Detailed solution paragraph 15 in geography for students in grade 8, authors Pyatunin V.B., Customs E.A. 2018

remember the name and geographical position large plains and mountain systems in Russia. How does the relief depend on the structure earth's crust? Into what groups are minerals divided according to their origin?

The terrain depends on the structure of the earth's crust. If the terrain is located on a plate or platform, the terrain will be flat, folding and mountains will form at the junction of the plates, especially deep lakes will form on the faults.

By origin, all minerals are divided into igneous, sedimentary and metamorphic.

1. East - European Plain

One of the largest plains on the planet, covering most of Eastern Europe, received a second name - Russian. The distance between the northern and southern borders exceeds 2500 km. And from west to east it stretches for 2700 km.

In the northwest - the Scandinavian mountains;

In the south - west - the mountains of Central Europe (Sudet);

In the southeast - the Caucasus Mountains;

In the west - the Vistula River;

In the north - the White and Barents Seas;

In the east - the Ural Mountains and Mugodzhary.

2. West Siberian Plain

The plain is located in the northern part of Asia and covers the entire territory of western Siberia. It has a characteristic trapezoidal shape, which narrows towards the north. The length from south to north is about 2500 km, and from west to east it varies from 800 to 1950 km.

In the west - the Ural Mountains;

In the east - the Central Siberian Plateau;

In the north - the Kara Sea;

In the south - the Kazakh uplands;

In the southeast - the West Siberian Plain and the foothills of Altai.

3. Central Siberian Plateau

Located in the eastern part of Russia and located on the Siberian platform, it covers the territories of the Irkutsk region, the Krasnoyarsk Territory and Yakutia.

In the south - the Eastern Sayan mountain system, as well as the mountainous regions of the Baikal and Transbaikalia;

In the west - the valley of the Yenisei River;

In the north - the North - Siberian lowland;

To the east is the valley of the Lena River.

The Caucasus mountain system stretches along the northeastern coast of the Black Sea for almost 1000 km. The border between Georgia and Russia runs along the Main Caucasian Range. In its central part there are several peaks over 5000 m high. The relief here is strongly dissected, sharp ridges, peaked peaks, and steep rocky slopes predominate.

1. The mountains of Southern Siberia are Mountain country in the south of Siberia, including Altai, Salair, Kuznetsk Alatau, Western and Eastern Sayan, the mountains of Tuva, Baikal, Transbaikalia, Stanovoy Range, as well as vast intermountain depressions - Kuznetsk, Minusinsk, Tuva, Todzhinsk. Altai consists of ridges that form the watershed of the Ob, Irtysh, Yenisei and rivers of the drainless region Central Asia. Length over 2000 km. It is divided into Altai proper, Gobi Altai and Mongolian Altai. The highest ridges of Altai - Katunsky, North - and South - Chuysky reach a height of 3000 - 4000 m (the highest point of Belukha is 4506 m) and carry modern glaciers (the total glaciation area is more than 900 km2). For Altai, ridges and massifs 1500 - 2500 m high with weakly dissected ridges are also typical, separated by intermountain basins, called the Chuya steppe, Kuraiskaya and others.

2. The Urals includes the Ural mountain system, which is elongated almost meridionally south of the coast of the Kara Sea. The length is more than 2000 km, the width is from 40 to 150 km. It consists of the main watershed ridge and several side ridges separated by wide depressions. It is divided into the Polar Urals, the Subpolar Urals, the Northern Urals, the Middle Urals and the Southern Urals. The highest point of Narodnaya (1895 m.).

3. The Main Caucasian (Dividing) Range - a continuous mountain range stretching for more than 1100 km from the northwest to the southeast from the Black Sea (Anapa region) to the Caspian Sea (Mount Ilkhydag northwest of Baku).

The Caucasus Range divides the Caucasus into two parts: Ciscaucasia ( North Caucasus) and Transcaucasia (South Caucasus).

The mountain system, which includes the Main Caucasian Range (or the Greater Caucasian Range), is called the Greater Caucasus, in contrast to the Lesser Caucasus, a vast highland located south of the Rioni and Kura valleys and directly connected with the uplands of Western Asia.

Using physical map atlas, find the highest and lowest points of the territory of Russia. Determine their absolute heights; calculate the amplitude of the heights. Within what tectonic structures are the required points located?

The highest point in Russia is a mountain called Elbrus with a height of 5642m. Stratovolcano.

The height of the lowest point of the coast of the Caspian Sea is minus 28 meters above sea level.

Tectonic structure.

The Caspian lowland includes several large tectonic structures (the Caspian syneclise, the Ergenin uplift, the Nogai and Terek depressions).

The height amplitude is 5670m.

2. Question

Why are platform areas expressed in relief as plains, and mountains correspond to folded areas?

Platform areas are calm, immovable parts of the lithospheric plate, therefore the relief on them is flat, the plates are the moving parts of the lithosphere, when they come into contact when approaching, the edges of the plates “crumple” forming folds - this is how mountains appear.

3. Question

Using physical and tectonic maps, determine what type of mountain systems in terms of height, age and structure the Ural Mountains and the Sredinny Range belong to.

The Ural Mountains are a mountain system in the Urals, located between the East European and West Siberian plains.

The structure of the Urals: according to the nature of the relief and landscapes, the Polar, Subpolar, Northern, Middle and Southern Urals are distinguished.

The Ural Mountains belong to the old mountains (600 million years old) of linear Hercynian folded systems, with a height difference from low mountains (Northern Urals) to middle mountains (Polar Urals).

The Sredinny Range is the main watershed range on the Kamchatka Peninsula, the length of the range is about 1200 km, the mountain range of the end of the Cenozoic folding, the mid-mountain range. The mountain system is mobile volcanic.

School of geographer - researcher

Exercise 1

Based on the diagram, answer the question: "Why is the Caucasus the highest mountains in our country"?

2. Question

Mountains whose folds were formed in the era alpine folding are usually high. Why are the young Crimean mountains lower than the Urals in their heights?

The Ural Mountains are composed of two structural tiers. The lower tier is represented by solid pre-Ordovician strata - gneisses, schists, quartzites, marble. The upper tier is represented by Triassic deposits (sandstone, limestone). Over time, the Triassic deposits of the Urals were destroyed, but the lower, more durable layer represents the mid-mountain heights.

Geologically, the main ridge of the Crimean Mountains is actually a region of classical Mediterranean karst and is composed at the base of clayey-sandstone deposits of the Upper Triassic and Lower Jurassic, sandstones, Middle Jurassic conglomerates, and in the upper part limestones, sandstones, Upper Jurassic conglomerates and, in some places, Lower Cretaceous clays . Under the influence of physical factors: the sun, wind, water, the mountains were destroyed with a decrease in their height to low mountains.

Therefore, the Crimean mountains are lower than the Ural ones.

3. Question

It's all the bumps earth's surface, which is formed due to the interaction of internal and external forces Earth.

Landforms are distinguished by size, structure, origin, etc. There are convex (positive) and concave (negative) relief forms.

This diversity is explained, first of all, by the large size of the territory and the complex geological history this territory. The largest plains: East European (Russian),. They are located on and have a two-tiered structure. The West Siberian Plain is located on the West Siberian Plate. It is often called the lowland, because. half of its territory has a height of less than 100 meters and only at the edges of its height reaches 150 - 200 m.

Divide East European and West Siberian Plain, low mountains (the highest peak of these mountains is Mount Narodnaya 1895 m). These are ancient, strongly destroyed and slightly renewed in the Neogene folded-block mountains.

In western Yakutia, potash and table salts c, mica in Eastern Siberia, as well as graphite in the Urals, Eastern Siberia and the Far East.

The country has significant reserves of peat, oil shale, construction sand, limestone, chalk and gypsum.
According to the reserves of many minerals Russian Federation occupies leading positions in the world, so 1st place in terms of reserves and iron ore, 3rd place in explored coal reserves, etc. and develops its economy almost entirely on its own mineral resources. Despite this, it must be remembered that minerals accumulated over long history development of the Earth - are exhaustible and non-renewable. Their careful, rational use is necessary. To do this, new technologies are being developed that ensure minimal losses during mining and processing, it is necessary to extract from the ore as much as possible all the useful components that are in it. In addition, the search and development of new deposits.

Australia is the only country that occupies almost the entire continent. Meanwhile, this is the flattest continent, and its small size is compensated big amount minerals that are mined here annually.

The country is among the top five in the extraction of raw materials; the latest equipment is used here to automate and speed up the extraction process. An interesting structure, various plains and elevations make it one of the most amazing continents in the world.

History of the formation of mainland Australia

The geological position of Australia was formed millions of years ago, when this land was still part of the supercontinent. Time and elements have formed a flat continent dominated by wide plains and plateaus. There are no land cordons, the shores are washed by three oceans - Indian, Pacific and Southern.

Once this continent was part of the large mainland of Gondwana, wind, water leveled its surface, which laid the foundation for the formation of the relief and minerals of Australia. The features of the foundation also explain the movement of the glacier from the south, which combed the mountainous terrain, turning it into lowlands and plains. Therefore, sometimes in the territory there are hills with flat tops.

The contours of Australia on the world map appeared thanks to the navigator James Cook. Prior to this, the land was closed for research, it was inhabited only by indigenous people. There is a theory that Portuguese sailors secretly discovered this mainland back in the 16th century, but when studying maps and their route, it was not confirmed.

Until the early twentieth century, Australia was a colony of Great Britain, which the locals called " white colony settlers." modern country is an independent state, but the Queen of England remains the head.

Features of the formation of the Australian relief

The central part of the mainland is located in a tropical climate zone, so a large territory of the Commonwealth of Australia is occupied by deserts, semi-deserts and tropical woodlands are also found. There is a very interesting tectonic structure here. Its basis is the Precambrian Australian platform, it makes up almost the entire continent. To the east is the Tasmanian Fold Belt, which was formed back in the Paleozoic era. To determine the features geological structure and the relief of Australia, it is necessary to distinguish the following parts of the continent:

• East End.
• Central lowland.
• West Side.

The Western Australian Plateau is considered the oldest part of the mainland. Coasts in the west may be limited by ridges, mountains, the tops of which are mostly truncated and flat. The average height along the western part starts from four hundred to five hundred meters and rises along the edges.

The relief of the Commonwealth of Australia is largely dominated by plains. This is justified by tectonic features. The highest point is Mount Kosciuszko, reaching 2.28 km in height. It is part of the only mountain system - the Great Dividing Range, which is located in the east of the country. The elevations are not covered with snow caps, because the temperature of the tropical zone does not fall below 5 degrees. But, the moving glacier left glacial landforms - lakes, granite scratches, polished rocks.

There are also eolian representatives formed under the action of winds, which blew out fragile crumbling particles. It plays a huge role in geological exploration, for the search for minerals.

Magnetite ores can be found here, but their quantity is inferior to sedimentary minerals.

Surprisingly, there is not a single active volcano on the mainland. The last representatives of the lava mountains froze millions of years ago. No less important for assessing the relief and minerals is the fact that almost ninety-five percent of the surface of the lowest continent does not exceed six hundred meters above sea level.

It is in Australia that the lowest point on land is located, which was formed on the shores of Lake Eyre. It has a glacial origin, which explains this feature.

Minerals of the Commonwealth of Australia

The features of the relief of Australia, as well as the unusual structure, influenced the amount of minerals that are mined throughout the country. The Australian Union is one of the world's most powerful suppliers of the planet's raw material potential, exporting mineral and organic raw materials mined on its territory.

metal resources

The mineral resources of the country are very diverse. Here is the world's leading producer of bauxite (aluminum ore), a large amount of iron ores, coal, oil. Nature did not deprive the land of this unusual continent of rare and precious metals: lead, gold, diamonds, uranium and zinc.

Non-ferrous metals are mined in the west and in the central part of the country. Australia ranks second in aluminum production behind Guinea. The largest deposits of this raw material:

• vape;
• Jarradale.

The land is also rich in polymetallic ores - which contain zinc, nickel, lead, copper. Most of their deposits are located in the north, as well as in New Wales and Queensland. One of the leading industries in the country is nickel mining. In terms of the production and export of this metal, Australia leads the world market. But in terms of gold mining, this small continent ranks 4th in the world.

The main deposits are located in the regions of the Western Australian plateau. Iron ore is mined in the Hamersley Basin, on the western side of the mainland. Most of these are brown, magnetic iron ore and hematite. Ores mined in the deposits have a high percentage of iron (up to 60). This explains the high quality of the raw material and its economic value.

Mineral resources

Mineral sand belongs to the group of heavy minerals that can usually be found and mined in the places of old beaches, rivers or dunes, after knowing the characteristics of the fossil.

On the mainland, three main elements are mined from the group of mineral sands:

• Titanium (ilmenite and rutile);
• Zirconium (zircon);
• Thorium (monazite).

A huge amount of these materials is explained by the sedimentary type of rock formation. Due to the constant impact of wind and water, the waste rock was destroyed very quickly, due to which heavy metals settled in one place.

Large deposits are found on the eastern and southwestern coasts. They are important not only for the Australian, but also for the global commodity market, because they are rare materials that are rarely found in such quantities. The content of metals in the rock can range from 1 to 60%, but in Australia it is more common from 20% or more. It is a very important part of the country's natural resources.

There are also deposits of precious and semi-precious stones. The most famous is opal - it is in Australia that the world capital for the extraction of this jewelry mineral - Coober Pedy is located. Every year, its production brings the country more than 30 million dollars.

Here, some people consider this stone sacred, it gives longevity, strength and protects its owner from adversity. After cutting, it loses its power, so in many stores you can find fragments that have a pristine appearance.

Quartzites, diamonds, emeralds are also found in this area, but their number is significantly inferior to other countries.

Fuel fossils

The Australian coal industry is highly developed. high level. Here, not only a huge amount of this mineral is mined, but also the most innovative technologies. The country is critically approaching issues environmental situation. Considering that the burning of coal emits a lot of harmful substances into the atmosphere, there is a policy of withdrawing this raw material from use. At the same time, it is encouraged to introduce alternative sources electricity that do not harm the environment.

In terms of coal exports, Australia ranks 4th, overtaking even Russia, where the maximum deposits of minerals. The oldest mine is in New Castle. It was discovered back in 1800, but is still being developed. The largest deposits of brown coal are located in the state of Victoria.

The mainland's oil industry is also breaking all world records. Most of it is found on the plume of Western Australia. There are deposits of not only liquid, but also shale black gold. This raw material has high quality, respectively, and the price is superior to the liquid alternative. The deposit was found in 2017, but its development will only begin when geologists and environmentalists find the most cost-effective, environmentally friendly and safe way to pump it out. It is planned to use the most innovative methods so as not to injure the ecosystem of the area.

Conclusion

Australia is an amazing country with a special relief and interesting history. There are a lot of minerals of different origin - igneous, metamorphic and sedimentary. The relief of the mainland is represented mostly by plains, but there are also elevations and mountain ranges.

It is now impossible to accurately assess the relief and minerals of Australia, because geologists are constantly exploring deposits that will increase production and improve the economic condition of the country. Mineral resources of the country have a very strong influence on its economic component. Now it is the world raw material base of gold, opals, coal, iron, manganese and aluminum ore.

Back forward

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Goals:

1. Create conditions for students to get acquainted with the nature of Africa.

2. To form an idea of ​​the tectonic structure, relief and minerals of the mainland - their composition, origin.

3. Continue the formation of the ability to establish causal 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 studied material.

Planned results:

subject

1. Name and show the mainland Africa;

2. Tell about the relief and minerals of Africa.

Personal

1. Recognize the value of geographical knowledge as an essential component of the scientific picture of the world; 2. Work in a team; make judgments that are supported by facts.

Metasubject

1. Organize their activities, determine its goals and objectives.

2. They conduct an independent search, analysis, selection of information, interact with each other and possess elementary practical skills in working with a textbook, atlas, contour map.

Universal learning activities:

• regulatory: accept and formulate a learning problem.
• cognitive: analyze, compare, classify and generalize facts and phenomena, identify the causes and effects of simple phenomena.
• communicative: the ability to communicate and interact with each other.

Equipment: map “The structure of the earth's crust”, a physical map of Africa, a map of the hemispheres, atlases, ICT.

During the classes

I Introduction

1. Class organization

2. Theme of the last lesson

II. Check of knowledge.

Two students at the blackboard are preparing to show geographical features of the mainland using cards.

First student:

1. The largest peninsula in Africa.
2. Bay in the west of the mainland.
3. The sea that washes the northeastern shores of Africa.
4. Strait (the longest), in the east of the mainland.
5. Warm current in the west of the mainland.
6. The most extreme northern point of the mainland.
7. Ocean in the east of the mainland

Second student:

1. The strait separating Africa from Europe.
2. Cold current in the east of the mainland.
3. A group of islands in the northwest of the mainland.
4. The sea that washes the northern shores of Africa.
5. The largest island in the east of the mainland.
6. The most extreme southern point of the mainland.
7. Canal connecting the Mediterranean and the Red Sea.

Orally at the blackboard:

1. Tell about the geographical location of the African continent.

a) What is the role of Russian travelers in the exploration of Africa.

2. Show the extreme points of the mainland and draw a conclusion about the size of the territory.

a) What contribution to the study of Africa did D. Livingston make.

III. Learning new material.

1. general characteristics relief of Africa.

a) landform

b) height characteristic

c) the structure of the earth's crust within the mainland.

2. Characteristics of the plains

a) East African plateau.

3. Characteristics of the mountains

a) the Ethiopian highlands

b) Atlas Mountains

c) Cape Mountains, Dragon Mountains

d) East African faults.

4. Minerals

a) ore

b) non-metallic

IV. Consolidation. Work on the contour map.

v. Homework: P paragraph 25, work on the contour map (sign the names of volcanoes on the mainland).

Abstract

In a notebook, write the topic of the lesson “Relief and minerals of Africa” (slide 1).

We have three tasks ahead of us:

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 landforms are characteristic of the mainland?

Conclusion: on the mainland, most of it is occupied by plains (they are located in the north and west of the mainland), the smaller part is occupied by mountains (in the east and south of the mainland) (slide 4).

b) On the map, characterize the heights of the mainland (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 contour map.

Conclusion: the prevailing heights are up to 1000 meters, the height fluctuation is significant.

c) open the atlas - the map “The structure of the earth's crust” (slide 8).

Tell us how the relief was formed?

Using conventional signs, name the most ancient part of the earth's crust (African-Arabian platform). Areas of ancient folding are characteristic of the northern and southern parts of the mainland. The region of ancient folding is characteristic of the northwest of the mainland. The region of new folding is characteristic of the extreme northwestern part.

In a very distant time, most of Africa was part of the vast ancient continent of Gondwana, which stretched across the southern hemisphere. The foundation of Africa is composed of crystalline rocks, granites, gneisses, they come to the surface in ancient mountains and plateaus (slide 9).

Conclusion: the relief on the territory of the mainland was formed over many millions of years and continues to be formed even now.

Thus, we solved the first problem, gave a general description of the relief of Africa, noticed that plains predominate, since the African-Arabian platform lies at the base - a stable, leveled section of the earth's crust.

Let's move on to the characteristics of the plains and mountains.

In the northern and western parts of the mainland there are more lowlands and basins, vast areas are covered with sedimentary rocks. In addition to continental deposits, marine deposits are widely developed, tk. much of northern and western Africa long time was occupied by the sea (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 contour map. Altitudes from 500 to 1500 meters. The plateau consists of separate ridges, valleys, gorges. On the plateau are the origins of the most major rivers Africa: Nile, Congo, Zambezi.

The Ethiopian highlands are located in northeast Africa, strongly elevated above the surrounding plains, the average height is 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 contour map.

In the northwest of the mainland there is a folded area - the Atlas Mountains (slide 13). Their northern ranges are the only area of ​​new folding on the mainland, formed simultaneously with the Himalayas and the Alps. The highest point is Mount Toubkal (4165m.) (slide 14). Sign on the contour map.

The low and flat-topped Cape Mountains are located in the extreme south of Africa. They consist of several parallel ranges, 800 km long. The highest point is Mount Kompassberg (2502 m) (slide 15). Sign on the contour map.

In the southeast of the mainland there is a rocky massif - the Dragon Mountains, the highest point of Mount Tkabana-Ntlenyana (3482 m) (slide 16). The caves of the Dragon Mountains are famous for their rock art (slide 17). Another attraction of the mountains is the second highest Tugela waterfall in the world (947 m). The fabulous name of the mountains has several versions of origin. One of them - supposedly local residents in the 19th century saw a huge lizard with a tail and wings of a dragon (slide 18). Sign on the contour map.

Along the eastern outskirts, a strip of faults in the earth's crust stretches for 4000 km. This is the East African Rift. 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 - the physical map of Africa.

• What two groups are minerals divided by origin? (ore and non-ore) (slide 21).
• What are non-metallic mineral deposits confined to? (they are confined to the strata of sedimentary rocks).
• What non-metallic minerals are found in Africa?

Large reserves of oil, natural gas, and coal have been found in the sedimentary rocks of northern and western Africa.

Apply to contour map deposits of non-metallic minerals.

What are the deposits of ore minerals?

(they are confined to mountainous areas or those territories where the foundation of the platform comes to the surface).

Ore minerals are mainly found in eastern and southern Africa.

Plot mineral deposits on a contour map.

IV. Anchoring(slide 22).

1. What landforms are typical for the mainland?

2. Why do plains prevail on the mainland?

3. Why is the northern and western part of the mainland covered not only by continental, but also by marine deposits?

4. What parts of Africa are the most elevated?

At the end of the lesson, conduct a test (slide 23).

Test.

1 option

1. What is the area of ​​Africa 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 landforms prevail in Africa?

1) Mountains 2) Lowlands 3) Plains

1) Toubkal city 2) Volk. Cameroon 3) volk. Kilimajaro 4) Atlas

5. The extreme southern point of Africa is:

1) Cape Agulhas 2) Cape Ras Hafun 3) Cape Galinas 4) Cape Byron

Option 2

1. Africa is washed by the oceans:

1) Pacific 2) Atlantic 3) Arctic 4) Indian

2. Area of ​​mainland Africa -

1) 54 million sq. km 2) 30.3 mln. km 3) 24.2 million sq. km

3. The highest point in Africa is the volcano -____________

Located on - ______________

4. The extreme western point of the mainland:

1) Cape Agulhas 2) Cape Almadi 3) Cape Froward 4) Cape Ras Hafun

5. A 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) Junker V.V.

We transfer the work to a neighbor, check and put marks.

V. Homework: paragraph 25, on the contour map, sign the volcanoes on the mainland (slide 24)

Date of: 30.11.2019

Relief

At the heart of the mainland lies the ancient African-Arabian platform, which forms the predominantly flat relief of the continent. The relief of Africa is dominated by plains, plateaus and plateaus, located at an altitude of 200-500 m above sea level (39% of the area) and 500-1000 m above sea level (28.1% of the area). Lowlands occupy only 9.8% of the area and are located mainly along the coastal margins. In terms of average height above sea level (750 m), Africa is second only to Antarctica and Eurasia.

Almost all of Africa north of the equator is occupied by the plains and plateaus of the Sahara and Sudan, among which the Akhaggar and Tibesti highlands rise in the center of the Sahara (Mt. Ami-Kussi, height 3415 m), in Sudan - the Darfur plateau (Mr. Marra, 3088 m) . In the northwest, the Atlas Mountains (Tubkal, 4165 m) rise above the plains of the Sahara; in the east, along the Red Sea, the Etbai Range (Oda, 2259 m) stretches. The plains of Sudan from the south are framed by the North Guinean Upland (Bintimani, 1948 m) and the Azande Plateau; from the east, the Ethiopian highlands rise above them (the city of Ras-Dashen; 4620). It abruptly breaks off to the Afar depression, where the deepest depression in Africa is located (Lake Assal, 150 m).

The Congo Depression is bounded from the west by the South Guinean Upland, from the south by the Lunda-Katanga Plateau, from the east by the East African Plateau, on which rise the highest peaks of Africa - Mount Kilimanjaro (5895 m), Rwenzori (5109 m).

South Africa is occupied by the high plains of the Kalahari, framed from the west by the plateaus of Namaqualand, Damaraland, Kaoko, from the east by the Dragon Mountains (Tabana-Ntlenyana, 3482 m). Along the southern edge of the mainland stretch the medium-altitude Cape Mountains. The predominance of the leveled relief is due to the platform structure of the mainland.

In the northwestern part of Africa, with a deep basement and a wide development of the sedimentary cover, heights of less than 1000 m predominate ( Low Africa); southwest Africa is characterized by heights of more than 1000 m ( High Africa). Troughs and protrusions of the African platform correspond to large depressions (Kalahari, Congo, Chadian, etc.).

The eastern margin of Africa is more uplifted and fragmented within the activated area of ​​the platform - the Ethiopian Highlands, the East African Plateau, where it extends a complex system East African faults. In the uplifted regions of High Africa, the largest area is occupied by basement plains and basement blocky mountains, framing the depressions of East Africa (including Rwenzori) and Katanga. In Low Africa, basement ridges and massifs, stretching along the coast of the Gulf of Guinea, protrude into the Sahara (in the Ahaggar, Tibesti, Etbai ranges). Lava plateaus and cones common in the Ethiopian highlands and in East Africa(Kilimanjaro, Kenya, etc.), crown the peaks of Ahaggar and Tibesti, are in Sudan (Marra), Cameroon (Cameroon Volcano, Adamawa Mountains), cover the Dragon Mountains in Lesotho.

The processes of volcanism are associated with faults in the earth's crust, which are the cause of the formation of high uplands and volcanic peaks. Mountains of Africa different ages: old ones are located in the south (Draconic and Cape), young ones (Atlas) - in the north.

Geological structure and minerals

Almost all of Africa, except for the Atlas Mountains in the northwest and the Cape Mountains in the extreme south, is ancient platform, which also included the Arabian Peninsula and about. Madagascar with the Seychelles.

At the heart of the mainland lies the old African-Arabian platform with significantly destroyed folded formations. In the south and east of the mainland, the crystalline basement comes to the surface. Here is a zone of deep faults in the earth's crust: handfuls (uplift) - the Ethiopian Highlands, the East African Plateau, the Dragon Mountains, grabens (lowering) - the Nyasa and Tanganyika basins. Mobile folded zones adjoin the platform: in the north - the Atlas, in the south - the Cape Mountains.

The foundation of the African-Arabian platform, composed of Precambrian rocks, mostly folded and metamorphosed, protrudes in many parts of Africa - from the Anti-Atlas and Western Arabia to the Transvaal. The basement includes rocks of all age subdivisions of the Precambrian, from the Lower Archean (more than 3 Ga) to the upper Proterozoic. The consolidation of most of Africa was completed by the middle of the Proterozoic (1.9-1.7 billion years ago); in the late Proterozoic, only peripheral (Mauritano-Senegalese, Arabian) and some internal (Western Congolese) geosynclinal systems developed, and by the beginning of the Paleozoic, the entire area of ​​\u200b\u200bthe modern platform was stabilized.

The rocks of the early Precambrian basement are represented by various crystalline schists, gneisses, metamorphosed volcanic formations, and are replaced by granites over large areas. They are characterized by deposits of iron ores, gold (in connection with granites), chromites. Large accumulations of gold and uranium ores are known in the clastic rocks of the base of the sedimentary cover in southern Africa.

Younger, weakly metamorphosed rocks of the Upper Proterozoic contain deposits of tin, tungsten (in or near granites), copper, lead, zinc, and uranium ores. Powerful volcanic eruptions and eruptions of the main (basaltic) magma belong to the beginning of the Jurassic, most common in South Africa, but also found in western North Africa. By the same time (the end of the Jurassic) is the formation of the modern contours of Africa, associated with the subsidence along the ruptures of the bottom of the Indian and Atlantic Oceans and the formation of a system of perioceanic troughs containing significant deposits of oil and gas (Nigeria, Gibon, Angola, etc.).

Madagascar separated from the continent at the end of the Paleozoic. At the same time, the modern coast of Tunisia and Libya was intensively submerged by the formation of oil deposits in the Cretaceous and Eocene deposits. In the middle and end of the Cretaceous, a significant transgression of the sea engulfed the Sahara Plate: sea straits arose that connected the Mediterranean Sea and the Gulf of Guinea and existed until the middle of the Eocene.

Africa has large deposits of iron ores (total reserves are estimated at about 16-23 billion tons), manganese ores (about 400 million tons), chromites (500-700 million tons), bauxite (3.3 billion tons), copper (reliable and probable reserves of about 48 million tons), cobalt (0.5 million tons), phosphorites (26 billion tons), antimony, lithium, uranium, asbestos, gold (Africa provides about 80% of the world's total production), platinum and platinoids (about 60 % of production), diamonds (98% of production). After the Second World War, large deposits of oil (total reserves are estimated at 5.6 billion tons) and natural gas were discovered in Africa (mainly in Algeria, Libya and Nigeria).

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FGP, research historyClimatic conditions

see also

Africa. Physical and geographical position. History of research and development