Cordillera glaciers on the map. The Cordillera Mountains are the longest mountain range in the world.

One of the largest mountain systems on our planet is the Cordillera Mountains.

They amaze with their huge scale (they are perfectly visible from space, if you look at the mainland), length and extraordinary beauty with their inherent uniqueness of the local climate, flora and fauna.

Where are the Cordillera

The Cordilleras (Cordilleras English origin of the name) are located on west coast America and extend from north to south. These are huge mountains several thousand kilometers long, up to 18,000 km long and 1,600 km wide.

Looking at physical map world, you can see that the mountains pass through 10 countries and capture the entire western hemisphere of the earth. The coordinates are impressive: south latitude 32/39/12; west longitude 70/00/42.

Note: the age of this system is simply enormous - the Cordilleras were formed in the Jurassic period, and scientists say that their formation has not yet ended, as evidenced by frequent volcanoes (more than 80 active).

The highest point of the Cordillera

The average height of the Cordillera is 3-4 thousand meters above sea level. The highest point of the Cordillera is Mount Aconcagua, located in South America in the Andes near the border with Chile.

Mount Aconcagua

And the place where the Andes formed is called the Patagonian platform. The absolute height of this mountain is about seven thousand kilometers (6961 m) above sea level.

In North America, the highest point of the Cordillera is Mount Denali, located in southern Alaska. Mountain just below Aconcagua, height 6190 m.

Characteristics of the Cordillera of North America

The mountains originate in Alaska and pass through the entire continent, through three countries (Canada, USA, Mexico) to a point in the south in the valley of the Mexican river Balasas on the border with Central America.

The tectonic structure is complex, there are: areas of ancient, middle and new folding, many active volcanoes.

Throughout the length of the Cordillera there are three main belts:

• internal - consists of plateaus and plateaus in the middle of the western and eastern, there are many tectonic depressions with rivers;
• eastern - the Rocky Mountain belt, large ridges separate the Pacific Ocean and the Gulf of Mexico from the Arctic Ocean;
• western - volcanic mountains parallel to the Pacific coast.

Three main arcs of the Cordillera

In Central America, the mountains diverge into arcs:

1. One arc forms mountains in Cuba and northern Puerto Rico and Haiti. The arc was formed from the eastern and western belts, from the north.
2. The other starts from the borders of Mexico from the south, further through Central America, to the western part of Panama. This arc smoothly transitions into .
3. The last arc from the south of the western belt takes the direction to the mountains of the southern side of Puerto Rico and Haiti, and the mountains of Jamaica.

Geological structure and minerals

The lowlands between the mountain ranges accumulated sedimentary rocks for a long time.

And now in the mountains North America large deposits of minerals were formed, while the mountains themselves are valuable in metal ore:

• there are oil fields in Alaska;
• the Rocky Mountains are rich in copper, gold, and tungsten;
• the coastal part of the ridges is of interest for the extraction of mercury and coal.

natural areas

Since the Cordilleras run through all of America, then natural areas mountains capture everything: forest-tundra, mixed forests, forest-steppes, forests, semi-deserts and deserts, tropical shrouds and forests. Only the arctic and subarctic zones are missing.

Rivers and lakes of the Cordillera

In the north of Alaska there are glaciers (large - Bering). Many rivers begin their journey in the Cordillera mountains, for example: Missouri, Yukon. Very full-flowing rivers of the Pacific basin.

The southern rivers are filled with rainwater, the northern rivers are fed by glaciers and snow.

Spring high water is typical for the northern regions of the mountains. The strong northern rivers are used for irrigation and power generation. Notable Reservoirs: Columbia, Colorado. There are also fresh and salt lakes.

Climate and climatic zones

The climate in the Cordillera is diverse due to the vast territory on which they are located:

1. Humidity in the southern part of the mountains is not more than 60%, and in the northern part up to 80%.
2. The average air t in summer in July is plus, in the south up to 30 degrees, and in the north up to 15. Winter average t in January in the north is -30, in the southern regions -17.
3. The amount of precipitation per year is the largest in southern Alaska up to 4000 mm, and the most meager in the Mojave Desert - 50 mm.

Mountains, passing through all climatic zones:

• the south is the tropics and subtropics;
• the north of the belt changes climate from arctic to subarctic, then temperate;
• in the central, inland regions - the continental belt, and on the Pacific slopes of the mountains - the soft oceanic.

Flora and fauna

The natural landscape of the mountains is very diverse (due to altitudinal zonation).

Allocate natural areas:

1. Northwestern consists mainly of glaciated mountain peaks and plateaus. The climate is harsh, permafrost, south coast- a little warmer. The landscape is tundra, woodland. Deer, lemings, and many birds live in the tundra. Bears, wolves, lynxes, cougars can be seen in the forests.
2. Canadian Cordillera in southeastern Alaska. Moderate climate, cedar and fir forests in the landscape. Tui grow on the slopes of the Pacific coast. The inhabitants of the forests are deer, mountain sheep, elks, bears, wolverines, cougars, foxes.
3. US Cordillera is the country where most of them are located. Nature is also very rich, on the slopes of the mountains - pine forests. There are dry plateaus. The low coastal mountains are covered with evergreen bushes and relict trees. The animal world is significantly exterminated. Lizards, snakes, rodents live in semi-deserts.
4. mexican cordillera- the climate is dry, there are many seismic zones. Shrubs, forests, cacti grow in the savannahs. Hares, wolves, cougars, rodents are inhabitants of the local desert. Wolves, lynxes, bears live in the forests, and monkeys, tapirs, and predators live in the tropics.

National parks in the Cordillera

In order to see the many sights, you must definitely visit the reserves located on the territory of the Cordillera.

Grand Canyon

To get acquainted with the peculiarities of flora and fauna, appreciate the beauty of the landscape, see volcanoes, you can go to one of national parks:

1. In the USA - Grand Canyon, Yellowstone, Sequoia, Yosemite, Glacier.
2. In Canada - Yoho, Banff, Jasper, Garibaldi, Nahanni.

Conclusion

The area and grandeur of the Cordillera is amazing, geographical position and a large number of mountain ranges with amazing secrets attracts and makes you want to go on a trip.

Cordillera- is the largest mountain system peace.

on which continent are the mountains of the Alps, Andes, Cordillera, Ural, Scandinavian, Himalayas, Appachi

It is located on the west coast of North and South America. That is, it is divided into two approximately equal parts. For this reason, sometimes its southern part, the Andes, is called the longest mountain system (9000 km). This is partly true, since the Andes, as a separate object, indeed have a large extent.

Description of the mountains of the Cordillera

The length of the Cordillera is about 18 thousand km. Approximately 9 thousand km for each of its parts - they are almost equal.

But if we talk about the size in general, then Northern part larger - it is wider (up to 1600 km). But the southern one is higher - 6962 meters at the highest point (Mount Aconcagua). In the northern part of the Cordillera, the height reaches 6190 meters (Mount Denali), which is also quite a lot.

In general, in terms of height, this mountain system is among the leaders, although it is far from in the first place.

Since the Cordilleras stretch for vast distances, they lie in almost all geographical zones.

And this means that the conditions here are very diverse. However, something similar is observed throughout the length of the mountains - glaciation. Even in the hottest climatic zones, there are snow caps on the mountains (due to the relatively high altitude mountains). The total area of ​​glaciation is 90 thousand km2.

Peaks of the Cordillera

Although the highest points of the mountain system are located at six thousand meters, average height mountains is 3-4 km. Although, the relief of this geological object is very diverse, so the designation of the height is rather conventional.

The highest peaks of the mountain system are:

• — Mount Aconcagua ( dormant volcano) - 6962 meters.
• - Mount Denali (McKinley) - 6190 meters.
• — Ojos del Salado ( largest volcano world) - 6891 meters.
• - Monte Pissis - 6792 meters.
• — Lullaillaco ( active volcano) - 6739 meters
• - Tupungato (active volcano) - 6565 meters.
• - Volcano Orizaba - 5700 meters.

• - The system consists of a large number of mountain arcs, which already gives a certain uniqueness to the Cordillera.

  You can also note the presence of mountain ranges and basins that form elevations and depressions of the relief - this is very interesting.

• - In the Cordillera there is a fairly high volcanic activity.

  True, we are not talking about erupting volcanoes.

• - In the mountains there are large reserves of non-ferrous and ferrous metals, as well as oil and brown coal.
• - Due to the large number of climatic zones, vegetable world The Cordillera is very diverse.

Andes or Andean Cordillera(Cordillera de los Andes) - the longest and one of the highest mountain systems of the Earth, limiting all of South America from the north and west.

The Andes mountain range rises in the west of South America and stretches for 6400 km from north to south.

The Cordillera Mountains are the longest mountain range in the world.

In Ecuador alone, 18 mountains rise above 4,500 meters above sea level. To the west of the Andes - a narrow strip of coast Pacific Ocean. The tributaries of the Amazon, the main river of South America, originate on the eastern slopes.

It was here, before the arrival of the Spanish conquistadors in the 1530s, that the great civilizations of the Chimu and the Incas flourished, which only in the 1820s were able to free themselves from Spanish domination.

Today there are four independent states - Colombia, Ecuador, Peru and Bolivia.

They are inhabited by descendants of European settlers and Indians such as the Aymara and Quechua. Official language of these countries - Spanish.

The area is rich in natural resources and timber, but many people work for very low wages. They grow corn, sugar cane, bananas, coffee, potatoes, and a grain called quinoa.

Where is it located and how to get there

The address: South America, Andean Cordillera

Andes in South America on the map

GPS coordinates:-20.923594, -69.658586

Cordillera(Spanish Cordillera, literally mountainous areas), the largest and largest in the world, which is not the same in the world, is a mountain system. The Cordillera mountain system is also one of the highest mountain systems, subordinate only to the Himalayan and mountain systems of Central Asia.

Geography of the Cordillero mountain system

The Cordillera stretches from the Arctic coast in Alaska (66° N.

) In the northwest of North America along the western coasts of North and South America, in most southern shores Tierra del Fuego (56°) south of South America. Cordillera on the road traveling through a number of countries on both continents: Canada, USA, Mexico, Central America, Venezuela, Colombia, Ecuador, Peru, Bolivia, Argentina, Chile.

The length of the Cordillero mountain system is more than 18,000 kilometers. The highest point is located in South America, on the top of Mount Aconcagua at an altitude of 6,960 m above sea level, and the highest peak in North America reaches the summit of the Cordillera on Mount McKinley (Alaska), reaching a height of 6193 m. The Cordillera form a huge barrier between the Pacific Ocean and the eastern parts of the two continents. The Cordilleras are an excellent watercourse between two oceans, the Atlantic and Pacific Oceans, and also the climatic limit between countries on both sides of the mountain system.

The entire mountain system of the Cordillera is divided into two parts, corresponding to areas of two continents: the Cordillero of North America and the Cordillero of South America or the Andes. The entire mountain system consists of several parallel ridges adjacent to the covering of internal tiles and plains (in North America - Yukon, Fraser, Columbia, B.

Basin, Colorado, Mexican; in South Peru and Central America). In North America, three parallel systems of mountainous regions are pronounced, one of them (Rocky Mountains) and extends east of the plateau area, the other system, the mountainous regions extends directly to the west of this area (the Alaska Range Coast Mountains of Canada, the Cascades, Sierra Nevada, etc.), and the third system of mountain regions runs along the Pacific coast, partly on coastal islands.

They come to Central America, the Cordilleras gradually fall and are divided into two branches. One branch is located in the east near Antilles, the other crosses the Isthmus of Panama and enters the continent of South America.

The Andes (Cordillera in South America) in the northern and central parts consist of four, and on the other hand, two systems of parallel ribs are separated by a deep longitudinal depression or intermountain plateau.

The highest peaks are the ridges of the Cordillera of the central part of the Andes, where the height of individual peaks reaches more than 6700 m (Aconcagua, 6960 m, Hoyos del Salado, 6880 m, Sajama, 6780 m, llullaillaco, 6723 m).

The width of the mountain range varies considerably, so in North America the width of the Cordillera mountain range reaches 1600 km, reaching only 900 km in the southern continent, which is almost a fifth less.

The main orogenic processes caused by any of the Cordillera began in North America during the Jurassic, in South America (where most of it takes on the structure of the Paleozoic Hercynian stacking) - at the end of the Cretaceous and are closely related to the formation of mountain ranges on other continents (see Fig.

Alpine styling). Educational processes are actively continuing in the Cenozoic. These processes largely determine the main orographic elements.

The Cordilleran fold structures are closely related to the mountains of northeast Asia and Antarctica. After recent observations on the design of the Cordillera, it is far from complete, confirming this observation, showing quite common and sometimes very destructive earthquakes and intense volcanism, often resulting in serious injury and casualties, both between people and animals.

Active areas of the Cordillera have more than 80 active volcanoes, the most active are Katmayu, Lassen Peak Colima Antisana, Sangay, San Pedro, volcanoes of Chile and others. Quaternary ice, especially north of 44°N, plays an important role in the formation of the Cordillera. sh. and south of 40°S

Where is the Cordillera?

sh. Cordilleras are rich in minerals. Here I extract important deposits of copper (especially rich deposits in Chile), zinc, lead, molybdenum, tungsten, gold, silver, platinum, tin, oil, etc.

The climate of the Cordillera mountain system

Due to the large extent from north to south, the strong collapse of the relief and high altitude mountains, the result is exceptional diversity natural conditions in the Cordillera mountain range.

The Cordilleras lie in almost all geographic regions of the world (except for the Antarctic and sub-Antarctic belt).

The climate of the Cordillera is very diverse and varies greatly depending on the width of the landscape, the height and exposure of the slopes.

The boundaries of the Cordillera are heavily wetted in the temperate and lower zones (western slopes) in the equatorial regions and subequatorial (possibly eastern paths). The interior plains have a strong continental climate, while in the subtropical and tropical zones they are exceptionally arid. Large parts of the plateau, internal depression and reef slopes, especially in the tropical bands, are occupied by stages, halves and deserts.

The heavily moistened frontier chains of mountains are covered with dense forests. In temperate zones, coniferous forests (in the north) and mixed forests of evergreen beeches and conifers (in the south), closer to the equator, are mixed (deciduous and evergreen) subtropical and tropical forests. On wet slopes of reefs of equatorial, subequatorial and subtropical bands, complex spectra of high bands, from gills to eternal snow. The snow border lies in Alaska at an altitude of 600 m above sea level, from 500 to 700 m in Tierra del Fuego, and in Bolivia and southern Peru it rises to 6000-6500 m.

In Alaska and southern Chile, glaciers descend to the ocean, while in the hot belt they cover only the highest peaks.

CORDILLERA OF NORTH AMERICA, part of the Cordillera mountain system, occupying the western margin of North America (including Central America) and extending for more than 9 thousand km from the Beaufort Sea (69 ° north latitude) to the Isthmus of Panama (9 ° north latitude). Width mountain belt in Alaska it reaches 1200 km, in Canada - 1000 km, in the USA - about 1600 km, in Mexico - 1000 km, in Central America - 300 km.

Relief. The Cordilleras of North America are the largest mountainous region of the mainland and are represented by a system of high-altitude linearly arranged ridges, mountain ranges and extensive denudation surfaces. The characteristic features of the relief are great fragmentation, mosaic morphostructures, the presence of chains of volcanoes and other forms of active relief formation. In the Cordillera of North America, 3 longitudinal belts are clearly expressed: eastern, inland and western.

The eastern belt, or the belt of the Rocky Mountains, is represented by a chain of high massive mountain ranges, for the most part serving as a watershed between the river basins of the Pacific, Atlantic and Arctic oceans. In the east, the belt abruptly breaks off to the foothill plateaus (Arctic, Great Plains), in the west it is limited in places by deep tectonic depressions (“Rocky Mountain Ditch”) or valleys major rivers(Rio Grande), and in some places gradually turns into mountain ranges and plateaus. In Alaska, the Brooks Range belongs to the Rocky Mountain belt, in the northwestern part of Canada, the Richardson Range (height up to 1753 m) and the Mackenzie Mountains, bounded from the north and south by the through valleys of the Peel and Liard rivers. In the northern part of the belt, peaked blocky-folded massifs with alpine landforms, large ice fields, cirques, cirques, and trough valleys predominate. In the Rocky Mountains of Canada, narrow straight ridges and longitudinal valleys are common. They are joined to the west by the Columbian Mountains. Between 45° and 32° north latitude, the eastern belt reaches its greatest width and is represented by the Rocky Mountains in the United States (altitude up to 4399 m, Mount Elbert). They are characterized by the predominance of large nodes of short arched-folded-block ridges separated by vast plateaus (the so-called basins, parks). The highest are the ridges of Peredovaya (height up to 4345 m), Wind River (up to 4207 m), Uinta Mountains (up to 4123 m), Absaroka (up to 4009 m). Alpine massifs in the area of ​​batholith development in the state of Idaho are distinguished by sharp forms (for example, the Lost River Range, height up to 3859 m). The southern part of the eastern belt is represented by the Eastern Sierra Madre Ridge (altitude up to 4054 m).

The inner belt, or belt of internal plateaus and plateaus, is located between the eastern belt and the belt of the Pacific ridges in the west. It is characterized by denudation plateaus and plateaus (Yukon, Inner, Nechako) 750-1800 m high, deeply dissected by river valleys. In the inner part of Alaska, vast tectonic depressions occupied by river valleys alternate with flat-topped mountain ranges 1500-1700 m high (mountains Kilbak, Cuscoquim, Ray). In Canada, this belt is narrow, in many places it is interrupted by the mountain ranges of Skin, Cassiar, Omineka (height up to 2469 m). Volcanic plateaus are common (eg Fraser, Columbia Plateau, Yellowstone). On the territory of the USA and Mexico, this belt is also represented by the Great Basin Highlands, the Colorado Plateau, and the Mexican Highlands. The southern part is characterized by vast areas of deserts (Mojave, Sonora, etc.).

The western belt consists of two parallel chains of ridges separated by longitudinal tectonic depressions. The highest chain of the Pacific ridges borders the inner plateaus of the Cordilleras of North America from the west and includes the Alaska Range (height up to 6194 m, Mount McKinley - the highest point of the mainland North America), the Wrangel Mountains (up to 5005 m, Mount Bona) and the mountains of St. Elijah ( up to 5951 m, Mount Logan). The line of the Pacific ridges is continued by the Alsek Mountains (height up to 2265 m), the Boundary Range (up to 3136 m), the Coast Range, the Cascade Mountains, complicated by a series of volcanoes (Rainier, 4392 m; Lassen Peak, Shasta, etc.). To the south, the Sierra Nevada, Western Sierra Madre, Transverse Volcanic Sierra ridges stretch with the volcanoes Orizaba (height 5610 m), Popocatepetl (5465 m), Istaxiuatl (5230 m) and others. To the south of the tectonic basin of the Balsas River, the Sierra Madre South mountain ranges are , Sierra Madre (height up to 4220 m, Tahumulco volcano - the highest point in Central America), Central volcanic Cordillera with volcanoes Poas (2704 m), Irazu (3432 m) and others; in the southern narrowed part of the mainland there are two arcs of uplifts of the Isthmus of Panama - the folded ridges of San Blas and Serrania del Darei (height up to 1875 m). The extreme western chain of the Pacific ridges includes the Aleutian Islands, the Aleutian Range, the Chugach Mountains (height up to 4016 m, Mount Marcus-Baker), a series of coastal mountainous islands (Kodiak Island, the Alexander Archipelago, Queen Charlotte Islands, Vancouver), Coast Ranges, mountains on the peninsula California (up to 3100 m, Mount Diablo).

In the northern part of the Cordilleras of North America (to the north of 40-49 ° north latitude), ancient glacial (troughs, kars, terminal moraine ridges, loess, outwash and lacustrine plains) and modern nival landforms (kurums, upland terraces, etc.) are widespread. confined to the highest levels of mountains (Alaska Range, Rocky Mountains). In areas not subjected to glaciation (the interior of Alaska), and in the Arctic Lowland, thermokarst and polygonal forms are widely represented. In the rest of the Cordillera of North America, water-erosion forms predominate: valley dismemberment - in the most humid areas (Cordillera Canada), table forms and canyons - in arid areas (Colorado Plateau, Columbia). Desert areas (Great Basin, Mexican Highlands) are characterized by denudation and eolian landforms.

Geological structure and minerals. In tectonic terms, the Cordillera of North America is a grandiose fold-cover mountain structure in the northern part of the East Pacific mobile belt. They experienced several phases of folding: Antlerian (Late Devonian; 370-330 million years ago), Sonomian (end of Permian - Middle Triassic; 250-235 million years ago), Nevada (Late Jurassic; 150-140 million years ago), Sevierian ( the end of the Early Cretaceous; 110-100 million years ago) and Laramian (the boundary of the Cretaceous and Paleogene; 65 million years ago). The extreme western Pacific part of the Cordillera of North America belongs to the area of ​​incomplete Alpine tectogenesis. There are 2 longitudinal tectonic mega-zones: outer (eastern) and inner (western). The Outer Megazone includes: the Brooks Range in the north, the Rocky Mountains in the central part, and the Eastern Sierra Madre Range in the south. In its main part (Rocky Mountains), the mega-zone is underlain by the Early Precambrian crystalline basement located to the east of the North American Platform (the boundary of the platform basement extends farthest to the west into the region of the top of the Gulf of California and into the Yukon River basin); the mega-zone developed during the Paleozoic and Mesozoic and experienced final deformations in the Laramian phase of folding. Within the Brooks and Eastern Sierra Madre ranges, the mega-zone is superimposed on the Paleozoic fold structures of the Innuit and Washita-Marathon systems, respectively; its development here is limited to the Mesozoic. The outer mega-zone is formed mainly by shelf carbonate and terrigenous deposits of the former passive margin of the North American continent, which compose a system of tectonic covers torn from the basement and displaced to the northeast and east (in the Brooks Ridge - to the north). In the western part of the Rocky Mountains, Upper Proterozoic predominantly detrital rocks with covers of basalts and horizons of glacial deposits (tillites) accumulated during the rifting stage, which preceded the formation of the passive margin of the ancient North American continent, are widespread. The outer megazone reaches its greatest width in the USA, which is due to the involvement of a large section of the North American Platform in the Laramian deformations. In the north of the deformed section of the platform, a series of differently oriented basement uplifts arose, which were pushed over the separating them. deep depressions filled with Cretaceous and Paleocene deposits. In the southern half of the site (Colorado Plateau), a large block of basement was uplifted, bounded on the east by linear uplifts of the Southern Rocky Mountains and a young Rio Grande rift. In the territory of Mexico, the extreme East End the outer mega-zone underwent folded deformations in the Miocene. A chain of foredeeps (filled with Cretaceous-Cenozoic molasses) stretches in front of the thrust front of the Cordillera of North America, which include basins: Colville in Alaska (the largest and deepest), Mackenzie and Alberta in Canada, Powder, Denver and Rayton in the USA, Chicontepec in Mexico .

The inner mega-zone of the Cordillera of North America has been developing since the Late Jurassic (there are relics of the oceanic crust - ophiolites of this age), since the passive margin of North America was transformed into an active one. The mega-zone is characterized by an exceptionally complex internal structure with numerous zones of melange, thrusts and strike-slips, formed as a result of deformations that began in the Permian and culminated in the Cretaceous. The mega-zone is a so-called collage (mosaic) of terranes, which arose as a result of the attachment (tectonic accretion) of many dozens of large and small blocks of the earth's crust of different nature and age: fragments of intra-oceanic uplifts, the crust of marginal seas, volcanic island arcs, micro-continents, sharply differing in the structure and composition of their sections and not revealing mutual transitions. Some of the terranes experienced northward movement along the edge of the continent for many hundreds (perhaps more than a thousand) kilometers.

After the end of the main deformations, intermountain troughs filled with Cretaceous and/or Cenozoic molasses were superimposed in places on the fold-and-thrust structure of the Cordilleras of North America, for example, the Central Valley trough in California, Bowser in Canada, and a number of troughs in western Alaska. The underthrust (subduction) of the lithosphere of the Pacific Ocean under the continent of North America was associated with the formation of Jurassic-Cretaceous granite batholiths of the Alaska Range, the Coast Range, the Sierra Nevada Range and the California Peninsula, the manifestation of Oligocene-Miocene volcanism in the Western Sierra Madre Range, the formation of still active volcanoes Aleutian Island Arc, Aleutian and Alaska Ranges, Cascade Mountains, Trans-Mexican Volcanic Belt. To the east, the intrusion of small granite intrusions occurred at the end of the Cretaceous - the beginning of the Paleogene only in the southern part of the Rocky Mountains and on the Colorado Plateau. In the Miocene, in the rear of the Cascades, basalt volcanism intensively manifested itself, creating the Columbia Plateau. The Cenozoic became the era of rifting, when an extensive polyrift system (basins and ridges zone) arose in the central part of the orogen with a reduced thickness of the earth's crust and lithosphere to 30 km or less, the Rio Grande rift, the Gulf of California rift, was formed, continuing on the continent.

The southern part of the Cordilleras of North America (to the south of the valleys of the Polochik and Matagua rivers, marking a large shear-fault zone) belongs to the tectonic Antilles-Caribbean region.

The Cordillera of North America, especially their Pacific part, retain high mobility with the manifestation of intense seismicity, which is associated with the processes occurring at the border of the North American continent - Pacific Ocean transition: subduction (subduction) of the Pacific lithospheric plate under the North American in the Aleutian deep-water trench and along the coast of Washington and Oregon (USA); horizontal slippage of the Pacific Plate along the North American plate along the Queen Charlotte and San Andreas shear zones; the subsidence of the East Pacific Rise (spreading ridge) under the North American continent at the top of the Gulf of California; subduction of the Cocos Plate (south of the Gulf of California) under the North American Plate in the Central American Trench. To the east, in the Cordillera of North America, seismic activity weakens, but does not completely die out: the western, southern, and eastern peripheries of the Great Basin and the Rio Grande rift are seismic.

The bowels of the Cordillera of North America are rich in minerals. Typical are copper-molybdenum-porphyry deposits. There are a number of ore zones and blocks: the gold-mercury zone of the Coast Range, the gold-copper and tungsten zones of the Sierra Nevada ridge, the gold-silver zone of the Great Basin, the uranium-bearing block of the Colorado Plateau, the zone of the Front Range with deposits of molybdenum and gold-silver ores, etc. There are known deposits of ores of iron, lead, zinc, nickel, as well as bauxites, phosphorites, barite, fluorite, etc. Deposits of oil and natural combustible gas, coal, rock and potassium salts, natural borates .

Climate. The northern regions of the Cordilleras of North America are located in the arctic (Brooks Ridge) and subarctic (most of Alaska, northern Canada) zones, the territory up to 42 ° north latitude on the coast (in the inner belt up to 37 ° north latitude) - in the temperate zone, to the south - in the subtropical, the Mexican Highlands and the California Peninsula - in the tropical, south of 12 ° north latitude - in the subequatorial zone. On the slopes facing the Pacific Ocean, almost all types of climate are characterized by relatively mild oceanic features, while for the interior regions they are sharper, continental. Altitudinal climate zonality is observed everywhere. In the northern part of the Cordillera of North America on the coast, winters are rainy, mild, summers are cool and damp, with frequent fogs. Average January temperatures, ranging from 0 to -5°C south of the Alaska Range, vary to -30°C (absolute minimum -62°C) in the Yukon Plateau; the average July temperatures are approximately the same - about 15°C. The annual amount of precipitation in the south of Alaska (mountains Chugach, St. Ilya, Wrangel) is 3000-4000 mm (the thickness of the snow cover is up to 150 cm or more), in the area of ​​the Yukon plateau - about 300 mm. In the temperate zone, cyclonic activity is observed throughout the year. In the coastal region of Canada, the average January temperatures are about 0 ° C, July 15.5 ° C. The annual amount of precipitation on the western slopes of the Coastal Range is 6000 mm, on the inner plateaus it decreases to 200-400 mm. In the Rocky Mountains, frosts down to -30°C are not uncommon in winter (the absolute minimum is -54°C), summers are sunny and dry, average temperature July 19-20°С. 600-1200 mm of precipitation falls annually.

In the subtropical zone in the southern part of the US Cordillera and the northern part of the Mexican Highlands on the slopes facing the Pacific Ocean, the climate is oceanic (at the latitude of San Francisco - Mediterranean), in the interior - dry continental. Average temperatures increase as you move deeper into the mainland in January from 0 to 5°C (minimum to -17°C, Great Basin), in July from 14-17°C to 20-28°C (absolute maximum 56.7°C). C, Death Valley). On the coast, winters are rainy, with a decrease in annual precipitation from north to south from 2000 to 350 mm. The inner zone has dry, hot summers and relatively cold, moderately humid winters. Precipitation from 100 to 400 mm per year. In the tropical zone, the southeastern part is best moistened. The climate of the northwestern part of Mexico and the California Peninsula due to the influence of the Hawaiian anticyclone is trade wind, dry all year round, on the coast - with high relative humidity and fogs. In the northern part of the belt, the average temperatures of the coldest month (January) are 13-14°С, the warmest (May) 20°С, in the southern part - 21-23°С and 26-27°С, respectively. In the western and central regions of the northern part, the annual precipitation is 100-200 mm and increases to 500 mm in the south. The dry winter season with temperatures from 21° to 24°C lasts up to 6-8 months. In the southern part of the belt, 1500-2000 mm of precipitation falls annually. In the subequatorial belt, the average annual temperatures are 26-27°C. In the mountains at an altitude of 3800 m, they drop to 6 ° C, on the constantly wet Atlantic slopes, 2000-4000 mm of precipitation falls per year. Tropical hurricanes are not uncommon in the eastern part, bringing heavy rainfall and destructive power.

Glaciation. The area of ​​modern glaciation of the Cordilleras of North America is 67 thousand km2. Large differences in the latitudinal and altitudinal position of the Cordilleras of North America, as well as a sharp difference in the moistening of the territory, led to the uneven development of glaciation. The lowest (300-450 m) snow line is located on the Pacific slope of the mountains of South Alaska, in some places descending to the ocean level. On the northern slopes of the Chugach and St. Elias mountains, the snow limit is at an altitude of 1800-1900 m, on the Alaska Range - from 1350-1500 m (southern slope) to 2250-2400 m (northern slope). The area of ​​glaciation in the northwestern part of the Pacific ridges is 52 thousand km2. In the Brooks Range and the Mackenzie Mountains, glaciation is developed only on the highest peaks. To the south, the snow limit passes at an altitude of 1500-1800 m in the Coast Range and up to 2250 m in the Columbian Mountains. The total area of ​​glaciation in the interior of Alaska and the Cordillera of Canada is only 15,000 km2. In the United States, the snow limit to the south rises to 2500-3000 m in the Cascade and Rocky Mountains, up to 4000 m or more in the Sierra Nevada, up to 4500 m or more in Mexico. The area of ​​modern glaciation in the USA is 0.5-0.6 thousand km 2, in Mexico - 0.01 thousand km 2. All major types of glaciers are represented in the Cordillera of North America: extensive ice fields and caps, foothill or foot glaciers (for example, Malaspina), valley glaciers (for example, Hubbard in the Coast Range), cirque and short hanging glaciers, mostly disappearing (Sierra -Nevada). Star-shaped glaciers with numerous glacial flows form on volcanic peaks (for example, on Mount Rainier).

surface waters. Within the Cordillera of North America, the sources of many river systems of the mainland are located: Yukon, Peace - Mackenzie, Saskatchewan - Nelson, Missouri - Mississippi, Columbia, Fraser, Colorado, Rio Grande. The main watershed between the Pacific and Atlantic Oceans is the eastern belt of mountains, so the rivers of the Pacific basin are the most full-flowing. To the north of 45-50 ° north latitude, the rivers are fed by glacier and snow with a clearly pronounced spring flood. In the south, rain feeding prevails with a winter maximum on the Pacific coast and spring-summer in the interior. In the southern part of the Cordillera of North America, significant territories do not have a runoff into the ocean and are irrigated mainly by streams ending in drainless salt lakes (the largest of them is the Big Salt Lake). In the north, there are numerous fresh lakes of glacial-tectonic origin (Atlin, Kooteney, Okanagan, etc.), in the south - tectonic (Chapala, Nicaragua). The rivers of the Cordillera of North America have a huge hydroelectric potential and are widely used for electricity and irrigation. Large reservoirs have been built on the Yukon, Columbia, Colorado, and other rivers.

Landscape types. Due to the significant height throughout the Cordillera of North America, the altitudinal zonality of natural landscapes is clearly expressed. At the same time, the stretching of mountain ranges in the direction perpendicular to the main flow of moisture causes significant differences between the landscapes of the coastal (Pacific) and inland parts of the territory. The biggest changes in landscapes are associated with the latitudinal position of the mountain system, with its transition from the subarctic belt to the temperate, subtropical, tropical and subequatorial. In the northern part of the Cordillera, the Cordillera of Alaska and Canada are distinguished, in the southern part, the Cordillera of the USA, Mexico and Central America.

Cordillera of Alaska. With the exception of the coast of the Gulf of Alaska, permafrost rocks are widespread throughout the Cordillera of Alaska. The spectrum of altitudinal zones is represented by foothill woodlands (forest tundra) in river valleys and mountain tundra on high plateaus and slopes of ridges in northern Alaska. On the southwest coast subarctic oceanic meadows (reed grass, pike, sedge, forbs) are developed on gleyzems and cryozems, on the slopes of the Aleutian Range from a height of 200-300 m - shrub tundra. On the southern slopes of the Alaska Range, forests rise almost to the snow line. Dense coniferous forests of Sitka spruce are common, to which, on the slopes of the Kenai, Chugach, Wrangel mountains, western hemlock, Nutkan cypress (red cedar) are mixed. In the river valleys flowing into Cook Inlet (for example, Matanuska), the land is partly used for agriculture.

Cordillera of Canada. The Pacific slopes up to a height of 1200-1500 m are covered with productive tall forests dominated by conifers: giant and folded arborvitae (red cedar), western hemlock, Sitka spruce, Douglas fir, or yew pseudo-hemlock. Engelman spruce and alpine fir grow higher, subalpine coniferous light forests are widespread. Soils vary from mountain brown-taiga to mountain-podzolic. In the interior regions north of 53° north latitude, taiga forests of white, black spruce and fir (balsamic, great, etc.) are widespread on podzolic soils, to the south (as evaporation increases) forests of pine (yellow, twisted) on gray forest soils are replaced by forest-steppe, in which islands of pine forests are combined with vast areas of dry meadows of fescue and feather grass, and in the southern part of the Fraser Plateau they turn into steppes. The altitudinal spectrum of landscapes of the Columbian Mountains includes steppes, mountain coniferous forests of giant fir, Weymouth pine, Douglas, white and red firs, red cedar, balsam pine on podzolic-brown mountain forest soils and subalpine meadows. The ridges of the Rocky Mountains up to a height of 1800-2400 m are covered with dense mountain taiga forests of white spruce, balsam fir, banks pine and white birch, the bald tundra, snowfields, glaciers are developed higher, subalpine meadows appear in the northern part.

In forest areas, a significant proportion is made up of forest landscapes. In the southern parts of the wide intermountain basins there are arable and pasture landscapes. Secondary pine forests after fires and logging are widespread.

The Cordilleras of the United States have a unique variety of natural landscapes. The western slopes of the Pacific Ranges and the Rocky Mountains are characterized by the most complex structure of altitudinal zonality. On the slopes of high ridges (Vedovaya, Sierra Nevada), belts of mountain pine forests (yellow, lodgepole, sugar, and edible pines), mountain spruce and fir forests, subalpine coniferous light forests, and alpine meadows are developed. In the more arid southern regions of the Rocky Mountains, a steppe-forest-meadow type of altitudinal zonality is developed. On the slopes descending to the Great Plains, mountain steppes are replaced by pine forests, and at an altitude of 1800-2200 m - by spruce-fir (Douglas fir, Engelman spruce) forests. The lower parts of the mountain ranges, facing the deserts of the interior plateaus, are occupied by patches of steppes of grama, selina, mesquite grass, scrub oaks, juniper, mesquite shrubs and succulents. The gentle western slope of the Sierra Nevada up to a height of 2800 m is covered with mixed forests dominated by yellow pine, Douglas, oaks (giant sequoia, or “mammoth tree” is found as an admixture), higher - fir and subalpine shrubs and meadows. On the dry eastern slopes, only pine-juniper woodlands grow. On the slopes of the northern part of the Coastal Ranges, mixed forests with douglas, arborvitae, western hemlock, and cypress on acidic mountain brown soils are common. The southern part of the ranges is characterized by summer-dry mixed hard-leaved forests of pines, Douglas, evergreen oaks, and strawberry trees on mountain brown soils. In northwestern California near Pacific coast preserved evergreen sequoia groves. On the slopes of the southernmost ranges, receiving 250-350 mm of precipitation per year, chaparral is common - a formation of dry-loving shrubby evergreen oaks with an admixture of acacia, sumac on gray-brown soils. The inner plateaus are occupied by sagebrush semi-deserts and deserts, in the eastern, more humid part, dry steppes of gram and bison grass are developed on chestnut soils. On the Columbian Plateau there are typical cereal steppes on ordinary chernozems. In the Great Basin, mid-mountain ranges covered with pine woodlands alternate mosaically, and hollows occupied by sagebrush semi-deserts with the participation of quinoa, a garden tree. In subtropical regions, the vegetation cover is dominated by creosote bush, acacia, mesquite tree, cacti (opuntia, echinocactus, columnar cacti, saguaro, agave, yucca). The soils are predominantly brown desert-steppe, gray soils, solonchaks and solonetzes (in basins), mountain brown. On the Colorado Plateau, forest-steppe subtropical vegetation is common - pines and acacias, junipers and creosote bushes, Mexican succulents, and cereals. In the southern part of the interior highlands exotic features of desert landscapes are given by the picturesque forms of weathering of sandstones in the form of arches and pedestals.

Most of the forests in the Coast Ranges have been cut down, and agricultural and residential landscapes predominate. Irrigated plantations (vineyards, citrus fruits) and pastures are concentrated in the intermountain valleys. The Great California Valley is the largest area of ​​irrigated agriculture.

Cordillera of Mexico. The low ridges of the northern part of the Mexican Highlands and the short slopes of the Western and Eastern Sierra Madre facing its interior are covered with mountain coniferous-hard-leaved forests. Moist forest landscapes predominate in the southeastern and southern regions. The rest of the territory is dominated by succulent and shrubby (with a creosote bush) deserts and semi-deserts. The Mexican Highlands is the richest genetic center of the endemic Mexican flora, there are about 500 species of cacti, 140 species of agave, and several species of yucca. The windward slopes of the peripheral ridges at the foot are occupied by low-growing spiny forests and light forests of caesalpinia (including quebracho), acacia, mimosa and mesquite on brown-red soils. To the south of 22° north latitude, on the southeast windward slopes of the Eastern Sierra Madre and on the southern slopes of the Transverse Volcanic Sierra, up to a height of 600-1000 m, constantly wet evergreen tropical forests grow with an abundance of ficuses, palms, and tree ferns on yellow ferrallitic soils. The forests are distinguished by an exceptionally rich species composition of woody plants: mahogany (mahogani, or caoba), paleto, allspice, breadfruit, cordia, andir, chlorophore. On the slopes facing the moisture-saturated trade winds, at an altitude of 1000-2500 m, broad-leaved forests of oaks, liquidambar, maples, willows, sambucus, spikes with tree-like ferns and podocarpus in the lower tier dominate. The trees are entwined with vines and epiphytes from begonias, bromeliads and orchids. The upper parts of the slopes are occupied by coniferous-deciduous and coniferous forests of Weymouth and Mexican pines and sacred fir. The Pacific slopes of the ridges and the lee slopes of volcanoes are covered with seasonally wet winter-dry deciduous-evergreen forests of various species composition. In the forests there are up to 100 species of tree species, including cordia, carapace, cedrela, mahogany, enterolobium, chimenea, andir, chlorophore, Brazilian calophyllum. Dry low-growing deciduous and semi-deciduous tropical forests grow in arid interior basins in the south of the Mexican Highlands. Breeds such as cedrela, bursera, morning glory, ceiba cotton tree, pseudobombax, cordia are widespread. In the northwest of the Mexican Highlands and on the California Peninsula, tropical coastal deserts dominate with peculiar tree and shrub formations with the participation of succulents, mesquite, yucca, and ironwood.

The Cordillera of Mexico is an area of ​​extensive grazing and irrigated agriculture. On the plains and in the foothills, large areas of forests have been cleared for plantations of sugar cane, bananas, cocoa, coffee and tropical fruits, in arid regions - cotton and agave.

In the Cordillera of Central America, the forest-meadow type of altitudinal zonality is clearly expressed. Oceanic tropical and subequatorial humid and moderately humid forests predominate on the abundantly moistened northeastern slopes and seasonally humid forests on the leeward southwestern slopes. In the mid-mountain belt on the slopes there are mixed evergreen-deciduous and coniferous forests on siallite yellow-brown soils. Savannahs and light forests are widespread in the basins and along coastal areas. The eastern part of Central America is dominated by evergreen and semi-evergreen (rain) forests of complex composition - selvas with an abundance of lianas and epiphytes, palms, ficuses, bamboo, trees with valuable wood, rubber plants on ferrsiallite and allite red-yellow soils. The biological diversity of forest formations is enormous, there are about 5,000 species of vascular plants. The most common tree species are mahogany, akhras, brasimum, paleto, allspice, breadfruit, ampelosera, mazakilla, cordia, Brazilian calophyllum, castilla, Amazonian terminalia. At an altitude of about 2000 m, “forests of fog” appear from beeches, lindens with thickets of tree-like ferns and bamboos. Alpine meadows are developed on high ridges and volcanoes. The monsoon-prone Pacific plains and low mountains of the extreme south of Central America are covered with deciduous evergreen forests (Tambelnia, Ipomoea, Bombax). Plantations of coffee, bananas, sugar cane, etc. predominate on the lowlands and gentle slopes of the mountains.

Environmental problems and protected natural areas. The adverse effects of human activities are manifested in a large area of ​​the Cordilleras of North America and are associated with intensive use natural resources, primarily forest, mineral, soil, water. In the southern part of the Cordillera of Canada and in the western United States, forests have been intensively cut down since the 2nd half of the 20th century. Plantations of Sitka spruce, Douglas, and redwoods were especially affected. In the south of the Coast Range and the Columbia Mountains, in the Cascade Mountains, clearings occupy not only gentle, but also steep areas. Deforestation, fires, shooting of animals and loss of their habitats, high recreational loads create an unfavorable ecological situation in a number of regions of the Cordilleras of North America. In large areas, accelerated erosion is manifested. Pollution of water sources with pesticides and nitrates is noted. Mexico has a deforestation rate of 0.8% per year, with the highest erosive loss in the Cordillera of North America. Valuable species of trees are cut down: cedrela, caoba, or mahogany, quebracho, ceiba, camphe tree, Brazilian calophyllum, pines, sacred fir. A serious problem associated with deforestation and oil pollution of the coastal waters of the Gulf of Mexico is the conservation of mangrove ecosystems. In the state of Arizona (USA), as well as in the basin of the city of Mexico City (Mexico), groundwater depletion is observed.

The largest and most famous protected natural areas in the Cordillera of North America - National parks Denali, Gates of the Arctic, Katmai, Lake Clark (USA); Montes Azules Biosphere Reserve, National Parks Nevado de Toluca, Tepozteco, Popocatepetl Istaxiuatl, Pico de Orizaba (Mexico). Add to list world heritage includes parks and reserves of Mount Wrangel and Mount St. Elias, Kluane, Glacier Bay, international park World Waterton Glacier (all in the USA and Canada), Canadian Rockies (Canada), National Parks Yellowstone, Olympic, Grand Canyon, Redwood, Yosemite (USA), Mariposa-Monarca Biosphere Reserve (Mexico), Rio National Parks -Platano (Honduras), Darien, Coiba (Panama), Talamanca - La Amistad (World Biosphere Project, Costa Rica and Panama), Guanacaste Protected Area (Costa Rica).

Lit .: Vitvitsky G.N. Climates of North America. M., 1953; King F. B. Geological development of North America. M., 1961; Tamayo J. L. Geografia general de Mexico. 2nd ed. Mekh., 1962. Vol. 1-4; Antipova A. V. Canada. M., 1965; Ignatiev G. M. North America. M., 1965; Thornbury W. D. Regional geomorphology of the United States. N.Y., 1965; Relief of the Earth. M., 1967; Sanderson A. North America. M., 1979; Kraulis J. A., Gault J. The Rocky Mountains. N.Y., 1986; Wilson K. M., Hay W. W., Wold C. M. Mesozoic evolution of exotic terranes and marginal seas, Western North America // Marine Geology. 1991 Vol. 102; Golubchikov Yu. N. Geography of mountainous and polar countries. M., 1996; Gebel P. natural heritage humanity. M., 1999; Khain V. E. Tectonics of continents and oceans (year 2000). M., 2001.

T. I. Kondratieva; V. E. Khain ( geological structure and minerals).

Any resident of North and South America knows where the Cordilleras are. These mountains stretch along the western side of the aforementioned continents: from Alaska (northwestern part of North America) to the island Tierra del Fuego which is located near Antarctica. This is the longest mountain range in the world. Its length is 18,000 kilometers, and the width of the North American part reaches 1,600 kilometers (the maximum width of the South American part is 900 km). The mountain chain is usually divided into two halves: the Cordillera of North America and the Andes.

Cordillera - one of the highest mountains in the world

The Cordilleras are one of highest mountains in the world. Only the Himalayas, as well as several other mountain systems of the central part of Asia, surpass them in height. highest point- Mount Aconcagua, whose height is 6962 meters. Aconcagua is located in the South American part of the Cordillera, and highest peak North American part - Mount Denali (Mount McKinley), reaching 6190 m.

The mountain chain passes through all the climatic zones of America (with the exception of the Antarctic, subantarctic), due to which the climate, as well as the flora and fauna of these mountains, changes greatly if you move from north to south (to a lesser extent from west to east). For example, the snow limit in the Cordillera of Alaska is 600 m, and in Bolivia it is 6500 m.

Minerals

Like any territory where mountains are located, the Cordilleras are the richest source of minerals, primarily a variety of ores:

• copper;
• zinc;
• gold;
• iron;
• platinum;
• tin.

The bowels of the mountains also contain many other metals, and oil, gas, coal, and even gems(the richest emerald deposits in Colombia and Brazil).

Significance

The influence of these mountains on the formation of culture, traditions, and lifestyle of the inhabitants of America is difficult to overestimate. On the territory where the Cordilleras are located, entire civilizations of the Indians were born, unique in their development and cultural heritage. And on a planetary scale, the Cordillera mountain range is a watershed between the Pacific basin and the Atlantic Ocean.

In the North American part of the mountains there is a range called the Rocky Mountains. This area is one of the most popular areas in the United States for tourism, recreation, mountaineering, skiing and so on. The most famous national parks are located here: Yellowstone (USA), Rocky Mountain (USA), Waterton Lakes (Canada) and others.

Despite the fact that few people live in large areas, the vulnerable nature of the region has been damaged, which is difficult to restore.

In Alaska, 13 national parks have been created, where typical natural complexes are protected, as well as local animal species - mountain sheep, caribou, black bear (baribal) and grizzly.

Cordillera of Canada and Northwestern United States

This part of the Cordillera system is characterized by a relatively low mountain height and relative narrowness. It includes the Canadian Coast Range, the inland Fraser Plateau, the Columbian Plateau, and the Rocky Mountains up to about 48°N. sh. The westernmost orotectonic zone passes into the islands here. It is only in the south that the region expands, as this zone "returns" to the mainland. Its southern border runs along the northern outskirts of the Great Basin and the Sierra Nevada mountains.

Young folded ridges of the coastal zone are fragmented and lowered. The intermountain valleys are flooded with the sea and are straits and narrow long bays, deeply protruding into the land. The coast ridge continues the Nevadian zone, but its height is less than that of Alaska (2000-3000 meters, in the south - up to 4000 meters). It is dissected and processed by glaciers. The coast here is fjord-like.

Some general lowering of the mountains of the region compared to other parts of the Cordillera is presumably explained by large area glaciation, both ancient and modern. It is possible that the earth's crust here, as it were, sags under the weight of ice. The inner plateaus are composed of lava covers reaching a thickness of up to 1200 meters. They are high (800-1500 meters), but narrow, expanding only to the south (Columbia Plateau - up to several hundred kilometers). Rivers, cutting through the plateau, form canyons. The Rocky Mountains consist of a series of longitudinal ridges up to 4000 meters high, separated by valleys and abruptly dropping to the east. A graben filled with glacial deposits stretches along the western slopes - the "Moat of the Rocky Mountains". It is believed that this is a continuation of the mid-ocean rift.

The amount of precipitation decreases from west to east (a common pattern for the Cordillera). The ocean coast receives 2000-3000 mm per year. Maximum - winter, snow cover in the mountains reaches an average thickness of up to 6-9 m. Summer is cool, cloudy. The climate is the same as on the coast of Alaska, only a little warmer.

Here, as well as on the coast of Alaska, "rain" coniferous forests of Sitka spruce, Douglas, western hemlock, etc. grow with dense undergrowth, epiphytic mosses, and ferns.

On the inner plateaus, features of continentality appear: there is little precipitation (300-400 mm), temperature amplitudes increase. In the north there are areas of taiga on podzolic soils, which are replaced by forest-steppe and steppe to the south. Wormwoods appear in the extreme south. The slopes of the Rocky Mountains are covered with pine forests and shrubs, while the valleys are treeless.

The Cordillera of Canada has a large number of mountain glaciers of various types.

The region is rich in minerals, both ore (copper, iron, lead, zinc, silver, gold) and non-metallic, such as coal. Forest resources and the hydro potential of rivers are used. Tourism is developed, especially in the mountains of British Columbia. A number of national parks have been created for nature protection - Jasper, Banff, Glacier, etc.

Cordillera of the Southwestern United States

The physiographic country is located approximately between 48 ° and 32 ° N. sh. in the widest and most diverse part of the Cordillera mountain system. The region experienced a general uplift in the Paleogene-Neogene, which was accompanied by faults, denudation, and large erosional dissection.

Here, the manifestations of faults are most clearly visible at the junction of the continental (North American) and oceanic (Pacific) crust. Quite clearly visible are the zones of deep subsidence of the oceanic crust under the continental crust in the California area, where there is a huge gap in the coastal areas. The San Andreas Fault extends in a northwesterly direction for almost 900 km. It has existed since the pre-Mello time, and is still very active today.

Three structural and morphological zones are clearly traced: axial, the most ancient - Nevadian, in the east - Laramian, in the west - young Cenozoic Coast Ranges, the development of which continues to the present.

Modern climatic conditions are characterized by high contrast, which is associated with the position in two climatic zones (temperate and subtropical), significant altitude amplitudes, and the presence of mountain barriers in the path of sea air masses.

Areas with annual precipitation up to 100 mm and maximum temperatures up to +57 ° C (Death Valley) are adjacent to mountains where annual precipitation is up to 2000 mm and negative temperatures prevail even in summer (upper parts of the Sierra Nevada). In the west it has a Mediterranean type climate. In other parts of the region, features of continentality appear in climatic conditions.

Different parts of the region differ significantly in all components of nature.

The eastern (Laramian) structures of the Rocky Mountains are often referred to as the continental divide, with elevations of 1,800 m and above.

The ridges are anticlinal folds that have Precambrian cores. Some of them are elongated in the general direction of the entire mountain system from northwest to southeast (the Front Range, Sangre de Cristo, etc.), but there are ranges of a different orientation, sometimes even sublatitudinal. Between them formed vast plateau-like areas connecting the Great Plains with the Great Basin - the so-called "parks". They are composed of sedimentary strata of Paleozoic-Mesozoic age. The summit areas were covered by the Wisconsin glaciation, preserved troughs and kars. Spruce-fir and pine forests are widespread on the slopes of the mountains, the bottoms of the "parks" are usually treeless. In the south and along the slopes of the mountains, steppes and semi-deserts rise.

In the northeast is the Yellowstone Plateau (“yellowstone” in English means “ yellow stone”) with a Paleogene cover and young lava covers with a thickness of more than 1000 meters.

It is known as one of the largest areas of the Earth with geysers and thermal springs. Under powerful lava covers (300-600 meters) forests of ancient sequoias are buried. Their petrified trunks are often found (there is a section with 12 layers of petrified forest covered with volcanic ash). In 1872, the Yellowstone National Park was founded here (an area of ​​about 900 thousand hectares, located at an altitude of 2100 m to 3400 m). There are 200 water thermal and mud springs, about 300 geysers on the territory of the park. The greatest geyser Exilor with a griffon diameter of 8-10 meters "works" here, which throws water up to 100 meters up. Mineral sediment forms geyserite of various shades - blue, purple, pink, etc. Rich animal world park - bison (their number has increased 20 times since the beginning of the century and amounts to several hundred heads), a variety of brown bear - grizzly, coyote, fox, skunk, badger, large predator cougar and 150 species of permanent birds. Access to the park is regulated. The park is divided into zones, each of which solves certain problems: there is a strict protection zone where no human influence is allowed, a “managed” protection zone (to preserve natural landscapes), an organized tourism zone and a tourist-administrative zone (camping sites, parking lots, cafes , administrative buildings).

In the inner part of the physiographic country, west of the Rocky Mountains, there is the largest inland highlands - the Great Basin and the Colorado Plateau.

The Great Basin has undergone a complex history of formation: Paleozoic and Mesozoic folding, Mesozoic sedimentation, and intense deformation of structures.

The modern relief was formed in the Cenozoic under the influence of submeridional faults along the rift between the Rocky Mountains and mountain range Sierra Nevada. Clastic material filled intermountain depressions. Active volcanism appeared in the northwest. At present, the rejuvenated relief with numerous internal drainless depressions has a wide variation in absolute heights - from 1500-2000 meters to -85 meters (Death Valley). This is the result of powerful vertical movements.

Due to the barrier role of the Cascade Mountains and the Sierra Nevada, which prevent the transfer of Pacific air masses, a climate with well-defined features of continentality has developed.

The annual amount of precipitation here does not exceed 90-100 mm. The result of the dry climate is the weak development of the river network, which has no flow into the ocean. There is no removal of destruction products outside the basin, so the clastic material buries and levels the mountainous terrain.

Within the highlands, there are a hundred relict lakes - the Great Salt Lake (the remnant of Bonneville Lake, most of which was drained by the Snake River).

The soil and vegetation cover and fauna are typical for deserts and semi-deserts of the temperate and subtropical zones. The Americas have a different appearance than the deserts of Eurasia.

Along with saline and rocky deserts, there are areas with a pronounced seasonality, when ephemera bloom brightly in spring. In the southern part of the basin, a “woodland” of cacti (up to 10 meters high) and yucca has formed. Pine and juniper with steppe grasses grow on the slopes of the ridges. Picturesque Sonoran Desert in Arizona. The hilly plain is composed of sedimentary rocks and has insular volcanic mountains. The desert is inhabited by many species of cactus, including the giant tree squaw. Volcanic mountains overgrown with this plant seem from afar to be covered with a sparse forest, devoid of small branches and leaves. The age of cacti is tens and hundreds of years, height 10-12 meters, trunk thickness up to 70 cm, coyotes and many poisonous snakes live under them. In addition to cacti, other xerophytic plants grow in Sonora, which can tolerate not only drought, but also extremely high air and soil temperatures. The fauna of the desert is diverse and interesting.

The Colorado Plateau is an area of ​​horizontal occurrence of Phanerozoic rocks of different lithological composition. A highly elevated structural plain (more than 3,500 meters in places) is framed by cuestas.

The deeply incised river network has created steep-sided canyons that expose all the different colored rocks that make up the plateau. On the outskirts of the plateau, volcanic rocks are widely represented in the form of intrusions and laccoliths. The main watercourse - r. Colorado, which cut through the plateau, creating the Grand Canyon. The main canyon has a winding shape, its depth is 1800 m, the maximum width is up to 25 km, and the length is more than 300 km.

To the west of the internal plateaus are Nevadian structures - the Sierra Nevada mountains. This is a large block structure (horst boulder with comb-like peaks), the blocks are inclined to the west, there are batholiths at the base. The Cascade Mountains are a prime example of a volcanic range with a number of active volcanoes. The folded structures within them are covered by Cenozoic lavas, and high (some higher than 4000 m) volcanic cones are planted on them. Among them there are also very active: in the 80s. 20th century Mount St. Helens erupted two years in a row, there were many deaths. There are also extinct, but showing post-volcanic activity.

The vegetation of the mountains is typically American.

Here in the valley Merset (Yosemite Valley) preserved forest (park) of the giant sequoiadendron. For their large size (the height of many trees reaches 80-100 meters) and for bending, like mammoth tusks, their branches were called mammoth trees. In the lower tier of the mountains - chaparral (American variety of maquis).

Coastal ridges - low (up to 2400 meters) Pacific structures are separated from the Nevadian structures by the Willamette and California valleys. This is the result of subduction with the latest formation of slips and faults, such as, for example, San Andreas.

This fault is especially active. The blocks of the earth's crust move horizontally relative to each other at high speed. The process is accompanied by strong earthquakes. So, for example, in 1992, an earthquake occurred 150 km from Los Angeles in the Mojave Desert, during which more than 5,000 shocks of various strengths were recorded in 10 days. Suffer from earth tremors big cities- San Francisco was badly damaged in 1906, in Los Angeles there were shocks of 7-8 points in 1971.

The climate here is subtropical with humid warm winters (up to 10°C) and dry summers. On the coast, summers are cool (average July temperatures are about 15°C), due to the influence of air masses with a northern component and cold currents. When moving inland, summer becomes much warmer (20-22°C). The annual amount of precipitation is 500-600 mm with a winter maximum. The lower tier of mountains is occupied by an analogue of the Mediterranean maquis - chaparral (thickets of shrubby oak, deciduous and evergreen, 1.5-2 meters high, less often - 3 meters, on brown, above 600 meters - stony soils). In the south - thickets of acacia, cacti, yucca. The upper tiers are dominated by coniferous forests of Sitka spruce, Douglasia, pines, sequoias.

On the northern parts of the western slopes there are national parks, where evergreen sequoia forests (mahogany) are taken under protection. national park Redwood is located north of San Francisco, in the valley of the river. Redwood Creek. Sequoias are the tallest and oldest trees, along with mammoth trees from the same family. Sequoia grows up to 2000 years. The phytomass of the thousand-year-old sequoia is more than 4,000 thousand c/ha (1% is needles, the rest is the trunk and branches), the yield of commercial wood is 10 thousand m 3 /ha. Trees are not afraid of fires.

Of all the regions of North America, the Cordillera of the southwestern United States stands out for its variety of natural attractions that attract tourists from all over the world.

In addition to recreational, this region has good agro-climatic and land resources. In the Great California Valley, the natural vegetation of dry wormwood steppes and semi-deserts has been completely replaced by cultivated vegetation. On lands irrigated by the waters of rivers flowing down from the mountains, a variety of subtropical crops are grown. On the Pacific coast, giant urban agglomerations have formed, connected by high-speed highways. From Richmond, Oakland, San Francisco to Los Angeles, including the famous Hollywood, continuous urban development stretches.

The most acute problem is pollution: all harmful emissions remain near the surface of the earth, since a significant part of the year is dominated by the anticyclonic regime and descending air currents. Frequent fogs.