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Geological structure, relief, minerals of South America. Relief and minerals of South America

The relief of South America is varied. According to the nature of the geological structure and features of the modern relief, South America is divided into two heterogeneous parts. The eastern part of the mainland is the ancient South American platform; western - actively developing folded belt of the Andes. The elevated sections of the platform - shields - correspond in relief to the Brazilian and Guiana plateaus. The troughs of the South American platform correspond to the giant lowland plains - the Amazonian, Orinoc, the system of internal plains (the Gran Chaco plain, the Laplata lowland), and the young Patagonian platform to the plains of Patagonia.

The Amazonian lowland is filled with marine and continental sediments. It was formed as a result of the activity of the Amazon River, as a result of the accumulation of sediments brought by the course. In the west, the lowland is very flat, the river valleys are slightly incised, the heights barely reach 150 m. Its northern and southern margins, underlain by crystalline rocks of the shields, are elevated and gradually turn into plateaus.

The Brazilian Plateau is located in the east of the mainland. It is a ledge of the crystalline foundation of the platform, between which there are troughs filled with sedimentary rocks and volcanic lavas. This is the largest rise within the platform. The Brazilian plateau has heights from 250-300 m in the north to 800-900 m in the southeast. The relief of the plateau is a relatively leveled surface, above which blocky massifs and plateaus rise.

In the north of the mainland, the Guiana Plateau (300-400 m) is confined to the vast ledge of the folded base of the platform. Its relief is dominated by stepped plateaus.

The vast plains and large sections of the plateaus of South America are convenient for the life and economic activity of the population. (Show on the map the largest lowlands and plateaus and determine their maximum heights.)

Andes - the longest Mountain chain on land with a length of 9000 km. The Andes are one of the highest mountain ranges the globe. In height, it is second only to the Tibetan-Himalayan mountainous country. Twenty peaks of the Andes rise to a height of more than 6 thousand meters. The highest of them is the city of Aconcagua (6960 m).

The formation of the Andes is the result of the interaction of two lithospheric plates when the oceanic Nazca plate "dived" under the continental South American. At the same time, the edge of the continental plate was crumpled into folds, forming mountains. Currently, mountain building continues. This is evidenced by the eruptions of numerous volcanoes and the strongest catastrophic earthquakes. Among the large volcanoes, one can note such as Chimborazo (6267 m), Cotopaxi (5897 m). The west coast, occupied by the Andes, belongs to the Pacific "Ring of Fire".

The strongest in the world recorded in 11-12 points occurred in 1960 in Chile. In 2010, an earthquake in Chile claimed several hundred lives. Serious disasters occur in the Andes every 10-15 years.

The Andes mountain system consists of several meridianally elongated mountain ranges. Between the ridges lie internal plateaus and plateaus, with a height of 3500 to 4500 m.

Minerals of South America

The mainland is rich in minerals. The richest deposits of iron and manganese ores are confined to the ancient shields of the South American Platform: the center and outskirts of the Brazilian Plateau, as well as the north of the Guiana Plateau. The largest mining area iron ores is Carajas. In the northern part, on the outskirts of both plateaus, there are very large deposits bauxite, a raw material for the aluminum industry. Bauxites occur at shallow depths and are mined open way.

Ores of copper (Peru, Chile), tin (Bolivia), lead and zinc (Peru) have been explored in the Andes. The foothills of the Andes, especially Venezuela and Colombia, are rich in oil and natural gas. Place of Birth hard coal less significant (Ecuador, Argentina). Many Andean countries known for mining gemstones. First of all, this applies to the extraction of emeralds in Colombia. Of the precious metals in South America, the largest reserves of silver are in Peru. The Andes belt is also famous for some non-metallic minerals. Saltpeter occupies the first place among them. The famous Chilean saltpeter and iodine are mined in the dried-up reservoirs of the Atacama.

The relief of South America is more diverse in comparison with Africa and Australia. The high Andes in the west separate the main flat part of the mainland from the Pacific Ocean. South America is characterized by active seismicity. South America is called the "pantry of the world." The mainland is rich in natural resources necessary for the development of many sectors of the economy.

In the relief of South America, as you already know, there are common features with Africa and Australia. Remember them and answer the following questions:

  1. What types earth's crust includes the South American lithospheric plate? In what direction is it moving? Why?
  2. How are folds formed? mountain belts? Why southern continents do they lie on the outskirts?

In the relief of South America, two parts stand out. The east is occupied by plains, and the Andes mountain ranges stretch to the west. How was the modern relief of the mainland formed? How is it currently changing?

Plain-flat-mountain East is located on the platform.

The western part of the mainland is the result of the interaction of two lithospheric plates. The oceanic plate moves under the continental one and plunges into the mantle, forming a trough. The edge of the continental plate is crumpled into folds. The formation of the Andes continues, there are frequent earthquakes, volcanic eruptions. The most powerful movements occur every 10-15 years. The last destructive earthquakes occurred in the Andes in 1960, 1970, 1985. Earthquakes are the worst natural disasters for peoples living in the Andes. As a rule, volcanic eruptions are associated with them, as well as shaking seabed and tsunami formation. In the mountains, earthquakes are accompanied by rockfalls, landslides, snow avalanches. In May 1970, a snow and ice avalanche descended from the slopes of a mountain in the Peruvian Andes. An ordinary snow avalanche set in motion a glacier 1.5 km long, as well as blocks of rocks. Within a matter of seconds, a city was buried under a 10-meter layer of ice, snow and mud, almost 14 km from the foot of the mountain. 25 thousand people died there. This tragedy is compared with the death of the city of Pompeii.

The east of the mainland does not have sharp fluctuations in elevation in the relief. Earthquakes are rare here, and there are no active volcanoes. The prolonged destruction of the platform and vertical movements led to the formation of the Brazilian and Guiana plateaus. Faults in the earth's crust broke them into separate arrays. The relief of the plateaus is varied, the bizarre outlines of the table mountains alternate with hilly spaces, they are replaced by low massifs cut by gorges.

In the troughs of the platform lie the low-lying plains - the Amazonian, Orinocskaya and La Platskaya. These are flat, often swampy spaces composed of sedimentary rocks. The plains of the mainland and areas of plateaus are convenient for agriculture, laying roads, and building cities.

The Andes form the longest mountain ranges on land. Their ridges sometimes diverge, sometimes approach and form mountain nodes with the highest peaks, among which there are many extinct and active volcanoes. The tops of the mountains are covered with caps of eternal snow and glaciers. Highest point Andes and the entire Western Hemisphere - Mount Aconcagua rises to 6960 m. Plateaus lie between the mountain ranges of the Andes. Internal and external forces have created a great variety of mountain shapes. Because of the faults, steep slopes were formed. Weathering formed at their foot stone rivers - talus. Volcanoes are confined to faults. Their eruptions also affect appearance mountains that sometimes change right before our eyes. Here is what A. Humboldt wrote in his diary, observing the volcanic eruption: “...immediately in one night, the thick snow cover of the mountain disappeared, and the black-gray body of the mountain appeared before my eyes in all its nakedness; a fiery column of ejected rain of slag rose to an enormous height with a dark red flame.

South America is rich in mineral deposits. On the plateaus of the East there are deposits of iron, manganese ores, nickel, bauxite deposits containing aluminum. Oil, natural gas, and coal have been found in the depressions and troughs of the platform.

The Andes are especially rich in non-ferrous and rare metals. The introduction of magma into sedimentary rocks led to the formation of the world's largest deposits copper ores, as well as molybdenum, tin, silver, etc. The name of the mountains comes from the word "anta", in the Inca language - "copper".

  1. What processes form the relief of the East of the mainland?
  2. How were the Andes formed?
  3. Explain the patterns of distribution of mineral deposits on the mainland.
  4. Compare the topography and minerals of South America and Africa. Make a conclusion based on the results of the comparison.

Features of the geological structure of South America

An ancient supercontinent existed millions of years ago gondwana . It broke up into three large blocks of the lithosphere, which formed the basis of four modern continents: Africa, Australia, Antarctica and South America . The latter will be discussed in this article.

In the geological structure of South America, a clear difference between the eastern and central parts from the western part of the continent. The east and center of the mainland are located on the old Precambrian South American platform . In the north and east of the platform, there are extensive areas where the ancient crystalline foundation of the platform comes to the surface - Guianan and Brazilian shields . The western part of the mainland is represented folded area , formed as a result of the collision of the continental platform and the oceanic lithospheric plate.

The oceanic plate sags and goes under the continental, forming a deep Peruvian trough (trough) along the entire west coast.

The edge of the continental plate is crumpled into folds. All along western edge mountains rose from the mainland. This is a young area Cenozoic folding . This is evidenced by volcanic eruptions and frequent earthquakes. There is an active process of mountain building. The west coast of South America is part of "Pacific Ring of Fire" – areas of active seismic activity.

The platform part of the mainland in the past experienced repeated subsidence and uplift. This is evidenced by deposits of sedimentary rocks, including marine sediments.

At present, erosion processes, intensified by economic activity person.

Features of the relief of South America

The folded region in the west of South America forms one of the largest mountain systems on the planet - andes mountains . In Indian language it means "copper mountains" .

The Andes Mountains stretch along the Pacific coast in three parallel mountain ranges. Many peaks rise above $6000$ m above sea level.

Highest point in South America Aconcagua ($6960$ m).

At the same time, it is the highest point of the entire Western Hemisphere.

There are also many active volcanoes here. The most famous of them are Cotopaxi, Ruiz, San Pedro . In the middle part of the mountain system there are internal plateaus, the heights of which reach $3500-4000$ m. The platform areas of South America are represented by plains - lowlands and plateaus.

Definition 1

Lowland is a flat area with absolute altitudes up to $200$ m.

Definition 2

Plateau - this is a section of the plain with absolute heights - more than $ 500 $ m.

The lowlands of South America are Orinoc, Amazon and La Plata . The elevation difference here is negligible. These are almost flat plains.

Remark 1

Amazonian lowland - the largest lowland in the world.

Thanks to marine deposits, the northern parts of the plains are rich in oil. Formed on crystalline shields Brazilian and Guiana Plateaus . As a result of ancient tectonic activity, the lowering and raising of the platform were accompanied by breaks in the earth's crust, lava outcrops. In some places, the relief of the plateaus has the appearance of table mountains. They are replaced by landscapes of hilly plains, low massifs cut by gorges.

Minerals

FROM geological structure associated with the distribution of minerals.

  • Deposits are located on ancient shields iron, manganese, uranium ores, bauxites, diamonds.
  • The Andes, justifying their name, are famous copper ores, deposits gold.
  • Large deposits discovered in the north of the mainland oil.
  • On the desert west coast, due to the peculiarities of the climate, deposits were formed sodium nitrate.

The center of the mainland (Amazon lowland) is still poorly studied and developed.

The bowels of South America, due to the unique relief, are exceptionally rich in deposits of iron and porphyry copper ores, ores of tin, antimony and other ores of ferrous, non-ferrous and rare metals, as well as silver, gold and platinum.

Troughs of the Andes, the territory of Venezuela and the Caribbean in in large numbers contain oil deposits and natural gas. There are also small deposits of coal on the continent.

In addition to oil and precious metals, the subsoil of South America is full of such riches as diamonds, emeralds and other precious and ornamental stones.

Features of the relief of South America and their impact on mineral deposits

South America is usually divided into two geologically different parts: the eastern part, which is based on the ancient South American platform, with elevated territories in the Guiana and Brazilian Highlands, and the western part, along which the longest land mountain range of the Andes stretches. Therefore, the mainland is rich both in minerals that form on the plains and plateaus, and rocks and minerals formed as a result of volcanic activity.

The Andes are rich in ores of ferrous and non-ferrous metals of metamorphic and magmatic origin, including zinc, tin, copper, iron, antimony, lead and others. also in the mountains are coming extraction of precious stones and metals (silver, gold, platinum).

The eastern highlands of the continent are rich in deposits of rare ores from which zirconium, uranium, nickel, bismuth and titanium are mined, as well as deposits of beryl ( precious stone). The occurrence of ores and beryl are associated with volcanic activity and the release of magma to the surface.

Extensive deposits of oil and natural gas have been formed in platform troughs, intermountain and foothill depressions. Due to the processes of weathering of the earth's crust, aluminum deposits appeared in the bowels of the continent. And biochemical processes in a company with a desert climate "worked" on the litter sea ​​birds, as a result of which deposits of Chilean saltpeter appeared on the continent.

Types of minerals in South America


Combustible minerals:

  • coal (Colombia, Chile, Brazil, Argentina) is one of the most demanded energy resources in the world;
  • oil (Caribbean) - a liquid oily substance, the occurrence of which is confined to continental depressions and margins;
  • natural gas.

Ferrous metal ores

Iron(deposits in Venezuela). It is used for smelting steel and alloys; it is contained in the composition of such minerals as limonite, hematite, chamosite, magnetite, etc.

Manganese(deposits in Brazil). It is used in the smelting of alloy cast iron and steel.

Chrome ores(reserves in Brazil). Chromium is an indispensable component of heat-resistant and stainless steel.

Ores of non-ferrous metals

Represented by bauxite reserves, from which aluminum(appreciated due to its lightness, hypoallergenicity and ease of processing), vanadium And tungsten ores.

There are huge deposits copper ores(copper is widely used in the electrical and engineering industries).

The bowels of the continent are rich lead(Peru) used in automotive, construction and other fields, nickel(used for the production of nickel steel and various metal coatings), zinc, tin("tin belt" stretching through Bolivia), molybdenum, bismuth(metal is mined directly from bismuth ore only in Bolivia), antimony (used for the production of fire retardants).

precious metal ores

The continent is rich platinum And silver ores, as well as deposits gold. Noble metals are exceptionally resistant to corrosion and have a special brilliance in products used for the production of jewelry, expensive tableware and luxury goods, as well as in industry.

Ores of rare and rare earth metals

Niobium And tantalum- rare metals used for the production of high-strength alloys and metal-cutting tools. Rare earth metals are found on the continent in the composition lithium, niobium And beryllium ores.

Non-metallic minerals of the continent:

  • sodium nitrate (Chile);
  • native sulfur (Chile, Peru, Columlia, Venezuela);
  • gypsum;
  • rock salt;
  • fluorite, etc.
  • diamonds (Brazil, Venezuela, etc.);
  • beryl, tourmaline and topaz - minerals formed in granite pegmatites (Brazil);
  • amethyst (formed in quartz veins);
  • agate (formed in Mesozoic basalts);
  • emeralds (large deposit in Colombia).

Gems:

Resources and major mineral deposits

Consider briefly the main mineral deposits of South America. Chile ranks second in the world in the production of molybdenum, has the world's largest reserves of sodium nitrate (about 300 million tons, a deposit in the Atacama Desert) and the largest reserves of copper on the continent.

Coal mining in South America is concentrated in Colombia in the area of ​​​​the huge El Serrejon coal mine, where the fossil is mined in an open way. The largest oil and gas basin - Maracaibo - is located in the territories of Colombia and Venezuela, which is the leading supplier of oil on the continent. Oil is also produced in the territories of Ecuador, Peru, Argentina, Brazil, Trinidad and Tobago. Venezuela accounts for 4.3% of world oil production.

Brazil, rich in rare ores and minerals, has 13% of the world's tantalum reserves, and is also the world's largest producer of raw materials from niobium (about 80% of the world's total).

Peru owns 11.4% of the world's copper reserves, and the entire continent as a whole - about 56 million tons of the world's iron ore reserves. The Andes contain some of the largest deposits of silver, molybdenum, zinc, tungsten and lead on Earth.

West-Kazakhstan region

Terektinsky district

Aksuat OSOSH

Geography teacher

Irzhanova G.K.

Lesson topic: Relief and minerals of South America.

    Class.

The purpose of the lesson: to study the relief of the mainland, their features; to determine the patterns of distribution of mineral deposits.

Equipment: Physical map of South America;

Lesson type: learning new material.

Lesson form: traditional.

During the classes:

1. Organizational moment: greeting, attendance check.

2. Checking homework.

1. Working with tables.

Determine which continent each statement refers to, put a “+” sign in the desired cell.

Mainland name

Question numbers

South America

1) Most of the mainland lies in southern hemisphere.

2) In the west it is washed by waters Atlantic Ocean.

3) Relative to the zero meridian, the mainland is located in the western hemisphere.

4) The hottest continent of the Earth, because his most of located between the tropics.

5) The area of ​​\u200b\u200bthe mainland is about 30 thousand km. sq.

6) The extreme northern point - Cape Galinas.

7) Washed Pacific Ocean in the West.

8) In the north it borders on Eurasia.

9) The name of the mainland comes from the name of the Berber tribe that once lived in the north of the mainland.

10) In the south of the mainland, the widest of all the straits of the Earth.

2. Checking the nomenclature.

Students take it in turns to come to the board and point it out. physical map South America.

List of nomenclature objects:

1. Isthmus of Panama.

2.Cape Galinas.

3. Peruvian current.

4. Amazonian lowland.

5. Archipelago Tierra del Fuego.

6. Cape Parinas.

7. The Amazon River.

8. Cape Horn.

9. Caribbean Sea.

10. Strait of Magellan.

11. Galapagos Islands

12. Cape Kaaba Branco

13. Panama Canal.

14. Andes Mountains.

15. Brazilian current.

3. Learning new material.

Exercise 1.

Open the map of the atlas "The structure of the earth's crust", pp. 4-5.

Questions: What is relief? Name the major landforms.

Task2.

1. Determine: what lithospheric plate lies at the base of the mainland? (South American);

2. In what part of the mainland is it located mountain system? (in the West);

3. How did the Andes mountains appear? (as a result of the collision of lithospheric plates);

4. How old are these mountains? (mountains are young - the area of ​​new folding);

5. Why is the eastern part of the mainland flat? What lies at its foundation? (platform)

Task 3.

Write a description of the relief of South America.

    Reference scheme:

Relief of South America

Mountain West Plain East

2. Description of the relief.

The east of the mainland is flat. There are no active volcanoes and earthquakes are rare. The large plains of South America - the Amazonian, La Plata and Orinoc occupy large areas. They lie in the deflections of the platform. Because The plains are low, large river systems.

large areas on the mainland they occupy plateaus - Guiana and Brazil. Often they consist of several plateaus - areas with a flat surface, but limited from neighboring areas by distinct steep slopes.

The west of South America is mountainous. The Andes are the longest mountains on earth. The highest point is the city of Aconcagua, 6960 m. The Andes are young mountains. They began to rise after the split of Gondwana, and are still growing. Numerous active and extinct volcanoes have formed along the deep faults. The Andes volcanoes are part of the Pacific Ring of Fire. Earthquakes often occur, they are accompanied by rockfalls, landslides, snow avalanches.

Most strong earthquake The 20th century happened precisely in South America, in the country of Chile. It happened on May 29, 1960 on the Pacific coast. As a result of this terrible seismic catastrophe, the cities of Concepción, which existed for more than 400 years, were completely destroyed, turned into the ruins of the city of Valdivia, Puerto Montt and others. About 10,000 people died, more than 2 million were injured and left homeless. One of distinctive features This catastrophic earthquake was the rapid subsidence of the main part of the coast under the sea level.

“... It seemed incomprehensible,” wrote the scientist G. Tagiev, “that a huge strip of land 20-30 km wide and 500 km long could suddenly sink and that an area of ​​1.5 million hectares fell by almost 2 meters in just 10 seconds ... ". Powerful tremors caused the birth of a colossal tsunami.

3. Minerals of South America.

According to one version, translated from the Inca language, "Andes" means copper, copper mountains. Copper deposits are found throughout the Andes.

In which part of the mainland are igneous minerals concentrated, and in which - sedimentary?

Determine from the map to the map, what minerals are still rich in the Andes? (molybdenum ores, tin, silver aluminum, etc.)

What minerals are there in the flat east of the mainland? (oil, gas, coal - in the troughs of the earth's crust, iron, manganese, nickel ores - on the plateaus).

4. Consolidation of the studied material.

1. Sign up for contour map the following objects: the Brazilian Plateau, the Guiana Plateau, the Amazonian Lowland, the La Plata Lowland, the Orinoc Lowland, the Andes Mountains, the city of Aconcagua.

2. According to the plan, make a description of one of the landforms of South America.

1) In what part of the mainland is the landform located?

2) In what direction is it pulling?

3) What are the approximate dimensions?

4) What are highest altitude, the prevailing heights?

5. Homework: paragraph 41.

6.Summary of the lesson: grading for class work.