Cenozoic era. Quaternary period (Anthropogen) Quaternary period of the Cenozoic era

“General biology. Grade 11". V.B. Zakharov and others (gdz

Question 1. Describe the evolution of life in the Cenozoic era.
In the Quaternary period of the Cenozoic era, cold-resistant grass and shrub vegetation appears, in large areas the forests are replaced by steppe, semi-desert and desert. Modern plant communities are being formed.
The development of the animal world in the Cenozoic era is characterized by further differentiation of insects, intensive speciation in birds, and extremely rapid progressive development of mammals.
Mammals are represented by three subclasses: monotremes (platypus and echidna), marsupials and placentals. Monotremes originated independently of other mammals back in the Jurassic period from animal-like reptiles. Marsupials and placental mammals evolved from a common ancestor in the Cretaceous and coexisted until the onset of the Cenozoic era, when there was an "explosion" in the evolution of placental mammals, as a result of which placental mammals displaced marsupials from most continents.
The most primitive were insectivorous mammals, from which the first carnivores and primates descended. Ancient carnivores gave rise to ungulates. By the end of the Neogene and Paleogene, all modern families of mammals are already found. One of the groups of monkeys - Australopithecus - gave rise to a branch leading to the genus man.

Question 2. What impact did extensive glaciation have on the development of plants and animals in the Cenozoic?
In the Quaternary period of the Cenozoic era (2-3 million years ago), glaciation of a significant part of the Earth began. Heat-loving vegetation recedes to the south or dies out, cold-resistant grass and shrub vegetation appears, in large areas forests are replaced by steppe, semi-desert and desert. Modern plant communities are being formed.
Mammoths, woolly rhinos, reindeer, arctic foxes, polar partridges were found in the North Caucasus and Crimea.

Question 3. How can you explain the similarities between the fauna and flora of Eurasia and North America?
The formation of large masses of ice during the glaciation of the Quaternary period caused a decrease in the level of the World Ocean. This decrease was 85-120 m compared to the current level. As a result, the continental shoals of North America and Northern Eurasia were exposed and land "bridges" appeared connecting the North American and Eurasian continents (in the place of the Bering Strait). On such "bridges" the migration of species occurred, which led to the formation of the modern fauna of the continents.

Paleogene

In the Paleogene, the climate was warm and humid, as a result of which tropical and subtropical plants became widespread. Representatives of the marsupial subclass were widespread here.

Neogene

see Hipparion fauna

By the beginning of the Neogene, the climate became dry and temperate, and by the end of it, a sharp cooling began.

These climate changes led to the reduction of forests, the emergence and wide distribution of herbaceous plants.

The class of insects developed intensively. Among them, highly organized species arose that contributed to the cross-pollination of flowering plants and fed on plant nectar.

The number of reptiles has decreased. Birds and mammals lived on land and in the air, fish lived in the water, as well as mammals that re-adapted to life in the water. During the Neogene period, many genera of currently known birds appeared.

At the end of the Neogene, marsupials gave way to placental mammals in the struggle for existence. The oldest placental mammals are representatives of the order of insectivores, from which other orders of placental animals, including primates, originated during the Neogene.

In the middle of the Neogene, apes developed.

Due to the reduction of forests, some of them were forced to live in open areas. Subsequently, primitive people descended from them. They were not numerous and constantly struggled with natural disasters, defended themselves from large predatory animals.

Quaternary (Anthropogenic)

great glaciation

great glaciation

In the Quaternary period, there was a repeated shift of the ice of the Arctic Ocean to the south and back, which was accompanied by cooling and the movement of many heat-loving plants to the south.

With the retreat of the ice, they moved to their former places.

29. Development of life in the Cenozoic era.

Such repeated migration (from Latin migratio - relocation) of plants led to the mixing of populations, the extinction of species that were not adapted to the changed conditions, and contributed to the emergence of other, adapted species.

human evolution

see Human evolution Material from the site http://wikiwhat.ru

By the beginning of the Quaternary period, the evolution of man is accelerating. The methods of manufacturing tools and their use are being significantly improved. People begin to change the environment, learn to create favorable conditions for themselves.

The increase in the number and wide distribution of people began to influence the flora and fauna. Hunting by primitive people leads to a gradual reduction in the number of wild herbivores. The extermination of large herbivores has led to a sharp decrease in the number of cave lions, bears and other large predatory animals that feed on them.

Trees were cut down and many forests turned into pastures.

On this page, material on the topics:

• Cenozoic era brief description

• Cenozoic era third period climate

• Cambrian briefly

• Rjqyjpjq

• Neogene in a nutshell

Questions for this article:

• Name the periods of the Cenozoic era.

• What changes occurred in the plant and animal world in the Cenozoic era?

• In what period did the main orders of mammals appear?

• Name the period in which the great apes developed.

Material from the site http://WikiWhat.ru

CENOSIOIC ERATEM (ERA), Cenozoic (from the Greek kainos - new and zoe - life * a. Cainozoic, Cenozoic, Kainozoic era; n. Kanozoikum, kanonisches Arathem; f. erateme cenozoique; and. eratema cenozoiso), - the uppermost ( young) erathema (group) of the general stratigraphic scale of the layers of the earth's crust and the latest era of the geological history of the Earth corresponding to it.

It began 67 million years ago and continues to this day. The name was proposed by the English geologist J. Phillips in 1861. It is divided into the Paleogene, Neogene and Quaternary (Anthropogenic) systems (periods). The first two until 1960 were combined into a tertiary system (period).

general characteristics. By the beginning of the Cenozoic, there were the Pacific and Mediterranean geosynclinal belts, within which thick strata of geosynclinal sediments accumulated in the Paleogene and almost throughout the entire Neogene.

The modern distribution of continents and oceans is taking shape. The disintegration of the previously unified southern continental massif of Gondwana, which took place during the Mesozoic era, is coming to an end. By the beginning of the Cenozoic, two large platform continents stood out in the Northern Hemisphere of the Earth - the Eurasian and North American, separated by the not yet fully formed northern basin of the Atlantic Ocean.

By the middle of the Cenozoic era, Eurasia and Africa formed the continental massif of the Old World, soldered by mountain structures of the Mediterranean geosynclinal belt. In the Paleogene, the site of the latter was occupied by the vast Tethys marine basin that had existed since the Mesozoic, stretching from Gibraltar to the Himalayas and Indonesia.

In the middle of the Paleogene, the sea penetrated from the Tethys and to neighboring platforms, flooding vast areas within modern Western Europe, the south of the European part of the CCCP, Western Siberia, Central Asia, North Africa and Arabia. Starting from the Late Paleogene, these territories gradually freed themselves from the sea.

In the Mediterranean belt, as a result of Alpine tectogenesis, by the end of the Neogene, a system of young folded mountains was formed, including the Atlas, Andalusian Mountains, Pyrenees, Alps, Apennines, Dinaric Mountains, Stara Planina, Carpathians, Caucasus, Hindu Kush, Pamir, Himalayas, mountains of Asia Minor, Iran , Burma and Indonesia.

Tethys began to gradually break up into parts, the long evolution of which led to the formation of a system of depressions of the Mediterranean, Black and Caspian Seas. The Pacific geosynclinal belt in the Paleogene (as well as in the Neogene) consisted of several geosynclinal regions stretching for thousands of kilometers along the periphery of the Pacific Ocean floor.

The largest geosynclines: East Asian, New Guinea-New Zealand (encircles Australia from the east), Andean and California. The thickness of terrigenous (clays, sands, diatomites) and volcanogenic (andesite-basalts, rare-acid volcanic rocks and their tuffs) strata in them reaches 14 km. Denudation dominated in the area of ​​mesozoid development (Verkhoyansk-Chukotka and Cordillera folded regions), highly elevated in the Paleogene. Sediments accumulated only in graben-like depressions (coal-bearing strata of small thickness).

From the middle of the Miocene, the Verkhoyansk-Chukotka region experienced epiplatform orogeny with a range of movements (Verkhoyansky, Chersky and other ranges) of 3-4 km.

The area of ​​the Bering Sea dried up, connecting Asia and North America.

In North America, uplifts were sometimes accompanied by massive outpourings of lavas. The bloc movements captured here the outskirts of the adjacent ancient North American (Canadian) platform, creating a chain of blocky Rocky Mountains parallel to the Cordillera.

The development of life in the Cenozoic era and its current stage

In Eurasia, arched uplifts and block displacements along faults covered even larger areas of folded structures of various ages, causing the formation of mountainous relief in spaces that had previously been strongly leveled by long-term denudation (Tien Shan, Altai, Sayans, Yablonovy and Stanovoy Ranges, mountains of Central Asia and Tibet , the Scandinavian Peninsula and the Urals).

Along with this, long-range fault systems are formed, accompanied by linearly elongated rifts, expressed in the relief in the form of deep valley-like depressions, in which large reservoirs are often located (the East African rift system, the Baikal rift system).

Within the folded epipaleozoic Atlantic folded geosynclinal belt, the depression of the Atlantic Ocean developed and took shape.

The Quaternary period is a typical theocratic era. The land area increased significantly by the end of the Neogene. By the beginning of the Quaternary period, two geosynclinal belts remained on the surface of the Earth - the Pacific and the Mediterranean. In the Early Quaternary, in connection with a major regression, Europe and North America united through Iceland, Asia - with Alaska, Europe - with Africa. The Aegean Sea, the Dardanelles, the Bosporus did not yet exist; in their place was land, connecting Europe with Asia Minor.

During the Quaternary period, the seas repeatedly changed their outlines. Anteclises and syneclises, which have existed since the Paleozoic, continue to develop on the platforms. Folded mountain structures still rise in the mountain belts (the Alps, the Balkans, the Carpathians, the Caucasus, the Pamirs, the Himalayas, the Western Cordillera, the Andes, and others), and the intermountain and foothill depressions are filled with molasses.

Volcanic eruptions are associated with young faults.

The climate of the Earth during the Paleogene was much warmer than today, but it was characterized by multiple fluctuations with a general trend towards relative cooling (from the Paleogene to the Quaternary period).

Even within the Arctic, mixed forests grew, and much of Europe, northern Asia, and North America had tropical and subtropical vegetation. Extensive uplifts of the continents in the 2nd half of the Cenozoic era caused the drainage of a significant part of the shelf of Northern Eurasia and North America. The contrasts between climatic zones increased, a general cooling set in, accompanied by powerful continental glaciations in Europe, Asia and North America.

In the Southern Hemisphere, the glaciers of the Andes and New Zealand have increased dramatically in size; Tasmania was also subjected to glaciation. Glaciation of Antarctica began at the end of the Paleogene, and in the Northern Hemisphere (Iceland) - from the end of the Neogene. The recurrence of Quaternary glacial and interglacial epochs caused rhythmic changes in all natural processes in the Northern Hemisphere, incl. and in sedimentation. The last ice sheet in North America and Europe disappeared 10-12 thousand years ago, see Fig.

Quaternary system (period). In the modern era, 94% of the volume of ice is concentrated in the southern hemisphere of the Earth. In the Quaternary period, under the influence of tectonic (endogenous) and exogenous processes, the modern relief of the Earth's surface and the bottom of the oceans was formed. In general, the Cenozoic era is characterized by repeated changes in the level of the World Ocean.

organic world. At the turn of the Mesozoic and Cenozoic, the groups of reptiles that dominated the Mesozoic die out and their place in the terrestrial animal world is occupied by mammals, which, together with birds, make up most of the terrestrial vertebrates of the Cenozoic era. On the continents, higher placental mammals predominate, and only in Australia does a peculiar fauna of marsupials and partly monotremes develop.

From the middle of the Paleogene, almost all existing orders appear. Part of the mammals for the second time passes to living in the aquatic environment (cetaceans, pinnipeds). From the beginning of the Cenozoic era, a detachment of primates appeared, the long evolution of which led to the appearance in the Neogene of higher anthropoid apes, and at the beginning of the Quaternary period, the first primitive people.

The invertebrate fauna of the Cenozoic era differs less sharply from that of the Mesozoic. Ammonites and belemnites are completely dying out, bivalves and gastropods, sea urchins, six-ray corals, etc. dominate. Nummulites (large foraminifera) develop rapidly, making up thick limestone strata in the Paleogene. In terrestrial vegetation, angiosperms (flowering plants) continued to dominate. Starting from the middle of the Paleogene, herbaceous formations of the savanna and steppe type appear, from the end of the Neogene, formations of coniferous forests of the taiga type, and then forest-tundra and tundra.

Minerals. Approximately 25% of all known oil and gas reserves are confined to Cenozoic deposits, the deposits of which are concentrated mainly in marginal troughs and intermountain depressions framing alpine folded structures.

In the USSR, these include the fields of the Pre-Carpathian oil and gas region, the North Caucasian-Mangyshlak oil and gas province, the South Caspian oil and gas province, and the Ferghana oil and gas region. Significant oil and gas reserves are concentrated in oil and gas basins: Great Britain (North Sea oil and gas region), Iraq (Kirkuk field), Iran (Gechsaran, Marun, Ahvaz, etc.), USA (California oil and gas basins), Venezuela (Maracaib oil and gas basin), Egypt and Libya (Sahara-Libyan oil and gas basin), Southeast Asia.

About 15% of coal reserves (mainly brown) are associated with the deposits of the Cenozoic era. Significant reserves of brown coal of the Cenozoic era are concentrated in Europe (CCCP - Transcarpathia, Carpathians, Transnistria, Dnieper coal basin; East Germany, Germany, Romania, Bulgaria, Italy, Spain), in Asia (CCCP - South Urals, Caucasus, Lena coal basin, island Sakhalin, Kamchatka, etc.; Turkey - Anatolian lignite basin; Afghanistan, India, Nepal, countries of the Indochinese Peninsula, China, Korea, Japan, Indonesia), North America (Canada - Alberta and Saskatchewan basins; USA - Green River, Mississippi, Texas), in South America (Colombia - Antioquia basins, etc.; Bolivia, Argentina, Brazil - Alta Amazonas basins).

In Australia (Victoria), the coal-bearing Paleogene is characterized by coal accumulation unique for the entire globe - the total thickness of adjacent seams is 100-165 m, and at their confluence 310-340 m (Latrobe Valley basin).

Sedimentary strata of the Cenozoic also contain large deposits of oolitic iron ores (Kerch iron ore basin), manganese ores (Chiatursky deposit, Nikopol manganese ore basin), rock and potassium salts in the CCCP (Carpathian potassium-bearing basin), Italy (Sicily), France (Alsace), Romania , Iran, Israel, Jordan and other countries.

Large reserves of bauxites (Mediterranean bauxite-bearing province), phosphorites (Arabian-African phosphorite-bearing province), diatomites, and various non-metallic building materials are associated with the Cenozoic strata.

Page navigation: Paleogene and Neogene periods organic world The structure of the earth's crust and paleogeography at the beginning of the era Quaternary period Quaternary glaciations State Institution of Education "Gymnasium of Chechersk" Abstract Cenozoic era

Essay on the Cenozoic era. Geological history of the earth in the Cenozoic era Geological history of the earth in the Cenozoic era Cenozoic era is divided into three periods: Paleogene, Neogene and Quaternary. The geological history of the Quaternary period has distinctive features inherent only to it, therefore it is considered separately. Paleogene and Neogene periods For a long time, the Paleogene and Neogene periods were united under a single name - the Tertiary period. Starting from 1960 they are considered as separate periods. The deposits of these periods constitute the corresponding systems, which have their own names. Three divisions are distinguished within the Paleogene: Paleocene, Eocene and Oligocene; within the Neogene - two: Miocene and Pliocene. These departments correspond to epochs with the same names. organic world The organic world of the Paleogene and Neogene periods differs significantly from the Mesozoic. Extinct or decayed Mesozoic animals and plants were replaced by new ones - Cenozoic. New families and genera of bivalves and gastropods, bony fishes and mammals begin to develop in the seas; on land - mammals and birds. Among terrestrial plants, the rapid development of angiosperms continues. The structure of the earth's crust and paleogeography at the beginning of the era At the beginning of the Cenozoic era, the structure of the earth's crust was quite complex and in many ways close to modern. Along with the ancient platforms, there were young ones that occupied vast areas inside geosynclinal folded belts. The geosynclinal regime has been preserved in large areas of the Mediterranean and Pacific belts. Compared with the beginning of the Mesozoic era, the areas of geosynclinal regions were greatly reduced in the Pacific belt, where by the beginning of the Cenozoic vast Mesozoic mountainous folded regions arose. There were all oceanic depressions, the outlines of which were somewhat different from modern ones. In the northern hemisphere, there were two huge platform arrays - Eurasia and North America, which consisted of ancient and young platforms. They were separated by a depression in the Atlantic Ocean, but connected in the region of the modern Bering Sea. In the south, the mainland of Gondwana no longer existed as a single entity. Australia and Antarctica were separate continents, and the connection between Africa and South America continued until the middle of the Eocene era. Quaternary period The Quaternary period is very different from all earlier ones. Its main features are the following: 1. An exceptionally short duration, which is estimated differently by various researchers: from 600 thousand to 2 million years. However, the history of this short geological period is so full of geological events of exceptional importance that it has long been considered separately and is the subject of a special science - Quaternary geology. The most important event in the history of the period is the emergence and development of man, human society and its culture. The study of the stages of development of fossil man helped to develop stratigraphy and clarify the paleogeographic setting. Back in 1922, Academician A.P. Pavlov proposed to replace the outdated name "Quaternary period" (the previously existing names "primary", "secondary" and "tertiary" periods were eliminated) with a more correct one - "anthropogenic period". 3. An important feature of the period is the giant continental glaciation caused by a strong cooling of the climate. During the maximum glaciation, more than 27% of the area of ​​the continents was covered with ice, i.e., almost three times more than at present. The scope and boundaries of the Quaternary system are still the subject of debate. Although the decision on the duration of the Quaternary period of 700 thousand years remains in force, there are new convincing data in favor of lowering the boundary to the level of 1.8 - 2 million years. These data are associated primarily with new discoveries of the ancestors of the most ancient people in Africa. The division of the Quaternary system into Lower Quaternary, Middle Quaternary, Upper Quaternary and modern deposits is accepted. These four subdivisions are used without adding any names (department, stage, etc.) and are subdivided into glacial and interglacial horizons. The division of the Quaternary system in Western Europe is based on the horizons identified in the Alps. organic world The flora and fauna of the beginning of the Quaternary period differed little from the modern one. Development of life in the Cenozoic era During the period, there was a wide migration of fauna and flora in the northern hemisphere in connection with glaciations, and during the maximum glaciation, many heat-loving forms died out. The most noticeable changes have occurred among the mammals of the northern hemisphere. To the south of the glacier borders, along with deer, wolves, foxes and brown bears, cold-loving animals lived: woolly rhinoceros, mammoth, reindeer, ptarmigan. Heat-loving animals died out: giant rhinos, ancient elephants, cave lions and bears. In the south of Ukraine, in particular in the Crimea, mammoth, ptarmigan, arctic fox, white hare, and reindeer appeared. Mammoths penetrated far to the south of Europe to Spain and Italy. The most important event that distinguishes the Quaternary period from all others is the emergence and development of man. At the turn of the Neogene and Quaternary periods, the most ancient people appeared - archanthropes. Ancient people - paleoanthropes, which include Neanderthals, were the predecessors of modern people. They lived in caves, widely used not only stone, but also bone tools. Paleoanthropes appeared in the Middle Quaternary. New people - neoanthropes - appeared in the post-glacial period, their representatives were first Cro-Magnons, and then modern man appeared. All new people are descended from the same ancestor. All races of modern man are biologically equivalent. Further changes that a person underwent depended on social factors. Quaternary glaciations Extensive glaciation has engulfed the northern hemisphere since the beginning of the Quaternary. A thick layer of ice (in some places up to 2 km thick) covered the Baltic and Canadian shields, and from here the ice sheets descended to the south. To the south of the area of ​​continuous glaciation, there were regions of mountain glaciation. When studying glacial deposits, it turned out that the Quaternary glaciation was a very complex phenomenon in the history of the Earth. Epochs of glaciation alternated with interglacial epochs of warming. The glacier either advanced or retreated far to the north; sometimes glaciers may have disappeared almost completely. Most researchers believe that there were at least three Quaternary ice ages in the northern hemisphere. The glaciation of Europe has been well studied; its centers were the Scandinavian mountains and the Alps. Moraines of three glaciations have been traced on the East European Plain: Early Quaternary - Oka, Middle Quaternary - Dnieper, and Late Quaternary - Valdai. During the maximum glaciation, there were two large glacial tongues that reached the latitudes of Dnepropetrovsk and Volgograd. In the west, this glacier covered the British Isles and descended south of London, Berlin and Warsaw. In the east, the glacier covered the Timan Ridge and merged with another vast glacier advancing from Novaya Zemlya and the Polar Urals. The territory of Asia has undergone a smaller area of ​​glaciation than Europe. Extensive areas were covered here by mountain and underground glaciation. State Institution of Education "Gymnasium of Chechersk" abstract Cenozoic era Made by Asipenko Kristina, student of 11 "B" class Checked by Tatyana Potapenko Mikhailovna Chechersk, 2012

Cenozoic era

The Cenozoic era is the current era that began 66 million years ago, immediately after the Mesozoic era. Specifically, it originates on the border of the Cretaceous and Paleogene, when the second largest catastrophic extinction of species occurred on Earth. The Cenozoic era is significant for the development of mammals that replaced dinosaurs and other reptiles, which almost completely died out at the turn of these eras.

In the process of development of mammals, a genus of primates stood out, from which, according to Darwin's theory, humans later arose. "Cenozoic" is translated from Greek as "New Life".

Geography and climate of the Cenozoic period

During the Cenozoic era, the geographic outlines of the continents acquired the form that exists today.

The North American continent moved further and further away from the remaining Laurasian, and now the Eurasian part of the global northern continent, and the South American segment moved further and further away from the African segment of southern Gondwana. Australia and Antarctica retreated more and more to the south, while the Indian segment was more and more “squeezed out” to the north, until, finally, it joined the South Asian part of the future Eurasia, causing the rise of the Caucasian mainland, and also largely contributing to the rise from water and the rest of the current part of the European continent.

The climate of the Cenozoic era gradually became more severe.

The cooling was not absolutely sharp, but still not all groups of animal and plant species had time to get used to it. It was during the Cenozoic that the upper and southern ice caps were formed in the region of the poles, and the climatic map of the earth acquired the zonation that we have today.

It is a pronounced equatorial belt along the earth's equator, and further in order of distance to the poles - subequatorial, tropical, subtropical, temperate, and beyond the polar circles, respectively, the arctic and antarctic climatic zones.

Let's take a closer look at the periods of the Cenozoic era.

Paleogene

Throughout almost the entire Paleogene period of the Cenozoic era, the climate was warm and humid, although a constant trend towards cooling was traced throughout it.

The average temperature in the North Sea area was kept within 22-26°C. But by the end of the Paleogene, it began to get colder and sharper, and at the turn of the Neogene, the northern and southern ice caps were already formed. And if in the case of the northern sea these were separate areas of alternately formed and melting wandering ice, then in the case of Antarctica, a persistent ice sheet began to form here, which still exists today.

The average annual temperature in the region of the current polar circles has dropped to 5°C.

But until the first frosts hit the poles, renewed life both in the sea and ocean depths and on the continents flourished. Due to the extinction of dinosaurs, mammals completely populated all continental spaces.

During the first two Paleogene divisions, mammals diverged and evolved into many different forms.

Many different proboscis animals arose, indicothere (rhino), tapir and pig-like. Most of them were chained to some kind of water bodies, but many species of rodents also appeared, which also felt excellent in the depths of the continents. Some of them gave rise to the first ancestors of horses and other one and artiodactyls. The first predators (creodonts) began to appear. New species of birds arose, and vast areas of the savannas were inhabited by diatryms - a variety of flightless bird varieties.

Insects multiplied unusually.

In the seas, cephalopods and bivalve molluscs multiplied everywhere. Corals grew very strongly, new varieties of crustaceans appeared, but bony fish received the greatest flourishing.

The most widespread in the Paleogene were such plants of the Cenozoic era as tree-like ferns, various sandalwood, banana and breadfruit trees.

Closer to the equator, chestnut, laurel, oak, sequoia, araucaria, cypress, and myrtle trees grew. In the first period of the Cenozoic, dense vegetation was also widespread far beyond the polar circles. These were mostly mixed forests, but coniferous and deciduous broad-leaved plants prevailed here, the prosperity of which was absolutely no obstacle to the polar nights.

Neogene

At the initial stage of the Neogene, the climate still remained relatively warm, but a slow trend towards cooling still persisted.

The ice heaps of the northern seas began to melt more and more slowly, until the upper northern shield also began to form.

The climate, due to cooling, began to acquire an increasingly pronounced continental color. It was during this period of the Cenozoic era that the continents became most similar to modern ones. South America merged with North America, and just at that time, climatic zoning acquired similar features to modern ones.

By the end of the Neogene in the Pliocene, the second wave of sharp cooling hit the globe.

Despite the fact that the Neogene was two times shorter than the Paleogene, it was he who was marked by explosive evolution among mammals. It was placental varieties that dominated everywhere.

The main mass of mammals was divided into anchitheria, the ancestors of horse-like and hipparion, also horse-like and three-toed, but gave rise to hyenas, lions and other modern predators.

All sorts of rodents were diverse at that time of the Cenozoic era, the first distinct ostrich-like ones began to appear.

Due to the cooling and the fact that the climate began to acquire an increasingly continental color, areas of ancient steppes, savannahs and light forests expanded, where the ancestors of modern bison, giraffe-like, deer-like, pigs and other mammals grazed in large numbers, which were constantly hunted by the ancient Cenozoic predators.

It was at the end of the Neogene that the first ancestors of humanoid primates began to appear in the forests.

Despite the winters of the polar latitudes, tropical vegetation was still rampant in the equatorial belt of the earth. Broad-leaved woody plants were the most diverse. Consisting of them, as a rule, evergreen forests interspersed and bordered on savannas and shrubs of other woodlands, subsequently it was they who gave diversity to modern Mediterranean flora, namely olive, plane trees, walnuts, boxwood, southern pine and cedar.

The northern forests were also varied.

There were no evergreens here, but in the majority chestnut, sequoia and other coniferous-broad-leaved and deciduous trees grew and took root. Later, in connection with the second sharp cooling in the north, vast areas of tundra and forest-steppes were formed.

The tundras have filled all the zones with the current temperate climate, and the places where until recently tropical forests have grown luxuriantly have turned into deserts and semi-deserts.

Anthropogene (Quaternary period)

In the Anthropogenic period, unexpected warmings alternated with equally sharp cold snaps.

The boundaries of the glacial zone of the Anthropogen sometimes reached 40° northern latitudes.

Cenozoic era (Cenozoic)

Under the northern ice cap were North America, Europe up to the Alps, the Scandinavian Peninsula, the Northern Urals, Eastern Siberia.

Also, in connection with glaciation and the melting of ice caps, there was either a decline or a re-advance of the sea to land. The periods between glaciations were accompanied by marine regression and a mild climate.

At the moment, one of these intervals is taking place, which should be replaced no later than in the next 1000 years by the next stage of icing.

It will last approximately 20 thousand years, until it is again replaced by another period of warming. It is worth noting here that the alternation of intervals can occur much faster, or it can be completely disturbed due to human intervention in earthly natural processes.

It is likely that the Cenozoic era could be ended by a global ecological catastrophe similar to the one that caused the death of many species in the Permian and Cretaceous periods.

Animals of the Cenozoic era during the Anthropogenic period, together with vegetation, were pushed southward by alternately advancing ice from the north. The main role still belonged to mammals, who showed truly miracles of adaptability. With the onset of cold weather, massive woolly animals appeared, such as mammoths, megaloceros, rhinos, etc.

All kinds of bears, wolves, deer, lynxes also bred strongly. Due to alternating waves of cooling and warming, animals were forced to constantly migrate. A huge number of species died out, and did not have time to adapt to the onset of cooling.

Against the background of these processes of the Cenozoic era, humanoid primates also developed.

They increasingly improved their skills in the possession of all sorts of useful objects and tools. At some point, they began to use these tools for hunting purposes, that is, for the first time, tools of labor acquired the status of weapons.

And since then, a real threat of extermination has hung over various species of animals. And many animals, such as mammoths, giant sloths, North American horses, which were considered by primitive people to be commercial, were completely destroyed.

In the zone of alternating glaciations, the tundra and taiga regions alternated with forest-steppe, and tropical and subtropical forests were strongly pushed to the south, but despite this, most plant species survived and adapted to modern conditions.

The dominant forests between periods of icing were broad-leaved and coniferous.

At the present moment of the Cenozoic era, man reigns everywhere on the planet. He randomly interferes in all sorts of earthly and natural processes. Over the past century, a huge amount of substances have been released into the earth's atmosphere, contributing to the formation of the greenhouse effect and, as a result, faster warming.

It is worth noting that the more rapid melting of ice and the rise in the level of the world ocean contributes to the disruption of the general picture of the climatic development of the earth.

Due to future changes, undercurrents may be disrupted, and, as a result, the general planetary intra-atmospheric heat exchange, which may lead to even more massive icing of the planet following the warming that has begun at the moment.

It is becoming more and more clear that how long the Cenozoic era will be, and how it will eventually end, will now depend not on natural and other natural forces, but on the depth and arrogance of human intervention in global natural processes.

To the table of the Phanerozoic eon

Cenozoic (Cenozoic era) - the latest era in the geological history of the Earth with a length of 65.5 million years, starting with the great extinction of species at the end of the Cretaceous period. The Cenozoic era is still going on.

Cenozoic era

Translated from Greek as "new life" (καινός = new + ζωή = life). The Cenozoic is divided into the Paleogene, Neogene and Quaternary period (anthropogen).

Historically, the Cenozoic was divided into periods - Tertiary (from Paleocene to Pliocene) and Quaternary (Pleistocene and Holocene), although most geologists no longer recognize such a division.

period 3: Paleogene, Neogene and Quaternary

Cenozoic (Cenozoic era) - the latest era in the geological history of the Earth with a length of 65.5 million years, starting with the great extinction of species at the end of the Cretaceous period.

The Cenozoic era is still going on. Translated from Greek as "new life" (καινός = new + ζωή = life). The Cenozoic is divided into the Paleogene, Neogene and Quaternary period (anthropogen). Historically, the Cenozoic was subdivided into periods - TERTIARY (FROM PALEOCENE TO PLIOCEN) and QUARTER (PLEISTOCENE AND HOLOCENE), although most geologists no longer recognize such a division.

http://ru.wikipedia.org/wiki/Cenozoic_era

The Cenozoic era is subdivided into the Paleogene (67 - 25 million years), Neogene (25 - 1 million years).

The Cenozoic era is divided into three periods: Paleogene (lower tertiary), Neogene (higher tertiary), Anthropogen (quaternary)

Cenozoic era The last stage in the development of life on Earth is known as the Cenozoic era. It lasted about 65 million years.

years and is of fundamental importance from our point of view, since it was at this time that primates developed from insectivores, from which man descends. At the beginning of the Cenozoic, the processes of Alpine folding reach their climax; in subsequent epochs, the earth's surface gradually acquires its modern outlines.

Geologists divide the Cenozoic into two periods: Tertiary and Quaternary. Of these, the first is much longer than the second, but the second - the Quaternary - has a number of unique features; this is the time of the ice ages and the final formation of the modern face of the Earth. The development of life in the Cenozoic era reached its peak in the history of the Earth. This is especially true for marine, flying and terrestrial species.

From a geological point of view, it was during this period that our planet acquired its modern appearance. Thus, New Guinea and Australia are now independent, although they were previously annexed to Gondwana.

These two territories have shifted closer to Asia. Antarctica, as it has become in its place, and remains on it to this day. The territories of North and South America were connected, but nevertheless today they are divided into two separate continents.

Paleogene, Neogene and Quaternary

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Currently, the Cenozoic era continues on Earth. This stage of the development of our planet is relatively short when compared with the previous ones, for example, the Proterozoic or Archean. While it is only 65.5 million years.

The geological processes that took place during the Cenozoic shaped the modern appearance of the oceans and continents. Gradually, the climate changed and, as a result, the flora in one or another part of the planet. The previous era - the Mesozoic - ended with the so-called Cretaceous catastrophe, which led to the extinction of many animal species. The beginning of a new era was marked by the fact that the empty ecological niches began to be filled again. The development of life in the Cenozoic era took place rapidly both on land and in water and in the air. The dominant position was occupied by mammals. Finally, human ancestors appeared. People turned out to be very "promising" creatures: despite repeated climate changes, they not only survived, but also evolved, settling all over the planet. Over time, human activity has become another factor in the transformation of the Earth.

Cenozoic era: periods

Previously, the Cenozoic (“era of new life”) was usually divided into two main periods: Tertiary and Quaternary. Now there is another classification. The very first stage of the Cenozoic is the Paleogene ("ancient formation"). It began about 65.5 million years ago and lasted 42 million years. The Paleogene is divided into three sub-periods (Paleocene, Eocene and Oligocene).

The next stage is the Neogene ("new formation"). This epoch began 23 million years ago, and its duration was approximately 21 million years. The Neogene period is divided into Miocene and Pliocene. It is important to note that the emergence of human ancestors dates back to the end of the Pliocene (although at that time they did not even resemble modern people). Somewhere 2-1.8 million years ago, the Anthropogenic, or Quaternary period began. It continues to this day. Throughout the Anthropogen, human development took place (and is happening). The sub-periods of this stage are the Pleistocene (epoch of glaciation) and Holocene (post-glacial epoch).

Climatic conditions of the Paleogene

The long period of the Paleogene opens the Cenozoic era. The climate of the Paleocene and Eocene was mild. At the equator, the average temperature reached 28 °C. In the North Sea area, the temperature was not much lower (22-26 °C).

On the territory of Svalbard and Greenland, evidence was found that plants characteristic of modern subtropics felt quite comfortable there. Traces of subtropical vegetation have also been found in Antarctica. There were no glaciers or icebergs in the Eocene yet. There were areas on Earth that did not lack moisture, regions with a variable humid climate and arid regions.

During the Oligocene period, it became sharply colder. At the poles, the average temperature dropped to 5°C. The formation of glaciers began, which later formed the Antarctic Ice Sheet.

Paleogene flora

The Cenozoic era is the time of the widespread domination of angiosperms and gymnosperms (conifers). The latter grew only in high latitudes. The equator was dominated by rainforests, which were based on palm trees, ficuses and various representatives of sandalwood. The farther from the sea, the drier the climate became: in the depths of the continents savannahs and woodlands spread.

In the middle latitudes, moisture-loving tropical and temperate plants (tree ferns, breadfruit, sandalwood, banana trees) were common. Closer to high latitudes, the species composition became completely different. These places are characterized by typical subtropical flora: myrtle, chestnut, laurel, cypress, oak, thuja, sequoia, araucaria. Plant life in the Cenozoic era (in particular, in the Paleogene era) flourished even beyond the Arctic Circle: in the Arctic, Northern Europe and America, the predominance of coniferous-broad-leaved deciduous forests was noted. But there were also subtropical plants listed above. The polar night was not an obstacle to their growth and development.

Paleogene fauna

The Cenozoic era provided the fauna with a unique chance. The animal world has changed dramatically: the dinosaurs were replaced by primitive small mammals that live mainly in forests and swamps. There are fewer reptiles and amphibians. Various proboscis animals predominated, including indicotheres (similar to rhinoceroses), tapir and pig-like animals.

As a rule, many of them were adapted to spend part of the time in the water. During the Paleogene period, the ancestors of horses, various rodents, and later predators (creodonts) also appear. Toothless birds nest on the tops of trees, predatory diatryms live in the savannas - birds that cannot fly.

Great variety of insects. As for the marine fauna, the flowering of cephalopods and bivalves, corals begins; primitive crayfish, cetaceans appear. The ocean at this time belongs to bony fish.

Neogene climate

The Cenozoic era continues. The climate in the Neogene era remains relatively warm and rather humid. But the cooling, which began in the Oligocene, makes its own adjustments: the glaciers no longer melt, the humidity drops, and the continental climate intensifies. By the end of the Neogene, the zoning approached modern (the same can be said about the outlines of the oceans and continents, as well as about the topography of the earth's surface). The Pliocene marked the beginning of another cold snap.

Neogene, Cenozoic era: plants

At the equator and in the tropical zones, either savannahs or moist forests still prevail. The temperate and high latitudes could boast of the greatest diversity of flora: deciduous forests, mostly evergreen, were widespread here. As the air drier, new species appeared, from which the modern flora of the Mediterranean gradually developed (olive, plane trees, walnut, boxwood, southern pine and cedar). In the north, evergreens no longer survived. On the other hand, coniferous-deciduous forests showed a wealth of species - from sequoia to chestnut. At the end of the Neogene, such landscape forms as taiga, tundra and forest-steppe appeared. Again, this was due to the cold. North America and Northern Eurasia became taiga regions. In temperate latitudes with an arid climate, steppes were formed. Where there used to be savannahs, semi-deserts and deserts arose.

Neogene fauna

It would seem that the Cenozoic era is not so long (in comparison with others): flora and fauna, however, have changed a lot since the beginning of the Paleogene. Placentals became the dominant mammals. At first, the anchitherian and then the hipparion fauna developed. Both are named after characteristic representatives. Anchiterium is the ancestor of the horse, a small animal with three fingers on each limb. Hipparion is, in fact, a horse, but still three-toed. There is no need to think that only relatives of horses and simply ungulates (deer, giraffes, camels, pigs) belonged to the indicated faunas. In fact, among their representatives were predators (hyenas, lions), and rodents, and even ostriches: life in the Cenozoic era was fantastically diverse.

The spread of these animals was facilitated by an increase in the area of ​​savannahs and steppes.

At the end of the Neogene, human ancestors appeared in the forests.

Anthropogenic climate

This period is characterized by alternation of glaciations and warmings. When the glaciers advanced, their lower boundaries reached 40 degrees north latitude. The largest glaciers of that time were concentrated in Scandinavia, the Alps, North America, Eastern Siberia, the Subpolar and Northern Urals.

In parallel with the glaciations, the sea attacked the land, although not as powerful as in the Paleogene. Interglacial periods were characterized by a mild climate and regression (drying of the seas). Now the next interglacial period is underway, which should end no later than in 1000 years. After it, another glaciation will occur, which will last about 20 thousand years. But it is not known whether this will actually happen, since human intervention in natural processes has provoked climate warming. It is time to think whether the Cenozoic era will end in a global ecological catastrophe?

Flora and fauna of Anthropogen

The onset of glaciers forced heat-loving plants to shift south. True, mountain ranges interfered with this. As a result, many species have not survived to this day. During the glaciations, there were three main types of landscapes: taiga, tundra and forest-steppe with their characteristic plants. Tropical and subtropical belts were greatly narrowed and shifted, but still remained. In the interglacial periods, broad-leaved forests dominated the Earth.

As for the fauna, the supremacy still belonged (and belongs) to mammals. Massive, woolly animals (mammoths, woolly rhinos, megaloceros) have become the hallmark of the ice ages. Along with them there were bears, wolves, deer, lynxes. All animals as a result of cooling and warming were forced to migrate. The primitive and the unadapted were dying out.

Primates also continued their development. The improvement of the hunting skills of human ancestors can explain the extinction of a number of game animals: giant sloths, horses of North America, mammoths.

Results

It is not known when the Cenozoic era, the periods of which we examined above, will end. Sixty-five million years by the standards of the universe is quite a bit. However, during this time, continents, oceans and mountain ranges managed to form. Many species of plants and animals have died out or evolved under the pressure of circumstances. Mammals have taken the place of dinosaurs. And the most promising of the mammals turned out to be man, and the last period of the Cenozoic - the anthropogen - is associated mainly with the activities of people. It is possible that it depends on us how and when the Cenozoic era will end - the most dynamic and shortest of the earth's eras.

Quaternary (Anthropogenic)

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Quaternary (Anthropogenic) originates 2.6 million liters. n. and continues to this day. During this time period, three main things happened:

• the planet entered a new ice age, during which sharp cooling alternated with warming;
• the continents took their final current outlines, a modern relief was formed;
• a reasonable man appeared on the planet.

Subsections of the anthropogen, geological changes, climate

Almost the entire length of the Anthropogen is occupied by the Pleistocene department, which, according to international standards of stratigraphy, is usually divided into the Gelaz, Calabrian, Middle and Upper stages, and the Holocene, which originates a little more than 11 thousand years ago. n. and continues to this day.

Basically, the continents in their present appearance were formed long before the beginning of the Quaternary period, but it was during this period of time that many young mountain ranges acquired their present form. The coastline of the continents took on its current shape, and due to the alternately advancing and retreating glaciers, the extreme northern continental archipelagos, such as the Canadian, Svalbard, Iceland, Novaya Zemlya, etc., were formed. 100 meters.

Retreating, the giant Anthropogene glaciers left behind a trail of deep moraines. During the periods of maximum glaciation, the total area of ​​glaciers exceeded the current one by more than three times. Thus, it can be said that large parts of North America, Europe and present-day Russia were buried under ice layers.

It is worth saying that the current ice age in the history of the earth is not the first. For several billion years, the first historical ice age lasted, originating 1.5 billion years ago. n. in the early Proterozoic. After prolonged heat, a 270-million-year cooling hit the planet again. It happened 900 million liters. n. in the Late Proterozoic. Then another significant icing took place, which lasted for 230 million years. n. in the Paleozoic (460 - 230 million years ago). And now the planet is experiencing another cooling, the beginning of which is usually attributed to 65 million years ago. It gradually gained strength and it is not yet known whether the Cenozoic global ice age has survived its apogee of low temperatures.

Rice. 1 - Anthropogene (Quaternary period)

During the current ice age, a great many warming and cooling events have occurred, and according to scientists, in this period of time, the Earth is experiencing a warming stage. According to their calculations, the last cooling was replaced by warming from 15 to 10 thousand years ago. During the strongest Pleistocene glaciations, the line of glaciers descended from 1500 to 1700 km south of the current line.

Anthropogenic climate was subject to frequent fluctuations. In those times when glaciers advanced, the climatic zones narrowed and retreated closer to the equator, and, conversely, during periods of warming and massive melting of glaciers, the temperate zone extended to the northernmost continental margins and, as a result, the rest of the climatic zones also expanded.

Quaternary sedimentation

On the Quaternary sedimentation left its mark on the rapid variability of lithological components and genesis. Sediments in the Quaternary period accumulated everywhere, but due to the complex structure of the sections, it is rather difficult to distinguish them. The rate of accumulation of anthropogenic deposits was too high, but due to the lack of pressure, the deposits still have a rather loose structure. The conditions of occurrence are also atypical. If sequential stratification is considered typical, then the term “leaning” against lower and older deposits is more appropriate here. Continental zones are more typical of continental deposits, such as glacial, water and eolian. For the seas, volcanic, organogenic, trigenic and chemogenic sediments are more typical.

Quaternary Animals

Among the invertebrates in the Pleistocene of the Quaternary period, all kinds of snails and other land molluscs developed unusually. The underwater world was in many respects similar to the previous Neogene. The world of insects also began to acquire similarities with the present, but the world of mammals was subject to the most interesting metamorphoses.

Since the beginning of the Anthropogen, elephant-like varieties have become widespread. At the beginning of the Pleistocene, they inhabited vast territories of the Eurasian continent. Some of their species reached a height of 4 m at the withers. Increasingly, species of elephants covered with long hair began to appear in the northern parts of the continents. By the middle of the Pleistocene, mammoths were already the most common and most common representatives of the northern tundra latitudes. Having migrated over the ice of the Bering Strait in one of the next periods of cooling to Alaska, mammoths also bred throughout the entire North American continent. It is believed that mammoths originated from trogontherian elephants, on the border of the Neogene and Pleistocene, widespread in the steppe latitudes.

In the southern latitudes of both North America and Eurasia, other elephant species were widely distributed. Among others, giant mastodons stood out. Tellingly, these representatives of elephants on the territory of the Eurasian continent completely died out by the end of the Pleistocene, while on the American continent they successfully survived all stages of the Earth's glaciation.

Rhinos also stood out among other giants of the Quaternary period. Their woolly varieties inhabited the tundra-steppes of the early and middle anthropogen along with mammoths.

were numerous quaternary animals from the category of horses. Tellingly, the ancient descendant of horses was from the North American part of Pangea. After the split of the mainland and the cessation of animal migration between the American and Eurasian segments, equines completely died out on the North American mainland, and only those species that managed to migrate to the Eurasian continent evolved. Subsequently, they reappeared in America only thanks to man.

Along with horses, which inhabited the European-Asian savannahs in large numbers, hippos were also active during periods of anthropogenic warming. In large numbers, their remains were found on the islands of Great Britain. Various artiodactyl varieties of deer were also numerous, the most common of which was the Irish bighorn. In the span of his horns sometimes reached up to 3 meters.

In the Quaternary period, the first goats appeared, among which the mountain varieties were the most numerous. The first tours appeared, the progenitors of domestic bulls. Huge pastures of all kinds of roe deer, bison, musk oxen grazed on the steppe expanses; to the south, the first varieties of camels appeared.

Also, along with herbivores, a detachment of predators also developed. For example, a variety of bears could be found both in the snowy areas of the northern latitudes and in the tundra forests. Many of them also lived to the south, descending to the steppe zone of temperate latitudes. Many of them, who inhabited the caves of the glacial Pleistocene, could not survive in the cold conditions of the Arctic at that time, but, one way or another, many of their varieties have successfully survived to this day.

Numerous were in the northern regions such deadly anthropogen predators(Fig. 2), like saber-toothed tigers, and cave lions, which were much more massive and larger and more dangerous than their modern relatives. Often, these dangerous predators became the themes of the art of ancient rock artists.

Rice. 2 - Predators of the Quaternary period

Also among others fauna of the Quaternary period other diverse species were also represented, such as hyenas, wolves, foxes, raccoons, wolverines, etc. There were also a large number of rodents in the form of lemmings, ground squirrels, beavers of various varieties, up to the giant Trognotherium cuvieri.

The kingdom of birds was also very diverse, among which both flying and flightless varieties stood out.

By the end of the Pleistocene, many varieties of mammals that previously inhabited the tundra-steppes died out. To such mammals of the Quaternary period can be attributed:

• on the territory of South America - the armadillo teticurus, the giant saber-toothed cat smilodon, hoofed macrouchenia, sloths megatherium, etc .;
• on the territory of North America - the last representatives of tyrant birds or fororakos - Waller's titanis, many representatives of ungulates, such as American horses, camels, steppe peccaries, deer, bulls and pronghorn antelopes;
• on the territory of the tundra-steppes of Eurasia, Alaska and Canada - mammoths, woolly rhinos, bighorn deer, cave lions and bears.

In the Holocene, such flightless bird species as dodos and epiornis died out, and the giant seal-like Stellarian cow disappeared from the depths of the sea.

Anthropogenic plants

The climate of the Pleistocene, with constant alternations of glacial and interglacial intervals, had an adverse effect on anthropogenic plants growing in northern continental latitudes. With the onset of cold snaps, the climatic life barrier was sometimes forced to shift to the line of 40 ° N. sh., and in some places even lower. Over the past two million years, vegetation has been forced to alternately retreat to the above latitudes, then grow again up to the shores of the Arctic Ocean. As a result of a cold snap, many heat-loving plants that had been in their genus since the Triassic were doomed to extinction. With the disappearance of many varieties of grasses, shrubs and other plants, the extinction of many species of Anthropogene animals is also associated. Therefore, it is not worth placing all the blame for the disappearance of such species as the same mammoth entirely on the shoulders of ancient people.

In the glacial epochs of the Quaternary, to the south of the tip of the glaciers, three belts of vegetation began to exist - tundra, steppe and taiga. The tundra was covered with mosses and lichens; to the south, dwarf birches, polar willows, and alpine silverworts began to grow. The tundra was also characterized by azaleas, saxifers, saplings, etc. The steppe zone was full of all kinds of herbs and low shrubs. But closer to the south, in some places, there were also woodlands, consisting of willow and birch forests. The taiga forests of the Anthropogen were mainly composed of pines and spruces, which mixed closer to the south with birches, aspens and other deciduous deciduous trees.

During the interglacial epochs, the composition of the flora of the Quaternary period changed significantly. Pushed aside to the south by glaciers, thickets of such flowering and shrubs as lilies, rhododendrons and roses returned to their places. But little by little, towards the approach of the Holocene, the interglacial vegetation became more and more sparse due to constant forced migrations. Many walnut and yew trees, which previously formed huge forest tracts, have now become rare. In the warmest interglacial periods, the Central European territory was completely covered with broad-leaved forests consisting of oak, beeches, lindens, maples, hornbeam, ash, hawthorn and some walnuts.

In places where interglacial plant migrations were not impeded by mountain ranges and seas, specimens of the ancient vegetation of the Triassic period were still preserved. For example, in North America, where migrations were not impeded, as in the case of the mountain ranges of Europe, as well as the Mediterranean Sea, magnolias, lilyodendrons, taxodiums and Weymouth pines (Pinus strobus) still grow in some areas.

Far to the south, the vegetation did not undergo any definite differences from the previous Neogene period.

The ancestors of today's people appeared at the end of the Neogene 5 million years ago. n. They were descended from one of the branches of hominids australopithecines, and their remains were found only on the African continent, which gives reason to say that the ancestral home of all mankind is Africa. The warm climate and rough vegetation of these places contributed to the increasing evolutionary development of Australopithecus, until, finally, the first of them at the turn of the Quaternary period mastered primitive types of tools. The next branch of the development of a skilled man (Homo habilis) was archanthropes, the direct ancestors of modern people, who in the second half of the Pleistocene actively began to settle on all continents. One of the most famous offshoots of the archanthropes are pithecanthropes, the remains of which archaeologists find almost everywhere. In the region of 400-350 thousand liters. n. the first transitional forms of ancient people from archanthropes to paleoanthropes began to appear, which include Neanderthals, which subsequently died out, unable to withstand competition from Cro-Magnons. Although, according to some scientists, these two species simply mixed with each other. Further, paleoanthropes developed into neoanthropes, who already differed little from modern people. It happened in the region of 40-35 thousand liters. n. In particular, the Cro-Magnons were the first representatives of the neoanthropes.

Rice. 3 - The formation of man during the Anthropogen period

Gradually, people mastered more and more complex tools. 13 thousand liters n. bow and arrows appeared, after that people learned how to burn pots and acquired the first items made of ceramics. They started farming and cattle breeding. 5 thousand liters n. the first products made of bronze and copper appeared, and somewhere between 3 and 2.5 thousand years ago. n. the age of iron began.

Since that time, the improvement of tools has gone much faster, in the Middle Ages, the development of science and technology began, which have now reached a level that allowed people to develop such sciences as genetics and genetic engineering.

Minerals of the Quaternary period

Quaternary deposits contain many different minerals. Alluvial deposits within mountain ranges and zones of tectonic activity are rich in gold, diamonds, cassiterite, ilmenite, etc. Deposits that form in humid tropical zones and are weathering crusts contain reserves of bauxite, manganese and nickel, as well as such non-metallic building materials as loams, clays, gravel, sandstone, limestone. There are also numerous accumulations of brown coal, deposits of natural gas, diatomites, salts, bean iron ores, sapropels, etc. Also in volcanic areas, deposits of sulfur and manganese can be found. Peat sedimentary accumulations are numerous and ubiquitous.

The layers of the Quaternary period contain a huge amount of fresh groundwater, some thermal springs originate in their depths, and various therapeutic muds formed in the Anthropogen are also intensively used in our time.

The time limits of the Cenozoic era are not difficult to determine: this is a period of geological time, originating from the Cretaceous-Paleogene extinction event that destroyed the dinosaurs 66 million years ago and continuing up to the present day. Informally, the Cenozoic era is often referred to as the "age of mammals" because it was only after the dinosaurs became extinct that mammals were able to fill the vacated ecological niches and become the dominant land life on the planet.

However, this characterization is somewhat unfair, since not only mammals flourished during the Cenozoic, but also reptiles, birds, fish, and even invertebrates!

Somewhat confusingly, the Cenozoic era is divided into various "periods" and "eras", and scientists do not always use the same terminology when describing their research or discoveries. (This situation contrasts sharply with the preceding Mesozoic era, which is more or less neatly divided into , and periods.)

In the case of the Cenozoic era, the following main periods and eras are distinguished:

Paleogene period

(66-23 million years ago) was the time when mammals began their dominance. The Paleogene consists of three distinct epochs:

Paleocene epoch

The Paleocene epoch, or Paleocene (66-56 million years ago) was quite calm from an evolutionary point of view.

During this time, the tiny mammalian survivors tasted their newfound freedom for the first time and began cautiously exploring new ecological niches. During the Paleocene era, large snakes, crocodiles and turtles were abundant.

Eocene epoch

The Eocene epoch, or Eocene (56-34 million years ago) was the longest epoch of the Cenozoic era.

In the Eocene there was an enormous abundance of mammalian species; at this time, the first four-legged ungulates appeared on the planet, as well as the first recognizable primates.

Oligocene epoch

The Oligocene epoch, or Oligocene (34-23 million years ago), differs in climate change from the previous Eocene, which opened up even more ecological niches for mammals. This was the era when some mammals (and even some birds) began to develop to gigantic sizes.

Neogene period

(23-2.6 million years ago) was marked by the ongoing evolution of mammals and other life forms, many of which were huge. The Neogene consists of two epochs:

Miocene epoch

The Miocene epoch, or Miocene (23-5 million years ago) occupies the lion's share of the Neogene. Most of the mammals, birds and other animals began to take on an appearance close to modern, although they were much larger.

Pliocene Epoch

The Pliocene epoch, or Pliocene (5-2.6 million years ago), is often confused with the subsequent Pleistocene. This was the time when many mammals migrated (often via land bridges) to the territories they continue to inhabit today. Horses, primates, and other animal species continued to evolve.

Quaternary period

(2.6 million years ago - to the present) is still the shortest of all the geological periods of the Earth. The Anthropogene consists of two even shorter epochs:

Pleistocene Epoch

The Pleistocene epoch, or Pleistocene (2.6 million - 12 thousand years ago), is characterized by large megafauna mammals, such as woolly and which died out at the end of the last ice age (partly due to climate change and predation by the earliest people).

Holocene epoch

The Holocene epoch, or Holocene (12,000 years ago - to the present day) represents almost the entire modern history of mankind. Unfortunately, this is also an era when many mammals and other life forms died out due to environmental changes caused by negative anthropogenic impacts from human activities.

This era is subdivided into the Paleogene, Neogene and Anthropogenic periods. There was a division of the Cenozoic era into two periods - Tertiary and Quaternary, of which the Tertiary united the Paleogene and Neogene, and the Quaternary corresponded to the Anthropogenic period.

In the Paleogene, and especially in the Neogene, a new powerful folding and mountain building took place, which was called the Alpine era. Several phases of folding are noted, of which the most stressful occur in the Neogene. During this era, the largest mountainous countries were formed (Atlas, the Andalusian Mountains, the Pyrenees, the Apennines, the Alps, the Carpathians, the mountains of the Balkan Peninsula, the mountains of Asia Minor, the Caucasus, the mountains of Iran, the Pamirs, the Himalayas, the mountains of Southeast Asia and the Malay Archipelago, the mountains of Kamchatka and Sakhalin, continued to form Kor-

dealers and the Andes of North and South America). In addition, in a number of more ancient mountainous countries, already severely destroyed by this time by denudation, new powerful faults arose, uplifts and subsidence occurred (central Europe, Tien Shan, Altai, etc.). Simultaneously with mountain building, which took place mainly in the northern hemisphere, Australia separated from Asia in the southern hemisphere, the Red Sea depression formed, deep faults cut through East Africa, large faults spread to the northern hemisphere, where the formation of the northern part of the Atlantic Ocean took place, the depression of which acquired outlines close to modern. The areas of manifestation of volcanism were close to those existing at the present time.

Mountain building, which took place along the outskirts of previously formed platforms, involved these platforms in its movement, in connection with which the outlines of the seas changed greatly. On the territory of the USSR, powerful transgressions swept the south of the Russian Plain, Central Asia, and Western Siberia.

The climate in the Paleogene (before the manifestation of intense mountain building) is warm, humid without sharp temperature fluctuations over vast areas. In the Neogene, the climate becomes more continental, with sharply defined climatic provinces, but generally remains warmer than today.

The flora of the Paleogene and Neogene, which was dominated by angiosperms, is very similar to the vegetation of modern tropical and subtropical latitudes, and these plant species spread in the Paleogene up to the northern islands of Europe and North America. In the Neogene, the area of ​​moisture-loving forests was greatly reduced, and drought-resistant flora and steppe spaces appeared in temperate latitudes.

The fauna of the Paleogene and Neogene is rich and diverse. On land, various mammals and birds dominate. Marine fauna becomes very close to modern; marine mammals appear. In the Neogene, with the appearance of steppe spaces, ungulates (antelopes, horses, etc.) quickly begin to evolve. At the same time, the development of humanoids takes place. In the Neogene deposits of the island of Java, the remains of an ape-man (pithecanthropus) were found, and in China - a man (sinatrop), who used stone tools and fire.

The deposits of the Paleogene and Neogene are rich in various minerals, among which deposits of oil, gas and coal are of great importance.

Climate change, which began in the Neogene, led at the beginning of the Anthropogenic (Quaternary) period to a significant cooling, as a result of which, first in the mountains, and then on the plains, powerful glaciation develops. In the Anthropogenic period, these glaciers either grew strongly or sharply reduced to approximately modern sizes. In this regard, it is customary to single out epochs of glaciation and epochs of interglacials. For Eastern European

plains, most researchers indicate four glaciations: Oka, Dnieper, Moscow and Valdai. The boundaries of the two glaciations are shown in Fig. 28.

Significant climate change has greatly affected the composition of flora and fauna. During the Anthropogenic period, polar and temperate

latitudes are inhabited by animals and plants adapted to harsh climatic conditions. Instead of the heat-loving flora of the Neogene, forests of the taiga type develop here, and later tundra flora also appears.

During this period, the duration of which is relatively short (1 000 000 years), there were no major changes in the outlines of the seas and continents. Small transgressions and regressions of the sea occurred in the coastal strip of the World Ocean in the interglacial and postglacial periods. The sizes of closed basins (Caspian Sea) changed more significantly. In this regard, deposits of marine origin in the area of ​​modern continents are very limited in distribution. Continental deposits (glacial, river, lacustrine, marsh, etc.) are more widespread.

After the intense manifestation of mountain building that occurred in the Neogene, the movements of the earth's crust in the Anthropogenic period did not stop and continue to the present, as evidenced by strong earthquakes, volcanism, uplift and subsidence of large blocks of the earth's crust occurring in the zones of Alpine folding. All these processes, together with the activity of external geological agents, affect the ancient relief of the lithosphere and are reflected in its modern relief.

On the whole, the Cenozoic era has now been marked by very important events. 1. A new thing happened - Alpine mountain building (see Fig. 27), mountain structures rose, which are currently the highest mountains of the Earth. 2. Mountainous countries that arose in the Paleozoic and Mesozoic eras. By the beginning of the Cenozoic, they were badly destroyed. In the era of Alpine folding, they experienced repeated movements, were broken by faults, raised to great heights and again turned into mountainous countries with sharp landforms. 3. There was a further reduction of geosynclines and platforms grew due to them. 4. The uplift of young mountain ranges was accompanied by the uplift of adjacent platform sections, which affected the distribution of land and sea. This was also influenced by the faults of the earth's crust, which separated the continents. 5. As a result of volcanism, vast lava plateaus and plains were formed, high volcanic mountains and highlands arose, new mineral deposits were formed in the bowels of the Earth (at present still hidden under a thick sedimentary cover). 6. The climate has changed a lot. From warm and monotonous, characteristic of the beginning of the Cenozoic era, it became sharp, with a large number of climatic zones and provinces. 7. Large glaciers arose, repeatedly spreading over vast expanses of land. 8. The animal and plant world have taken on their modern look. 9. A man appeared and began his activity.

Finishing a brief description of the geological history of the Earth, its complexity should be noted. Without touching on the development of the organic world, let us turn to the development of the lithosphere and its relief, taking the territory of the USSR as an example.

By the beginning of the Paleozoic era, two rigid masses of the earth's crust were located within this territory: the Russian and Siberian platforms with their most rigid parts, shields. As a result of repeated epochs of folding and mountain building, the pliable zones (geosynclinal belts) located between these platforms, filled with thick strata of sediments, were crushed into folds and turned into mountain structures, attached to the outskirts of the platforms or connecting the platforms to each other. This process is clearly traced in the history of the Ural-Tyan-Shan geosyncline. At the beginning of the Paleozoic era, thick layers of sediments accumulated near the southern margin of the Siberian platform.

and mountain building took place (the Caledonian era of folding), as a result of which mountains arose in the area of ​​\u200b\u200bthe modern Baikal region, in the Sayans, in Altai. For the rest of the geosynclinal belt, this epoch was expressed as a preliminary one, since the mountains that arose here quickly collapsed and were again largely flooded by the sea (Kazakhstan, Western Altai, etc.). On the outskirts of the mountainous countries that had arisen, in actively sagging sections of the geosyncline that had not yet closed, the accumulation of new sediment layers continued, culminating in a new folding and mountain building that developed at the end of the Paleozoic era (the Hercynian epoch). Vast mountainous countries were formed: the Urals, Tien Shan, the Kazakh mountainous country and mountains in the place of a significant part of the West Siberian lowland. The subsequent history of these mountainous countries is different. Most of them were destroyed by denudation agents, experienced subsidence and are currently under a thick layer of Meso-Cenozoic deposits that make up the sedimentary cover of the West Siberian Lowland. The marginal western part, which has experienced minor uplifts as a result of recent movements, stretches along the edge of the Russian Platform in the form of the low Ural Mountains. Significant expanses of the ancient mountainous country, heavily destroyed by denudation agents, which did not experience significant uplifts and subsidences, are observed in Central Kazakhstan. The southernmost parts of the ancient mountainous country, once already destroyed to the state of small hills and later under the influence of powerful mountain-building movements of the Alpine folding era, were broken into blocks and raised to a great height, which led to the formation of the mountainous terrain of the Tien Shan.

The above example indicates that the earth's crust, developing according to the general plan from a pliable geosyncline, through a mountain structure to a rigid platform with a flat relief. achieves this in different parts in different ways. These paths are often clearly reflected in the relief and can explain its diversity.

GEOLOGICAL MAP AND PROFILES General information about geological maps

Among the maps reflecting natural phenomena, one of the first places is occupied by geological maps created as a result of geological surveys. A geological map gives an idea of ​​the geological structure of a section of the earth's surface and is essentially a vertical projection of bedrock outcrops plotted on a topographic base of a certain scale. Such a map is called a geological map proper, since its construction is based on the principle of separating rock strata of different ages.

The geological map is the basis for all other maps compiled in the course of complex geological mapping. The latter provides for the compilation of a series of maps that highlight certain aspects of the geological structure of the region. The noted complex of maps includes: lithological-petrographic, structural-tectonic, hydrogeological, facies-paleogeographic, geomorphological, engineering-geological, various geophysical, minerals.

Depending on the scale, all geological maps are divided into overview, regional medium-scale and large-scale.

Overview maps highlight the structure of individual continents and states. The largest scale is 1:1,000,000. The topographic base has been simplified.

Regional maps (small-scale) - display a section of the earth's surface, characterized by the unity of the geological structure (Caucasus, Urals, Donbass, etc.). Map scale from 1:1,000,000 to 1:200,000. The topographic base has been simplified.

Medium-scale - display in detail the geology of a relatively small area. Their scale is from 1:200,000 to 1:25,000. The topographic base is simplified.

Large-scale geological maps - compiled for mineral deposits. The scales are from 1:1000 to 1:500. The topographic base is often compiled on purpose.

Geological work in the field usually begins with reconnaissance routes, which make it possible to get a general idea of ​​the area and identify the features of its individual parts. After the reconnaissance, the plan of field work and research is specified, time is allocated, and the order of routes is outlined. In this case, the degree of exposure of the area is of great importance, which can be judged with a sufficient degree of reliability from aerial photographs.

The most complete are subjected to priority research - supporting outcrops (sections) or wells with continuous core sampling (rock samples obtained from wells during drilling). Intermediate outcrops, in which only parts of the main section are exposed, are studied later.

Simultaneously with the description of natural and artificial sections, the vertical and planned binding of the marking (reference) layers and horizons identified in them, which are important for mutual coordination, is carried out. Depending on the scale of the shooting, the binding can be instrumental or visual. When describing the stratigraphic sequence of layers in sections, their thickness and occurrence elements must be measured. As a result, a summary section (column) is compiled.

Comparison of sections and tracking of identified stratigraphic units over the entire area of ​​the region makes it possible to

get an idea of ​​their structure (forms of occurrence) and facies changes. Binding the outcrops of these layers to the earth's surface makes it possible to draw the contours of the age boundaries of bedrock (pre-Quaternary) rocks on a topographic map - to create a geological map.

Proper geological maps

The methodology for compiling a geological map depends on the scale of the survey, exposure, and mainly on the geological structure of the area. With horizontal, inclined and folded occurrence of layers, it is different.

Horizontal occurrence is characterized by a close value of the absolute height marks of the roof or bottom of the layer. Depending on the depth of the dissection of the mapped area, with a horizontal occurrence on the surface, either only the upper layer (with a shallow dissection) or deeper layers (with a deep dissection) will be exposed. The horizontal occurrence of the layers is easily determined by the coincidence or almost parallel arrangement of the outlets of the mapped layer and the contours of the topographic base (Fig. 29).

If the layers are removed from their original horizontal position and have acquired a slope in one direction, then their occurrence is called monoclinal (one-slope). To determine the position of monoclinal layers in space, the method of finding the lines of strike and dip of layers is used. A straight line, which is obtained by crossing a monoclinal layer with a horizontal plane, is called the strike line (Fig. 30). Perpendicular to the strike line there is a dip line directed towards the greatest slope of the layer. The determination of the occurrence elements, the orientation of the lines of strike and fall according to the cardinal points is carried out using a mountain compass.

As mentioned above, in case of a horizontal occurrence, the lines of the exits of the layers will coincide with the contour lines of the topographic map or be located parallel to them. With a vertical occurrence, the terrain will not affect the configuration of the lines of intersection of the layer by the plane, since in this case all stretch lines are projected onto the plane in one line, which will be straight with a straight vertical layer and curved with a curved vertical surface.

In addition to the above two extreme cases of images on the projection plane of horizontally and vertically lying layers, there can be countless variants of projections of obliquely lying layers, and their configuration will be directly dependent on the angle of incidence and the terrain. With a highly dissected relief and a gentle dip of the layers, the outcrop of the reservoir will have a more complex contour than with a steep bedding and weak

bohm dismemberment of the relief. The dip direction of inclined layers on geological maps is determined by their age sequence. The slope will always be towards the location of younger deposits (Fig. 31).

The folded forms of the occurrence of the layers significantly conditional / bend the pattern of the geological map. The exits of the selected age subdivisions are located in stripes, closed rounded or elliptical contours. Layers of the same age within the fold are always arranged symmetrically with respect to the central (axial) part of the fold, which does not have a paired exit. When reading geological maps depicting a folded structure, it is first necessary to determine the age relationships of the layers in order to establish the position of symmetrically located bands of ancient and young layers with respect to the central unpaired band. The position of the latter determines the presence of the axial part of the anticline or syncline. In the core of the anticline, older layers always outcrop, bordered by outcrops of layers of younger deposits. In the core of the syncline, on the contrary, younger layers lie surrounded by older ones (Fig. 32).

Tectonic disturbances on a geological map are represented by lines that break geological boundaries. The image of displacements of age boundaries in the plan and the configuration of the lines of discontinuities depend on the type of structure, the angles of incidence of the layers, the angle of inclination of the ejector, and other factors.

In the geological mapping of igneous rocks, the relationship of the latter with the enclosing strata is taken into account. Mutually

the ratios of intrusions are presented differently when studying intrusive rocks intruded into the sedimentary strata of the earth's crust and exposed as a result of denudation processes and igneous rocks formed on the earth's surface as a result of volcanic processes. On geological maps, the contour of the outcrop of igneous bodies is depicted and their age and geological composition are indicated with the help of indices.

When compiling geological maps, the established symbols of three types are used: color; indices (alphabetic and digital); dashed.

Color symbols determine the age of rocks, and when depicting outcrops of intrusions, their composition. Indices - determine the age of the distinguished units and sometimes their origin (intrusion and effusion indices). Stroke symbols can replace color symbols or, when applied to a color background, indicate the composition of rocks. Standards for color symbols for subdivision of the geochronological scale were proposed by the Russian geologist A.P. Karpinsky and approved in 1881 by the II International Geological Congress.

In the geochronological scale, two types of subdivisions are used. Some correspond to the period of time of the selected subdivision, others are thicker than the rocks formed at that time. Accordingly, an era is parallelized with a group, a period with a system, an epoch with a department, a century with a tier, and time with a zone.

Color designation standards are adopted for period systems.

Anthropogenic period, system - light gray color

Neogene » » -yellow

Paleogene » » -orange

Cretaceous » » - green

Jurassic » » -blue

Triassic » » -violet

Perm » » -brown-red

Coal » » - gray

Devon » » -brown

Silurian "" - light olive

Ordovician » » - olive dark

Cambrian » » - pink

Outcrops of Archean (AR) and Proterozoic (PR) rocks are indicated by various shades of red (large-scale maps of areas of the indicated age are colored with colors and strokes adopted for igneous rocks and formations). More subdivisions of the geochronological scale (departments, stages, etc.) are painted over with tones of the main color of the period (system), and the density of the tone weakens from ancient subdivisions to young ones.

When compiling a geological map on a scale larger than 1: 100,000, the standard color scale may not be enough. In this case, symbols are added in the form of specks, stripes and others, but in colors adopted for a given period (system).

Igneous rocks are indicated by bright colors with indices corresponding to the name of the rocks. Acid and intermediate rocks are indicated in red, alkaline in orange, basic rocks in green, and ultrabasic rocks in purple.

Effusive rocks on the maps of the old edition were indicated by different colors with indices put down in accordance with the composition of the rocks. Acid effusives were colored orange, basic ones - green. On the maps of the latest editions, effusives are painted over with a color showing their age, with the addition of indices and strokes that determine the composition of the rocks.

The system (period) index is used as the basis for the alphabetic and numerical designation of sedimentary, igneous and metamorphic rocks in the geochronological scale and on the geological map. When designating a department, a number is added to it, corresponding to the lower, middle, upper departments (epochs), or when divided into two parts - lower and upper. When subdividing a department (epoch) into tiers (centuries), letter designations are added to the department (epoch) index, consisting of the first letter of the tier name and the first consonant letter in this name. The above can be illustrated by the example of the index of the Cretaceous system (period): the index of the system (period) - (K), the indices of departments (epochs) - (K 1) and (K 2), the index of one of the tiers (ages) - Valanginian - TO 1 v. Parts

tiers are indicated in Arabic numerals, put down at the bottom right of the index - TO 1 v 1 .

On detailed geological maps at the top right, above the index of the period (system), sometimes indices are affixed indicating the facies composition of the rocks: T- marine sediments, J- lake, h- coal-bearing, f- flash *.

In addition to age groups, it often becomes necessary to single out local subdivisions that correspond to certain stages of the geological development of a given area. In this case, the rocks are divided into series, suites, subsuites, and horizons. Where possible, local divisions are linked to a generally accepted age scale. Indices of local divisions are formed from two lowercase Latin letters (the first letter of the name and the nearest consonant). Letters are written to the right of the group, system or department index. For example: J 1 bg- Lower Jurassic section, Bezhitinskaya suite.

For a division covering two adjacent departments or systems, the index is formed by connecting them with a + (plus) sign or a dash - (hyphen). The + sign is put if two neighboring subdivisions are combined, represented in their full development J + K; dash (hyphen) is used in all other cases. The J-K index indicates the presence of the contact between the Cretaceous and the Jurassic in the selected subdivision without determining their more accurate age boundaries.

On geological maps, in the case of replacing color designations with dashed ones, the latter are chosen arbitrarily. When depicting the composition of rocks, dashed symbols have a certain standard.

A geological section is an image of the sequence of stratification and the structure of the layers of the surface parts of the earth's crust in a vertical section. When constructing a section with any occurrence of layers, its horizontal scale must correspond to the scale of the map. The choice of vertical scale depends on the thickness of the layers. The thinnest layer in the chosen scale should not be less than 1 mm. Ideally, the value of the vertical scale should be equal to the horizontal scale. In this case, there will be no distortion in the angles of incidence and powers on the profile.

With inclined and folded occurrence of layers, it is necessary to take into account the direction of the profile section in relation to the strike line of inclined and folded layers; to eliminate the distortion of angles, a correction calculated according to special tables must be introduced.

With a horizontal occurrence of layers, the most complete section will be the line of which passes through the highest and lowest points of the relief. To build a section with a horizontal occurrence

* Flysch - powerful monotonous and rhythmic sedimentary strata of shallow marine sediments.

layers on the geological map, the places of intersection of geological boundaries with the profile line on the map should be transferred to the terrain profile and connect the obtained points with horizontal lines.

When constructing a geological section with an inclined occurrence of layers, it must be remembered that a section built in the direction of dip, with equivalent vertical and horizontal scales, will always have the true angle of inclination of the layers and thickness. In the case when the cut passes in the direction of strike, the layers have a horizontal position.

When constructing a profile section on a geological map that reflects the folded occurrence of layers, as well as with horizontal and inclined occurrence, first of all, a topographic profile is built on the scale adopted for vertical constructions. Outcrops of geological boundaries and dip angles on the wings of folds are applied to the topographic profile. Then the geological section is drawn taking into account the position of the axial surfaces of the folds in the plan.

Compilation of profile sections crossing the territory with outcrops of secant intrusions requires solving problems that are not considered in the program of this book. In the general case, when a section passes through an intrusion, it should be shown as a body that interrupts the bedding of layers in the same way as in case of discontinuities.

Engineering geological maps

Engineering-geological maps reflect the engineering-geological conditions of the mapped territory and provide a comprehensive natural assessment necessary for construction. The task of engineering geology is to determine the geological features of the study area in order to establish its suitability for the construction and operation of engineering structures.

The geological structure has an impact on the choice of location, layout, construction of the structure and on the methods of construction work.

The engineering-geological map, together with profile sections, stratigraphic columns and comprehensive characteristics of soils, is the main document obtained as a result of engineering-geological surveys. Among engineering-geological maps for various purposes, general survey, special survey, schematic and detailed maps are usually distinguished. General overview maps serve to design various types of construction and are compiled on a small scale (1: 200,000 and smaller). The remaining categories of carts are used to design a specific type of engineering structures and are drawn up on a scale that meets the requirements of construction.

When engineering and geological surveys and mapping, the nature of the relief, the geological structure must be taken into account.

tur, composition of rocks, hydrogeological conditions and dynamics of modern processes. Terrain information is needed to select a construction site, estimate the amount of earthworks, lay access roads and other design data. The geological structure gives an idea of ​​the occurrence of bedrocks and the position of their roof in relation to the modern hydrographic network. The composition of rocks (ground conditions) is subject to particularly careful study and is depicted on the map in accordance with the established geological and petrographic classification.

The study of water content is essential. On the maps, conventional signs indicate the depth of groundwater, water abundance, pressure, and chemical characteristics. In some cases (on large-scale maps), the groundwater surface is depicted as isolines. The dynamics of modern geological processes is reflected on large-scale maps by conventional signs and boundaries that outline areas where certain processes develop (landslides, karst, permafrost, subsidence of rocks, various forms of erosion, etc.). The qualitative and quantitative assessment of dynamic processes is noted on the maps, the intensity of the development of the process is indicated.

When drawing up an engineering-geological map, it is essential to select colors and symbols that determine its visibility and ease of reading.

Tectonic maps

Tectonic maps depict structural elements of various scales, categories and ages.

The compilation of tectonic maps is one of the most important and active methods of studying and analyzing the development of the structures of the earth's crust. Depending on the size of the territory for which the map is being compiled, the scale and symbols, it is customary to distinguish between general (summary) and regional tectonic maps. In addition, so-called structural maps are compiled to display the morphology of tectonic structures. On general tectonic maps, structural elements of a large scale are depicted, which are the main structures of the earth's crust. The symbols (legend) used in the preparation of such maps are common to the entire surface of the Earth and can be used in any of its regions. Regional maps reflect the structure of a particular section of the earth's crust; the conventions adopted for it may be of little use for their use in compiling a map of another area.

The relief of the surface of a particular structure depicted on a tectonic map is transmitted using isolines (horizontals) connecting points with an equal value of occurrence marks, calculated from the level of the World Ocean.

The starting point for general tectonic mapping is to establish the age of folding of the main structures,

the time of formation of the geosyncline, i.e. in time

graduation geosynclinal and the beginning of the platform stages of development of the study area. The moment of transformation of the geosynclinal folded system into a platform is a natural boundary in the development of the earth's crust.

Within Europe and neighboring parts of other continents, territories are distinguished that have survived the following main epochs of folding, the age of which is determined by the time of completion of the geosynclinal stage of development: Precambrian (Archaean and Proterozoic), Baikal, Caledonian, Hercynian and Alpine. Larger subdivisions (cycles) in the development of the earth's crust, uniting many eras and periods (stages) of folding, are called megachrons. In the history of the formation of the earth's crust, several megachrons can be distinguished, but the most studied is the last one, called neogey. In this new, last, megachron, a radical restructuring of the earth's crust and the formation of its modern structure took place. The age of these structures is reflected on tectonic maps by special indices and colors.

On the tectonic maps of the territory of the USSR, for the Baikal folding (Proterozoic) the blue color is accepted, for the Caledonian - lilac, for the Hercynian (Varisian) - brown, for the Alpine - yellow. Older megachrons are depicted in shades of red.

When depicting various zones of geosynclinal regions - eugeosynclines and miogeosynclines, shades of colors are used that determine the age of a particular folded structure and an alphabetic index is put. For example, the eugeosyn-clinal zone of the Caledonian folding is designated by the index - eC. Structural floors in folded structures are also distinguished by the density of tone of the adopted age coloration, and the lower structural floors are painted over with a more intense shade. Letter indices are supplemented with numbers. K 1, for example, denotes the lower floor of the Karelian folding (Proterozoic), C 2 - the middle floor of the Caledonian folding, A 3 - the upper structural floor of the Alpine folding, etc. There are alphabetic and numeric designations for more fractional divisions - subfloors. For example, A 2 1 is the upper sublevel of the lower structural level of Alpine folding.

The marginal troughs are indicated by a striped horizontal color of the color of the upper structural stage of a given folding. In the case of overlapping the marginal deflection with a platform cover, translucent shading is used under the paint of the platform cover. Internal intermountain depressions, developing simultaneously with the marginal foredeeps, are indicated by the color of the upper structural stage with molasse specks *. Fill in the middle arrays

*Molasses are clastic rocks that fill deep troughs of geosyn-clinal zones in major eras of mountain building.

are colored by folding, which turned them into rigid blocks (for example, Hercynian massifs among the structures of Alpine folding in the Caucasus, etc.).

With the introduction of general tectonic maps of designations of eu- and miogeosynclines, structural levels and internal depressions into the legend, with appropriate detail of the contours, these maps raise their accuracy to the level of regional maps.

Within platform structures, on general tectonic maps, areas of outcrops of a folded basement (shields) and slabs, on the area of ​​which the basement is covered by a sedimentary cover, are distinguished. On shields and exposed anteclise vaults, the folded foundation is subdivided according to the epochs of folding with the allocation of structural floors. On the territory of the slabs, the surface of the folded foundation is depicted using isohypses and stepped coloring, shading the areas of subsidence and uplifts. (The submerged areas are lighter than the uplifted ones.) The age of the platforms is emphasized on tectonic maps in a certain color, which differs from the folded areas in a paler tone. To designate the sedimentary cover of the platforms, the following color tones are adopted: the sedimentary cover of the ancient platforms is indicated by a brownish-pink color, the Epicaledonian - violet-green, the Hercynian - brownish-gray.

Outcrops of intrusive massifs are depicted in the same way as on geological maps, within their modern erosional cut. The division of intrusions is made according to their belonging to certain stages of tectogenesis (early orogenic, late orogenic and anorogenic). The age of the intrusions is indicated by indexes, the composition - by color and icons adopted for geological maps.

Large discontinuities are depicted on general tectonic maps by solid and dashed red lines. In addition, tectonic maps show zones of intensive development of metamorphism and centers of modern and ancient volcanism.

Conventional signs have been worked out in great detail to designate folded and discontinuous faults displayed on tectonic maps, as well as to designate boundaries and lines separating structures of various orders and ages.