8th grade
Option 1
1. In which of the following eras did plants and animals appear?
1) The age of the Earth is about 5 billion years.
3. What is the name of the upper layer of the platform, consisting of limestone, clay, sandstone?
a) basaltic c) sedimentary
b) granite d) lime
4. Stable areas of the earth's crust are called:
a) platforms c) shields
b) folded areas d) avalanche
5. The plains are located on:
a) platform c) in folded areas
b) boundaries of lithospheric plates d) on shields
6.In the Mesozoic folding, ridges rose:
a) Altai c) Sikhote-Alin
b) the Caucasus d) the Urals
7.The following deposits are confined to the ancient folded areas:
a) coal, oil, gas c) uranium
b) iron ores, gold d) table salt
8. What is the name of the science of minerals?
b) paleontology d) geology
9. Establish a correspondence between the mountains and their highest peaks:
1. Caucasus a) Pobeda
2. Altai b) Belukha
3. Sayan c) Elbrus
4. Chersky ridge d) Munku-Sardyk
10.The structure of the earth's crust is shown on the map:
11.Underwater earthquakes often occur here, which generate tsunamis in the Pacific Ocean:
a) Sakhalin c) Kamchatka
b) Madagascar d) Byrranga
12. Name the largest coal basin.
a) Vladimirsky c) Yakutsky
b) Kuznetsky d) Kursk
13. Where are diamonds mined in Russia?
a) Tunguska basin c) Yakutia
b) Lena basin d) Buryatia
14. What are the names of the areas within which there is a large number of deposits of the same type of fossils?
a) deposit c) blockage
b) storage d) pool
15. The most severe region of our country, its relief is represented by middle-altitude mountains of middle age.
16. What is the richness of the Tunguska basin in Eastern Siberia?
a) gas c) coal
b) oil d) furs
17. Where in Russia can you find echoes of an ancient glacier?
a) Far East c) Yakutia
b) Valdai Upland d) Karelia
18. The main destroyer and creator of the nature of the Caspian lowland is
a) pressure c) precipitation
b) wind d) air temperature
19. In what geological period of which geological era did we finish the study of the topic "Geological structure and relief of Russia"?
a) Cambrian c) Neogene
b) Cretaceous d) Quaternary
20. What platform is the school you are on?
a) Russian c) Amur
Cartographic workshop
8th grade
Verification work on the topic "Geological structure and relief"
Option 2
1. In which of the following eras did reptiles dominate?
a) Cenozoic c) Paleozoic
b) Mesozoic d) Proterozoic
2. Are the following statements true?
1) The age of the Earth is about 8 billion years.
2) The Great Glaciation influenced both the diversity of flora and fauna and the relief of the earth's surface.
a) only 1 statement is true c) both statements are true
b) only statement 2 is true; d) both statements are wrong
3. What is the name of the lower tier, which represents the base of the platform?
a) base c) foundation
b) shield d) horst
4. Mountains are located in ……. areas
a) platform c) folded
b) weathered d) foundation
5. In what era did the Caucasus Mountains begin to form?
a) Alpine c) Hercynian
b) Baikal d) Caledonian
6. What mountains were formed during the period of the Caledonian and Hercynian folding between the ancient platforms and gradually began to collapse?
a) Altai c) Sikhote-Alin
b) Caucasus d) Ural
7. What minerals are located in the areas of folded regions?
a) coal c) oil
b) iron and copper ores d) gas
8. What is the name of the teaching about the structure of the earth's crust and its movements?
a) petrography c) geotectonics
b) paleontology d) geology
9.Set the correspondence between the mountains and their peaks:
1. Caucasus a) Ichinskaya Sopka
2. Altai b) Belukha
3. Sayan c) Dykhtau
4. Kamchatka d) Munku-Sardyk
10. Map with information about the age of the rocks:
a) physical c) tectonic
b) geological d) climatic
11. Where is the country's only region of modern volcanism located?
a) Sakhalin c) Kamchatka
b) Kuril Islands d) Byrranga
12. What is the name of the richest iron ore basin on the planet?
a) KMA c) KMZh
b) BZHB d) KAM
13. What is the richness of the Udokan deposit in Transbaikalia?
a) potassium salts c) oil
b) gold d) copper ore
14. Useful substances are not scattered throughout the earth's crust, but are concentrated in certain parts of it, which are called ...
a) deposit c) deposits
b) storage d) pool
15. What natural area are we talking about: “No other region of our country has such a huge length from north to south. The youngest mountains of Russia are located here "
a) North-East of Siberia c) Ural
b) Far East d) Western Siberia
16. What is the richness of the Kuznetsk basin?
a) coal c) gas
b) oil d) diamonds
17. What are the names of mud-stone streams resulting from heavy rains?
a) avalanche c) mudflows
b) moraine d) cobblestones
18. What village in Russia was completely destroyed in 1995, as a result of a strong earthquake?
a) Neftekamsk c) Oil and gas
b) Neftegorsk d) Severodvinsk
19. In what geological period of which geological era did you study the topic "Russian explorers of the 11th - 17th centuries"?
a) Cambrian c) Neogene
b) Cretaceous d) Quaternary
20.What platform did you have breakfast on today?
a) Russian c) Amur
b) West Siberian d) North American
Cartographic workshop
Identify the geographical features depicted on the fragments of the map of Russia.
8th grade
Verification work on the topic "Geological structure and relief"
ANSWERS
CARTOGRAPHIC ASSESSMENT PRACTICE
Option 1 Option 2 "5" - 10 - 9
"4" - 8 -7
"3" - 6 - 5
1.Russian Plain 1.Caspian Lowland
2.Sayans 2.Timan ridge
3.d. Khibiny 3.Central Siberian plateau
4.Aldan Highlands 4.Ural
5.Verkhoyansk ridge 5.g. Byrranga
6, Altai 6. Sikhote - Alin deposit
7.West Siberian Plain 7.West - Sakhalin Mountains
8. Caucasus 8. Sayan
9.Midian ridge 9.storage Dzhugdzhur
10.Cherskogo deposit 10. Valdai Upland
ANSWERS ESTIMATES
Option 1 Option 2 "5" - 20 - 18
1.A 1.B "4" - 17 - 14
2.В 2.Б "3" - 13 - 9
3.В 3.АВ
4.A 4.B
5.A 5.A
6.V 6.G
7.A 7.B
8.A 8.B
9.1V, 2B, 3G, 4A 9.1V, 2B, 3G, 4A
10.C 10.B
11.АВ 11.ВБ
12.B 12.A
13.V 13.G
14.G 14.A
15.A 15.B
16.V 16.A
17.VG 17.V
18.B 18.B
19.G 19.G
20.A 20.A
- (Pacific folding Yenshan folding), the era of tectogenesis, manifested during the Mesozoic era mainly along the periphery of the Pacific approx. The main phases are Cimmerian (late Jurassic, early Cretaceous; Crimea and northeastern Russia), Laramian (late ... ... Big Encyclopedic Dictionary
Mesozoic folding- The era of mountain building, which manifested itself during the Mesozoic era mainly along the periphery of the Pacific Ocean, the main phases are the Cimmerian and Laramian folding ... Geography Dictionary
- (Pacific folding, Yenshan folding), the era of tectogenesis, which manifested itself during the Mesozoic era mainly along the periphery of the Pacific Ocean. The main phases are Cimmerian (Late Jurassic - Early Cretaceous; Crimea and Northeast Russia), ... ... encyclopedic Dictionary
A set of geological processes of folding, mountain building and granitoid magmatism that took place during the Mesozoic era. It manifested itself most intensively within the Pacific mobile belt. Distinguish between folding: ... ... Geographical encyclopedia
- (Pacific folding, Yeishan folding), the era of tectogenesis, manifested during the Mesozoic era of Ch. arr. along the periphery of the Quiet approx. Ch. phases Cimmerian (end of Jurassic beginning of Cretaceous; Crimea and northeastern Russia), Laramian (end of Cretaceous beginning ... ... Natural science. encyclopedic Dictionary
Manifested during the Mesozoic era, ch. arr. within the Pacific mobile belt. Recently (and by some tectonists even now) the S. m. Was considered as part of the Alpine folding. The main phases of S. m. Did not appear simultaneously in ... ... Geological encyclopedia
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78.1.
MESOZOIC FOLDING(Greek mesos - middle) - the development of geosynclines with deep deflections of the earth's crust and the accumulation of powerful sediments, which were crumpled into folds, raised in the form of mountains, broken by intrusions of granite magma and volcanic eruptions that lasted from the end of the Triassic to the beginning of the Paleogene period. In different areas, this folding manifested itself with unequal intensity and at a time, in this regard, it has several names.
The earliest Mesozoic folding began in Southeastern Europe, South Asia, and Taimyr; it passed especially for a long time and intensively along the continental margins of the Pacific Ocean and, after a short break, resumed already in the Alpine folding. Various minerals and numerous deposits of non-ferrous metals and gold are associated with its granite intrusions, especially in North America and northeastern Russia.
Mesozoic folding
Mesozoic folding is a set of geological processes of folding, mountain building and granitoid magmatism that took place during the Mesozoic era. It manifested itself most intensively within the Pacific mobile belt. Distinguish folding: ancient Cimmerian, or Indo-Sinian, manifested in the end. Triassic - early. Jurassic; Young Cimmerian (Kolyma, Nevada, or Andean); Austrian (at the turn of the Early and Late Cretaceous) and Laramian. Pacific folding is independently distinguished in areas adjacent to the Pacific Ocean: in the East. Asia, Cordillera and Andes. Ancient Cimmerian folding manifested itself in the late. Triassic - early. Jurassic in the mountain structures of the Crimea, North. Dobrudzha, on Taimyr, in the North. Afghanistan, South-East. Asia, Patagonian Andes and Northeast. Argentina; Young Cimmerian - at the end. Jurassic - early. chalk in the Verkhoyansk-Chukotka region., Center. and South-East. Pamir, in Karakorum, Center. Iran, the Caucasus, in the West. Cordillera North America, Andes and other areas. Laramian folding - one of the youngest epochs of the Mesozoic folding, manifested itself in the end. chalk - early. Paleogene in the regions of the North Rocky Mountains. America, in the Andes South. America, etc.
Areas of Mesozoic folding
By the end of the Paleozoic era, as already mentioned, all geosynclines and mobile regions turned into vast rigid fields. As a result of the upward movements of the earth's crust, they were freed from sea waters. A theocratic regime was established.
The Mesozoic era (the era of middle life) began, an era of a new, higher stage in the development of the nature of the Earth as a whole.
In the Mesozoic, the foundations of the modern relief of our planet were laid, including within the territory of the CIS, the main outlines of the continents and oceans were determined.
Mesozoids occupy vast spaces, closing and connecting the territories of the more ancient parts of the consolidation of the earth's crust. Various forms of Mesozoic folding are expressed in the east and north-east of Siberia, the Far East, i.e., on a territory with a total area of about 5 million km2. But the Mesozoic tectogenesis was reflected in more ancient structures - the Precambrian, Baikal and Paleozoic stages.
The Mesozoic structures include Eastern Transbaikalia, the south of the Far East with the Sikhote-Alin and the Verkhoyansk-Kolymo-Chukotka fold system. Thus, the west of the Pacific geosynclinal belt belongs to the Mesozoic structures. The modern surface of the East Siberian part and the Far East is characterized by a wide distribution of mountain structures. In addition to the typical mountainous relief in Eastern Siberia and the Far East, there are numerous highlands, plateaus, plains (the area of the latter is generally not large) and, finally, the Predverkhoyansk foredeep, which is vast across the territory. The manifestation of Mesozoic folding is noted in the Kopetdag, Mangyshlak, Donbass, in the Crimea, the Caucasus.
In the area of the Mesozoic fold systems of Eastern Siberia and the Far East, the main movements were the New Cimmerian and Laramian movements of the Cretaceous period. The geosynclinal basin extended eastward from the Siberian platform, i.e., within the territory of the Far East. It was a huge sea, in which thick sediments accumulated, amounting to many thousands of meters. In the geosynclinal sea basin, there were ancient mountainous middle land massifs: the Kolymo-Indigirsky, Omolonsky and others, the protrusion of the Siberian platform - the Aldan shield, and in the southeast - the Chinese shield, stood out. The accumulation of sediments in the geosynclinal basin occurred due to the erosion and destruction of the ancient middle massifs and the platforms surrounding the geosynclinal - Siberian, De Long, and Okhotsk. Tectogenesis in the ancient platforms and mountain structures of the Paleozoic, which surrounded the Mesozoids from the west, north-west and south, proceeded in a complex and peculiar way. One of the indicators of this uniqueness was the difference in timing of tectonic processes and the difference in the forms of their manifestation. But in general, the Mesozoic era in the east of our country ended with the change of the maritime regime to the continental one.
The Mesozoic folding was most actively manifested between the Kolyma massif and the Siberian platform (Verkhoyansk zone). Folding movements here were accompanied by volcanic outpourings, intrusions of granitoids, which led to a varied and very rich mineralization (rare metals, tin, gold, etc.). The middle massifs were subjected to deep faults, along the cracks of which effusive rocks poured onto the surface. The mesozoids of East and North-East Siberia are characterized by folded zones with anticlinal and synclinal structures.
The geological development of the south of the Far East is similar to the development of the northeast. Fold structures were also formed in the Mesozoic stage of tectogenesis, but the middle massifs of the Precambrian and Paleozoic arose even much earlier: the Zeisko-Bureya plate and the Khanka massif, which was the outskirts of the Manchurian platform. In the Poleozoic, the cores of the axial parts of the ridges were also formed - Tukuringra-Dzhagdy, Bureinsky, Sikhote-Alin, etc. Ancient folds here were accompanied by intense intrusions of granitoids, which caused mineralization.
Mineral resources of the entire territory of the Mesozoic folding in the east of Siberia and the Far East are diverse. Mineralization zones are usually confined to ancient rigid massifs (or to their edges): iron ores, non-ferrous metal ores, tungsten, molybdenum, gold, etc. Deposits of coal and brown coal, gas, oil, etc. are associated with sedimentary deposits.
78.2.
Lavrasia is the northern of the two pra-continents that formed the foremother of Pangea. Laurasia included Eurasia and North America. They broke away from the ancestral land and became the modern continents from 135 to 200 million years ago.
In ancient times, Laurasia was a supercontinent and was part of Pangea, which existed in the late Mesozoic era. This continent was formed by those territories that today are the continents of the Northern Hemisphere. In particular, it was Lawrence (the continent that existed in the Paleozoic era in the eastern and central part of Canada), Siberia, the Baltic, Kazakhstan, as well as the north and east continental shields. The mainland got its name from Laurentia and Eurasia.
Origin
Foremother Laurasia is a phenomenon of the Mesozoic era. At present, it is believed that the continents that formed it, after the collapse of the Motherland (1 billion years ago), formed one supercontinent. To avoid confusion with the name of the Mesozoic continent, it was simply attributed to Proto-Laurasia. Referring to current ideas, after joining the southern continents, Laurasia formed a late Precambrian supercontinent called Pannotia (early Cambrian), and was no longer separated.
Rift and formation
In the Cambrian era, for the first half a million years, Laurasia was in equatorial latitudes. The supercontinent began to disintegrate into Siberia and North China, continuing to drift northward; in the past they were farther north than 500 million years ago. By the beginning of the Devonian period, North China was near the Arctic Circle and was the northernmost landmass throughout the Carboniferous Ice Age (300-280 million years ago). To date, there is no evidence of large icing on the northern continents. During that cold period, the Baltic and Laurentia joined the Appalachian plateau, creating huge reserves of coal. It is this coal that is today the basis of the economy of such regions as Germany, West Virginia and part of the British Isles.
In turn, Siberia, moving to the south, merged with Kazakhstan - a small continent, which today is considered the result of a volcanic eruption in the Silurian era. With the completion of these reunions, Laurasia significantly changed its shape. At the beginning of the Triassic era, the shield of eastern China reunited with Laurasia and Gondwana, resulting in the formation of Pangea. Northern China continued to drift from near-arctic latitudes and became the last mainland to never join Pangea.
Final separation
About 200 million years ago, the Pangea practical continent disintegrated. The breakaway North America and northwest Africa were divided by a new Atlantic Ocean, while Europe and Greenland (along with North America) were still one. They were divided only 60 million years ago in the Paleocene. After that, Laurasia split into Eurasia and Laurentia (present-day North America). Ultimately, India and the Arabian Peninsula were annexed to Eurasia.
78.3.
The collapse of Gondwana began in the Mesozoic, Gondwana was literally pulled apart piece by piece. By the end of the Cretaceous - the beginning of the Paleogene periods, the modern post-Gondwana continents and their parts - South America, Africa (without the Atlas Mountains), Arabia, Australia, Antarctica - were isolated.
Gondwana (named after the historical region in Central India) is a hypothetical continent, which, according to many scientists, existed in the Paleozoic and partly Mesozoic eras in the southern hemisphere of the Earth. It consisted of: most of modern South America (east of the Andes), Africa (without the Atlas Mountains), about. Madagascar, Arabia, the Indian subcontinent (south of the Himalayas), Australia (to the west of the mountain ranges of its eastern part), and possibly most of Antarctica. Proponents of the hypothesis of the existence of Gondwana believe that extensive glaciation developed in the Proterozoic and Upper Carboniferous in the territory of Gondwana. Traces of Upper Carboniferous glaciation are known in Central and South Africa, southern South America, India and Australia. In the Carboniferous and Permian periods, a peculiar flora of the temperate and cold zone developed on the mainland, which was characterized by an abundance of glossopteris and horsetails. The disintegration of Gondwana began in the Mesozoic, and by the end of the Cretaceous - the beginning of the Paleogene, modern continents and their parts separated. Many geologists believe that the destruction of Gondwana was a consequence of the horizontal expansion of its modern parts, which is confirmed by paleomagnetism data. Some scientists suggest not the expansion, but the collapse of individual sections of Gondwana, which were on the site of the modern Indian and southern Atlantic oceans.
79. 2 .
Features of sedimentation. The Triassic is characterized by continental red-colored strata and weathering crusts. Marine sediments were localized in geosynclinal areas. Trap magmatism manifested itself on a large scale on the Siberian, South American and southern African platforms. There are three types - explosive, lava and intrusive (sills). In the Jura, sediments are more diverse. Among the marine ones there are siliceous, carbonate, clayey and glauconite sandstones; continental - weathering crust deposits predominate, and coal-bearing strata form in the lagoons. Magmatism manifested itself in the geosynclinal areas - the Cordillera and Verkhoyansk-Chukotka, and trap - on the platforms of the South American and African. A feature of the Cretaceous deposits is the maximum accumulation of writing chalk (consists of foraminifera and remains of coccolithophore algae shells).
Paleogeography of the Mesozoic. The greatest sea regression in the history of the Earth is associated with the formation of the supercontinent Pangea-2. Only small areas adjacent to the geosynclinal belts were covered by shallow seas (areas adjacent to the Cordillera and the Verkhoyansk-Chukotka geosyncline). The Hercynian fold belts represented areas of rugged relief. The Triassic climate is arid continental, only in the coastal regions (Kolyma, Sakhalin, Kamchatka, etc.) - moderate. At the end of the Triassic, the transgression of the sea begins, which was widely manifested in the late Jurassic. The sea extended into the western part of the North American platform, almost the entire eastern European platform, in the northwestern and eastern parts of the Siberian platform. The maximum transgression of the sea was manifested in the Upper Cretaceous. The climate of these periods is characterized by an alternation of humid tropical and dry arid ones.
79.3.
Geocratic periods in the history of the Earth (from geo ... and Greek. Kratos - strength, power), periods of significant increase in land area, in contrast to the thalassocratic periods, characterized by an increase in sea area. The geographic regions are confined to the second half of tectonic cycles, when general uplifts in the earth's crust transform a significant part of the continents previously flooded by the shallow sea into dry land. They are characterized by a large contrast of climates, in particular, a sharp increase in the areas of dry (arid) and cold climatic zones. The accumulation of continental red-colored strata, composed of aeolian, alluvial, and lacustrine sediments of arid plains, partly of true deserts, and also of glacial deposits, is typical of the geographic area. No less typical are deposits of internal closed and semi-closed sea basins with increased salinity of sediments of highly saline lagoons (dolomite, gypsum, salt). The G. p. Can include: the end of the Silurian and a significant part of the Devonian periods, the end of the Carboniferous, Permian and part of the Triassic periods, the Neogene and Anthropogenic periods (including the modern era).
Thalassocratic periods in the history of the Earth, periods of wide spread of the seas on the surface of modern continents. Contrasted with geocratic periods, which are characterized by a significant increase in land area. In time, the Thalassocratic periods refer to the middle of tectonic cycles (stages), when subsidence of the earth's crust prevailed on most of the earth's surface, in connection with which, almost everywhere, a significant area of the continents was flooded by the sea. The increase in the area of the hydrosphere contributed to the development of a humid marine climate with low temperature fluctuations. During the Thalassocratic periods, predominantly marine sedimentary strata accumulated, among which carbonate rocks played an important role. The Thalassocratic periods include the Middle Cambrian, Upper Silurian, Middle and Early Late Devonian, Early Carboniferous and Late Cretaceous.
80.1.
Eustatic sea level fluctuations (from the Greek éu - well, completely and stásis - standing still, rest, position), ubiquitous slow changes in the level of the World Ocean and associated seas. Eustatic movements (eustasia) were originally identified by E. Suess (1888). There are coastline movements: 1) as a consequence of the formation of sea troughs, when true changes in the ocean level occur, and 2) as a result of tectonic processes leading to the apparent movement of the ocean level. These fluctuations, causing local transgressions and regressions, caused by differently acting tectonic forces, were called displacement, and wide transgressions and regressions, caused by fluctuations in the level of the water envelope itself, were called hydrokinematic (F. Yu. Levinson-Lessing, 1893). A.P. Pavlov (1896) called the negative movements of the coastline geocratic, and the advancing sea - hydrocratic. Among the hypothetical factors determining eustasia, there is a change in the total volume of ocean water in the geological history of the Earth, which was determined by the evolution of the continents. At the initial stages of the development of the earth's crust, the importance of juvenile waters in ecology was decisive; later the significance of this factor weakened. The stabilization of the volume of water began, according to A.P. Vinogradov, in the Proterozoic, and from the Paleozoic the volume of the water mass of the hydrosphere varied within insignificant limits; the processes of sedimentation and volcanic eruption at the bottom of the seas (sedimentary eustasia) and, as a consequence, the rise in the level of the World Ocean are of little importance. The tectonic factor (tectonic eustasia), which affects the change in the capacity of the sea, was of decisive importance, starting from the Paleozoic. and oceanic depressions with a change in the relief and structure of the oceanic bottom and adjacent continents. Apparently Ch. fluctuations in the level of the World Ocean are associated with the development of the system of mid-ocean ridges and with the phenomenon of the spreading of the seabed - spreading. Against the background of the action of tectonoeustasia in recent geological time, the climatic factor in the form of glacioeustasia has played a large role (see Oscillatory movements of the earth's crust, Modern tectonic movements). During glaciations, when water was concentrated on the continents, forming ice sheets, the level of the World Ocean dropped by about 110-140 m; after melting, glacial waters again entered the oceans, raising its level by about 1/3 of the original. A decrease in temperature and a change in salinity at the same time influenced the density of water, due to which the level of the World Ocean at high latitudes differed by several meters from the level of the World Ocean in the equatorial regions. These factors are associated with the formation of the lowest terrace - 3-5 m. Planetary factors (change in the Earth's rotation rate, pole shift, etc.) also played a role in the mechanism of eustasia. The study of the processes of eustasia is of great importance for historical geology and understanding of the features of the formation of shelf zones, which are associated with the formation of various minerals.
80.2.
Mesozoic climate
Using well-known climatically modern analogues of Mesozoic lithogenetic formations and modern ecological analogues of Mesozoic vegetation and the Mesozoic organic world, as well as using paleothermal data, we obtain the necessary data for an approximate quantitative assessment of the climatic conditions of the past.
Early and Middle Triassic
The climate of the Mesozoic and especially the Triassic was almost isothermal; therefore, the natural zoning of the continent at that time was determined mainly by the distribution of atmospheric precipitation and not so much by volume as by the mode of precipitation during the year. For the Early and Middle Triassic, three main natural zones are established within Eurasia: extra-arid (desert), which included the predominant part of Europe, Arabia, Iran, Central and Central Asia; moderately arid (dry savanna), the landscapes of which were dominant in Northern Europe, Western and Southern Siberia, Transbaikalia, Mongolia and Eastern China, and semi-arid (moderately humid savanna), covering northeast Asia from Khatanga and Chukotka to the Japanese islands, and also Southeast Asia.
81.2.
IRIDIUM ANOMALY is an amazing find made by the American geologist Walter ALVARES in 1977 in a gorge near the city of Gubio, 150 kilometers from Rome. At great depths, a thin layer of clay was found with an iridium content 300 times higher than the norm. This layer lay at a depth corresponding to the geological boundary between the Mesozoic and Cenozoic, the time when the dinosaurs became extinct. Comparing this fact with the fact that usually the content of iridium in the earth's crust is negligible - 0.03 weight parts per billion, and in meteorites the concentration of this substance is almost 20,000 times higher, Alvarez suggested that the iridium anomaly arose as a result of the fall of a large cosmic body, which caused a global the disaster that killed the dinosaurs. This assumption remains a hypothesis. Meanwhile, iridium anomalies with approximately the same concentration as in the Gubio gorge have already been found in many places on the planet - in Denmark, Spain, on the Caspian Sea coast. ...
82.1.
Cenozoic (Cenozoic era) is an era in the geological history of the Earth stretching 65.5 million years, starting with the great extinction of species at the end of the Cretaceous period to the present. It is translated from Greek as "new life" (καινός = new + ζωή = life). The Cenozoic is divided into Paleogene, Neogene and Quaternary (Anthropogen). Historically, the Cenozoic was subdivided into periods - Tertiary (from Paleocene to Pliocene) and Quaternary (Pleistocene and Holocene), although most geologists no longer recognize such a division.
Life in the Cenozoic
The Cenozoic is an era characterized by a wide variety of land, sea and flying animal species.
Geologically, the Cenozoic is the era in which the continents acquired their modern shape. Australia and New Guinea seceded from Gondwana, moved northward, and eventually approached Southeast Asia. Antarctica took its current position at the South Pole, the Atlantic Ocean expanded, and at the end of the era, South America joined North America. Cenozoic is the era of mammals and angiosperms. Mammals have undergone a long evolution from a small number of small primitive forms to a wide variety of terrestrial, marine and flying species. Cenozoic can also be called the era of savannas, flowering plants and insects. Birds also evolved to a large extent during the Cenozoic. Grain crops appear among the plants.
82.2.
The stratigraphic division and lithological characteristics of the Paleozoic deposits developed in the Belousovsky ore region were developed by us taking into account the definitions of fauna and flora in Carboniferous deposits, as well as spores and pollen in the formations of the Upper and Middle Devonian. The dumb rock strata occurring between the dated Frasnian and Lower Carboniferous deposits are conditionally attributed to the Famennian. The stratigraphic position of these strata was determined by comparing their lithological composition with the faunistically dated sections of other regions.
In the Byolousovsky ore region of the Irtysh region, the following formations are distinguished: Glubochanskaya - B2e-gv, Shipulinskaya - D2gv, Belo-Usovskaya - Defri, Garaninskaya - Difri, Irtyshskaya - Dafmi (?), Pikhtovskaya (Grebenyushinskaya) - Bzgtg - Cit2 -Binsk - Cin-C'2. The first four of them were established by M.I.Drobyshevsky in 1954. Ore deposits of the deposit located among hydrothermally altered rocks are confined to the contact of the Glubochanskaya Formation with the Shi-Pulinskaya and Belousovskaya Formations.
Structurally, the study area covers a part of the northeastern wing of the Irtysh anticlinorium, which is complicated by fold and ruptured faults of the northwest strike. A characteristic feature of such folds is that their axial surfaces roll back to the southwest.
All rocks of the Paleozoic underwent a significant change under the influence of regional contact and, in some narrow zones, hydrothermal metamorphism. At the base of the stratigraphic section, there is a deeply metamorphosed complex of rocks, conventionally attributed to the pre-Middle Devonian age. This complex is represented by biotitized, epidotized amphibole-pyroxene gneisses and mica-quartz schists, which are exposed on an erosional section in the core of the Irtysh anticlinorium in the southeast of the region. The rocks of the above formations come to the surface in small areas. The rest of the area is covered with loose sediments.
82.4.
One of the most important global metallogenic structures is the Mediterranean belt - the product of the ocean, which received the name Tethys from E. Zyuss. From a metallogenic standpoint, the Mediterranean belt was specially studied by outstanding followers of V.I.Smirnov and my late friend G.A.Tvalchrelidze, and I would like to dedicate this very short essay to the long and complex history of the Tethys Ocean and the Mediterranean belt to the blessed memory of both scientists.
The concept of the "Tethys Ocean" appeared at the end of the last century (1893) in the famous work of E. Zyuss "Face of the Earth". Somewhat earlier, another Austrian geologist M. Neimayr, who compiled the first world paleogeographic map of the Jurassic period, identified the "Central Mediterranean Sea" on it. For both scientists, the most convincing evidence of the existence of such a body of water between the northern and southern rows of continents was the striking similarity of the Triassic and Jurassic marine faunas from the Alps, through the Himalayas to Indonesia (Timor Island), which had been established by that time. G. Stille expanded this concept in time and showed that the Tethys Ocean appeared already in the Late Precambrian, after the "Algonkian fragmentation" he identified. In this work, I proceed from this point of view, despite the fact that it was based on a fixist premise, which is now completely discredited. It will be shown further that the Tethys Ocean in its long evolution passed through a number of stages, including its partial closure "and re-opening in another place. The sequence of these stages makes it possible to distinguish the Late Proterozoic-Cambrian Prototethys, Ordwick-Carboniferous Paleotethis, Permian-Jurassic Mesothaleogene and Jurassic-Paleogene Neotethis, partially overlapping each other in space and time.
Birth of Tethys and Protethis
At present, it is almost generally accepted that as a result of the Grenville orogeny, about 10 billion years ago, a supercontinent emerged, which was recently named Rodinia. This supercontinent existed until about the middle of the Late Riphean, about 850 million years ago, and then began to experience destruction. This destruction began with rifting, which further led to spreading and new formation of the oceans: the Pacific, Iapetus, Paleo-Asian and Prototethys among them. The birth of this first incarnation of Tethys is proved by the outcrops of late Riphean ophiolites in the Anti-Atlas, the Arabian-Nubian shield on its southern periphery, in the Alps, and the Bohemian massif on the northern. In the Vendian-Early Cambrian period, the first generation of the Tethys-Prototethis 1 ocean disappeared (partially?) As a result of the manifestation of the Pan-African-Kadoma orogeny, and a significant area increased the Gondwana supercontinent, forming the Epicada Perigondwanan platform. It formed the most ancient foundation of Western Europe, stretching northward to the English Midlands and the edge of the East European ancient platform.
But very soon the destruction of this newly formed continental crust began and the ocean basin reappeared (or recovered). The remains of its bark are known in the Southern Carpathians, the Balkans (Stara Planina), in the northern Transcaucasia (Dzirul massif) and further to the east, in particular in Tsilyanshan (China). This Vendian-Cambrian basin can be called Prototethis II, in contrast to the Late Riphean Prototethys I. It was formed, possibly, along the suture between the Epicadian Perigondwanan platform and Fennosarmatia (Baltic). Interestingly, the same two generations of ophiolites are known in the south of Siberia (Eastern Sayan) and in Western Mongolia, which belonged to the Paleo-Asian Ocean at that time. Prototethys II closed (again partially?) In the second half of the Cambrian and finally at the beginning of the Ordovician due to the Salairian orogeny. At the same time, a new ocean was formed - the Paleotethis.
Paleotethis
It can be assumed with good reason that this was precisely the ocean basin that later gave rise to the main trunk of the European variscides (Hercynides). Its eastern continuation can be seen in the North Caucasus and further up to Qinling in Central China. In accordance with the age of the ophiolites, two generations of basins are from the oceanic or suboceanic, i.e. thinned and processed continental crust can be distinguished. The oldest of them is documented by ophiolites of the Ordovician age, outcropped in the Western Alps, Western Carpathians, and the Foremost Ridge of the Greater Caucasus.
The opening of the Paleothetis I was connected from Gondwana by the epicadam microcontinent of Avalonia and its drift to the north. At the same time, that (most) part of the Epicadamian platform, which remained attached to the Early Precambrian skeleton of Gondwana, separated from the East European craton-Baltic along the "Tornquist Sea" underlain by thinned continental crust.
In the left half of the Devonian, the Renohercynian back-arc basin opened up on the northern periphery of the Paleotethis in the rear of the Middle Germanic crystalline uplift. Ophiolites of the Lizard Peninsula in Cornwall, MOR-type basalts in the Rhine Slate Mountains and ophiolites of the Sudetenland are relics of the oceanic crust of this basin.
In the middle of the Devonian, however, a chain of uplifts arose in the central zone of Paleotethis I; it is known as the Ligerian Cordillera. It subdivided the main oceanic basin into two - the northern one, including the Saxo Thuringian and Renohercynian variscid zones and finding its southwestern continuation in the Iberian Meset, and the southern one, representing the Paleotethis proper and may be called Paleotethis II.
Paleotethis I or Reikum entered the final stage of its evolution in the Late Paleozoic, transforming into the Varissian fold-thrust belt of Western and Central Europe, the North Caucasus, its buried continuation in the south of the Turanian young platform, the Hindu Kush, the southern zone of the Southern Tien Shan, Northern Pamirs, Kunlun and Qinling.
Paleotethis closed completely only in its western part, to the west of the meridians of Vienna and Tunisia, forming Pangea. Further to the east, it was inherited by Mesothethis.
Mesotethis
The history of Mesothetis proper begins in the Late Permian-Triassic and lasted until the Late Triassic - Early Jurassic, until the Early Cimmerian orogeny - Mesotethis I or the Late Jurassic - Early Cretaceous - Mesotethis II. The main basin of Mesothetis I extended from the border region of Northern Hungary - Southern Slovakia in the Inner Carpathians through the basement of the superimposed Pannonian basin to the Vardar zone in Yugoslavia and further to the Pontids of northern Anatolia and possibly to central Transcaucasia, where its continuation may be hidden under the molasses of the Kura intermountain trough. Its further continuation can be assumed along the Early Cimmerian suture between the Turanian platform and the fold-thrust system of Elbrus on both sides of the South Caspian depression in northern Iraq. Further to the east, Mesothetis I can be traced through the southern zone of the Northern Pamirs, the southern slope of the Kunlun and Qinling, the famous Sunpan Kanze triangle and, with a turn to the south, through Yunnan, Laos, Thailand, Malaya - the classical region of the Indosinids or early Cimmerids (early Yanshanids in China). The northern branch of Mesothetis I, which merged with the main basin somewhere in northern Afghanistan, extended through the Kopetdag, the southern slope of the Greater Caucasus, Mountainous Crimea and up to northern Dobrudja, where its blind end was located.
Mesotethis I was replaced by Mesothethis II at the end of the Middle Jurassic (Late Bathonian-Callovian). At this time, the Tethys was transformed from a wide bay opening to the east into the Pacific Ocean, into a continuous oceanic belt that divided Laurasia and Gondwana along its entire length. This division was due to the emergence of the Caribbean, the Central Atlantic and the Liguro-Piedmont "ocean". The latter joined in the east with the residual Vardar basin, which was partially closed in the northeast by the Early Cimmerian folding. But further to the east, the continuation of this basin, in contrast to Mesothetis I, deviated south from the Pontids and extended on the other side of the "Cimmerian continent" of J. Schenger, then crossing the Lesser Caucasus through Lake Sevan and the Akery valley and reaching the Iranian Karadag. Outcrops of ophiolites disappear further to the southeast, but reappear in the Sabzevar region south of eastern Elbrus. To the east of the transform Gerirud fault, the continuation of Mesotethis II can be seen in the Farahrud zone of central Afghanistan and further, after crossing another, Afghan-Pamir strike-slip, in the Rushap-Pshart zone of the Central Pamir and, having experienced a new strike-slip along the Pamir-Karakorum fault, in the Bangong zone -Nujiang of central Tibet. Then this basin, like Mesotethis I, turned south (in modern coordinates) and continued in Myanmar to the west of the Sinobirman massif (Mogok zone).
The entire eastern part of Mesothetis II, starting from Sabzevara-Farahrud, was finally closed as a result of the Late Cimmerian orogeny. The western, European part also experienced this diastrophism, in particular, the Vardar zone, but here it was not final. The decisive role in this respect was played by the intra-Senonian, subhercynian tectonic phase.
In the Late Jurassic, another basin with oceanic or suboceanic crust arose north of the main basin of the Mesothetis in Europe and extended roughly parallel from the Velis zone of the Alps through the Pieninsky "cliff" belt of the Carpathians and further, possibly, the Nish-Troyan zone of eastern Siberia - western Bulgaria. The Australian orogenic phase during the mid-Cretaceous period played the most important role in the closure of this basin.
This northern basin was not the only one in the Mesozoic Tethys system. Another was the Budva-Pindos basin in the Dinarids-Helinids and its likely extension into the Taurus system of southern Anatolia. The third was the back-arc basin of the Greater Caucasus. The final closure of both basins took place in the Late Eocene. But in the meantime, two more back-arc basins formed in the Late Cretaceous-Early Paleocene:
Black Sea and South Caspian.
Thus, the closure of the European and West Asian segments of Mesothetis II took place gradually, through a series of compression impulses, from the Late Cimmerian to the Pyrenean. And gradually the leading role in the Mediterranean mobile belt passed from Meso to Neotethis.
Neotethis
This was the last incarnation of the great ocean. Neotethis was located south of Mesothetis and was formed due to the separation and drift to the north of several fragments of Gondwana - Adria (Apulia), central Iran, Lut block, central Afghanistan, southern Tibet (Lhasa). The opening of Neotetica was preceded by continental rifting, which is most clearly expressed in its eastern, Himalayan-Tibetan segment, where it began in the Late Permian. Spreading in the Neotethis area continued from the Late Triassic-Early Jurassic to the Late Cretaceous-Early Paleogene. Neotethis proper stretched from the Gulf of Antalya, Cyprus and northwestern Syria around the northern protrusion of the Arabian plate and then in the rear of the Baluchistan chains and the Himalayas, turning to the south of the Sunda-Bandi arc. As for the western ending of Neotethis, two versions are possible: 1) he could find his blind ending somewhere between Adria and Africa, in the region of the Ionian Sea and Sicily; 2) it could represent the continuation of the southwestern Dinarid-Helinid trough - the Budva-Pindos trough.Likewise as it was in the case of Paleo- and Mesotethis, the main Neotethis basin was accompanied by side and beyond arc basins of various ages and with various degrees of destruction and transformation of the continental crust and the role of spreading. One of them is the Levant Sea of Jurassic age, the other is the Seistan Late Cretaceous-Early Paleogene basin in the far east of Iran. Three others, in the far west, are the Tyrrhenian Neogene basin in the rear of the Calabrian arc and the Aegean basin of the same age in the rear of the subduction zone of the same name, and finally, the Adaman Sea of the same age, in the far east, behind the Sunda subduction zone. The closure of Neotethis began in the Senonian. and significantly accelerated in the Middle-Late Eocene, when India and a number of micro-continents that had previously split off from Gondwana, from Adria in the west to Transcaucasia and the micro-continent Bitlis-Sanandaj-Sirijak in the east collided with the southern edge of Eurasia, and the same process manifested itself between the Indian plate and the southeastern salient of Europe, leading to the formation of the Indo-Burmese chains. As a result, Neotethis turned out to be dismembered and only some of its remnants survived in the Mediterranean and the Black Sea-South Caspian region and in the Gulf of Oman, as well as relict subduction zones - Calabrian, Aegean, Makran, Sunda. Is this really the end of the long history of Tethys or just the beginning of a new phase of its evolution remains an open question.
Conclusion
Considering that for the first time the ocean formed between Laurasia and Gondwana as a single and special supercontinent at the end of the Precambrian and finally ceased to exist as a whole by the Oligocene, we can consider this huge time interval as corresponding to the Wilson cycle, since for a single moment of this interval it is impossible to assume the absence of such a vast Zvodnoy space, even during the existence of Pangea, sometimes it was reduced to a very vast bay comparable in size to the Indian Ocean. However, we can talk about two separate Wilson cycles, separated by the period of existence of Pangea - Late Proterozoic-Paleozoic and Mesozoic-Cenozoic. the main, axial basin from time to time shifted, mainly in a southerly direction, constantly retaining the role of the water division between Laurasia and Gondwana or their fragments. These changes did not occur gradually, but in leaps and bounds, and it was this that made it possible to distinguish between individual stages in the evolution of Tethys and, accordingly, to introduce the concepts of Proto-, Paleo-, Meso-, and Neotethis, despite the fact that some intervals of their "life" overlap some others ... The closure of these changing oceans was due to orogeny, long known under the names of the Baikal-Kadom, Caledonian, Hercynian-Varissian, Cimmerian, Alpine. Each of these orogenes was accompanied by the accretion of new terranes to Eurasia, which, as a rule, was compensated by the separation of other terranes from Gondwana. Some of these newly accredited terranes later experienced at least partial regeneration of mobility, but others remained attached to Eurasia, increasing its size. These different stages of the evolution of the Tethyan region correspond to the cycles identified a hundred years ago by Marcel Bertrand, and I proposed to call them Bertrand cycles. In relation to the Wilson cycles, these cycles are of the second order, since they correspond not to complete, but only to partial death of the ocean (and at the beginning of the shift in the axis of its opening). It should be emphasized that the internal structure of the Tethyan region, or the Mediterranean mobile belt during each stage of evolution remained complex and, in addition to the main basin, included several of its branches of various sizes, micro- and minicontinents, often superimposed on ensialic volcanic arcs. However, this is completely natural for the intercontinental ocean, for the Mediterranean Sea - Mittelmeer - as M. Neymayr defined it, the same century ago. Separations of continental fragments, their return approach and, in general, their mutual movements were determined not only by rifting and spreading, not only by subduction, collision and obduction, but also largely by transform faults and shears. It goes without saying that a complete deciphering of complex history and structural development Mediterranean belt. Along their entire length allows you to better understand the features of metallogeny. However, so far this can be done only partially, in relation to the western part of the Tethys and the latest stage of its development, starting from the Mesozoic. Therefore, this remains a task for the future and clearly requires international and multidisciplinary (stratigraphy, paleontology, lithology, petrology, tectonics, geophysics, geochemistry) research.
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Objectives: to acquaint with the influence of internal and external factors on the formation of the relief; show the continuity of the development of the relief; consider the types of natural phenomena, the reasons for their occurrence; talk about the influence of a person on the relief.
Equipment: physical map, tables, pictures, video film about natural phenomena, books, diagrams.
During the classes
I. Organizational moment
II. Homework check
1. Repetition of terms and concepts
Platform, shield, folded area, tectonics, paleontology, deposit.
Option 1
1. Stable areas of the earth's crust are called:
a) platforms;
c) folded areas.
2. Plains are located:
a) at the boundaries of lithospheric plates;
b) on platforms;
c) in folded areas.
3. Mountains are located:
a) on platforms;
b) on slabs;
c) in folded areas.
4. Ridges rose into the Mesozoic folding:
b) Sikhote-Alin;
c) the Caucasus.
5. The revived mountains are:
b) the Caucasus;
6. The following deposits are confined to the ancient folded areas:
a) coal, oil, gas;
b) iron ores, gold;
c) both.
7. The largest coal basins are:
a) Samotlor, Kansko-Achinsky;
b) Tunguska, Lensky;
c) Urengoy, Yamburg.
8. Landforms of glacial origin include:
a) moraines, trogs, lamb foreheads;
b) ravines, beams;
c) dunes, dunes.
9. The surface of Russia is falling:
b) to the north;
c) to the west;
d) to the east.
Answers: 1 - a; 2 - b; 3 - c; 4 - b; 5 - a; 6 - b; 7 - b; 8 - a;
Option 2
a) Proterozoic;
b) Paleozoic;
c) Archean.
2. The geological era, which continues today, is called:
a) Mesozoic;
b) Cenozoic;
c) Paleozoic.
3. The science of minerals is called:
a) petrography;
b) paleontology;
c) geotectonics.
4. Find the correspondence between the mountains and their highest peaks:
1) Caucasus: a) Victory;
2) Altai; b) Beluga whale;
3) Sayan; c) Elbrus;
4) the Chersky ridge. d) Munku-Sardyk.
5. Select the correct statements:
a) large plains are located on platforms;
b) aeolian processes create moraines:
c) the Kamchatka Peninsulas and the Kuril Islands - the most seismically active zones in Russia;
d) the main part of the mountains is located in the west and north of Russia;
e) the Ural Mountains are located between the Russian and West Siberian plains.
6. Find the correspondence between concepts and their definitions:
1) mud-stone flow;
2) snow falls from mountain slopes;
3) loose clay-boulder glacial deposits.
a) avalanche;
c) moraine,
7. Which map shows the structure of the earth's surface (crust)?
a) physical;
b) geological;
c) on the tectonic.
Answers: 1 - c; 2 - b; 3 - a; 4 - 1) c, 2) b, 3) d, 4) a; 5 - a, c, d; 6 - 1) b, 2) a, 3) c; 7 - c.
III. Learning new material
(The following concepts are written on the board: endogenous processes, exogenous processes, volcanism, earthquakes, recent tectonic movements, glaciation, moraines, aeolian relief, dunes, talus, landslides, avalanches, mudflows, erosion.)
Look at the desk. We will consider these terms in the lesson today, and remember some of them.
The relief is constantly changing under the influence of exogenous (external) and endogenous (internal) factors.
(The teacher draws a diagram on the board while explaining.)
The relief is constantly changing under the influence of exogenous (external) and endogenous (internal) factors. Both of these factors act simultaneously.
Endogenous processes are called neotectonic or recent. They can appear both in the mountains and on the plains.
In the mountains, the movements of the earth's crust are most active. In the Caucasus, movements occur at a speed of 5-8 cm per year, in young mountains, where the earth's crust is plastic, movements are accompanied by the formation of folds. In areas of ancient folding (Ural, Altai, Sayan, etc.), where the earth's crust is more rigid, faults and faults are formed. Sections make vertical movements, some blocks rise, others fall, forming intermontane basins.
On the platforms, the latest movements are manifested in secular slow vibrations of the earth's crust, some areas slowly rise, while others fall at a speed of about 1 cm per year. But there can be faults on the platforms, an example of this is faults in the east of Africa (Great African faults).
Exogenous processes are processes that occur under the influence of flowing waters (rivers and glaciers, mudflows), permafrost, and wind.
Glacial landforms
In the Quaternary period, a huge shell of ice up to 4 km thick buried almost all of Europe beneath it. The centers of glaciation were Scandinavia, the Polar Urals, the Putorana plateau and the Byrranga mountains on the Taimyr Peninsula. The cold was approaching the Earth in giant waves. There were several such waves. The formation of glaciers is connected with them. Since the Cambrian, scientists have counted up to five such glaciations. At the beginning of the Quaternary, the great glaciation began for the fifth time. It happened more than 200 thousand years ago. The glacier retreated relatively recently - only 12-15 thousand years ago.
1. Moraine (French moraine) is a geological body composed of glacial deposits. The boulders in the moraines are composed mainly of granites and gneisses. In addition to rounded boulders on the surface of the moraine, there are some large, up to several tens of meters in diameter, poorly rounded boulders of rapakivi granites - rejects. The colossal boulder is widely known, which was used as a pedestal for the erection of a monument to Peter the Great in St. Petersburg. This boulder called "Thunder-stone" was found near the village of Lakhta on the shores of the Gulf of Finland. Its length is 13 m, width - 7 m, height - 8 m. Its delivery to St. Petersburg took two years.
Moraine is an unsorted mixture of clastic material of various sizes - from giant boulders up to several hundred meters in diameter, to clay and sandy material formed as a result of rubbing fragments of a glacier during its movement. It is difficult to note any regularity in the distribution of debris of different sizes in the body of the glacier; therefore, the rocks deposited by the glacier are unsorted and non-layered.
2. Terminal moraine ridges - this is the boundary of the movement of the glacier, represents the brought in debris. The grandiose terminal moraines and the associated glacier-water ridges are found in Finland and on the Karelian Isthmus. These include the Michurinsk ridge, Northern Uvaly, which are a water-glacial formation.
3. On the Baltic and Canadian shields, rocks are smoothed by a glacier, there are numerous sheep's foreheads - protrusions of igneous and metamorphic rocks with scratches and scars on the surface; the slopes facing towards the movement of the glacier are gentle, the opposite ones are steep.
4. Oz (ridge, ridge) is a ridge with rather steep slopes (30-45 °), reminiscent of a road embankment. The basins are usually composed of sand, often with pebbles and gravel; pine loves sandy soils, so it often grows on lake beds. There is no consensus about the origin of the ozov. There is a stream of water along the glacier, it carries a lot of sand, pebbles, boulders; Having reached the edge of the glacier, the stream forms an alluvial cone, the edge of the glacier recedes, and the cone receding with it gradually forms a ridge. There is another explanation: a stream flowing on the surface of the glacier or inside it deposits sandy rocks with large fragments along its channel; when the glacier melts, all these deposits fall on the underlying surface, forming a ridge on it. One way or another, lakes are formed by streams moving along the glacier or in it, as evidenced by the layering of the rocks that compose the lake, such as form water flows. The height of the lake can reach several tens of meters, the length - from hundreds of meters to tens (sometimes even hundreds) of kilometers. The peculiarity of the ozov is that they do not take into account the relief at all: the ozone ridge can stretch along the watershed, then go down the slope, cross the valley, rise again, then go into the lake, forming a long peninsula, dive and dive on the other side. And so, until its length is enough.
5. A lump (English kate or German katt - ridge) is a hill, usually outwardly difficult to distinguish from moraine, but the material composing it is sorted better than moraine, layered. The origin of the kams, like the oz, is explained in different ways: it can be deposits of lakes that existed on the surface of the glacier or near its edge.
6. Vast areas are occupied by zandry (Icelandic sand - sand) - surfaces on which sands brought by melt glacial waters are widespread (Pripyat Polesie, Meshcherskaya lowland, etc.). The zander has a characteristic landscape, but they are also not particularly perceived as landforms.
7. Lakes in glacial basins. Examination occurs unevenly, since the rocks underlying the glacier are unequally stable. As a result, depressions are formed, usually elongated in the direction of movement of the glacier. Most of the lakes of Karelia and Finland, as well as the Canadian Shield, are located in such basins. The depressions of the large lakes are tectonic troughs, but they also experienced glacier treatment. So, on the northern shores of Ladoga and especially Onega lakes there are bays that are clearly of glacial origin, this is evident if only because they are stretched from northwest to southeast, which is a common direction for Karelian lakes.
8. Ice moves in streams in mountain valleys, expanding and deepening them, forming trough-like valleys - troughs (German trog - trough).
9. For mountains where there is glaciation or it was in the geologically recent past, steep ridges, sharp peaks are characteristic; in the upper parts there are kars (German kar), bowl-shaped niches with steep slopes in the upper parts and more gentle below. Karas, or mountain circuses, are formed under the influence of frosty weathering, serve as a place for the accumulation of snow and the formation of glaciers. When the adjacent punishments are connected by their lateral parts, a protrusion in the form of a three- or four-sided pyramid often remains between them. Karas and troughs can be seen not only in the mountains, where there is modern glaciation. There are almost no glaciers in the mountains of Transbaikalia, but the forms formed during the Quaternary glaciation are perfectly preserved in solid crystalline rocks.
Aeolian landforms
Dunes are a kind of dunes, relief mobile formations of sand in deserts, blown by the wind and not fixed by plant roots. They reach a height of 0.5-100 m. They resemble a horseshoe or sickle in shape. In cross section, they have a long and gentle windward slope and a short, steep leeward slope.
Depending on the wind regime, the clusters of dunes take different forms. For example, there are sandy ridges stretched along the prevailing winds or their resultant; dune chains, transverse to mutually opposite winds; dune pyramids in places of convection of vortex flows, etc.
Without being fixed, the dunes under the influence of winds can change their shape and mix at a speed from several centimeters to hundreds of meters per year.
Thermal landforms in our country are mainly represented by frost weathering.
1. Frost heaving is typical for various regions of the cold belt, although it is developed unevenly due to local features of the composition, structure and properties of rocks. Small mounds of heaving can occur directly by increasing the pound of freezing water. But migratory mounds have large values, when new volumes of water from the underlying thawed part of the soil migrate to the freezing front, which is accompanied by intense segregation of ice formation. This is often associated with peatlands, to which, during freezing, moisture migrates from rocks with much higher moisture content. Such mounds were observed in Western Siberia.
2. In such a cold climate, small-polygonal structural forms are also developed, associated with cracking of the soil into small polygons, uneven freezing of the seasonally thawed layer and the development of stresses, and often ruptures, in closed systems. Among such small-polygonal structures are medallion spots. When freezing from above and along cracks inside the landfill, hydrostatic pressure is created, the liquefied soil of the upper permafrost crust breaks through and spreads over the surface. The second type of polygonal structural forms are stone rings and polygons. This occurs in loose rocks of heterogeneous composition, containing inclusions of stone fragments (crushed stone, pebbles, boulders). As a result of repeated freezing and thawing, large clastic material is pushed out of the rock to the surface and moved towards the fractured zones, with the formation of stone curbs.
3. Slope processes in the areas of permafrost development include two types: solifluction and kurums (stone streams). Solifluction is understood as a slow flow along the slopes of loose, highly waterlogged dispersed sediments. During the seasonal thawing of the ice-saturated dispersed pounds of the seasonally thawed layer, they are greatly overmoistened by melt and rainwater, lose structural connections, pass into a viscoplastic state, and slowly move down the slope. In this way, drip forms are formed in the form of tongues, or terraces. Kurums represent stone mobile placers in the mountains and plateaus of Eastern Siberia and other regions where rocks come close to the surface. The formation of clastic material of curums is associated with frost weathering during periodic seasonal freezing and thawing and with other processes. Kurums in places form continuous stone fields (ranging in size from the first hundred square meters to several tens of square kilometers).
4. One of the most famous examples of permafrost degradation is thermokarst. This name was given to the process of thawing of underground ice, accompanied by subsidence of the earth's surface, the formation of depressions, shallow thermokarst lakes.
Natural phenomena
Open the textbooks, find a map of the latest tectonic movements (according to R: fig. 26 on p. 26; according to B: fig. 22 on p. 46).
Newest tectonic movements → earthquakes, volcanism.
(To create an image of natural phenomena, you can show the video "Natural phenomena".)
Consider the structure of the landslide (according to R.: p. 72; according to B.: fig. 27 on p. 51).
Reason: gravity → landslides, avalanches, mudflows
What natural phenomena are possible in your area? How to protect yourself from dangerous phenomena?
Homework
1. According to R .: § 12, 13.
2. Draw on the contour map the relief forms formed under the influence of external factors. To do this, create and write down conventional signs for these landforms in the map legend.
Additional material
Plains of Russia
Name |
Geographical position |
Relief shape |
Prevailing heights, m |
Maximum height, m |
Valdai |
Eastern Europe |
Elevation |
||
Privolzhskaya |
Elevation |
|||
Northern Uvaly |
Elevation |
|||
Smolensk-Moscow |
Elevation |
|||
Central Russian |
Elevation |
|||
Caspian |
Flat lowland |
|||
West Siberian |
Flat lowland |
|||
Siberian Uvaly |
North of Western Siberia |
Elevation |
||
North Siberian |
Eastern Siberia |
Hilly lowland |
||
Central Siberian |
Plateau |
|||
Vitimskoe |
Belt of mountains of Southern Siberia |
Plateau |
||
Yano-Indigirskaya |
North-east of Siberia |
Lowland |
||
Kolyma |
Lowland |
Mountains of Russia
Name |
Geographical position |
Highest peak, m |
||
Ural |
East of the Russian Plain |
Hercynian folding |
Mountain People's, 1895 |
|
Belt of mountains in the south of Siberia |
Mount Belukha, 4506 |
|||
Western Sayan |
Caledonian, Hercynian folding |
Mount Kyzyl-Taiga, 3121 |
||
Eastern Sayan |
Mount Munsu-Sardyk, 3491 |
|||
South of the Russian Plain |
Alpine mountain building |
Mount Elbrus, 5642; Mount Kazbek, 5033; Mount Dykhtau, 5204 |
||
Sikhote-Alin |
Primorye |
Mesozoic folding |
Mount Tordoki-Yani, 2077 |
|
Chersky ridge |
North-east of Siberia |
Mesozoic folding |
Mount Victory, 3147 |
Option 1.
1) 5895 m 2) 6960 m 3) 5642 m
2. Mountains in Russia occupy about ...
1) the third part of the territory
2) a quarter of the territory
3) half of the territory
3. The greatest length in Russia has a mountain structure ...
1) Caucasus 2) Sikhote-Alin 3) Ural
4. The foundation of the most ancient platforms in Russia is ... age
1) Paleozoic 2) Precambrian 3) Mesozoic
5. The foundation of the Siberian platform comes to the surface in the form of shields ...
1) Baltic and Anabar 3) Aldan and Anabar
2) Aldan and Baltic
6. The foundation of the West Siberian young platform was formed simultaneously with ...
1) Ural 2) Caucasus 3) Sikhote-Alinem
7. In the first half of the Paleozoic ... folding took place
1) Alpine 2) Caledonian 3) Hercynian
8. At the boundaries of modern lithospheric plates ...
1) Koryak Upland and Kamchatka Mountains 3) Timan Ridge and Ural
2) Ural and Taimyr mountains
9. In the Mesozoic folding, a folded base was formed ...
1) ridges: Chersky, Verkhoyansk, Sikhote-Alin
2) Caucasus, Koryak Upland, Sakhalin
3) Ural, Altai, Sayan
10. The height of the mountains depends on ...
1) the rate of uplift of the earth's crust
2) the rate of destruction of the relief
3) the relationship between the rate of uplift and the rate of destruction
11. The Caucasus is higher than Altai, because ...
1) later formed
2) composed of harder rocks
3) experiences more intense uplift
12. The ravine and ravine network on the East European Plain is the most developed ...
1) on the Caspian lowland 3) on the Valdai upland
2) on the Central Russian Upland
13. The relief created by river sediments is the most widespread ...
1) on the West Siberian lowland 3) on the Central Siberian plateau
2) on the East European Plain
14. Active volcanoes in Russia are located ...
1) in the Caucasus
2) in the Urals
3) in Kamchatka and the Kuril Islands
15. There are minerals on the platforms ...
1) only of magmatic origin
2) magmatic and sedimentary origin
3) magmatic, sedimentary and metamorphic origin
Relief, geological structure.
Option 2.
1. The highest point of Russia is located within ...
1) Caucasus 2) Altai 3) Sayan
2. The highest and most dissected plain in Russia is ...
1) East European Plain
2) Central Siberian plateau
3) West Siberian Plain
3. The relief of the East European Plain is an alternation ...
1) plateaus and hills
2) highlands and lowlands
3) lowlands and plateaus
4. On ancient platforms are located ...
1) East European and West Siberian plains
2) West Siberian Plain and Central Siberian Plateau
3) Central Siberian Plateau and East European Plain
5. The foundation of the East European platform comes to the surface in the form of ... a shield
1) Baltic 2) Anabar 3) Aldan
6. In the second half of the Paleozoic ... folding took place
1) Caledonian 2) Hercynian 3) Baikal
7. On the borders of modern lithospheric plates are located ... the outskirts of Russia
1) northern 2) western 3) eastern
8. In the Paleozoic folding, a folded base arose ...
1) the Caucasus and the Urals
2) Ural and Altai
3) Verkhoyansk ridge and Sikhote-Alin
9. The revived folded-block mountains include: ...
1) Ural, Altai, Sayan 2) Sayan, Koryak highlands, Kamchatka mountains
2) Caucasus, Sikhote-Alin, Altai
10. If the rate of uplift of the earth's crust is equal to the rate of destruction, then ...
1) mountains 2) depressions 3) plains
11. Moraine relief was formed as a result of geological activity ...
1) wind 2) flowing water 3) glacier
12. Quaternary cover glaciers on the territory of Russia spread furthest to the south ...
1) in the European part 3) in the Far East
2) in Siberia
13. Areas of manifestation of strong earthquakes in Russia are ...
1) Ural, Central Siberian plateau
2) Kola Peninsula, West Siberian Lowland
3) Kamchatka, Kuril Islands, Caucasus
14. The largest active volcano in Russia ...
1) Kronotskaya Sopka 3) Avachinskaya Sopka
2) Klyuchevskaya Sopka
15. The mountains are dominated by minerals ...
1) ore magmatic
2) ore sedimentary
3) combustible (oil, gas, coal)
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