salt, gypsum
proteo rose			Baikal	Powerful volcanism, mountain building around ancient platforms. On the territory of Russia - the mountain systems of Transbaikalia, the Baikal region, the Timan and Yenisei ridges	Multicellular creatures, algae. The simplest cellular forms in the depths of the oxygen-free Ocean	Huge reserves of iron ores, polymetallic ores, graphite, building materials
archaeus	(over 3500) (over 900)		The most ancient volcanism and mountain building, the formation of the cores of ancient platforms. On the territory of Russia - the East European and Siberian platforms		The first forms of life

On this page, material on the topics:

The stratigraphic scale (geochronological) is the standard by which the history of the Earth is measured in terms of time and geological magnitude. is a kind of calendar that counts time intervals in hundreds of thousands and even millions of years.

About the planet

The current conventional wisdom about the Earth is based on various data, according to which the age of our planet is approximately four and a half billion years. Neither rocks nor minerals that could indicate the formation of our planet have yet been found either in the bowels or on the surface. Refractory compounds rich in calcium, aluminum and carbonaceous chondrites, which were formed in the solar system before anything else, limit the maximum age of the Earth to these figures. The stratigraphic scale (geochronological) shows the boundaries of time from the formation of the planet.

A variety of meteorites were studied using modern methods, including uranium-lead, and as a result, estimates of the age of the solar system were presented. As a result, the time that has elapsed since the creation of the planet was divided into time intervals according to the most important events for the Earth. The geochronological scale is very convenient for tracking geological times. The eras of the Phanerozoic, for example, are delimited by the largest evolutionary events when the global extinction of living organisms occurred: the Paleozoic on the border with the Mesozoic was marked by the largest extinction of species in the entire history of the planet (Permo-Triassic), and the end of the Mesozoic is separated from the Cenozoic by the Cretaceous-Paleogene extinction.

History of creation

For the hierarchy and nomenclature of all modern subdivisions of geochronology, the nineteenth century turned out to be the most important: in its second half, sessions of the IGC - the International Geological Congress took place. After that, from 1881 to 1900, a modern stratigraphic scale was compiled.

Its geochronological "stuffing" was later repeatedly refined and modified as new data became available. Quite different signs have served as themes for specific names, but the most common factor is geographical.

Titles

The geochronological scale sometimes associates the names with the geological composition of the rocks: the carboniferous one appeared in connection with the huge number of coal seams during excavations, and the chalk one simply because writing chalk spread throughout the world.

Construction principle

To determine the relative geological age of the rock, a special geochronological scale was needed. Eras, periods, that is, age, which is measured in years, is of little importance to geologists. The entire lifetime of our planet was divided into two main segments - Phanerozoic and Cryptozoic (Precambrian), which are delimited by the appearance of fossil remains in sedimentary rocks.

Cryptozoic is the most interesting thing hidden from us, since the soft-bodied organisms that existed at that time did not leave a single trace in sedimentary rocks. Periods of the geochronological scale, such as the Ediacaran and Cambrian, appeared in the Phanerozoic through the research of paleontologists: they found in the rock a large variety of mollusks and many species of other organisms. Findings of fossil fauna and flora allowed them to dissect the strata and give them the appropriate names.

Time slots

The second largest division is an attempt to designate the historical intervals of the life of the Earth, when the four main periods were divided by the geochronological scale. The table shows them as primary (Precambrian), secondary (Paleozoic and Mesozoic), tertiary (almost the entire Cenozoic) and Quaternary - a period that is in a special position, because although it is the shortest, it is replete with events that left bright and well-read traces.

Now, for convenience, the geochronological scale of the Earth is divided into 4 eras and 11 periods. But the last two of them are divided into 7 more systems (epochs). No wonder. It is the last segments that are especially interesting, since this one corresponds to the time of the appearance and development of mankind.

Milestones

For four and a half billion years in the history of the Earth, the following events have occurred:

• Pre-nuclear organisms (the first prokaryotes) appeared - four billion years ago.
• The ability of organisms to photosynthesis was discovered - three billion years ago.
• Cells with a nucleus (eukaryotes) appeared - two billion years ago.
• Multicellular organisms evolved - one billion years ago.
• The ancestors of insects appeared: the first arthropods, arachnids, crustaceans and other groups - 570 million years ago.
• Fish and proto-amphibians are five hundred million years old.
• Terrestrial plants appeared and have been delighting us for 475 million years.
• Insects have lived on the earth for four hundred million years, and plants in the same time period received seeds.
• Amphibians have been living on the planet for 360 million years.
• Reptiles (reptiles) appeared three hundred million years ago.
• Two hundred million years ago, the first mammals began to evolve.
• One hundred and fifty million years ago - the first birds tried to master the sky.
• One hundred and thirty million years ago flowers (flowering plants) blossomed.
• Sixty-five million years ago, the Earth lost the dinosaurs forever.
• Two and a half million years ago, a man appeared (the genus Homo).
• One hundred thousand years have passed since the beginning of anthropogenesis, thanks to which people have acquired their present form.
• For twenty-five thousand years, Neanderthals have not existed on Earth.

The geochronological scale and the history of the development of living organisms, merged together, albeit somewhat schematically and generally, with rather approximate dates, but provide a clear idea of ​​the development of life on the planet.

Bedding rocks

The Earth's crust is mostly stratified (where there are no disturbances due to earthquakes). The general geochronological scale is drawn up according to the location of the strata of rocks, which clearly show how their age decreases from lower to upper.

Fossil organisms also change as they move up: they become more complex in their structure, some undergo significant changes from layer to layer. This can be observed without visiting paleontological museums, but simply by going down the subway - eras that are very distant from us left their imprints on facing granite and marble.

anthropogen

The last period of the Cenozoic era is the modern stage of the earth's history, which includes the Pleistocene and Holocene. What just didn’t happen in these turbulent millions of years (specialists still think differently: from six hundred thousand to three and a half million). There were repeated changes of cooling and warming, huge continental glaciations, when the climate was humidified south of the advancing glaciers, water basins appeared, both fresh and salty. Glaciers absorbed part of the World Ocean, the level of which dropped by a hundred or more meters, due to which continents were formed.

Thus, there was an exchange of fauna, for example, between Asia and North America, when a bridge was formed instead of the Bering Strait. Closer to the glaciers, cold-loving animals and birds settled: mammoths, hairy rhinos, reindeer, musk oxen, arctic foxes, polar partridges. They spread south very far - to the Caucasus and the Crimea, to Southern Europe. Along the course of the glaciers, relict forests are still preserved: pine, spruce, fir. And only at a distance from them did deciduous forests grow, consisting of such trees as oak, hornbeam, maple, beech.

Pleistocene and Holocene

This is the era after the ice age - not yet completed and not fully lived segment of the history of our planet, which indicates the international geochronological scale. Anthropogenic period - Holocene, is calculated from the last continental glaciation (northern Europe). It was then that the land and the World Ocean received their modern outlines, and all the geographical zones of the modern Earth also took shape. The predecessor of the Holocene - the Pleistocene is the first epoch of the anthropogenic period. The cooling that began on the planet continues - the main part of this period (Pleistocene) was marked by a much colder climate than the modern one.

The northern hemisphere is experiencing the last glaciation - thirteen times the surface of glaciers exceeded modern formations even in interglacial intervals. Pleistocene plants are closest to modern ones, but they were located somewhat differently, especially during periods of glaciation. The genera and species of the fauna changed, those that adapted to the Arctic form of life survived. The southern hemisphere did not recognize such huge upheavals, so Pleistocene plants and animals are still present in many forms. It was in the Pleistocene that the evolution of the genus Homo took place - from (archanthropes) to Homo sapiens (neoanthropes).

When did mountains and seas appear?

The second period of the Cenozoic era - the Neogene and its predecessor - the Paleogene, including the Pliocene and Miocene about two million years ago, lasted about sixty-five million years. In the Neogene, the formation of almost all mountain systems was completed: the Carpathians, the Alps, the Balkans, the Caucasus, the Atlas, the Cordillera, the Himalayas, and so on. At the same time, the outlines and sizes of all sea basins changed, since they were subjected to severe drying. It was then that Antarctica and many mountainous regions glacied.

Marine inhabitants (invertebrates) have already become close to modern species, and mammals dominated on land - bears, cats, rhinos, hyenas, giraffes, deer. Great apes develop so much that Australopithecus could appear a little later (in the Pliocene). On the continents, mammals lived separately, since there was no connection between them, but in the late Miocene, Eurasia and North America nevertheless exchanged fauna, and at the end of the Neogene, the fauna migrated from North America to South America. It was then that the tundra and taiga were formed in the northern latitudes.

Paleozoic and Mesozoic eras

The Mesozoic precedes the Cenozoic era and lasted 165 million years, including the Cretaceous, Jurassic and Triassic periods. At this time, mountains were intensively formed on the peripheries of the Indian, Atlantic and Pacific oceans. Reptiles began their dominance on land, in water, and in the air. Then the first, still very primitive mammals appeared.

The Paleozoic is located on the scale before the Mesozoic. It lasted about three hundred and fifty million years. This is the time of the most active mountain building and the most intensive evolution of all higher plants. Almost all known invertebrates and vertebrates of various types and classes were formed at that time, but there were no mammals and birds yet.

Proterozoic and Archean

The Proterozoic era lasted about two billion years. At this time, the processes of sedimentation were active. Blue-green algae developed well. There was no opportunity to learn more about these distant times.

Archean is the oldest era in the recorded history of our planet. It lasted for about a billion years. As a result of active volcanic activity, the very first living microorganisms appeared.

is the totality of all forms of the earth's surface. They can be horizontal, inclined, convex, concave, complex.

The height difference between the highest peak on land, Mount Chomolungma in the Himalayas (8848 m), and the Mariana Trench in the Pacific Ocean (11,022 m) is 19,870 m.

How was the relief of our planet formed? In the history of the Earth, two main stages of its formation are distinguished:

• planetary(5.5-5.0 million years ago), which ended with the formation of the planet, the formation of the core and mantle of the Earth;
• geological, which began 4.5 million years ago and continues to this day. It was at this stage that the formation of the earth's crust occurred.

The source of information about the development of the Earth during the geological stage is primarily sedimentary rocks, which in the vast majority were formed in the aquatic environment and therefore occur in layers. The deeper the layer lies from the earth's surface, the earlier it was formed and, therefore, is more ancient with respect to any layer that is closer to the surface and is younger. This simple reasoning is based on the concept relative age of rocks, which formed the basis for the construction geochronological table(Table 1).

The longest time intervals in geochronology are − zones(from Greek. aion- century, epoch). There are such zones as: cryptozoic(from Greek. cryptos- hidden and zoe- life), covering the entire Precambrian, in the deposits of which there are no remains of skeletal fauna; phanerozoic(from Greek. phaneros- explicit, zoe- life) - from the beginning of the Cambrian to our time, with a rich organic life, including skeletal fauna. The zones are not equal in duration, so if the Cryptozoic lasted 3-5 billion years, then the Phanerozoic lasted 0.57 billion years.

Table 1. Geological table

Era. letter designation, duration	The main stages of the development of life	Periods, letter designation, duration	major geological events. The shape of the earth's surface	Most Common Minerals
Cenozoic, KZ, about 70 Ma	dominance of angiosperms. The rise of the mammalian fauna. The existence of natural zones close to modern ones, with repeated displacements of boundaries	Quaternary, or Anthropogenic, Q, 2 million years	General uplift of the territory. repeated glaciations. The appearance of man	Peat. Alluvial deposits of gold, diamonds, precious stones
		Neogene, N, 25 Ma	The emergence of young mountains in the areas of Cenozoic folding. The revival of mountains in the regions of all ancient foldings. Dominance of angiosperms (flowering) plants	Brown coals, oil, amber
		Paleogene, P, 41 Ma	Destruction of the Mesozoic mountains. Wide distribution of flowering plants, development of birds and mammals	Phosphorites, brown coals, bauxites
Mesozoic, MZ, 165 Ma		Cretaceous, K, 70 Ma	The emergence of young mountains in the areas of Mesozoic folding. Extinction of giant reptiles (reptiles). Development of birds and mammals	Oil, oil shale, chalk, coal, phosphorites
		Jurassic, J, 50 Ma	Formation of modern oceans. Hot, humid climate. The rise of reptiles. dominance of gymnosperms. Appearance of primitive birds	Coals, oil, phosphorites
		Triassic, T, 45 Ma	The greatest retreat of the sea and the rise of the continents in the entire history of the Earth. Destruction of pre-Mesozoic mountains. Vast deserts. First mammals	rock salts
Paleozoic, PZ, 330 Ma	The flowering of ferns and other spore plants. Time for fish and amphibians	Permian, R, 45 Ma	The emergence of young mountains in areas of Hercynian folding. Dry climate. The emergence of gymnosperms	Rock and potash salts, gypsum
		Carboniferous (Carboniferous), C, 65 Ma	Widespread swampy lowlands. Hot, humid climate. Development of forests from tree ferns, horsetails and club mosses. The first reptiles The heyday of amphibians	Abundance of coal and oil
		Devonian, D, 55 million years	Reduction of the seas. Hot climate. First deserts. The appearance of amphibians. Numerous fish	Salt, oil
	The appearance of animals and plants on Earth	Silurian, S, 35 Ma	The emergence of young mountains in the areas of the Caledonian folding. The first land plants
		Ordovician, O, 60 Ma	Decrease in the area of ​​marine basins. Appearance of the first terrestrial invertebrates
		Cambrian, E, 70 Ma	The emergence of young mountains in the areas of Baikal folding. Flooding of vast areas by the seas. The rise of marine invertebrates	Rock salt, gypsum, phosphate rock
Proterozoic, PR. about 2000 Ma	Origin of life in water. Bacteria and algae time		Beginning of the Baikal folding. Powerful volcanism. Bacteria and algae time	Huge reserves of iron ores, mica, graphite
Archean, AR. over 1000 million years			Ancient folding. Intense volcanic activity. Time of primitive bacteria	Iron ores

The zones are divided into era. In the cryptozoic, there are Archean(from Greek. archaios- primordial, ancient aion- century, era) and Proterozoic(from Greek. proteros- earlier, zoe - life) era; in the Phanerozoic Paleozoic(from Greek ancient and life), Mesozoic(from Greek. tesos - middle, zoe - life) and Cenozoic(from Greek. kainos- new, zoe - life).

Eras are divided into shorter periods of time - periods established only for the Phanerozoic (see Table 1).

The main stages in the development of the geographical envelope

The geographical envelope has come a long and difficult path of development. There are three qualitatively different stages in its development: pre-biogenic, biogenic, and anthropogenic.

pre-biogenic stage(4 billion - 570 million years) - the longest period. At this time, the process of increasing the thickness and complicating the composition of the earth's crust took place. By the end of the Archean (2.6 billion years ago), a continental crust about 30 km thick had already formed over vast expanses, and in the Early Proterozoic, protoplatforms and protogeosynclines separated. During this period, the hydrosphere already existed, but the volume of water in it was less than now. Of the oceans (and then only by the end of the early Proterozoic) one took shape. The water in it was salty and the salinity level most likely was about the same as now. But, apparently, in the waters of the ancient ocean, the predominance of sodium over potassium was even greater than now, there were also more magnesium ions, which is associated with the composition of the primary earth's crust, the weathering products of which were carried into the ocean.

The Earth's atmosphere at this stage of development contained very little oxygen, and there was no ozone screen.

Life most likely existed from the very beginning of this stage. According to indirect data, microorganisms lived already 3.8-3.9 billion years ago. The discovered remains of the simplest organisms are 3.5-3.6 billion years old. However, from the moment of its inception to the very end of the Proterozoic, organic life did not play a leading, determining role in the development of the geographical envelope. In addition, many scientists deny the presence of organic life on land at this stage.

The evolution of organic life to the pre-biogenic stage proceeded slowly, but nevertheless, 650-570 million years ago, life in the oceans was quite rich.

Biogenic stage(570 million - 40 thousand years) lasted during the Paleozoic, Mesozoic and almost the entire Cenozoic, with the exception of the last 40 thousand years.

The evolution of living organisms during the biogenic stage was not smooth: eras of relatively calm evolution were replaced by periods of rapid and deep transformations, during which some forms of flora and fauna died out and others became widespread.

Simultaneously with the appearance of terrestrial living organisms, soils began to form in our modern understanding.

Anthropogenic stage began 40 thousand years ago and continues today. Although man as a biological species appeared 2-3 million years ago, his impact on nature for a long time remained extremely limited. With the advent of Homo sapiens, this impact has increased significantly. It happened 38-40 thousand years ago. From here the anthropogenic stage in the development of the geographic envelope takes its countdown.