Relief of Russia characterized by three main features:
- it is diverse, that is, there are both high mountains and vast plains;
- 2/3 of the territory is occupied by plains;
- mountains are located mainly on the southern and eastern outskirts of the country.
These features are explained by the large size of the territory, its varied tectonic structure, and the location of the main tectonic structures. Plains are located on platforms, mountains have arisen within folded areas.
The country's territory is located on two ancient (Russian and Siberian) and three young (West Siberian, Scythian and Turanian) platforms, as well as in three folded belts (Alpine-Himalayan (Mediterranean), Ural-Mongolian, Pacific). Within the ancient platforms stand out four shields... On the East European platform, these are the Baltic and Ukrainian shields, on the Siberian - Aldan and Anabar shields.
IN western part of the country is the East European (Russian) Plain, it is located on the ancient Russian platform. The relief of the plain is diverse - it is characterized by the alternation of lowlands (Upper Volga, Meshcherskaya) and uplands (Valdai, Central Russian, Smolensk-Moscow). In its southern part, there is the Caspian Lowland located below sea level. The lowest point in the country (–28 m) is located here. The average height of the Russian Plain is about 200 m. The Ural Mountains are located along its eastern edge. These low (max. Height 1894 m - Mount Narodnaya) mountains stretch from north to south - from the Arctic Ocean to the steppes of Kazakhstan.
TO east from the Urals is the vast West Siberian Plain. Half of it has a height of less than 100 m and only at the edges of a height of 150-200 m. To the east of it, between the Lena and the Yenisei, lies the Central Siberian plateau, located on the ancient Siberian platform. Its average height is 500-700 m, the maximum is 1701 m.
TO south from the Russian Plain are the highest ( Elbrus 5642 m) mountains of Russia - Caucasus.
In the upper reaches of the Ob and Yenisei, there are the Altai ridges (Mount Belukha, 4506 m) and Sayan (8). From the east, the Sayan mountains are adjacent to the Baikal and Transbaikal mountains: Stanovoe Upland, Stanovoy Ridge. To the east
The Verkhoyansk and Chersky ridges lie on the Central Siberian Plateau. In the Far East, the Sikhote-Alin ridge stretches along the Pacific coast. There are high mountains on the Kamchatka Peninsula (Klyuchevskaya Sopka volcano, 4750 m).
On the territory of Russia there are active and extinct volcanoes ... The existing ones are located on the Kamchatka Peninsula and the Kuril Islands, the extinct ones are located in the Caucasus, the Far East, and Transbaikalia. All the largest volcanoes are located on the Kamchatka Peninsula: Klyuchevskaya Sopka (highest), Avachinskaya Sopka, Ichinskaya Sopka, Kronotskaya Sopka, etc.
About 25% of the territory of Russia can be subject to earthquakes with a magnitude of at least 7.0. The most earthquake-prone region of the country is the Pacific coast.
They study the relief of South America in the 7th grade, so many, most likely, have heard about the Andes, Patagonia, the Amazonian lowland, etc. Perhaps our article will be of interest not only to school students, but also to those who want to refresh their knowledge of the distant continent ... In it we will talk about the main landforms of South America.
Mainland geography
On the map, the continent is located below North America, connected with it by the narrow Isthmus of Panama. Most of it is located in the Southern and Western Hemispheres. Its shores are washed by the waters of the Atlantic and Pacific Oceans.
The area of \u200b\u200bSouth America is the fourth in the world and occupies 17 840 000 km 2. Its territory is home to 390 million people, there are 12 independent and 3 dependent states. The largest of them are: Brazil, Argentina, Bolivia, Colombia and Peru. All of them, except for French Guiana, belong to the countries of Latin America. A huge, though not always positive, role in their development was played by colonists from Spain, France and Portugal.
The relief forms on the mainland of South America are very diverse and represent both high mountains and medium-altitude plateaus and lowlands. From north to south, the continent stretches for 7350 kilometers, covering six climatic zones - from northern subequatorial to southern temperate. Most of the conditions are hot and very humid, and the temperature does not drop below +5 ° C.
The peculiar climate and relief of South America made it a record holder in some areas. Thus, the continent has the highest volcano, the world's largest river and the highest waterfall. And thanks to the large amount of precipitation, the mainland is the wettest on the planet.
Relief of South America
South America was once part of the continent of Gondwana along with Antarctica, Australia and Africa. After their separation from each other, it briefly turned into a huge island, until the Isthmus of Panama arose.
The landforms located on the mainland South America divide it into two large areas: flat-plateau in the east and mountainous in the west. The average height of the entire continent is approximately 600 meters.
The eastern part of South America is based on an ancient platform, so the local landscapes are predominantly flat. They are represented by the Amazonian, Orinoco and La Plata lowlands, the Patagonian plateau, the Brazilian and Guiana plateaus. In the extreme southeast is the Salinas-Chikas depression - the lowest point on the continent with a height of -42 meters.
The Andes mountains stretch in the west. These are young geological formations formed during relatively recent (about 50 million years ago) volcanic activity. However, the process of their formation is not finished, therefore volcanic eruptions and earthquakes can be observed even now.
Hills
In the relief of South America, there are several elevated regions called highlands and plateaus. One such area (the Central Andean Highlands) is located right in the middle of the Andes. Here volcanic plateaus are interspersed with flat plains, and the average heights reach 4000 meters.
The landforms in the east are much lower. There is located the vast Brazilian Highlands, covering about 5 million km 2. Its highest point is Mount Bandeira (2890 m), although in most of the territory it rises to an altitude of 200 to 900 meters. The highlands are flat areas with individual ridges of mountain ranges and plateaus with very steep, almost vertical slopes. Similar is the small Guiana Plateau in the north, which is part of the Brazilian Plateau in origin.
Lowlands
Low-lying plains cover a large part of the mainland, and occupy the area between the mountains and plateaus of South America. They are located in the places of deflections of the basement platform, which creates excellent conditions for the formation of swamps and rivers with deep valleys (Amazon, La Plata, Orinoco, Parana).
The Amazonian lowland is the largest on the continent and on the entire planet. It stretches in the north of the continent from the foot of the Andes to the coast of the Atlantic Ocean. In the southeast, it is framed by the Brazilian Highlands.
The area of \u200b\u200bthe Amazonian lowland is 5 million km 2. Here flows the largest river on earth, the Amazon, along with numerous tributaries. In the west, the relief of the lowland is flat and even, in the east it is cut by crystalline rocks that emerge to the surface. The rivers in the eastern part of the Amazon are not as muddy as in the western, dotted with numerous rapids.
Huge tracts of lowland are swampy and covered with impenetrable jungles of humid equatorial forests. It is one of the least explored regions in the world, inhabited by anacondas, caimans, pumas, tapirs, armadillos, capybaras, mazas and other unique inhabitants.
Andean Cordillera
By origin, the Andes are part of the North American Cordilleras. They run along the entire western coast of the continent, across the territory of seven states, and are the longest mountain range in the world (9,000 km). This is the main watershed of the mainland, where the Amazon River originates, as well as the tributaries of the Orinoco, Paraguay, Parana, etc.
The Andes are the second highest mountain system. Its highest point is Mount Aconcagua in Argentina (6960.8 m). In terms of relief and other natural features, the Northern, Central and Southern Andes are distinguished. In general, the mountains consist of numerous meridional ridges parallel to each other, between which there are depressions, plateaus or plateaus. Some massifs have permanent snow and glaciers.
Islands and coasts
In the north, the outlines of the mainland are mostly simple, the coastline is not very indented. It does not form bays deeply protruding into the land and peninsulas strongly elongated into the sea. The shores are mostly smooth and only in the Venezuela region is there a cluster of small islands.
To the south, the situation is changing. The mainland is gradually narrowing, and its shores are dotted with coves, bays and lagoons. Along the coasts of Chile and Argentina, many islands adjoin South America. Only in the Tierra del Fuego archipelago there are more than 40 thousand of them.
Not all of them are inhabited, for example, the Falkland Islands. But many have fjords, mountains covered with glaciers, gorges and a huge variety of animals. That is why most of the southern coastal areas are included in national parks and even protected by UNESCO.
Minerals
The geological structure and the diversity of the relief of South America are reflected in its natural resources. The continent is especially rich in minerals, in its bowels you can find at least half of the periodic table.
The mountain ranges of the Andes contain iron, silver, copper, tin, polymetallic ores, as well as antimony, lead, gold, saltpeter, iodine, platinum and precious stones. Colombia is considered the leader in the extraction of emeralds, Chile takes the first positions in the world in the extraction of copper and molybdenum, Bolivia is famous for its tin reserves.
The troughs flanking the Andes contain deposits of oil, coal and natural gas. Oil is also rich in the ocean floor near the mainland and the vast plains in the east. In the Amazonian Lowland alone, proven oil reserves are about 9,000 million tons.
A powerful source of minerals is the Brazilian Highlands, completely located in Brazil. On the territory of the country there are large deposits of diamonds, zirconium, tantalum, mica, tungsten; it is the world leader in the extraction of niobium.
On the territory of Argentina - the second largest country on the continent, there are deposits of marble, granite, sulfur, brown coal, beryllium, uranium, tungsten, copper, natural gas and oil.
Conclusion
The relief of South America combines ancient geological formations and very young and active forms. Due to this, the landscapes of the continent are represented by mountains and volcanoes, plateaus and plateaus, lowlands and depressions. There are glaciers, fjords, deep river valleys, high waterfalls, canyons and a gorge. Such a variety of relief was reflected in the nature of the continent, making many of its objects a real property of the planet.
Circle Native Land Grade 6
Subject; relief features and minerals Rtishchevo
Goal:The development of the student's personality based on the assimilation of local history content.
Objectives: Using the map as information, figurative-symbolic models of reality.
Understanding of the meaning of one's own activity and personal qualities.
Awareness of the role of the course in the comprehensive study of Russia.
Occupation type:a lesson in the discovery of new knowledge
In the lessons of geography, history, you studied the methods and methods of research work Let's remember themSpeaking about the etymology of the word "research", we note that this concept contains an indication to extract something "from the trace", i.e. restore a certain order of things by indirect signs, random objects. Therefore, we must be able to compare, analyze facts and predict the situation,
Basically you have listed the active forms of research. But there are others:
In your opinion, quiet reading of literature is a form and method of research? Why?
When working with text, you need to see
information:
Factual (which is explicitly stated in the text)
Subtext (which is implicitly reported in the text, read "between the lines")
Conceptual (the main idea of \u200b\u200bthe text, its main meanings)
Students repeat the material, study the memo
selection of grounds and criteria for comparison, serialization,
object classification;
Statement of the educational problem
Today we will work with tests, but not simple ones, but with the text of the map. What can we learn from a physical map? That is, we can also highlight the factual, subtext, conceptual parts
Students make assumptions and determine the topic: rp and relief
the formulation of a cognitive goal;
"Discovery" of new knowledge by students
The city of Rtishchevo is located on the western outskirts of the Volga Upland, 214 km northwest of Saratov. Covers an area of \u200b\u200b32.95 km². The length of the city is 5.25 km in length and 4.5 km in width, the height above sea level is about 210 meters.
The surface of the territory of the city of Rtishchevo, located in the southeastern part of the Oka-Don lowland on the Don Plain, is a flat-wavy, slightly hilly plain, dissected to varying degrees by an erosion network. There are quite a few ravines on the territory of the city: in the west - Popov, in the northwest - Krasny Luch, in the southwest - Tretyak, and in the south - Dubovy. In the ravines Krasny Luch and Dubovy, ponds with an area of \u200b\u200babout 15 thousand square meters and about 12 thousand square meters respectively were built.
Within the city of Rtishchevo there are several small rivers, the largest of which are the Khopra tributaries - Olshanka and Iznair. The Olshanka River flows along the northern border of the city and is one of the water intakes of its hydraulic system. The Iznair River flows south of Rtishchevo. The water from it was used for the needs of the city from 1940 until the construction of a water pipeline from the Khoper River in the late 1980s.
According to hydrogeological zoning, the territory of the city of Rtishchevo belongs to the Sursko-Khopersky artesian basin. On the territory of this region, waterless boulder loams and clays of Middle Quaternary age lie almost everywhere to a depth of 10-20 m. Only in places do they contain a weak aquifer - groundwater, occasionally used through mine wells.
Minerals
In the vicinity of the city, a complex of various types of non-metallic minerals and solid fossil fuels has been identified and explored. Nonmetallic minerals are represented by raw materials for the production of building materials - brick and expanded clay; glass and construction sands. Brick clay, as a building material in Rtishchevo, is a common type of raw material. Building sands are widespread, half or more than half of which are suitable for concrete production. The building stone deposits are small, only partially meeting the needs of local construction.
There are peat deposits of solid fossil fuels, but at the present time it is not mined.
In general, the city of Rtishchevo is well supplied with a mineral resource base for construction materials, has promising deposits of mineral raw materials for agricultural and industrial purposes.
Students get acquainted with the features of the GP and the relief of Rtishchevo
Asking questions (proactive cooperation in the search and collection
information).
Independent work
Now let's execute a table of 2 columns in a notebook
Relief and minerals
Students complete an assignment in a notebook
selection and awareness by students of what has already been mastered and what else is subject to assimilation, awareness of the quality and level of assimilation
Reflection
Completing the detonation mission:
R - what to relate to Rtischevo
Students perform and discuss the results obtained
Awareness by students of their learning activities, self-assessment of the results of their activities and the whole class.
D / z.
Find literature in the library, analyze it according to the plan of productive reading.
Back forward
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Objectives:
1. Create conditions for acquainting students with the nature of Africa.
2. To form an idea of \u200b\u200bthe tectonic structure, relief and minerals of the continent - their composition, origin.
3. Continue the formation of the ability to establish cause-and-effect relationships, working with various geographical maps.
4. Formation of skills to work in a team, assess the level of their knowledge, develop memory, the ability to systematize the material studied.
Planned results:
Subject
1. The continent of Africa is named and shown;
2. Talk about the relief and minerals of Africa.
Personal
1. Realize the value of geographical knowledge as the most important component of the scientific picture of the world; 2. Work in a team; make judgments, confirming them with facts.
Metasubject
1. Organize their activities, define its goals and objectives.
2. Conduct an independent search, analysis, selection of information, interact with each other and have basic practical skills in working with a textbook, atlas, contour map.
Universal learning activities:
- regulatory: accept and formulate an educational problem.
- cognitive: analyze, compare, classify and generalize facts and phenomena, identify the causes and consequences of simple phenomena.
- communicative: ability to communicate and interact with each other.
Equipment:map "Structure of the Earth's crust", physical map of Africa, map of hemispheres, atlases, ICT.
During the classes
I. Introduction
1. Organization of the class
2. Topic of the last lesson
II. Knowledge check.
Two students at the blackboard are preparing to show the geographic features of the mainland using cards.
First student:
- The largest peninsula in Africa.
- Bay in the west of the mainland.
- The sea washing the northeastern coast of Africa.
- Strait (longest), in the east of the mainland.
- Warm current in the west of the mainland.
- The most northern point of the mainland.
- Ocean in the east of the mainland
Second student:
- The strait separating Africa from Europe.
- Cold current in the east of the mainland.
- A group of islands in the northwest of the mainland.
- The sea washing the northern shores of Africa.
- The largest island in the east of the mainland.
- The most extreme southern point of the mainland.
- Canal connecting the Mediterranean and the Red Sea.
Verbally at the blackboard:
1. Tell about the geographical location of the continent of Africa.
a) What is the role of Russian travelers in the study of Africa.
2. Show the extreme points of the continent and make a conclusion about the size of the territory.
a) What contribution did D. Livingston make to the study of Africa?
III. Learning new material.
1. General characteristics of the relief of Africa.
a) relief form
b) characteristic of heights
c) the structure of the earth's crust within the continent.
2. Characteristics of the plains
a) East African plateau.
3. Characteristics of the mountains
a) Ethiopian Highlands
b) Atlas mountains
c) Cape Mountains, Drakensberg Mountains
d) East African faults.
4. Minerals
a) ore
b) non-metallic
IV. Anchoring. Work on the contour map.
V. Homework: naragraph 25, work on the contour map (sign the names of volcanoes on the mainland).
Abstract
In a notebook, write down the topic of the lesson "Relief and minerals of Africa" \u200b\u200b(slide 1).
We have three tasks:
1. Give a general description of the relief of Africa.
2. Consider the features of the plains and mountains.
3. Get acquainted with the minerals of the mainland (slide 2).
I. a) Open the atlas, the physical map of Africa (slide 3).
What forms of relief are typical for the mainland?
Conclusion: on the mainland, most of the plains (they are located in the north and west of the mainland), a smaller part - mountains (in the east and south of the mainland) (slide 4).
b) On the map, describe the heights of the continent (name the prevailing heights, maximum, minimum) (slide 5).
Prevailing up to 1000 m, max - 5985 m - Mount Kilimanjaro, rises above the plains, covered with a snow cap at the top, the mountain has become a real symbol of the country of Tanzania (slide 6), min - 155 m, the level of Lake Assal (slide 7 ). Sign on the outline map.
Conclusion: prevailing heights up to 1000 meters, fluctuations in heights are significant.
c) open the atlas - map “Structure of the Earth's crust” (slide 8).
How did the formation of the relief go?
Using conventional signs, name the most ancient site of the earth's crust (African-Arabian platform). Areas of ancient folding are characteristic of the northern and southern parts of the continent. The area of \u200b\u200bancient folding is characteristic of the north-west of the mainland. The area of \u200b\u200bnew folding is characteristic of the extreme northwestern part.
In a very distant time, most of Africa was part of the huge ancient continent of Gondwana, which stretched in the southern hemisphere. The base of Africa is composed of crystalline rocks, granites, gneisses, they come to the surface in ancient mountains and on plateaus (slide 9).
Conclusion: the relief on the mainland has been forming over many millions of years and continues to form now.
Thus, we solved the first problem, gave a general description of the relief of Africa, noticed that plains predominate, since at the base lies the African-Arabian platform - a stable, leveled area of \u200b\u200bthe earth's crust.
We turn to the characteristics of the plains and mountains.
In the northern and western parts of the continent, there are more lowlands and depressions, huge areas are covered with sedimentary rocks. In addition to continental deposits, marine deposits are widely developed; a significant part of northern and western Africa was occupied by the sea for a long time (slide 10).
The East African Plateau is located in eastern Central Africa, between the Ethiopian Highlands in the north and the northern tip of Lake Nyasa in the south (slide 11). Sign on the outline map. Heights from 500 to 1500 meters. The plateau consists of individual ridges, valleys, gorges. On the plateau are the sources of the largest rivers in Africa: Nile, Congo, Zambezi.
The Ethiopian Highlands are located in northeastern Africa, strongly elevated above the surrounding plains, with an average elevation of 2000-3000 meters. The Highlands are sometimes called the "Roof of Africa". The highest point is Mount Ras Dashen (4623 m.), The fourth highest on the mainland (slide 12). Sign on the outline map.
In the northwest of the mainland there is a folded area - the Atlas Mountains (slide 13). Their northern ridges are the only area of \u200b\u200bnew folding on the mainland, formed simultaneously with the Himalayas and the Alps. The highest point is Mount Toubkal (4165m.) (Slide 14). Sign on the outline map.
The low and flat-topped Cape Mountains are located in the extreme south of Africa. They consist of several parallel ridges, 800 km long. The highest point is Mount Compassberg (2502 m) (slide 15). Sign on the outline map.
In the southeast of the mainland there is a rock massif - Drakonovy Gory, the highest point is Mount Tkabana-Ntlenyana (3482 m) (slide 16). The caves of the Drakensberg Mountains are famous for their rock art (slide 17). Another attraction of the mountains is the world's second highest waterfall Tugela (947 m.). The fabulous name of the mountains has several versions of its origin. One of them - allegedly local residents in the 19th century saw a huge lizard with the tail and wings of a dragon (slide 18). Sign on the outline map.
A strip of crustal faults stretches along the eastern outskirts for 4000 km. This is the strip of the East African rifts. It runs along the Red Sea, through the Ethiopian Highlands and the East African Plateau (slide 19). On the contour map, first draw a line of faults with a pencil, and then sign.
Conclusion: in Africa, the eastern and southern parts of the mainland are higher than the western and northern ones.
4. Let's get acquainted with the minerals of the mainland (slide 20).
Africa is rich in various minerals.
Open the atlas - a physical map of Africa.
- What are the two groups of minerals by origin? (ore and non-metallic) (slide 21).
- What are the deposits of nonmetallic minerals confined to? (they are confined to sedimentary rocks).
- Which nonmetallic minerals are found in Africa?
Large reserves of oil, natural gas, and coal have been found in sedimentary rocks of northern and western Africa.
Draw on a contour map of non-metallic mineral deposits.
What are the deposits of ore minerals confined to?
(they are confined to mountainous areas or those territories where the platform foundation comes to the surface).
Ore minerals are mainly found in eastern and southern Africa.
Draw ore deposits on a contour map.
IV. Anchoring (slide 22).
1. What forms of relief are typical for the mainland?
2. Why are plains dominant on the mainland?
3. Why is the northern and western parts of the continent covered with not only continental but also marine sediments?
4. Which parts of Africa are the most elevated?
At the end of the lesson, conduct a test (slide 23).
Test.
Option 1
1. What is the area of \u200b\u200bAfrica among other continents?
1) 1 2) 2 3) 3 4) 4
2. Africa is:
1) State name 2) Part of the world 3) Mainland
3. What forms of relief prevail in Africa?
1) Mountains 2) Lowlands 3) Plains
1) Toubkal 2) volc. Cameroon 3) volc. Kilimajaro 4) Atlas
5. The southernmost point of Africa is:
1) Cape Agulhas 2) Cape Ras Khafun 3) Cape Galinas 4) Cape Byron
Option 2
1. Africa is washed by oceans:
1) Quiet 2) Atlantic 3) Arctic 4) Indian
2. The area of \u200b\u200bthe mainland Africa -
1) 54 million sq. km 2) 30.3 million sq. km 3) 24.2 million sq. km
3. The highest point in Africa is the volcano -____________
Located at - ______________
4. The westernmost point of the mainland:
1) Cape Agulhas 2) Cape Almadi 3) Cape Froward 4) Cape Ras Khafun
5. The famous traveler who crossed South Africa from west to east, explored the Zambezi River, discovered the Victoria Falls.
1) Vavilov N.I. 2) Vasco da Gama 3) D. Livingston 4) Juncker V.V.
We transfer the work to a neighbor, check and give grades.
V. Homework: paragraph 25, sign the volcanoes on the mainland on the contour map (slide 24)
"," Minerals ". They are considered in the physical and geographical characteristics of a region.
Definition 1
Geological structure - this is the structure of a section of the earth's crust, the features of the bedding of rock layers, their mineralogical composition, origin.
When studying the geological structure of continents, the concepts of "platform" and "folded area" are encountered.
Definition 2
Platform Is a large, relatively immobile area of \u200b\u200bthe earth's crust.
Platforms are at the core of every continent. In the relief, the platforms correspond to the plains.
Definition 3
Folded area - a movable area of \u200b\u200bthe earth's crust, where active mountain-forming processes (earthquakes, volcanic eruptions) are taking place.
In the relief, folded areas are represented by mountain systems.
Definition 4
Relief Is a set of irregularities on the earth's surface.
Definition 5
Minerals - this is the wealth of the earth's interior that can be used by man to meet his needs
Finished works on a similar topic
- Coursework 430 rubles.
- abstract Geological structure and relief of Africa 260 RUB
- Test Geological structure and relief of Africa RUB 250
Features of the geological structure of Africa
About $ 180 million years ago, the territory of Africa was an integral part of the ancient supercontinent of Gondwana. When Gondwana split apart, the African lithospheric plate separated. The modern territory of Africa is based on a part of this plate, namely, the ancient (Precambrian) African-Arabian platform .
In most of the territory, active mountain building stopped another $ 1000 - $ 500 million years ago. Later, the hard core of the continent did not experience folded processes.
The lower part of the platform, that is, its foundation, is made up of crystalline rocks - basalts and granites of magmatic and metamorphic origin. They are very ancient in age. As a result of weathering, continental sediments accumulated on the basement, and marine sediments in depressions. Over millions of years, they have formed a powerful sedimentary cover on the platform. It should be noted that the sedimentary cover unevenly covers the basement, because the platform experienced several slow uplifts and subsidences over a long period of time. In those areas where there was a long process of uplift, the ancient crystalline rocks of the basement appeared on the surface, thus forming shields.
Definition 6
The shield is the place where the crystalline basement of the platform exits to the surface.
In other parts of the platform, the processes of subsidence and flooding by waters of ancient seas took place. In these places, the foundation was overlapped by a huge layer of marine sedimentary deposits, and plates formed on such parts of the platform. Millions of years later, the platform in its northwestern and southern parts was "completed" by parts of the ocean floor, while the strata of its sedimentary rocks were crumpled into folds and formed folded regions (area Atlas and Cape mountains ). More than $ 60 million years ago, the African-Arabian platform began to rise intensively. This rise was accompanied by giant fractures in the earth's crust. During these faults, the largest land-based system was formed East African faults (rifts) ... It stretches for $ 4000 $ km from the Isthmus of Suez along the bottom of the Red Sea and overland to the Zambezi River. The rift width in some places reaches $ 120 km. The above faults, like a knife, cut through the African-Arabian platform. Along them there are earthquakes, manifestations of volcanism.
Relief of africa
The relief of Africa is dominated by flat areas. This is due to the fact that almost the entire continent is based on a platform. A feature of the African plains is the predominance of high plains:
- hills,
- plateau,
- plateaus.
This can be explained by the general uplift of the entire territory of Africa in the Cenozoic. The lowlands extend only in narrow strips, mainly along the sea coasts.
The largest plains are located in the northern and western parts of the mainland. Their surface is very heterogeneous. At the same time, the alternation of highlands with lowlands and plateaus is characteristic of Africa. In places where crystalline basement rocks emerge on the surface, ahaggar and Tibesti highlands , with a height of more than $ 3000 m. Among the high plateaus (up to $ 1000 m) lies the Congo swampy depression. The Kalahari Depression is also surrounded by plateaus and plateaus on all sides.
A relatively small area in Africa is occupied by mountains. The highest marks are East african highlands ... On it are the extinct volcanoes kenya ($ 5199 m) and Kilimanjaro ($ 5895 $ m) - the highest point in Africa.
These volcanic mountains are confined to the East African Rift Zone. Ethiopian highlands with numerous extinct volcanoes, it is raised by $ 2000- $ 3000 m. It drops abruptly in the east and descends in ledges in the west. In the northwestern part of the mainland rise atlas mountains (or Atlas Mountains), formed at the junction of two lithospheric plates, in the place where the earth's crust was crumpled into folds. In the south of the mainland, low and flat-topped Cape Mountains ... They outwardly resemble cups turned upside down (hence the name). Dragon mountains - higher, from the coast they descend in giant ledges to the interior regions of the mainland.
Minerals
The bowels of Africa are rich in a variety of minerals, their location is closely related to the geological structure of the continent. Deposits of ore minerals are confined to the ancient foundation of the platform. In particular, this applies to gold and ores such as:
- iron,
- copper,
- zinc,
- pewter,
- chrome.
The largest deposits are concentrated in the south and east of Africa, in places of shallow bedding. There, in particular, are significant deposits gold and copper , in terms of the amount of their reserves, Africa ranks respectively first and second in the world. The bowels of the continent are rich and uranium ores ... Africa is famous for deposits diamonds - valuable precious stones.
Remark 1
They are used not only for the manufacture of expensive and exquisite jewelry, but also as materials that are unsurpassed in their hardness. Half of the world's diamonds are mined in Africa.
Their deposits were found on the southwestern coast and in the center of the mainland. Deposits of nonmetallic minerals occur in sedimentary rocks that cover the lowered areas of the platform with a thick cover. These breeds in Africa include:
- coal,
- natural gas,
- oil,
- phosphorites and others.
There are huge deposits in the north of the Sahara and on the shelf of the Gulf of Guinea. Developed deposits of phosphorites, widely used in the production of fertilizers, are located in the north of the continent. In sedimentary strata there are also ore fossils, which were formed as a result of the weathering of igneous and metamorphic rocks. For example, deposits are known in the southern and western regions of Africa iron, copper, manganese ores and gold of sedimentary origin.
