What are the Andes in geography. Description of the Andes mountain system. Tourism and locals

The Andean West subcontinent occupies the entire western part mainland. It is the longest (9 thousand km) and one of the highest mountain systems on the mainland. The width of this mountain system reaches 500 km. In total, the Andes cover an area of ​​about 3,370,000 km². The Andes Mountains face a broad front towards, in the north, the Caribbean Sea. The eastern border with the countries of the Extra-Andean East runs along the foot of the Andean ridges. The unity of the physical-geographical countries of the subcontinent is due to the fact that they are located within the folded belt on the border of the lithospheric plates of the Pacific Ocean and South America.

A complex system of orotectonic zones of predominantly submeridional strike extends from the northern coast of the continent to. The different-aged ridges of the Coastal, Western and Eastern Cordillera stretch throughout the Andes mountain system. Mountain formation, especially active in the Paleogene and Neogene, continues to this day, accompanied by volcanic processes and earthquakes.

The region is also united by its position in the west of the continent, which limits the influence of the Pacific Ocean on the internal regions of the system and creates a contrast in the natural conditions of the western and eastern macroslopes.

The Andes are dominated by high-mountain relief, which determines the pronounced altitudinal zonation and the formation of significant modern glaciation. The huge extent from north to south determines big difference in heat supply and in moistening individual parts of the system: the Andes mountains are located in several climatic zones, therefore the structure of altitudinal zones also differs. The orotectonic structure is also different.

Despite the mountainous nature of the subcontinent, its territory has long been quite densely populated. The peoples of the Andean countries developed basins, intermountain valleys and high plains within the Andes mountain system and adapted to life in these conditions. The Andes are home to the highest mountain cities, villages and cultivated lands.

Within the Andes, a number of physical and geographical countries are distinguished: Caribbean, Northern (Equatorial), Central (Tropical), Chilean-Argentine (Subtropical) and Southern (Patagonian) Andes. Tierra del Fuego has some special features - this region is either considered as a separate country or included in the Southern Andes.

Caribbean Andes Mountains

Caribbean Andes Mountains - the most Northern part of the Andes Mountains and the only one where the ridges have a sublatitudinal trend. Here the Andes mountains stretch for 800 km along the northern coast of the Caribbean Sea from the river delta. Orinoco to the lowlands of Maracaibo. In the south, the region borders the Orinoco plains; in the west, the ridges of the Caribbean Andes are separated from the Cordillera de Merida in the Eastern Andes system by a tectonic valley occupied by one of the tributaries of the river. Apure. Unlike other parts of the Andean mountain system, the Caribbean Andes are formed within the Caribbean-Antilles folded region, which possibly represents the western part of the ancient Tethys Ocean and moved there as a result of the opening of the North Atlantic trench. The region is located on the border of tropical and subequatorial belts in the zone of action of the northeastern trade winds. Its nature is significantly different from the rest of the Andes mountains. This is Venezuelan territory.

The country's topography, compared to other Andean regions, is simple in structure: these are young folded mountains, consisting of two parallel anticlinal ridges (Cordillera da Costa - Coast Range and Sierranía del Interior - Interior Ridge), separated by a synclinal longitudinal depression. It contains Lake Valencia, one of the few drainless lakes on the mainland.

Folded structures are broken by transverse and longitudinal faults, so the mountains are divided into blocks by tectonic and erosional valleys. Frequent earthquakes testify to the youth and incompleteness of mountain formation, but there are no active ones here. The height of the Caribbean Andes does not reach 3000 meters. The highest point (2765 meters) is located in the Coastal Cordillera near Caracas, the capital of Venezuela.

The region is exposed to tropical air masses throughout the year, which enter here with the northeast trade wind. Only the southern slopes of the mountains fall under the influence of the equatorial monsoon in summer.

In winter, when the trade wind flow weakens somewhat and the southwest monsoon gives way to the winter northeast, a relatively dry period begins. Since precipitation is mainly orographic, its amount on the coast and leeward mountain slopes is small - 300-500 mm per year. Windward slopes receive up to 1000-1200 mm in the upper zones. The region has very small temperature amplitudes - 2-4°C. Caracas, located in a transverse valley at an altitude of 900-1000 meters, is called the city of “eternal spring”.

The Andes Mountains are cut by numerous deeply incised valleys of short, wild rivers that carry masses of debris onto the coastal plain, especially during the rainy season in summer. There are karst areas, practically devoid of surface water.

The region is dominated by xerophytic vegetation. At the foot of the mountains and in the lower belt, monte formations (mesquite bush, cacti, milkweed, prickly pear, etc.) are common. On the low-lying coast, mangroves along the shores of lagoons are common. On the mountain slopes above 900-1000 meters, sparse mixed forests of evergreen, deciduous and coniferous trees grow. In some places they are replaced by xerophytic shrub thickets such as chaparral. Palm groves stand out as bright spots. Higher up are meadows, often covered with shrubs. The upper limit of forests is artificially reduced, since meadows are used as pastures, and in the border part of forests, under conditions extreme for woody vegetation, it gradually disappears and is not restored.

The coastal strip and intermountain troughs of the Caribbean Andes are oil-bearing. The entire Caribbean coastline with sandy beaches, hot dry climate with stable weather conditions - an excellent resort area. Coffee, cocoa, cotton, sisal, tobacco, etc. are grown on the gentle slopes of the mountains and in the valleys. Cattle are grazed in the mountain meadows.

This part of Venezuela is quite densely populated. In the Caracas area, the population density is over 200 people/km 2 . Here are located big cities and ports. Nature has been significantly modified by various human activities: flat areas and more or less gentle slopes have been plowed, forests have been destroyed, and the coastline has been transformed. A network of national parks has been created here, used to protect landscapes and for tourism.

Northern Andes Mountains

This is the northernmost part of the Andean system proper, extending from the Caribbean coast to 4-5° S. w. The eastern border with the Orinoco plains runs along the foot of the Andes mountains, and the southern border follows transverse tectonic faults. Approximately in the same area is the border of climatic zones - tropical and equatorial with sharp differences in moisture conditions and the structure of altitudinal zones on the slopes of western exposure. The region includes the western regions of Venezuela, Colombia and Ecuador. The lower zones of the western mountain slopes and coastal plains are characterized by a humid, hot, equatorial climate. But also in areas with subequatorial climatic conditions At some altitude above sea level, constantly moist forests grow - hyleas, which is why the Northern Andes Mountains are called Equatorial.

The Andes Mountains within the region consist of several ranges separated by deep depressions. The northern part of the country has a particularly complex structure.

Along the Pacific Ocean stretches a narrow, low, highly dissected Coastal Cordillera, separated from the neighboring zone (Western Cordillera) by the tectonic valley of the river. Atrato. The Western Cordillera begins at the Gulf of Darien and extends to the borders of the region. The Eastern Cordillera branches within the Northern Andes: at about 3° N. w. it is divided into Central with the Sierra Nevada de Santa Marta massif (up to 5800 meters high) in the north and Eastern, which, in turn, with two branches (Sierra Perija and Cordillera de Merida) covers a vast depression with a lagoon Maracaibo. The graben-shaped valley between the Western and Central Cordilleras is occupied by the river. Which one, and between the Central and Eastern - the river. Magdalena. The entire mountainous region is 400-450 km wide. South of 3° N. w. The Western and Eastern Cordilleras are moving closer together, and within Ecuador the system narrows to 100 km. Between the mountain ranges there is a zone of powerful faults. The main peaks of the ridges are, as a rule, extinct and active volcanoes (Cotopaxi, Chimborazo, Sangay, etc.), covered with snow and ice. The region is also characterized by high seismicity. The epicenters of earthquakes are usually confined to the faults of the intermountain depression.

The region has a hot, constantly humid climate. The slopes of the Andes mountains facing the Pacific Ocean receive 8,000-10,000 mm per year.

Unstablely stratified, forming above warm currents equatorial latitudes of the ocean, dominates here throughout the year. Rising along the slopes of the ridges, it gives off moisture in the form of heavy rains. The eastern slopes are influenced by the monsoon circulation, but orographic precipitation also falls here in winter, although the annual amounts are slightly less - up to 3000 mm. Even the interior regions are not particularly arid. A short dry period in winter occurs only in the northeast of the region.

In the Northern Andes Mountains the system of altitudinal zones is most clearly and fully expressed.

The lower belt is tierra caliente (“ hot earth"") with constantly high temperatures (27-29°C) and big amount sediments are occupied by hylaea, almost no different from the Amazonian jungle. Due to unfavorable conditions for humans, the belt is sparsely populated. Only in some places at the foot of the mountains are forests cleared for sugarcane and banana plantations. Above 1000-1500 m the tierra templada begins (“ temperate land"). It is cooler here (16-22°C), precipitation up to 3000 mm on windward slopes and 1000-1200 mm on leeward slopes. This is a belt of evergreen mountain hylea or deciduous evergreen forests with the best living conditions. It is quite densely populated. Most of the population of the Northern Andes Mountains lives here, and there are large cities, such as the capital of Ecuador, Quito. More or less gentle slopes are plowed, coffee trees, corn, tobacco, etc. are grown. The belt is called the “coffee” belt or the “eternal spring” belt. Above 2000-2800 meters there is tierra fria (“cold land”). Average monthly temperatures here are 10-15°C. It is at these heights that orographic structures are constantly formed, therefore the high-mountain hylea of ​​low-growing evergreen trees (oaks, myrtle, some conifers) with an abundance of ferns, bamboos, mosses, mosses, and lichens is called nephelogeia (“foggy forest”). There are many vines and epiphytes in it. Cool weather with constant fog and drizzling rain is unfavorable for life. A few Indian tribes live in the basins, where they grow corn, wheat, potatoes, legumes, and engage in cattle breeding. At an altitude of 3000-3500 meters, Tierra Helada (“frosty land”) begins. Average monthly temperatures in this zone are only 5-6°C, daily amplitudes are more than 10°C, all year round There may be night frosts and snowfalls. In the subnival zone, the vegetation of mountain meadows (paramos) is formed from grasses (bearded grass, feather grass), low-growing shrubs and tall (up to 5 meters) heavily pubescent Asteraceae with bright flowers. In the periglacial zone, rocky placers are common, sometimes covered with mosses and lichens. The nival belt begins at an altitude of 4500-4800 meters.

Among the natural resources of the Northern Andes Mountains are large oil reserves in the depressions. Especially rich oil and gas basin the Maracaibo depression, where there are several dozen large deposits, and the tectonic Magdalena Valley. In the river valley The Kaukas mine hard coal and, on the Pacific coast, placer gold and platinum. There are also known deposits of iron, nickel, molybdenum, copper ores and silver in mountainous areas. Emeralds are mined near Bogota. The region also has good agroclimatic conditions allowing for the cultivation of tropical crops. There is a lot in the mountain hyla valuable species trees, including cinchona, cola, balsa with light non-rotting wood. Long sea voyages were once carried out on balsa rafts. In our time, Thor Heyerdahl's expedition traveled several thousand kilometers on such a raft across the Pacific Ocean.

The intermountain valleys and basins of the Northern Andes Mountains at altitudes of 1000-3000 meters are densely populated and developed. Fertile soils are plowed. Large cities are located in graben valleys and basins, including the capitals of Ecuador (Quito - at an altitude of about 3000 meters) and Colombia (Bogota - at an altitude of about 2500 meters). The nature of the valleys, basins and mountain slopes of the Tierra Templada belt with conditions favorable for humans has been greatly changed. In the 60-70s. XX century reserves were created in Ecuador and Colombia and National parks for the protection and study of natural landscapes.

Central Andes Mountains

The Central Andes Mountains are the largest of the Andean physiographic countries. It starts south of 3° S. w. The mountain system here is expanding; between the chains of the Western and Eastern Cordillera there are high-mountain plains in the middle massif. The total width of the mountain region reaches 800 km. The southern border is drawn approximately at 27-28° S. sh., where the Eastern Cordillera pinches out, and the tropical climate characteristic of the Central Andes Mountains gives way to subtropical. The region contains mountainous parts of Peru, Bolivia, northern Chile and northwestern Argentina.

The orotectonic structure is distinguished by the presence of high mountain (3000-4500 meters) plateaus and plateaus - Puna (in Bolivia they are called Altiplano). The rigid middle mass, within which these plains were formed, is divided into blocks; magma rises along cracks and lavas flow out.

As a result, areas of peneplain, accumulative plains in relief depressions, and lava plateaus with volcanoes are combined here. From the west, the plains are limited by high young folded chains of the Western Cordillera with a large number of. In the east, the ridges of the Eastern Cordillera rise on Mesozoic and Paleozoic folded structures, many of whose peaks above 6000 meters are covered with caps of glaciers and snow. In the south (within Chile), the low Coastal Cordillera rises along the coast, separated from the Western depression. One of them is the Atacama Desert.

The climate in most of the Central Andes is arid. The coastal part of the region is dominated by the extremely arid and cool tropical climate of the western coasts of the continents (the climate of coastal, “wet” or “cold” deserts, as it is often called). At 20° south w. average most warm months 18-21°C, annual amplitude 5-6°C. A flow of cold air from the south passes far north over the Peru Current, lowering summer temperatures. There is very little precipitation. Within the Central Andes Mountains, this climatic region has the greatest extent from north to south (from 3° to 28°S) and rises high along the mountain slopes of western exposure.

The largest areas in the region are occupied by high-mountain arid climates with desert and semi-desert landscapes.

Average temperatures summer months on the Central Andean high plains are 14-15°C, during the day they can rise to 20-22°C, and at night drop to negative values. This is explained by the rarefaction and transparency of mountain air. In winter, average monthly temperatures are positive, but a large diurnal amplitude remains, and at night there are frosts down to -20°C. The large Lake Titicaca has some moderating influence. Not far from it is La Paz - the capital of Bolivia - the highest capital in the world (3700 metro). The amount of precipitation in Pune is small and increases from west to east - from 250 mm to 500-800 mm. The windward slopes of the Eastern Cordillera receive up to 2000 mm due to the influence of.

The soil and vegetation cover of the Central Andes is formed according to the distribution of precipitation and temperature conditions.

In coastal deserts, plants adapt to the rainless regime and obtain moisture from dew and fog. Rare xerophytic shrubs and cacti make up the sparse vegetation cover. Characteristic are peculiar bromeliads with hard gray leaves and weak roots and lichens. In some places there is no vegetation; moving sands with dune and hilly relief are common. Where the annual amount of precipitation (in the form of fog) reaches 200-300 mm. Lomas plant formations appear, represented by ephemerals and a few perennial herbs and cacti. Lomas come to life in winter, when evaporation decreases, and dry out in summer. The interior plains are dominated by puna, a steppe dominated by fescue, reed grass, other poppies, and occasional low-growing shrubs and trees, such as the thorny bromeliad puya and kenoa, growing along the valleys. In western arid regions, they are common with hard grasses, tola shrubs, cushion-shaped llareta plants, and cacti. In saline areas, of which there are many, wormwood and ephedra grow. On the eastern slopes there is a pronounced altitudinal zonation, characteristic of the humid regions of the Andes mountains. Even where the lower mountain belt is adjacent to the dry savannas of the Gran Chaco, higher up, at the level of formation of orographic clouds, wet mountain hylaea of ​​the Tierra Templada belt appear, giving way to formations of the Tierra Fria and Tierra Helada belts.

The fauna of the Central Andes Mountains is interesting and unusual, rich in endemic species.

Among the ungulates - guanaco and vicuña, which have almost disappeared at present, and the Peruvian deer. Many rodents (viscacha, chinchilla, acodon, etc.), birds (from tiny hummingbirds in the Lomas Formation to giant predatory condors). Many animals, including birds, live in burrows, like the inhabitants of the highlands of Tibet.

The subtropical climate of the Pacific coast and adjacent mountain slopes differs well pronounced features Mediterranean type: dry summers and rainy winters with average monthly positive temperatures. As you move away from the ocean, the degree of continentality increases and the climate becomes drier.

On the western slopes of the Cordillera Main there is more precipitation, the eastern slopes facing the Pampian Sierras and the Dry Pampa are quite dry. On the coast, seasonal temperature amplitudes are small (7-8°C); in the Longitudinal Valley, temperature fluctuations are greater (12-13°C). The regime and amount of precipitation change from north to south. On the border with the tropics climatic regions the climate is extremely dry - 100-150 mm per year, and in the south, where the influence of the South Pacific baric maximum weakens and the westerly transport of temperate latitudes intensifies, the annual precipitation reaches 1200 mm with a uniform regime.

The nature of surface runoff is also different and varies both from west to east and from north to south. In the northern regions of the country, river flows are mostly periodic. In the central part there is a fairly dense network of rivers with two rises of water - in winter, when it rains, and in summer, when snow and ice melt in the mountains. The river network is especially dense in the south of the region. The rivers here are full-flowing all year round, and maximum flow occurs in winter. Sometimes they give rise to rivers. In the south, at the foot of the Main Cordillera, there are terminal lakes dammed by lavas or moraines.

Natural vegetation in the region is poorly preserved. Beneath Mediterranean-type formations similar to maquis or chaparral, brown soils have developed that are suitable for growing subtropical crops, so wherever possible the land is ploughed. Even more fertile dark-colored chernozem-like soils are developed in the Longitudinal Valley on volcanic rocks. These lands are occupied by agricultural crops.

Only on mountain slopes that are inconvenient for plowing are thickets of evergreen xerophytic shrubs - espinal - preserved. On the Main Cordillera, up the slopes, they are replaced by deciduous and mixed forests, where teak, litra, perel, canelo, nothofagus, honey palm, etc. grow. Above the forests (from an altitude of 2500 meters), a belt of mountain meadows begins, within which ordinary and For alpine meadows Of the Old World, buttercups, saxifrage, primroses, etc. On the arid eastern slope, forests are practically absent. Semi-desert landscapes are also typical for the northern part of the region, including the north of the Longitudinal Valley. In the extreme south, hemihyleas appear with a predominance of evergreen noto-fagus on brown forest soils. In the forest belt of volcanic massifs there are many plants brought from other areas of the world. Artificial tree plantations surround villages and fields.

Land and agroclimatic resources are the main natural resources of the Chilean-Argentine Andes. They allow you to grow here crops common to the Mediterranean (grapes, citrus fruits, olives, etc.). There are vast fields of wheat and corn. In the Longitudinal Valley, where the capital of Chile, Santiago, is located, half the country’s population lives (the population density here reaches 180 people/km2), despite the fact that this is a seismic area where strong earthquakes are frequent. Nature here has been changed to the greatest extent. In Chile and Argentina there are national parks and natural reserves created to protect mountain and lakeside landscapes and the remaining natural flora and fauna.

Southern (Patagonian) Andes Mountains

This is the southern part of the Andean system, bordering on the east with.

South of 42° S. w. The Andes mountains are declining. The coastal Cordillera passes to the islands of the Chilean archipelago, a longitudinal tectonic depression forms bays and straits along the coast. The territory of the Patagonian Andes, like the Chilean-Argentine Andes, belongs to Chile and Argentina. Mountain-building processes in the region are still ongoing, as evidenced by modern active volcanism. The main (Patagonian) Cordillera is low (up to 2000-2500 meters, rarely above 3000 meters) and highly fragmented.

It is a chain of separate massifs, within which glacial morphosculpture is widely developed. Unusual type for South America coastline- These are fjords of glacial-tectonic origin. There are many extinct and active volcanoes in the Patagonian Cordillera.

The region is located in temperate latitudes. In the west, the climate is maritime with heavy rainfall (up to 6000 mm per year). The eastern slopes of the mountains also receive a large number of precipitation. People penetrate here from the Pacific Ocean along the vast depressions separating the mountain ranges.

Average monthly temperatures on the coast in winter are 4-7°C, in summer - 10-15°C. In the mountains, already at an altitude of 1200 meters, temperatures in the summer months drop to negative values. The snow line lies very low: in the south of the region it descends to 650 meters.

The Patagonian Andes are characterized by a large area of ​​modern glaciation - more than 20,000 km 2 (out of 33,000 km 2 for the entire Andes). Humid climate and low temperatures in the mountains contribute to the development of mountain-cover type glaciers.

The Northern and Southern glacial plateaus form continuous glacial fields that overlap intermountain depressions. Outlet glaciers on the western slopes descend in places to ocean level, producing icebergs. On the eastern slopes there is mountain-type glaciation, and the glacial tongues end in lakes located at the foot of the mountains at an altitude of 180-200 meters above sea level. Mountain ranges and nunataks rise above the ice sheets, dividing them into separate fields. It is believed that the weight of the huge masses of ice contributes to the general decline of the region's surface. Indirect confirmation of this is the fact that there is a similar decrease in heights and a similar structure of the coastline in those regions of the Cordillera North America, which are located in abundantly moist latitudes of the temperate zone and carry large masses ice.

Glaciers and heavy rainfall provide food for many deep rivers. Their valleys cut deeply into the surface, increasing the ruggedness of the mountainous terrain. Natural features unique to South America include the abundance of lakes, of which there are few on the mainland. IN Southern Andes there are many small and several large glacial lakes, formed mainly as a result of the damming of river flows by moraines.

The slopes of the Southern Andes are covered with forests.

In the north, where it is warmer, the lower parts of the slopes up to a height of 500-600 meters are covered with moist evergreen subtropical forests with lianas and epiphytes. In them, along with teak wood, canelo, Perseus, nothofagus, etc., bamboo and tree ferns grow. Higher up, dominance passes to nothophagus, sometimes forming pure dark stands without undergrowth or groves with an admixture of conifers (podocarpus, Fitzroy and other types of Antarctic flora). Even higher rise crooked forests of deciduous nothofagus and mountain meadows, often swampy. To the south, the vegetation gives way to Magellan subantarctic forests of nothophagus with an admixture of some conifers. Similar forests grow on the eastern slopes of the Southern Andes. At the foot of the mountains they give way to shrubs and steppes characteristic of the Patagonian Plateau.

The main natural resources of the Patagonian Andes are hydroelectric resources and forests. Natural resources are used insignificantly. This contributes to the good preservation of the natural landscapes of this part of the Andes. On the territory of Chile and Argentina there are several national parks where mountain, lake, glacial landscapes, fjord coasts, forests of nothofagus, Fitzroyas, etc., endangered species of animals (pudu deer, chinchilla, viscacha, guanaco, Pampas cat, etc.) are protected .).

Tierra del Fuego

It is an island physical-geographical country on the southern edge of the mainland, separated from it by the narrow, winding Strait of Magellan. The archipelago consists of dozens of large and small islands with a total area of ​​more than 70 thousand km 2. The largest one is Fr. Tierra del Fuego, or the Big Island, occupies almost 2/3 of the archipelago's area. The islands belong to Chile and Argentina.

The western part of the region is a continuation of the Andes mountain system. In many natural features - geological structure and relief, the nature of the coastline, modern glaciation, mountain vegetation, etc., this part of the archipelago is similar to the Southern Andes. In the east of the Big Island, the rolling plains are an extension of the Patagonian Plateau.

The western part of the archipelago is highly dissected. Many mountain ranges up to 1000-1300 meters high are separated by intermountain valleys, often flooded with ocean waters - fjords and straits. The highest point of the mountains (2469 meters) is on the Big Island. Ancient and modern glacial relief dominates. There are many lakes dammed by moraines.

The climate is temperate maritime. Humidity changes from west to east.

The western part of the region receives heavy rainfall (up to 3000 mm) throughout the year, mainly in the form of drizzle. There are up to 300-330 rainy days a year. In the eastern part, washed by the cold Falkland Current, precipitation is much less (up to 500 mm).

Summers are cool, average monthly temperatures are 8-10°C, winters are relatively warm (1-5°C). They say that summer here is like in the tundra, and winter (in terms of temperatures) is like in the subtropics. As you rise into the mountains, temperatures quickly decrease, and already from an altitude of 500 m negative values ​​predominate.

The humid climate and relatively low temperatures contribute to the development of glaciation. The snow line in the west lies at an altitude of about 500 m. The outlet glaciers reach sea level, and icebergs break off from them.

The border of the forests covering the western slopes of the mountains sometimes reaches almost to the snow line. The forests are of the same composition as in the Southern Andes. They are dominated by nothophagus, canelo (from the magnolia family), and some conifers. In places above the forest belt, and in the east and on the plains, subantarctic meadows with peat bogs, reminiscent of tundra, are common.

The fauna is similar to the Southern Andes (guanacos, Magellanic dogs, rodents, including burrowing tuco-tucos, also living in Patagonia). The southernmost islands of the archipelago are inhabited by birds, and among mammals only a few species of bats and one species of rodent live there. One of the islands ends at Cape Horn - the southern tip of the entire mainland.

Found on Tierra del Fuego, but the main occupation of the population who have long inhabited the east of the region is sheep breeding. Despite the winter lack of food, sheep provide good income. The pastures here are richer than on the Patagonian Plateau. In some places they are degrading due to the destruction of natural vegetation. Several national parks have been created on the islands.

The Andes Mountains serve as the most important climatic barrier in South America, isolating the territories to the west of the Main Cordillera from the influence of the Atlantic Ocean, and to the east from the influence of the Pacific Ocean. The mountains lie in 6 climatic zones (equatorial, northern and southern subequatorial, southern tropical, subtropical and temperate) and are distinguished by sharp contrasts in the moisture content of the eastern and western slopes.

Due to the considerable extent of the Andes, their individual landscape parts differ significantly from each other. Based on the nature of the relief and other natural differences, as a rule, three main regions are distinguished - Northern, Central and Southern Andes. The Andes stretch across the territories of seven South American countries - Venezuela, Colombia, Ecuador, Peru, Bolivia, Chile and Argentina.

Highest point: Aconcagua (6962 m)

Length: 9000 km

Width: 500 km

Rocks: igneous and metamorphic

The Andes are revived mountains, erected by new uplifts on the site of the so-called Andean (Cordilleran) folded geosynclinal belt; The Andes are one of the largest systems of alpine folding on the planet (on the Paleozoic and partly Baikal folded basement). The beginning of the formation of the Andes dates back to Jurassic time. The Andean mountain system is characterized by troughs formed in the Triassic, subsequently filled with layers of sedimentary and volcanic rocks of considerable thickness. Large massifs of the Main Cordillera and the coast of Chile, the Coastal Cordillera of Peru are granitoid intrusions of Cretaceous age. Intermountain and marginal troughs (Altiplano, Maracaibo, etc.) were formed in Paleogene and Neogene times. Tectonic movements, accompanied by seismic and volcanic activity, continue in our time. This is due to the fact that a subduction zone runs along the Pacific coast of South America: the Nazca and Antarctic plates go under the South American plate, which contributes to the development of mountain building processes. The southernmost part of South America, Tierra del Fuego, is separated by a transform fault from the small Scotia plate. Beyond the Drake Passage, the Andes continue the mountains of the Antarctic Peninsula.

The Andes are rich in ores of mainly non-ferrous metals (vanadium, tungsten, bismuth, tin, lead, molybdenum, zinc, arsenic, antimony, etc.); the deposits are confined mainly to the Paleozoic structures of the eastern Andes and the vents of ancient volcanoes; There are large copper deposits in Chile. There is oil and gas in the foredeep and foothill troughs (in the foothills of the Andes within Venezuela, Peru, Bolivia, Argentina), and bauxite in the weathering crusts. The Andes also contain deposits of iron (in Bolivia), sodium nitrate (in Chile), gold, platinum and emeralds (in Colombia).

The Andes consist primarily of meridional parallel ridges: the Eastern Cordillera of the Andes, the Central Cordillera of the Andes, the Western Cordillera of the Andes, the Coastal Cordillera of the Andes, between which lie internal plateaus and plateaus (Puna, Altipano - in Bolivia and Peru) or depressions. The width of the mountain system is generally 200-300 km.

ANDES (Andes, from anta, in the Inca language copper, copper mountains), Andean Cordillera (Cordillera de los Andes), the longest (estimated from 8 to 12 thousand km) and one of the highest (6959 m, Mount Aconcagua) mountain systems of the globe; frames South America to the north and west. In the north they are limited by the Caribbean Sea basin, in the west they face the Pacific Ocean, in the south they are washed by the Drake Passage. The Andes are the main climatic barrier of the continent, isolating the eastern part from the influence of the Pacific Ocean and the western part from the influence of the Atlantic Ocean.

Relief. The Andes consist mainly of the submeridional ranges of the Western Cordillera of the Andes, the Central Cordillera of the Andes, the Eastern Cordillera of the Andes, and the Coastal Cordillera of the Andes, separated by internal plateaus and depressions (see map).

In aggregate natural features and orographies are distinguished by the Northern, Peruvian, Central and Southern Andes. The Northern Andes include the Caribbean Andes, Colombian-Venezuelan and Ecuadorian Andes. The Caribbean Andes are latitudinal and reach an altitude of 2765 m (Mount Naiguata). The Colombian-Venezuelan Andes have a northeastern strike and are formed by the Western, Central and Eastern (altitude up to 5493 m) Cordillera. The ridges fan out north of 1° north latitude and are separated by the valleys of the Cauca and Magdalena rivers. The northern branches of the Eastern Cordillera cover the intermountain depression of Maracaibo. The isolated Sierra Nevada de Santa Marta massif (altitude 5775 m, Mount Cristobal Colon) rises steeply above the Caribbean coast. Along the Pacific coast there is a lowland up to 150 km wide, with low (up to 1810 m) ridges separated from the Western Cordillera by the Atrato River valley. The Ecuadorian Andes (1° north latitude - 5° south latitude), less than 200 km wide (the minimum width of the Andes), are elongated submeridionally and formed by the Western (altitude up to 6310 m, Mount Chimborazo) and Eastern Cordillera, separated by a depression - the Quito graben. Along the coast there are lowlands and low mountains. The Peruvian Andes (5°-14° south latitude), up to 400 km wide, have a northwest strike. The coastal plain is almost absent. The Western (height up to 6768 m, Mount Huascaran), Central and Eastern Cordillera are separated by the valleys of the Marañon and Huallaga rivers. In the Central Andes (Central Andean Highlands, 14°28°S) the strike changes from northwestern to submeridional. The Western Cordillera (altitude up to 6900 m, Mount Ojos del Salado) is separated from the Central and Cordillera Real by the vast Altiplano basin. The Eastern and Central Cordillera are separated by a narrow depression with the upper reaches of the Beni River. The Coastal Cordillera stretches along the coast, framed in the east by the Longitudinal Valley. The Southern Andes (Chilean-Argentine Andes and Patagonian Andes), 350-450 km wide, are located south of 28° south latitude and have a mainly submeridional strike. They are formed by the Coastal Cordillera, the Longitudinal Valley, the Main Cordillera (altitude up to 6959 m, Mount Aconcagua) and the Precordillera. To the south, the heights decrease to 1000 m (in Tierra del Fuego). The Patagonian Andes are heavily dissected by modern and ancient (Quaternary) glaciers into numerous massifs and ridges. The Coastal Cordillera turns into a chain of islands of the Chilean archipelago with deep valleys and fjords, and the Longitudinal Valley into a system of straits. The Andes are part of the Pacific volcanic ring, and the appearance of the relief is largely determined by volcanic forms - plateaus, lava flows, volcanic cones. There are up to 50 large active, 30 extinct volcanoes and hundreds of small volcanic structures. In the Northern Andes - the volcanoes Cotopaxi (5897 m), Huila (5750 m), Ruiz (5400 m), Sangay (5230 m), etc.; in the Central Andes - Llullaillaco (6723 m), Misti (5822 m), etc.; in the Southern Andes - Tupungato (6800 m), Llaima (3060 m), Osorno (2660 m), Corcovado (2300 m), Berni (1750 m), etc.

Geological structure and minerals. The Andes, as the newest mountain structure, formed at the Alpine stage (in the Cenozoic) in connection with the evolution of the active margin of South America. In their position, the Andes inherit the Andean fold system, which developed throughout the Phanerozoic, the largest of the systems in the eastern part of the Pacific mobile belt. The modern Andes are a typical continental-margin volcano-plutonic belt. At earlier stages of development (late Triassic - Cretaceous), island arc systems of the Western Pacific type existed here. According to the geological structure, the Andes have transverse and longitudinal zoning. From north to south, three segments are distinguished: Northern (Colombian-Ecuadorian), Central (with Peruvian-Bolivian and Northern Chilean-Argentinean subsegments) and Southern (Southern Chilean-Argentinean). The easternmost element of the Andes is a strip of Subandian foredeeps, gradually narrowing to the south and consisting of individual units separated by transverse uplifts. The troughs are filled with slightly deformed Eocene-Quaternary molasse. The Orogen of the Andes, thrust to the east, consists of several large uplifts with a folded structure (expressed in relief by the Cordillera mountain ranges) and separating them narrower intermountain troughs or plateaus (Altiplano), filled with thick Neogene-Quaternary molasse. The eastern (outer), partly central zones of the orogen are composed of fragments of the Early Precambrian metamorphic basement of the platform, its Paleozoic cover, and Late Precambrian (Brazilians) and Hercynian metamorphic fold complexes. The structure of the western (internal) zones involves Mesozoic (partly Paleozoic) sedimentary, volcanogenic-sedimentary, volcanogenic complexes that formed in volcanic island arcs, back-arc basins on the ancient active margin of South America, as well as ophiolites of various origins. These formations were attached (accreted) to the margin of South America in the Late Cretaceous. At the same time, the intrusion of giant multiphase granite batholiths (Coastal Cordillera of Peru, Main Cordillera of Chile, Patagonian) occurred. In the Cenozoic, chains of large terrestrial stratovolcanoes formed along the active continental margin. Three volcanic groups are currently active: northern (Southern Colombia and Ecuador), central (Southern Peru - Northern Chile) and southern (Southern Chile). The Andes retain high tectonic mobility and are characterized by intense seismicity associated with the subduction (subduction) of the Nazca Plate under the South American Plate.

The interior of the Andes is extremely rich in minerals. The deposits of the Copper Belt of South America are associated with granite batholiths. Cenozoic volcanic and subvolcanic formations are associated with ore deposits of silver, copper, lead, zinc, tungsten, gold, platinum and other rare and non-ferrous metals (deposits in Peru and Bolivia). Oil and natural combustible gas deposits are associated with the strip of foredeeps filled with Cenozoic molasse, especially in the north (Venezuela, Ecuador, Northern Peru) and the extreme south of the Andes (Southern Chile, Argentina). Large deposits saltpeter, iron ores in Chile, emeralds in Colombia.

Climate. The Andes cross 6 climatic zones (equatorial, northern and southern subequatorial, southern tropical and subtropical, temperate), characterized by sharp contrasts in the moisture content of the western (windward) and eastern (leeward) slopes. In the Caribbean Andes, 500-1000 mm of precipitation falls per year (mainly in summer), in the equatorial Andes (Ecuador and Colombia) on the western slopes - up to 10,000 mm, on the eastern - up to 5,000 mm. The western slopes of the Peruvian and Central Andes and the interior of the Central Andes are characterized by a tropical desert climate, the eastern slopes receive up to 3000 mm of precipitation per year. South of 20° south latitude, precipitation increases on the western slopes and decreases on the eastern slopes. The western slopes south of 35° south latitude receive 5,000-10,000 mm of precipitation per year, and the eastern slopes receive 100-200 mm. Only in the very south, with a decrease in altitude, does some leveling out in the moisture content of the slopes occur. The snow line is located in Colombia at an altitude of 4700-4900 m, in Ecuador - 4250 m, in the Central Andes 5600-6100 (in Pune 6500 m - the highest on Earth). It decreases to 3100 m at 35° south latitude, 1000-1200 m in the Patagonian Andes, 500-600 m in Tierra del Fuego. South of 46°30'S latitude, glaciers descend to ocean level. Large centers of glaciation are located in the Cordillera de Santa Marta and in the Cordillera de Merida (total ice volume about 0.5 km 3), in the Ecuadorian Andes (1.1 km 3), Peruvian Andes (24.7 km 3 ), in the Western Cordillera of the Central Andes (12.1 km 3), in the Central Cordillera (62.7 km 3), in the Chilean-Argentine Andes (38.9 km 3), Patagonian Andes (12.6 thousand km 3, in including the Uppsala glacier). The Patagonian ice sheet is formed by two vast fields with a total length of 700 km, a width of 30-70 km, and a total area of ​​13 thousand km 2.

Rivers and lakes. The interoceanic divide runs through the Andes, where the constituents and tributaries of the Amazon, as well as tributaries of the Orinoco, Paraguay, Paraná and Patagonian rivers originate. In the Northern and Peruvian Andes, in narrow depressions located between the ridges, large rivers flow: Cauca, Magdalena, Marañon (the source of the Amazon), Huallaga, Mantaro, etc. Most of their tributaries and the rivers of the Central and Southern Andes are relatively short. The rivers of the Western and Coastal Cordillera between 20° and 28° south latitude have almost no permanent watercourses, the river network is sparse. The Central Andes are home to vast areas of internal drainage. The rivers flow into lakes Titicaca, Poopo and salt marshes (Coipasa, Uyuni, etc.). In the Southern, especially Patagonian, Andes there are many large lakes of glacial origin (Buenos Aires, San Martin, Viedma, Lago Argentino, etc.) and hundreds of small ones (of course moraines and cirques).

Soils, flora and fauna. The location in several climatic zones, contrasts in moisture on the western and eastern slopes, and the significant altitudes of the Andes determine a wide variety of soil and vegetation cover and pronounced altitudinal zonation. In the Caribbean Andes there are deciduous (during winter drought) forests and shrubs on mountain red soils. On the eastern slopes of the Colombian-Venezuelan, Ecuadorian, Peruvian and Central Andes there are montane tropical rainforests (montane hylea) on lateritic soils, including the Yungas natural region. On the western slopes of the Peruvian and Central Andes are the Tamarugal and Atacama deserts, and in the interior highlands - Puna. In the subtropical Andes of Chile - evergreen dry forests and shrubs on brown soils, south of 38° south latitude - moist evergreen and mixed forests on brown forest soils, in the south - podzolized soils. The high plateaus are characterized by special alpine types of vegetation: in the north - equatorial meadows (paramos), in the Peruvian Andes and in the northeast of Puna - dry cereal steppes (halka). The Andes are home to potatoes, cinchona, coca and other valuable plants.

The fauna of the Andes is similar to the fauna of the adjacent plains; Among the endemic species are the relict spectacled bear, llamas (vicuna and guanaco), Magellan's dog (culpeo), Azar's fox, pudu and huemul deer, chinchilla, Chilean opossum. Birds are numerous (especially in the Coastal Cordillera): condor, mountain partridge, geese, ducks, parrots, flamingos, hummingbirds, etc. It is possible that the horse, sheep and goat brought to South America contributed to the desertification of the Andean landscapes.

There are 88 national parks in the Andes with a total area of ​​19.2 million hectares, including: Sierra Nevada (Venezuela), Paramillo, Cordillera de los Picachos, Sierra de la Macarena (Colombia), Sangay (Ecuador), Huascaran, Manu (Peru), Isiboro Secure (Bolivia), Alberto Agostini, Bernardo O'Highns, Laguna - San Rafael (Chile), Nahuel Huapi (Argentina), as well as numerous reserves and other protected areas.

Lit.: Lukashova E. N. South America. Physiography. M., 1958; Cordillera of America. M., 1967.

M. P. Zhidkov; A. A. Zarshchikov (geological structure and minerals).

In the west of South America, along the Pacific coast, a long mountain system, the Andes, stretches for 9 thousand km. Almost along their entire length they consist of a system of parallel ridges and intermountain basins. The mountains have gone through a long geological path of development, and in accordance with the differences in development and structure in the Andes, the following zones can be distinguished:

The Eastern Andes are mountain ranges that arose in Cenozoic era thanks to blocky uplifts of Paleozoic folded structures that formed earlier. Between the Western and Eastern Cordilleras there are highlands that have not experienced significant changes in the process of Alpine mountain building. The steep slopes of the Andes mountains were created by faults earth's crust. The Andes are confined to the boundaries of lithospheric plates, so earthquakes and volcanic eruptions occur here - Llullaillaco, San Pedro, Cotopaxi. This indicates that the Andes are young mountains and their growth continues. A catastrophic earthquake occurred in the Andes in 1960 (Chile). Tremors of enormous force continued for seven days. During this time, 35 cities were destroyed, hundreds of settlements were wiped off the face of the earth. At least 10 thousand people died. More than 2 million people were left homeless; the tsunami washed away and destroyed port facilities and fishing villages.

The Western Andes are high and medium-height folded-block mountains that arose in the middle or at the end of the Alpine orogeny.

The highest peak of the Andes is Mount Aconcagua (6960 m).

The subsoil of the Andes is very rich in minerals, especially ores of non-ferrous and rare metals. Intermountain and foothill troughs are rich in oil.

The large extent of the mountains from north to south determined the diversity of climate in the northern and southern territories, western and eastern slopes. Temperatures at the surface of the Andes vary in January from +16°C (in the north) to +8° (in the south). At the equator, the January temperature is usually 4-24°C. In July in the north near the surface of the mountains +24°C, in the south 0°C. The greatest amount of precipitation falls in equatorial latitudes. There, on the Pacific coast, up to 7660 mm falls, and the mountain tops are covered with glaciers. Pacific coast between 5° and 30° S. lies in the area of ​​coastal deserts. This climate is most pronounced in the tropical zone on the central plateaus of the Andes, where the air is extremely dry. A lot of precipitation falls in the southwest of the Andes, since these territories lie on the paths of westerly winds from the Pacific Ocean. Within the temperate zone, precipitation on the slopes of the Andes falls mainly in winter; in summer there is less rain, and cloudy cloudy weather predominates.

Most of rivers originating in the Andes flow into the Atlantic Ocean. Only relatively small streams originating in the western part of the Andes flow into the Pacific Ocean. The Andes are home to the largest lake, Titicaca, located on the Andean plateau at an altitude of 3812 m. Maximum depth its depth is 304 m, the water is fresh. On the interior plateaus of the Andes there are many lakes of tectonic origin, shallow, drainless, and saline.

The mountainous terrain of the Andes determines the development of altitudinal zones here. Vegetable world formed gradually, as the mountain system itself emerged. The large extent of the Andes is the reason that different areas differ in the composition of the belts, as well as their number. Ridges that are of great height and located in equatorial latitudes include the following belts:

— up to 1000 meters are located equatorial forests, not unlike the Amazon forests;

— up to 3000 meters there are mountain and alpine forests, in which bamboo, cinchona, and ancient ferns are found;

- up to 4000 meters, low trees, shrubs, and open forests begin to appear in the forests. Heather, myrtle, and low-growing bamboos are found here;

— above 4000 meters there are alpine meadows. The vegetation here consists of sparsely growing turf grasses, cushion-shaped. Flat areas are characterized by moss swamps, while steep slopes are characterized by barren rocky areas;

- over 4500 meters - a belt of eternal snow and ice.

In the subtropical climate zone, the number and composition of vertical zonation belts are somewhat different. There, at the foot of the mountains, there are deserts that turn into a belt of hard-leaved forests that extend to an altitude of approximately 2000 meters. On the eastern slopes, which are drier, the forest boundary lies 200 m lower. Now these forests are mostly destroyed. Woody vegetation It is found here in the form of artificial plantings around populated areas and along fields. Here you can find plane trees, pine trees, and in the undergrowth there are thickets of brightly blooming geraniums. The hard-leaved evergreen forests above give way to deciduous beech forests, and above 2500 meters there is a belt of mountain meadows that are used as pastures.

Large spaces are occupied by cultivated vegetation grown by humans. The largest part of the arable land is occupied by wheat and corn. In the equatorial latitudes of the Andes, cocoa is grown on slopes up to 1600 meters; higher up there are fields where coffee, cotton, tobacco, bananas, vegetables, potatoes, and legumes are grown. Mountain meadows are excellent pastures for livestock.

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 height is about 4000 m. The Andes are a large interoceanic watershed; to the east of the Andes flow the rivers of the Atlantic Ocean basin (the Amazon itself and many of its large tributaries, as well as the tributaries of the Orinoco, Paraguay, Parana, the Magdalena River and the rivers of Patagonia originate in the Andes), to the west - the rivers of the Pacific Ocean basin (mostly short). The Andes serve as the most important climatic barrier in South America, isolating the territories to the west of the Main Cordillera from the influence of the Atlantic Ocean, and to the east from the influence of the Pacific Ocean. The mountains lie in 5 climatic zones (equatorial, subequatorial, tropical, subtropical and temperate) and are distinguished (especially in the central part) by sharp contrasts in the moisture content of the eastern (leeward) and western (windward) slopes.

Due to the considerable extent of the Andes, their individual landscape parts differ significantly from each other. Based on the nature of the relief and other natural differences, as a rule, three main regions are distinguished - Northern, Central and Southern Andes.
The Andes stretch across the territories of seven South American countries - Venezuela, Colombia, Ecuador, Peru, Bolivia, Chile and Argentina.
According to the Italian historian Giovanni Anello Oliva (1631), the eastern ridge was originally called “Andes or Cordilleras” by European conquerors, while the western ridge was called “sierra”. Currently, most scientists believe that the name comes from the Quechuan word anti (high ridge, ridge), although there are other opinions.

Geological structure and relief

The Andes are revived mountains, erected by new uplifts on the site of the so-called Andean (Cordilleran) folded geosynclinal belt; The Andes are one of the largest systems of alpine folding on the planet (on the Paleozoic and partly Baikal folded basement). The beginning of the formation of the Andes dates back to Jurassic time. The Andean mountain system is characterized by troughs formed in the Triassic, subsequently filled with layers of sedimentary and volcanic rocks of considerable thickness. Large massifs of the Main Cordillera and the coast of Chile, the Coastal Cordillera of Peru are granitoid intrusions of Cretaceous age. Intermountain and marginal troughs (Altiplano, Maracaibo, etc.) were formed in Paleogene and Neogene times. Tectonic movements, accompanied by seismic and volcanic activity, continue in our time. This is due to the fact that a subduction zone runs along the Pacific coast of South America: the Nazca and Antarctic plates go under the South American plate, which contributes to the development of mountain building processes. The southernmost part of South America, Tierra del Fuego, is separated by a transform fault from the small Scotia plate. Beyond the Drake Passage, the Andes continue the mountains of the Antarctic Peninsula.
The Andes are rich in ores of mainly non-ferrous metals (vanadium, tungsten, bismuth, tin, lead, molybdenum, zinc, arsenic, antimony, etc.); the deposits are confined mainly to the Paleozoic structures of the eastern Andes and the vents of ancient volcanoes; There are large copper deposits in Chile. There is oil and gas in the foredeep and foothill troughs (in the foothills of the Andes within Venezuela, Peru, Bolivia, Argentina), and bauxite in the weathering crusts. The Andes also contain deposits of iron (in Bolivia), sodium nitrate (in Chile), gold, platinum and emeralds (in Colombia).
The Andes consist primarily of meridional parallel ridges: the Eastern Cordillera of the Andes, the Central Cordillera of the Andes, the Western Cordillera of the Andes, the Coastal Cordillera of the Andes, between which lie internal plateaus and plateaus (Puna, Altiplano - in Bolivia and Peru) or depressions. The width of the mountain system is generally 200-300 km.

Orography

Northern Andes

The main system of the Andes mountains (Andean Cordillera) consists of parallel ridges stretching in the meridional direction, separated by internal plateaus or depressions. Only the Caribbean Andes, located within Venezuela and belonging to the Northern Andes, stretch sublatitudinally along the coast of the Caribbean Sea. The northern Andes also include the Ecuadorian Andes (in Ecuador) and the Northwestern Andes (in western Venezuela and Colombia). The highest ridges of the Northern Andes have small modern glaciers, and eternal snow on the volcanic cones. The islands of Aruba, Bonaire, and Curacao in the Caribbean Sea represent the peaks of the extension of the Northern Andes that descend into the sea.
In the Northwestern Andes, fan-shaped diverging north of 12° N. sh., there are three main Cordilleras - Eastern, Central and Western. All of them are high, steeply sloped and have a folded blocky structure. They are characterized by faults, uplifts and subsidences of modern times. The main Cordilleras are separated by large depressions - the valleys of the Magdalena and Cauca-Patia rivers.
The Eastern Cordillera has its highest altitude in its northeastern part (Mount Ritakuva, 5493 m); in the center of the Eastern Cordillera - an ancient lake plateau (predominant heights - 2.5 - 2.7 thousand m); The Eastern Cordillera is generally characterized by large planation surfaces. In the highlands there are glaciers. In the north, the Eastern Cordillera is continued by the Cordillera de Merida (highest point - Mount Bolivar, 5007 m) and Sierra de Perija (reaches a height of 3,540 m); Between these ranges in a vast low-lying depression lies Lake Maracaibo. In the far north there is the Sierra Nevada de Santa Marta horst massif with altitudes up to 5800 m (Mount Cristobal Colon)
The Magdalena River Valley separates the Eastern Cordillera from the Central Cordillera, which is relatively narrow and high; in the Central Cordillera (especially in its southern part) there are many volcanoes (Hila, 5750 m; Ruiz, 5400 m; etc.), some of them active (Kumbal, 4890 m). To the north, the Central Cordillera decreases somewhat and forms the Antioquia massif, strongly dissected by river valleys. The Western Cordillera, separated from the Central Valley by the Cauca River, has lower altitudes (up to 4200 m); in the south of the Western Cordillera - volcanism. Further to the west is the low (up to 1810 m) Serrania de Baudo ridge, which turns into the mountains of Panama in the north. To the north and west of the Northwestern Andes are the Caribbean and Pacific alluvial lowlands.
As part of the Equatorial (Ecuadorian) Andes, reaching up to 4° S, there are two Cordilleras (Western and Eastern), separated by depressions 2500-2700 m high. Along the faults that limit these depressions (depressions) there is one of the highest volcanic mountains in the world chains (the highest volcanoes are Chimborazo, 6267 m, Cotopaxi, 5897 m). These volcanoes, as well as those of Colombia, form the first volcanic region of the Andes.

Central Andes

In the Central Andes (up to 28° S) the Peruvian Andes (extending south to 14°30 S) and the Central Andes proper are distinguished. In the Peruvian Andes, as a result of recent uplifts and intensive incision of rivers (the largest of which - Marañon, Ucayali and Huallaga - belong to the upper Amazon system), parallel ridges (Eastern, Central and Western Cordillera) and a system of deep longitudinal and transverse canyons were formed, dismembering the ancient alignment surface . The peaks of the Cordillera of the Peruvian Andes exceed 6000 m (the highest point is Mount Huascaran, 6768 m); in the Cordillera Blanca - modern glaciation. Alpine landforms are also developed on the blocky ridges of the Cordillera Vilcanota, Cordillera de Vilcabamba, and Cordillera de Carabaya. To the south is the widest part of the Andes - the Central Andean Highlands (width up to 750 km), where arid geomorphological processes predominate; a significant part of the highland is occupied by the Puna plateau with altitudes of 3.7 - 4.1 thousand m. Puna is characterized by drainage basins (“bolsons”) occupied by lakes (Titicaca, Poopo, etc.) and salt marshes (Atacama, Coipasa, Uyuni, etc. .). East of Puna is the Cordillera Real (Ankouma Peak, 6550 m) with thick modern glaciation; between the Altiplano plateau and the Cordillera Real, at an altitude of 3700 m, is the city of La Paz, the capital of Bolivia, the highest in the world. To the east of the Cordillera Real are the sub-Andean folded ridges of the Eastern Cordillera, reaching up to 23° S. latitude. The southern continuation of the Cordillera Real is the Cordillera Central, as well as several blocky massifs (the highest point is Mount El Libertador, 6720 m). From the west, Puna is framed by the Western Cordillera with intrusive peaks and numerous volcanic peaks (Sajama, 6780 m; Llullaillaco, 6739 m; San Pedro, 6145 m; Misti, 5821 m; etc.), included in the second volcanic region of the Andes. South of 19° S. The western slopes of the Western Cordillera face the tectonic depression of the Longitudinal Valley, occupied in the south by the Atacama Desert. Behind the Longitudinal Valley is the low (up to 1500 m) intrusive Coastal Cordillera, which is characterized by arid sculptural landforms.
In Puna and in the western part of the Central Andes there is a very high snow line (in places above 6,500 m), so snow is recorded only on the highest volcanic cones, and glaciers are found only in the Ojos del Salado massif (up to 6,880 m in height).

Southern Andes

In the Southern Andes, extending south of 28° S, there are two parts - northern (Chilean-Argentine, or Subtropical Andes) and southern (Patagonian Andes). In the Chilean-Argentine Andes, narrowing to the south and reaching 39°41 S, a three-member structure is clearly expressed - the Coastal Cordillera, the Longitudinal Valley and the Main Cordillera; within the latter, in the Cordillera Frontal, there is the highest peak of the Andes, Mount Aconcagua (6960 m), as well as the large peaks of Tupungato (6800 m), Mercedario (6770 m). The snow line here is very high (at 32°40 S - 6000 m). To the east of the Cordillera Frontal are the ancient Precordilleras.
South of 33° S. (and up to 52° S) is the third volcanic region of the Andes, where there are many active (mainly in the Main Cordillera and to the west of it) and extinct volcanoes (Tupungato, Maipa, Llymo, etc.)
When moving south, the snow line gradually decreases and at 51° S. reaches 1460 m. High ridges acquire features of the Alpine type, the area of ​​modern glaciation increases, and numerous glacial lakes appear. South of 40° S. The Patagonian Andes begin with lower ridges than in the Chilean-Argentine Andes (the highest point is Mount San Valentin - 4058 m) and active volcanism in the north. About 52° S the strongly dissected Coastal Cordillera plunges into the ocean, and its peaks form a chain of rocky islands and archipelagos; The longitudinal valley turns into a system of straits reaching the western part of the Strait of Magellan. In the area of ​​the Strait of Magellan, the Andes (called the Andes of Tierra del Fuego) sharply deviate to the east. In the Patagonian Andes, the height of the snow line barely exceeds 1500 m (in the extreme south it is 300-700 m, and from 46°30 S latitude glaciers descend to ocean level), glacial landforms predominate (at 48° S latitude - powerful Patagonian ice sheet) with an area of ​​over 20 thousand km², from where many kilometers of glacial tongues descend to the west and east); some of the valley glaciers on the eastern slopes end in large lakes. Along the coasts, heavily indented by fjords, young volcanic cones rise (Corcovado and others). The Andes of Tierra del Fuego are relatively low (up to 2469 m).

Vegetation and soils

The soil and vegetation cover of the Andes is very diverse. This is due to the high altitudes of the mountains and the significant difference in moisture content between the western and eastern slopes. Altitudinal zone in the Andes it is clearly expressed. There are three altitudinal zones - Tierra Caliente, Tierra Fria and Tierra Elada.
In the Andes of Venezuela, deciduous (during winter drought) forests and shrubs grow on mountain red soils. The lower parts of the windward slopes from the Northwestern Andes to the Central Andes are covered with montane moist equatorial and tropical forests on lateritic soils, as well as mixed forests of evergreen and deciduous species. The appearance of equatorial forests differs little from appearance these forests in the flat part of the mainland; Characteristic are various palm trees, ficus trees, bananas, cocoa trees, etc. Higher (up to altitudes of 2500-3000 m) the nature of the vegetation changes; typical are bamboos, tree ferns, coca bush (which is a source of cocaine), and cinchona. Between 3000 m and 3800 m - high-mountain hylea with low-growing trees and shrubs; Epiphytes and lianas are widespread, bamboos, tree ferns, evergreen oaks, myrtaceae, and heathers are typical. Higher up there is predominantly xerophytic vegetation, paramos, with numerous Asteraceae; moss swamps on flat areas and lifeless rocky areas on steep slopes. Above 4500 m there is a belt of eternal snow and ice.
To the south, in the subtropical Chilean Andes - evergreen shrubs on brown soils. In the Longitudinal Valley there are soils whose composition resembles chernozems. Vegetation of the high mountain plateaus: in the north - mountain equatorial meadows of paramos, in the Peruvian Andes and in the east of Puna - dry high-mountain tropical steppes of the halka, in the west of Puna and throughout the Pacific west between 5-28 ° south latitude - desert types of vegetation (in the Atacama Desert - succulent vegetation and cacti). Many surfaces are saline, which prevents the development of vegetation; In such areas, mainly wormwood and ephedra are found. Above 3000 m (up to about 4500 m) there is semi-desert vegetation called dry puna; Dwarf shrubs (tholoi), grasses (feather grass, reed grass), lichens, and cacti grow. To the east of the Main Cordillera, where there is more precipitation, there is steppe vegetation (puna) with numerous grasses (fescue, feather grass, reed grass) and cushion-shaped shrubs. On the humid slopes of the Eastern Cordillera, tropical forests (palm trees, cinchona) rise up to 1500 m, low-growing forests reach 3000 m evergreen forests with a predominance of bamboo, ferns, vines; at higher altitudes there are high-mountain steppes. A typical inhabitant of the Andean highlands is polylepis, a plant of the Rosaceae family, common in Colombia, Bolivia, Peru, Ecuador and Chile; these trees are also found at an altitude of 4500 m.
In central Chile the forests have been largely cleared; Once upon a time, forests rose along the Main Cordillera to altitudes of 2500-3000 m (higher up were mountain meadows with alpine grasses and shrubs, as well as rare peat bogs), but now the mountain slopes are practically bare. Nowadays forests are found only in the form of individual groves (pines, araucarias, eucalyptus, beeches and plane trees, with gorse and geranium in the undergrowth). On the slopes of the Patagonian Andes south of 38° S. - subarctic multi-tiered forests of tall trees and shrubs, mostly evergreen, on brown forest (podzolized to the south) soils; there are a lot of mosses, lichens and lianas in the forests; south of 42° S - mixed forests (in the area of ​​42° S there is an array of araucaria forests). Beeches, magnolias, tree ferns, tall conifers, and bamboos grow. On the eastern slopes of the Patagonian Andes there are mainly beech forests. In the extreme south of the Patagonian Andes there is tundra vegetation.
In the extreme southern part of the Andes, Tierra del Fuego, forests (of deciduous and evergreen trees - such as southern beech and canelo) occupy only a narrow coastal strip in the west; Above the forest line, the snow belt begins almost immediately. In the east and in some places in the west, subantarctic mountain meadows and peatlands are common.
The Andes are the birthplace of cinchona, coca, tobacco, potatoes, tomatoes and other valuable plants.

Zhifotny world

The fauna of the northern Andes is part of the Brazilian zoogeographic region and is similar to the fauna of the adjacent plains. The fauna of the Andes south of 5° south latitude belongs to the Chilean-Patagonian subregion. The Andean fauna in general is characterized by an abundance of endemic genera and species. The Andes are home to llamas and alpacas (representatives of these two species are used local population for obtaining wool and meat, and also as pack animals), prehensile-tailed monkeys, relict spectacled bear, pudú and gaemal deer (which are endemic to the Andes), vicuña, guanaco, Azar's fox, sloths, chinchillas, marsupial possums, anteaters, degu rodents. In the south - the blue fox, the Magellanic dog, the endemic rodent tuco-tuco, etc. There are many birds, among them hummingbirds, which are also found at altitudes above 4000 m, but are especially numerous and diverse in the “foggy forests” (humid tropical forests Colombia, Ecuador, Peru, Bolivia and the extreme north-west of Argentina, located in the fog condensation zone); endemic condor, rising to a height of up to 7 thousand m; and others. Some species (such as chinchillas, which were intensively exterminated in the 19th - early 20th centuries for the sake of their skins; wingless grebes and the Titicaca whistler, found only near Lake Titicaca; etc.) are under threat of extinction.
A special feature of the Andes is the large species diversity of amphibians (over 900 species). Also in the Andes there are about 600 species of mammals (13% are endemic), over 1,700 species of birds (of which 33.6% are endemic) and about 400 species of freshwater fish (34.5% are endemic)

Information

• Countries: Venezuela, Colombia, Ecuador, Peru, Bolivia, Chile, Argentina
• Length: 9000 km
• Width: 500 km
• highest peak: Aconcagua

Source. wikipedia.org