Brief description of South America's relief. Geological structure and topography of the South American continent. Minerals of South America

South America has a fairly simple orotectonic structure. The large, western part of the continent is located on the South American Platform, part of the South American lithospheric plate. In the south, in Patagonia, an ancient platform is connected to a young Epipaleozoic platform with a flat topography. These are flat areas with different altitude characteristics from lowlands to plateaus. In the west of the continent there is an area of ​​alpine folding represented in relief by the longest mountain range on Earth - the Andes.

Extra-Andean East

Located on the South American platform. Its uplifts are expressed in relief by plateaus (Guiana and Brazil), and troughs - by lowlands (Amazonian, Orinoco, La Plata) and highlands (Gran Chaco). At the base of the platform lie the cores of the most ancient (Early Precambrian) igneous and metamorphic rocks that come to the surface in the Guiana, South Brazilian, and West Brazilian shields.

Tectonic movements divided the plateaus, in particular the Brazilian plateau, into separate blocky massifs. Basalt outpourings formed the Paraná lava plateau, the largest on Earth, in the southern part of the Brazilian Plateau.

The EpiPaleozoic Pampa-Patagonian plate, attached to the southeastern part of the Andes and the south of the South American platform, formed much more mobile. It often alternates between uplifts and subsidences with sedimentary strata folded into short gentle folds.

The relief of the low-lying plains is extremely monotonous. They were formed in the syneclises of the South American platform plate, which were gradually filled with sedimentary deposits. The relief of the Amazonian lowland, covering an area of ​​5 million km°, is extremely monotonous. Even at the foot of the Andes, the altitude in the Amazon Valley is only 150 m above sea level. seas. In the less extensive Orinoco Lowland and on the Interior Plains, the areas closest to the Andes are usually elevated due to the removal of abundant sediment from the mountains and lowered to the axes of troughs, emphasized by the flow of the main rivers - Orinoco, Mamore, Paraguay, Parana; along the latter stretches the swampy La Plata lowland.

Andean West.

The Andes are the greatest land mountain system, stretching for almost 9000 km, with average heights of 4-5 thousand m. The highest point, Mount Aconcagua, rises to 6960 m. The Andes are a fragment of the Pacific Ring of Fire (Pacific lithospheric compression belt). The main phase of mountain building took place at the end of the Cretaceous - beginning of the Paleogene periods. Since the Cretaceous period, the Andes have been characterized by strong volcanic activity. Along the lines of splits and faults in the Andes, numerous volcanic cones were formed, concentrated in three main areas: between 6° N. w. and 2° S. latitude, from 15° to 29° south. w. and between 33-52° S. w. The Andes have three distinct main mountain ranges: the Cordillera Oriental, the Cordillera Central and the Cordillera Occidental. Also, in some areas the low Coastal Cordillera is most often expressed. In the Central Andes, the intermountain plateaus of Puna (Punas) and Altiplano appear. South of 28° S. w. The Eastern and Central Cordilleras disappear and the Western one becomes the main one, and south of 42° S. w. The coastal Cordillera turns into a system of islands (Chinos Island, Chiloe Archipelago). In the Colombian Andes, the large rivers Magdalena, Cauqui, Atrato and others flow through intermountain valleys. In the Chilean-Argentine Andes, a large tectonic depression of the Longitudinal Valley stands out.

Target: to form an understanding of the features of the relief, tectonic structure and mineral resources of South America, to continue to develop the ability to compare atlas maps of different contents, to develop curiosity and interest in geography.

Tasks:

• check the knowledge gained while studying the topic “ Geographical position South America"
• find out the relief features of South America;
• find out the patterns of placement of large landforms, tectonics and minerals;
• complete practical work No. 18.

Equipment: Wall maps “Physical map of South America”, “Structure of the Earth’s crust”, a set of diagrams “relief of South America”, cards for checking homework.

Lesson type- combined.

Lesson plan - lesson plan

1. Introduction

1 Class organization

2 Announcement of the topic.

3 Checking homework

Crossword “South America” (Slide 1)

1 What is the name of the westernmost point of South America (Pariñas). (Slide 2)

2 What current runs along the western coast of South America (Peruvian). (Slide 3)

3 Which ocean washes South America from the east. (Atlantic) (Slide 4)

4 Which part of the world does South America belong to (America) (Slide 5)

5 Name the northernmost point of Young America (Gallinas) (Slide 6)

6 What is the largest island located south of South America (Terra del Fuego) (Slide 7)

7 Which strait separates the mainland of South America and the island of Tierra del Fuego (Magellan) (Slide 8)

8 Russian botanist who, during his expedition to the mainland, established the geographical centers of ancient centers of agriculture and the origin of some cultivated plants, whose homeland is South America (N.I. Vavilov) (Slide 9)

9 The traveler who discovered America in 1492 (H. Columbus) (Slide 10)

10 In the 15th century, he was the first to express the idea of ​​​​the existence of a new continent. Following his colorful descriptions of distant lands, Spanish and Portuguese conquerors rushed to America (Amerigo Vespucci) (Slide 11)

4 Assimilation of new knowledge

1) Announcing the topic of the lesson, setting tasks (Slide 12, 13)

Relief is a set of irregularities on the earth's surface that vary in size, origin and age. (Slide 14) Relief has a great influence on the formation, development and distribution of all components of nature on the surface of the continent. Therefore, knowledge of the relief is simply necessary when studying the continent.

In the relief of South America, as you already know, there is common features with Africa and Australia there are differences.

What are the features of the relief of South America?

Working with a physical map of South America

What landforms predominate on the mainland.

How are the landforms located in the study area?

What are the highest and most dominant altitudes? (Slide 15)

Consolidation

Scheme on the board and in a notebook

Thus, we see with you that the relief of South America is diverse: a combination of high mountains and plains of varying heights; large fluctuations in altitude; There are two parts: the mountainous West and the flat East. (Slide 18)

A minute of relaxation “Geo-focus”(Slide 19)

Why are mountains predominant in the west of the continent, and plains and plateaus in the east? (Slide 20)

To do this, we will look at a map of the “structure of the earth’s crust”

Using the “Physical Map of South America” and the “Structure of the Earth’s Crust” map, establish connections between the structure of the earth’s crust and the location of the main landforms. Based on the comparison, enter the results of the map analysis into a table (Slide 21, 22)

Dependence of relief on the structure of the earth's crust

What landforms mainly correspond to ancient platforms? - Which – folded areas

Why are the mountains of South America high?

Which indicates the formation of the Andes mountains at the present time.

Why are mineral resources located in such a location on the South American mainland?

Conclusion:

• the location of large landforms depends on the tectonic structure;
• the placement of ore and non-metallic minerals is confined to a specific tectonic structure. (Slide 23)

5 Consolidation

Practical work No. 18* Identification of large landforms and mineral deposits on the map.

Target:

• Get acquainted with the placement of the main landforms of South America
• Mark major landforms and mineral deposits on the map. Determining the similarities and differences in the topography of Africa and South America

Progress

1 Identify and label large landforms on the outline map of South America:

a) plains: Amazonian, La Plata, Orinoco;

b) plateau: Brazilian;

c) Mountains: Andes;

d) peaks: Aconcagua, Cotapahi volcano

2 Indicate mineral deposits using symbols

6 Homework(Slide 25)

• paragraph 41, questions 1-4;
• learn the nomenclature on the topic “Relief of South America”

South America has a different geological structure, which is associated with the formation of the earth's crust in different archaeological periods. The eastern part was formed back in the Precambrian period, and there the relief of South America is a plain - this is the South American Platform. The West has been actively formed since the Paleozoic period and the Andes are located there.

Lowland South America

The flat platform has depressions and raised areas. In place of the first ones (also called “shields”), there are two highlands - the Brazilian and Guiana. During the period when they rose, the slopes became almost vertical. The part that rose the most was the part of the Brazilian Highlands in the east, where the sierras formed. At 2890 meters above sea level, the highest point of the highlands is located here - the Bandeira Massif.

Rice. 1. Relief of South America.

As for the troughs, there are three plains of enormous scale - La Plata, Orinoco, and Amazonian.

The topography and mineral resources of South America are closely related to its geological history. Thus, the ancient shields of the platform are the richest in iron ore - these are the Brazilian (center and outskirts) and Guiana (north) highlands. The highlands have rich reserves of bauxite containing aluminum) and manganese. Where the platform sags, there are reserves of oil and accompanying natural gas, as well as rock. Venezuela can rightfully be considered the leader in the production of “black gold” and gas. These facts must be noted in the textbook for grade 7.

Rice. 2. Brazilian Highlands.

Where igneous rocks lie close to the surface or even flowed onto it, uranium, titanium, nickel and zirconium are found.

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South America contains 38% of the total iron ore reserves on the planet.

Mountainous part of South America

The mountainous part of South America is called the English West, and it is located in the west.

The Andes chain is one of the highest on Earth. If we compare the topography of Africa and South America, one of the differences will be due to these mountains: when glaciers descended from their peaks, they “cut up” the coast, which is not observed on the African continent.

There are twenty peaks in the Andes whose height exceeds 6 thousand meters above sea level. And the highest point of the chain is Mount Anoncagua. It is located in the Chilean-Argentine part of the mountain range and rises to 6960 meters. Moreover, the total length of the entire mountain chain is almost nine thousand kilometers, making it the longest on Earth.

Rice. 3. Andes.

The Andes began to form during the Paleozoic period, during the Hercynian folding, but the Alpine period became the main period for them. During the Cretaceous period, folding resulted in the Western Cordillera (Colombia-Terra del Fuego). But the relief features of the Central Andes are associated with Alpine orthogenesis, when ancient Hercynian structures were broken and partially uplifted. This is how the main high mountain plateau was formed.

The Andes continue to form in the modern period. This is evidenced by the strongest earthquakes (the last of which happened less than half a century ago, in 1970 in Peru). The epicenters of the earthquakes are confined to the Peruvian Trench, which stretches along the western coast of the continent. The consequences of earthquakes are tsunamis. The highest active volcano in this part of the world is Llullaillaco; its brothers Osorno, San Pedro, Cotopaxi, and Ruiz are also not sleeping.

Thus, in the western part, the prevailing landforms determine the presence of corresponding minerals. Ores of metamorphic and igneous origin are located in rich deposits in the Andes. Precious stones and non-ferrous metals, considered rare, are also found in significant quantities in these places. Thus, Chile ranks second in the world ranking of countries mining copper and molybdenum ore, and tin reserves in Bolivia are regarded by experts as significant. This is not to mention Colombia, the “land of emeralds”. In addition to the minerals listed above, the western part of South America has reserves of gold, zinc and platinum, as well as antimony, silver, lead and tungsten. Many of them began to be developed by the ancient Incas, who even named one of the lakes Titicaca, that is, “lead rock.”

Chile is rich in saltpeter deposits, which were formed from the droppings of seabirds through biochemical decomposition. The main factor in their formation was the desert climate.

What have we learned?

We received a description of the relief of South America with reference to historical periods its formation, and also learned that certain part The continent continues to form. The formation process is manifested by earthquakes and volcanic eruptions. We figured out how the origin of landforms affects what minerals are common in a particular region and learned Interesting Facts about it. In addition, we received information about the main plains of South America and the Andes mountain range, as well as about the features of the continental topography and resource distribution.

Test on the topic

Evaluation of the report

Average rating: 4.6. Total ratings received: 191.

The relief of South America is varied and contrasting. Based on the nature of the surface structure on the continent, two parts are distinguished. The greater eastern part is dominated by lowland, elevated plains and plateaus, while the longest mountain ranges of the Andes are in the west.

The lowland plains (Amazonian, Orinoco, La Plata) have a flat topography and are composed of marine and lacustrine-fluvial deposits. The relief of the western part of the continent is the result of the interaction of several lithospheric plates, on the border of which mountain-building movements occur.

The formation of the Andes began in the Paleozoic and has not ended yet. The Andes continue to rise, volcanoes erupt, and strong earthquakes occur.

South America is rich in mineral deposits. The ancient shields of the platform contain the richest deposits of iron, manganese, nickel ores, uranium, and deposits of bauxite containing aluminum. Oil, natural gas, and coal were discovered in the depressions and troughs of the platform. Deposits of non-ferrous and rare metals have been found in the Andes. For example, the famous “tin belt” of Bolivia stretches from north to south for 940 km. The Andes are home to the world's largest deposits of copper ores, as well as molybdenum, silver, tungsten, lead and zinc ores. Sulfur, boron, iodine, and saltpeter are mined from non-metallic minerals on the Pacific coast and in the foothills of the Andes. There is oil in the intermountain basins.

South America is made up of two main geological elements: the Andes, a folded mountain belt in the east, and the South American mountain platform. Throughout its existence, the platform has been lowered and raised several times. Sedimentary rocks accumulated in subsided areas, and crystalline rocks in uplifted areas. Due to the different rates of uplift, the earth's crust cracked and lava splashed to the surface.

Mainland, thanks to its features internal structure, can be divided into two parts:

1. Vast lowlands.

Landforms of South America

La Plata, Orinokska and Amazonian lowlands, located in the troughs of the South American platform, occupy almost half the area of ​​the continent.

2. Plateaus. In the east Guiana and the Brazilian plateau are formed by projections of the basement. In some places their height reaches 3000 m. The plateaus on the mainland are dotted with numerous river valleys, which can be seen if you look video in English.

central part Guiana The plateau is notable for its huge flat-topped massifs, the walls of which are almost vertical. It is cut by abysses and deep canyons, but from a great height it seems that the surface is absolutely flat.

The Andes mountain system stretches along the Pacific coast, the average heights of which range from 3000 to 5000 m. The highest point is Mount Aconcagua (6960 m). These are young mountains, strong earthquakes and volcanisms are occurring here and now, resulting in the formation of the San Pedro and Cotopaxi.

Gold, uranium, aluminum, manganese, and iron ore are mined on the Guiana and Brazilian plateaus. The Andes are home to deposits of precious stones, zinc, lead and copper ores.

Thanks to the arid climate in the west of the South American continent, deposits of Chilean sulfur, which is a raw material for nitrogen fertilizer and iodine, have formed in dry reservoirs.

Volcanic phenomena in Andes contributed to the formation of deposits of building materials and sulfur. In the foothills and troughs of the platform in sedimentary deposits there are deposits of gas, oil, and coal. The largest oil fields are concentrated on the coast of the Caspian Sea and in the foothills of the Andes.

South America. PHYSICAL AND GEOGRAPHICAL POSITION.

The area of ​​the mainland is 17.8 million sq. km without islands and 18.3 million sq. km with islands. Extent from north to south -70 degrees. w.d. exceeds 7500 km, from west to east (in the widest part) more than 45oo km. South America in the northern part is crossed by the equator. The northernmost point is Cape Galinhas, 13 deg. N; southernmost continental point Cape Froward, 54 deg. S, Cape Horn island, 56 deg. S The continent lies entirely in the Western Hemisphere. Westernmost point Cape Parinhas, 81 deg. w.d.; extreme eastern point of Cape Cabo Branco, 34 deg. w.d.

South America lies in the equatorial, two subequatorial, two tropical climate zones; the southern part is located in the subtropics and temperate zone.

The continent is connected to North America by the Isthmus of Panama and separated from it by the Panama Canal, and from Antarctica by the Drake Passage.

Geological structure and main landforms of South America

It is washed in the west by the Pacific Ocean, in the south by the Drake Irrigation, in the east by the Atlantic Ocean, and in the north by the Caribbean Sea of ​​the Atlantic Ocean. In the north there is the warm North Trade Wind Current, in the northeast - the warm Guiana Current, in the east - the warm Brazilian Current, in the southeast - the cold Falkland Current, in the south - the cold West Wind Current, in the west - the cold Peruvian Current, in the north -west - warm El Niño current. The coastline is slightly indented. Small bays are located at the mouths of rivers (La Plata, Maracaibo). Adjacent islands: in the north - the Lesser Antilles, in the southeast - the Falklands (Malvinas), in the south - Tierra del Fuego, in the southwest - the Chilean archipelago. The geographical position of the continent, mainly in low latitudes, determines the predominance of tropical types of landscapes - the “kingdom of tropical nature”.

TECTONIC STRUCTURE, RELIEF, MINERAL RESOURCES.

The relief of South America is asymmetrical. Most of the continent is occupied by vast plains of varying altitudes. In the west is one of the highest mountain systems in the world - the South American Cordillera (Andes). The average height of the continent is 580 m, the highest point is Mount Aconcagua 6960 m, the lowest is the Valdes Peninsula - 40 m. The relief features are determined by the tectonic structure. At the base of South America lies the ancient South American Platform with a Precambrian basement. Within the platform there are large shields in the north and east, which correspond to the Guiana and Brazilian plateaus. Powerful block processes occurred within the Guiana Plateau, which is why the plateau has a highly dissected topography. The highest point is Mount Roraima 2771 m, average heights range from 500 to 1000 m.

The Brazilian plateau corresponds to three shields: Southern Amazonian, Eastern Brazilian, Western Brazilian. This plateau rises gently from the north and northwest to the southeast. The highest point is Mount Bandeira 2890 m. Active magmatism occurred within this territory, traps and volcanic plateaus are found here. This territory is finished

its formation. Peneplains (leveling surfaces, denudation plains) are formed here.

Between the shields there are syneclises (deflections) of the platform foundation, which are filled with thick layers of sedimentary rocks. They correspond to the vast lowland plains of South America: Amazonian, La Plata, Orinoco.

In the west, the platform is adjacent to an area of ​​folding of Alpine age, which was formed in the Cenozoic as a result of the subduction of the Nazca plate and the South American lithospheric plate. This area of ​​folding corresponds to the Andes, which belong to the highest and highest mountains. The highest point is Mount Aconcagua 6960 m. Mountain building processes here have not yet been completed and are accompanied by earthquakes and volcanism (volcanoes Cotopaxi, Chimborazo). Tectonic processes are strong in the Caribbean, Northern and Southern Andes, calm in the Central and Patagonian Andes. The Andes are made up of parallel ridges. As they come closer, they form mountain nodes, and where the ridges diverge lie the Central Andean highlands and plateaus with an altitude of 3500-4000m.

South America has a huge mineral resource base. Ore deposits are confined to outcrops of the crystalline basement and to the Andean fold belt. Non-metallic - to the cover of sedimentary rocks of the platform. Significant deposits of iron (Minas Geras - Brazil), manganese, bauxite, titanium and uranium ores were formed in ancient igneous and metamorphic rocks and weathering crusts. Reserves of beryllium, niobium, zirconium, and tantalum are concentrated here. Vein deposits of gold and diamonds in Brazil play a significant role. On the Guiana Plateau there are large deposits of iron ore, bauxite and gold; large reserves of copper are concentrated in the Andean belt in Peru and Chile; in Bolivia there is a tin belt. Emeralds are mined in Colombia. In the sedimentary cover of the Orinoco, Amazon and La Plata lowlands there are oil deposits, especially in Venezuela. 99% of the world's saltpeter reserves are concentrated in Atacama.

South America is the wettest continent on Earth, but not as hot as Africa, since the southern part lies in the temperate zone. Within the continent, an equatorial, two subequatorial, and two tropical climatic zones are formed; the southern part lies in the subtropics and temperate zone.

In general, the climate of South America is more varied than that of Africa and Australia. Average annual temperatures in most of the continent are from +20 to +28, and only in the south are these figures lower (from +8 in winter to + 16 in summer). The maximum recorded temperature is +46 (Cordoba), the minimum is -33 (Sariento). Antarctica has a huge influence on the climate of South America, from which the cold pampero wind blows into the temperate and even subtropical zones. In Patagonia, temperatures can drop to 0 in summer and -30 in winter; in the subtropics in the south of the Brazilian Plateau in summer up to +15, in winter up to +8.

The distribution of precipitation is extremely uneven, but the size of the precipitation layer is enormous - on average 1700 mm. The drainage layer into the hydrographic network is 700 mm. These values ​​are twice the earth's average. Maximum

the amount of precipitation falls in the western part of the Amazonian lowland (3000-4000 mm), on the western slopes of the equatorial Andes (up to 7000 mm) and on the western slopes of the Patagonian Andes (up to 4000-5000 mm). Minimal amount precipitation - inland regions of the tropical belt, the south of the La Plata lowland, the zone of barrier rain shadow - in Patagonia. In general, the climate of South America, which is characterized by an abundance of warmth and light over most of the territory, creates favorable conditions for year-round plant growth.

INLAND WATERS.

Since South America is the wettest continent on Earth, one of the largest hydrographic networks in the world has formed here. South America covers 12% of the world's land area, but accounts for 36% of the world's ocean flow, 15% of which comes from the Amazon. The pattern of the hydrographic network is extremely asymmetrical, which is determined by the features of the relief. The main watershed runs along the tops of the Andes near the Pacific Ocean, so all the major rivers belong to the Atlantic Ocean basin (Amazon, Parana, Orinoco, San Francisco). Most of the rivers are fed by rain, and only the rivers of Patagonia and the Patagonian Andes are fed by snow and glaciers. The regime of rivers is determined by their position in climatic zones. For example, the rivers of the Amazon basin, which are fed by rain, are full of water throughout the year with two maximums in spring and autumn during the period of zenithal rains. Rivers of the subequatorial type are also fed by rain. These are major tributaries of the Amazon, Orinoco and Paraguay Rivers. They have maximum flow at the end of summer, beginning of autumn and winter low water. The rivers of the tropical zone in inland areas are low-water, but in the southeast of the Brazilian Plateau they are full-flowing throughout the year. Most of the rivers in the upper reaches are mountainous in nature, as they begin in the Andes and on the plateaus. There are an abundance of rapids and waterfalls. On the Guiana Plateau is the world's highest Angel Falls (1054 m). On the Iguazu River (Brazilian Plateau) is the world's longest Iguazu Falls (length about 3000 m, includes more than 270 cascades).

There are few large lakes. In the southern part of the Andes there are glacial lakes, in the north there is the lake-lagoon Maracaibo of tectonic origin, in the Central Andes at an altitude of 3800 m lies the largest alpine lake Titicaca with depths of up to 300 m.

Modern glaciation is relatively weak due to the high position of the snow line. Maximum glaciation in the Patagonian Andes and Tierra del Fuego.

NATURAL AREAS.

Due to its large extent from north to south, the continent has a clearly represented natural zonation from equatorial forests in the center to semi-deserts and temperate deserts in the south. Due to the predominance of a hot, humid climate on the mainland, forests are widespread here and there are relatively few deserts and semi-deserts.

1) The zone of moist equatorial forests (selva) is located on both sides of the equator in the Amazon basin, on the slopes of the Andes and in the north of the Pacific coast. The zone is formed within the equatorial and subequatorial climatic zones. Thanks to the processes of chemical weathering, fertile red-yellow ferralite soils are formed in the jungle. They grow here different kinds palm trees, cocoa, hevea, many orchids, vines, melon tree, ceiba. Many animals are adapted to life in trees: prehensile-tailed monkeys, sloths, arboreal porcupines; Tapirs, anteaters, and jaguars also live here;

many species of parrots, hummingbirds; the world of insects is very rich; Snakes, including anacondas, are common. The forests have up to 12 tiers.

2) The zone of variable-humid equatorial forests is located north and south of the jungle, in the west of the Atlantic coast. It is formed within subequatorial climatic zones. Red soils and yellow soils are formed here. Vegetation and fauna are the same as in

3) The savannah zone occupies the Orinoco Lowland and most of the Guiana and Brazilian plateaus. It is located in the subequatorial climate zone. Red ferralitic and red-brown soils are formed here. Savannahs of the northern and southern hemispheres within the Southern

Americas are different. In the northern savannas (llanos), palm trees and acacias, mimosas, milkweeds, and bottle trees grow among the grasses. In the southern savannas (campos) the vegetation is poorer due to less rainfall: there are low-growing woodlands of Quebracho with very hard

wood. Among the animals in the savannas live small deer, wild peccary pigs, armadillos, anteaters, jaguars, pumas, and rhea ostriches.

4) The tropical desert zone occupies a small coastal strip on the west coast. Here, not far from the ocean, lies one of the most waterless deserts in the world - the Atacama. Cacti and thorny cushion-shaped bushes grow here and there on the rocky, infertile soils. On the shore

There are bird colonies on the rocks.

5) The steppe zone (pampa) is located south of the savannas. In the hot tropical climate, fertile red ferralite soils were formed here. The main vegetation is grasses, among which feather grass, wild millet and other cereals predominate. In the southwest, where there is less

precipitation, there are thickets of thorny grasses and shrubs. Fast-running animals are typical for the pampas: pampas deer, pampas cat, several types of llamas. Lots of rodents (nutria, viscacha), as well as armadillos and birds.

6) The zone of semi-deserts and temperate deserts was formed in Patagonia in a temperate climate with low rainfall. The soils are poor brown and grey-brown. The vegetation is represented by dry grasses and cushion-shaped shrubs. The fauna is similar to the pampa, with rodents and burrowing animals living there. Among them are nutria and small armadillos.

7) Altitudinal zone.

In the equatorial zone: up to 1000 m - humid equatorial forests.

Up to 3000 m there are mountain and high-mountain forests where bamboo and tree ferns and cinchona are found.

Up to 4000 m - low trees and shrubs and woodlands appear. There are heather and myrtle thickets, and low-growing bamboos.

Above 4000 m there are alpine meadows (paramos). The vegetation consists of rare cereals and cushion-shaped shrubs. Flat areas have moss swamps, while large slopes are characterized by rocky, barren deserts.

Above 4500 m there are bare rocks, a belt of eternal ice.

In the subtropics, at the foot, there are deserts, turning into a belt of hard-leaved forests, extending to an altitude of 2000 m on the western slopes and up to 1800 m on the eastern slopes. Here you can find plane trees, glanders, and in the undergrowth there are thickets of flowering geraniums. Hard-leaved forests give way to deciduous beech forests, and above 2500 m there are mountain meadows.

SEE MORE:

Tectonic map

At the base of the continent lies the South American Plate, so most of the terrain is plain. In the west there is an area of ​​new folding, where the relief is mountainous. The central and eastern parts are occupied by plains (lowlands, hills and plateaus), and the Andes mountains in the west.

The Andes are the longest (9000 km) and one of the highest (Mount Aconcagua, 6962 m) mountain systems on Earth, bordering all of South America from the north and west; southern part of the Cordillera. In some places, the Andes reach a width of over 500 km (the greatest width - up to 750 km - in the Central Andes, between 18° and 20° S). The average altitude is about 4000 m.

The relief of the eastern part was formed on the ancient South American platform. The rise of its foundation in relief corresponds to plateaus, and low-lying plains have formed in the troughs. The most powerful tectonic movements occurred on the shields; they are broken by cracks and there are faults. Erosion processes, weathering, and tectonic processes have created a wide variety of landforms on the Guiana and Brazilian plateaus.

The lowland plains (Amazonian, Orinoco, La Plata) have a flat topography and are composed of marine and lacustrine-fluvial deposits.

Features of the relief forms of South America

The relief of the western part of the continent is the result of the interaction of several lithospheric plates, on the border of which mountain-building movements occur. The formation of the Andes began in the Paleozoic and has not ended yet. The Andes continue to rise, volcanoes erupt, and strong earthquakes occur.

Physiographic characteristics of the Interior Plains of South America.

The interior plains are located between the Brazilian Plateau and the Andes in the central part of the continent and are confined to three zones - subequatorial, tropical and subtropical. The Interior Plains includes five natural regions: Mamore, Pantanal, Gran Chaco, the interfluve of Parana and Uruguay, and Pampa.

Mamore Plains— flat alluvial plains . In summer, equatorial air masses bring heavy precipitation here, up to 2000 mm per year. In winter there is less rain, but the dry season is weakly expressed, so the composition of woody vegetation is closer to the hylae of the Amazon.

N variability of the Pantanal , dry in winter and flooded in summer with rainwater. It is composed of a thick layer of sedimentary rocks. The Pantanal plains are dominated by tall grasses and here and there trees and shrubs. Moisture-loving forests grow along the rivers.

Plains of the Gran Chaco. This is the hottest place in South America, the average January temperature is + 28, + 29 ° C, the absolute maximum is + 47 ° C. The alternation of the winter dry and summer rainy seasons is well expressed in the region. Precipitation is predominantly rainfall. In the western, more elevated part of the region, there are forests of prickly acacias, cacti, and agaves; areas of steppes and forests appear to the east. In wetter places the wax palm grows. In the north of the region there are extensive wetlands.

Interfluve of Parana and Uruguay It is a plain up to 100 m high. The climate here is subtropical, humid, with an even distribution of precipitation over the seasons, with over 1000 mm falling during the year. The northern part is swampy; the center and south of the interfluve are a well-drained, slightly hilly plain, composed of sandstones covered with marls. The black-colored soils of subtropical savannas are well developed; forests of mimosa and acacia grow here. There are areas of subtropical steppes.

The southern part of the Interior Plains is occupied by Pampa - grassy plains. The climate of Pampa is subtropical. The average temperature in January is + 22 - + 24° C, in July + 7 - + 9° C; precipitation falls 1000-1200 mm per year, it is distributed evenly across the seasons.

In the flora of Pampa there are up to a thousand species of different cereals. There are areas devoid of grass. On the clayey soils of Pampa, the grass silvery gynerium is present. The fauna of Pampa is not rich and monotonous. Vizcacha, a large rodent, is often found. Rare predators (puma). Typical birds are the ibis, ipikaha, and tinamous, which are similar in size and appearance to a partridge.

44. Precordillera and Pampinsky Sierras (physiographic characteristics).

Precordillera - Characterized by great contrasts in relief, climate, soil and vegetation cover. Against the background of elevated plains, steep mountain ranges with a height of 2500-4000 m often rise here. They are composed of Precambrian and Paleozoic rocks, and were subjected to long-term destruction and leveling. Between the mountain ranges, wide valleys formed - bolsons and depressions (Salinas Grande).

The Precordillera is characterized by a continental arid climate. Precipitation falls unevenly. The amount of precipitation decreases from east to west, with the eastern slopes of the mountain ranges receiving more precipitation than the western ones. The river network is poorly developed. A large area is occupied by salt marshes.

The vegetation has a xerophytic appearance; shrub formations of the Monte type are widespread. At an altitude of 500-1000 m, the remains of subtropical forests with hard-leaved evergreen trees and shrubs have been preserved. Above 2500 m the mountain cereal steppe begins.

To the south the forests become thinner. In the southwest, large areas are occupied by semi-deserts with gray soils and salt marshes.

The southeastern part of the Precordillera is occupied by Patagonia. The surface of this natural area is a stepped plateau composed of Meso-Cenozoic deposits. Lowlands are found only in the northeast and southeast. Patagonia's position in temperate latitudes in the western transport zone, between two oceans, should have led to a mild climate and good development of the hydraulic network. The main reason for the aridity of Patagonia is that the dominant westerly winds in these latitudes carry moist sea air from the Pacific Ocean and encounter the Andes mountain barrier. The annual precipitation in Patagonia is 120 - 200 mm. IN vegetation cover cushion-shaped and creeping forms of shrubs with pronounced xeromorphism predominate; there are few trees. Among the cereals there are plentiful thorny, inconspicuous bushes of harilla, dense cushions of bolax and azorella; southern species of cacti are found.

Among the endemic representatives of the fauna of Patagonia, we should note the Zorillo skunk, the fox-like Magellan's dog, and the Darwin ostrich (the southern species of rhea). Rodents (mara, tuco-tuco, etc.) are also typical, and the Pampas cat and armadillos are also found.

46. ​​Northern Andes (physiographic characteristics).

The mountain ranges of the Northern Andes, dissected by river valleys, extend from the shores Caribbean Sea up to 5° south w. The Northern Andes include the Caribbean Andes, located along the coast of the Caribbean Sea, the Northwest Andes (the Andes of Colombia and Venezuela) and the Andes of Ecuador.

Caribbean Andes Unlike other parts of the mountain system, they have a latitudinal strike. These are the northernmost and youngest ranges, they are more arid than the nearby plains. The mountains are almost devoid of forest cover. The main folding formations in the Caribbean Andes occurred in the Pliocene, when two main anticlinal folds arose - the Coastal and Inner Cordillera. They are separated by a longitudinal depression, now occupied by lacustrine alluvial deposits. The Caribbean Andes have a distinct winter dry season. The lower belt of the mountains is represented by summer-green open forests or thorny shrubs (chaparro) growing on red-brown soils. Higher up, with decreasing temperatures, precipitation becomes greater, so the forests are denser, and evergreens appear at an altitude of 1500-1600 m.

North of the Caribbean Andes are located Caribbean lowlands composed of alluvium. Lake Maracaibo once occupied the entire lowland; now its area is shrinking due to filling with alluvial sediments. At the same time, coastal areas are experiencing gradual subsidence.

The second tectonic trough is occupied by the lowlands of the Magdalena and Cauca rivers, composed of alluvium and coarse clastic material demolished from the Andean mountain ranges Northwestern Andes- the most branched and complexly constructed part of the Andean mountain system. They are located mainly in Colombia. Three main ridges are well defined here - Western, Central and Eastern Cordillera with a height of more than 5000 m. Among mountain peaks there are many extinct and active volcanoes. The Central Cordillera reaches the highest average height (Hila volcano, 5750 m, Ruiz peak, 5400 m). The Western and Eastern Cordillera are lower; the latter is divided in the north into two ranges (Sierra de Mérida and Sierra de Perija), covering the lowland of Maracaibo. Between the Eastern and Central Cordillera there is a valley of the Magdalena River - a graben filled with a thick layer of Cretaceous and Cenozoic sediments. To the north-west along the coast of the Pacific Ocean stretches the low Sierra de Baudo, composed of Cretaceous and Tertiary tuffaceous strata.

The Northwestern Andes are located in a subequatorial and equatorial climate. In the direction from north to south, the duration of the dry period gradually decreases, which is practically absent south of Bogota. Mountain ranges in general are abundantly moistened, and on the Pacific coast, due to local circulation and orographic conditions, the amount of precipitation reaches 8000 m (the highest amount in South America). Inland areas are less moistened, but aridity is not pronounced. Climatic features are also reflected in the zonation of soil and vegetation cover. In the west, on the Pacific coast and the slopes of the Sierra de Baudo ridge, a dense mountain hylea is formed. To the east, the amount of precipitation decreases, so the lower parts of the slopes are covered with summer-green open forests and shrubs, higher up - with mixed, deciduous-evergreen forests, and only at an altitude of 1000 m does wet mountain hylea begin. Here you can find the toquilla palm, balsa wood with very light wood, and a number of wood species typical of the Amazon. The avifauna is richly represented - up to 1500 species. Parrots, hummingbirds, and sunbirds are typical.

Higher up, as the temperature decreases, belts of open forests and crooked forests appear; at an altitude of 2500-3500 m, the mountain meadows of paramos extend.

Geological structure, relief, minerals of South America

Even higher up there are peculiar associations of uplands of herbaceous vegetation with individual shrubs and cacti. The interior slopes of the northwestern Andes are drier. Hard-leaved or summer-green forests grow here.

Andes of Ecuador(from 2° N to 5° S) - the narrowest part of the Andes, high-mountain and tectonically active. Two parallel chains are well defined in them - the Eastern Cordillera and the Western Cordillera, separated by a number of intermountain basins. The total width of the mountain system here is about 90 km. The ridges consist of separate mountain ranges, separated by saddles that are poorly defined in relief. The main peaks are, as a rule, active and extinct volcanoes, including the highest of them, the Chimborazo volcano (6267 m). The active volcanoes of Cotopaxi, Antisana, and Sangay are known. Intermountain basins are located at an altitude of 2500-2800 m, they are filled with a layer of volcanic ash, tuff and alluvium. The epicenters of earthquakes are most often located in the area of ​​the intermountain valley separating these Cordillera chains.

To the west of the Andes mountain range lies a strip of the Costa coastal plain, with a hot and humid climate. Here there is a rapid decrease in precipitation from 1200-1500 mm in the northern part (with high relative humidity) to 400 mm in the south. These changes are reflected in the vegetation cover. Savannas with areas of wet equatorial forests, occupying the northern part of the Costa, are gradually replaced to the south by dry steppe vegetation. In the mountainous part, vertical zonality is well defined. Up to 800-1000 m, the change in climate and vegetation cover is still weakly felt, then the amount of precipitation increases noticeably, the amplitude of temperatures decreases, with a general decrease. Cinchona, balsa, and ceiba trees appear in this belt. From an altitude of 1500-1800 m, palm trees disappear, and tree ferns become more numerous. Above 3000 m, vegetation of the paramos type predominates on mountain meadow and mountain steppe soils. Eternal snow begins at an altitude of 4200-4500 m. The mountain climate is more favorable for human life than the climate of Costa and Gil.

They study the relief of South America in the 7th grade, so many have most likely 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 about the distant continent . In it we will talk about the main landforms of South America.

Geography of the mainland

On the map, the continent is located below North America, connected to 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 ​​South America is the fourth largest 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 French Guiana, belong to the countries Latin America. Colonists from Spain, France and Portugal played a huge, though not always positive, role in their development.

Landforms on the mainland of South America are very diverse and represent... high mountains, so mid-altitude plateaus and lowlands. From north to south, the continent stretches for 7,350 kilometers, covering six climate zones - from northern subequatorial to southern temperate. In most parts the conditions are hot and very humid, and the temperature does not fall below +5 °C.

The peculiar climate and topography of South America made it a record holder in some areas. Thus, the continent is home to the highest volcano, the world's largest river and the highest waterfall. And thanks to the large amount of precipitation, the continent is the wettest on the planet.

Relief of South America

South America was once part of the continent of Gondwanaland, 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 of South America divide it into two large areas: flat-platform in the east and mountainous in the west. The average altitude 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 Chicas depression, the lowest point on the continent with a height of -42 meters.

To the west are the Andes mountains. These are young geological formations formed during relatively recent (about 50 million years ago) volcanic activity. However, the process of their formation is not completed, so volcanic eruptions and earthquakes can still be observed.

Hills

The topography of South America contains several elevated areas called highlands and plateaus. One such region (the Central Andean Highlands) is located right in the middle of the Andes. Here, volcanic plateaus are interspersed with flat, flat areas, and average altitudes reach 4000 meters.

Landforms in the east are much lower. There is the vast Brazilian Highlands, covering about 5 million km 2. Its highest point is Mount Bandeira (2890 m), although in most of the area it rises to an altitude of 200 to 900 meters. The highlands are flat areas with isolated ridges and plateaus with very steep, almost vertical slopes. Similar is the small Guiana plateau in the north, which is part of Brazil in origin.

Lowlands

Lowland plains cover a large part of the continent, and occupy the territory between the mountains and plateaus of South America. They are located in areas of deflection of the foundation 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 Plateau.

The area of ​​the Amazonian lowland is 5 million km2. The largest river on Earth, the Amazon, flows here, 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 come to the surface. The rivers in the eastern part of the Amazon are not as muddy as in the western part, and are dotted with numerous rapids.

Huge areas of the lowlands are swampy and covered with impenetrable jungle of humid equatorial forests. This is one of the least explored regions of the world, inhabited by anacondas, caimans, pumas, tapirs, armadillos, capybaras, maz deer and other unique inhabitants.

Andean Cordillera

By origin, the Andes are part of the North American Cordillera. They run along the entire western coast of the continent, across the territory of seven states, and are the longest mountain system in the world (9,000 km). This is the main watershed of the continent, in which the Amazon River, as well as tributaries of the Orinoco, Paraguay, Paraná, etc., originate.

The Andes are the second highest mountain system. Its highest point is Mount Aconcagua in Argentina (6960.8 m). Based on relief and other natural features, the Andes are distinguished between the Northern, Central and Southern Andes. In general, mountains consist of numerous meridional ridges located 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 protruding deeply into the land and peninsulas strongly elongated into the sea. The shores are mostly smooth and only in the area of ​​​​Venezuela is there a cluster of small islands.

To the south the situation changes. The mainland is gradually narrowing, and its shores are dotted with bays, bays and lagoons. There are many islands adjacent to South America along the coasts of Chile and Argentina. There are more than 40 thousand of them in the Tierra del Fuego archipelago alone.

Not all of them are inhabited, for example, the Falkland Islands. But many have fjords, glaciated mountains, gorges and a huge variety of animals. That is why most of the southern coastal areas are included in national parks and are even protected by UNESCO.

Minerals

Geological structure and the diversity of South America's topography were reflected in its natural resources. The continent is especially rich in minerals; at least half of the periodic table can be found in its depths.

The Andes mountain ranges contain iron, silver, copper, tin, polymetallic ores, as well as antimony, lead, gold, saltpeter, iodine, platinum and precious stones. Colombia is considered a leader in emerald mining, Chile ranks first in the world in copper and molybdenum mining, Bolivia is famous for its tin reserves.

The troughs that frame the Andes contain deposits of oil, coal and natural gas. The ocean floor near the mainland and the vast plains in the east are also rich in oil. In the Amazonian lowland alone, proven oil reserves amount to about 9,000 million tons.

The Brazilian Highlands, located entirely within Brazil, are a powerful source of mineral resources. The country contains large deposits of diamonds, zirconium, tantalum, mica, tungsten, and is the world leader in niobium mining.

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. Thanks 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 gorge. Such diversity of relief was reflected in the nature of the continent, making many of its objects a real treasure of the planet.