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The North American Cordillera Mountains occupy. The Cordillera Mountains are the longest mountain system in the world. The highest mountain

), occupying western North America and extending within the United States proper and Alaska, Canada and Mexico. The total length is more than 7 thousand. km(from 19°N to 69°N). The width of the mountain belt in Alaska reaches 1100-1200 km, in Canada - up to 800 km, in the US proper - about 1600 km, in Mexico - up to 1000 km. The southern border of the K.S.A. is the tectonic depression of the river valley. Balsas dividing North and Central America.

Orography. In K.S.A. three longitudinal belts are clearly expressed - eastern, internal and western. The eastern belt, or the belt of the Rocky Mountains, is represented by a chain of high massive ridges, mostly serving as a watershed between the basin Pacific Ocean and the basins of the Gulf of Mexico and the Arctic Ocean. In the east, the belt abruptly ends at the foothill plateaus (Arctic, Great Plains); in the west, it is in some places limited by deep tectonic depressions (“Ditch of the Rocky Mountains”) or the valleys of large rivers (Rio Grande), and in some places it gradually turns into mountain ranges and plateaus. In Alaska, the Rocky Mountain belt includes the Brooks Range, in northwestern Canada - the Richardson Range and the Mackenzie Mountains, bounded to the north and south by the through valleys of the Peel and Liard rivers.

To the south, in Canada and the USA, up to 32° N. sh., the Rocky Mountains themselves stretch. Between 45° N. w. and 32° N. w. the eastern belt reaches its greatest width and is represented by isolated high (over 4000 m), but small in length ridges and massifs, separated by vast areas of plateau (“parks”): the Sawatch Massif, the San Juan Mountains, the Front Range, the Uinta Mountains. In the area between 32° and 26° N. sh., cut through the valley of the river. Rio Grande, the belt is not clearly defined: the mountain ranges are separated by sections of plateaus and basins, which in the west merge with the Bolsons of the Mexican Highlands, and in the east they pass into the Eduardo Plateau. The southernmost segment of the eastern belt forms the Sierra Madre Oriental (altitude up to 4054 m).

The internal belt of the K.S.A., or the belt of internal plateaus and highlands, is contained between the eastern belt and the belt of the Pacific ridges in the west. In interior Alaska, it includes extensive tectonic depressions occupied by river valleys and alternating with flat-topped mountain ranges up to 1500- 1700 m(Mounts Kilbuck, Kuskokwim, Ray); in Canada - numerous high plateaus (Yukon, Stikine, Fraser), mountain ranges and ranges that are not inferior in height to the Rocky Mountains (Cassiar-Omineca Mountains, 2590 m; Columbia Mountains, up to 3581 m); within the USA and Mexico proper - high mountain ranges in the area of development of batholiths in the state of Idaho (altitude up to 3857 m), Snake and Columbia volcanic plateaus (average altitudes up to 1000 m), Great Basin plateau and north East End Mexico, as well as the strata-stepped Colorado Plateau and the Mexican Highlands.

The western belt consists of a belt of Pacific ridges, a belt of intermountain depressions and a belt of coastal chains. The belt of Pacific ridges, bordering the inner region of K.S.A. with 3., includes the highest ridges of the mountain system, including the Alaska Range with the highest point of the entire continent - Mount McKinley (6193 m), chain of volcanic Aleutian islands, Aleutian Range (Iliamna Volcano, 3075 m), high mountain node of the St. Elias massif (Logan, 6050 m), highly dissected Coast Range (Waddington, 4042 m), forming a characteristic fjord coast along its entire length. In the territory of the USA and Mexico proper, this belt includes the Cascade Mountains with a series of volcano peaks (Rainier volcano, 4392 m), Sierra Nevada Range (4418 Whitney m), ridges of the California Peninsula (heights up to 3078 m), separated from the inner belt by the Gulf of California depression, the Transverse Volcanic Sierra with the Orizaba volcanoes (5700 m), Popocatepetl (5452 m), Nevado de Colima (4265 m). Intermountain longitudinal depressions are represented by both sea bays and straits (Cook Bay, Shelikhov Straits, Georgia Straits, Sebastian Vizcaino Bay) and a series of lowlands and plateaus (Susitna Lowland, Copper River Plateau, Willamette Valley, Great California Valley). The belt of coastal chains bordering the western edge of the continent is the most fragmented part of the mountain structure of the K.S.A., represented by low and medium-high ridges (Coast Ranges of the USA., Sierra Vizcaino on the California Peninsula) and a series of mountainous coastal islands (Kodiak Islands, Queen Charlotte, Vancouver, Alexandra Archipelago). This belt reaches its greatest height in southern Alaska, in the Chugach Mountains (Marquez-Baker, 4016 m).

Geological structure and minerals. K.S.A. are formed by different tectonic elements. In the southern United States, their borders include the raised the latest movements western part of the Precambrian North American platform(Colorado Plateau and eastern ridges of the Rocky Mountains), where the folded basement (absolute age about 2.4 billion years) is covered by a horizontal cover of the Paleozoic and Mesozoic. To the west extend the myo- and eugeosynclinal troughs of the mesozoids of the Sierra Nevada and the Rocky Mountains (Nevadids). In Canada, mesozoids are separated from the platform by the Pre-Cordilleran foredeep, filled with carbonate and salt-bearing formations of the Middle Paleozoic and molasse of the Jurassic and Lower Cretaceous, and in Alaska - from the ancient Yukon massif - by the deep Tintin fault. Similar faults separate the mesozoids of Mexico from the Precambrian Central American massif. The formation of the Nevadad geosynclinal troughs occurred in the late Precambrian and the accumulation of sediments in them continued until the end of the Jurassic. In the east of the Nevadian belt, carbonate (Paleozoic) and terrigenous (Mesozoic) strata of miogeosynclines with a thickness of up to 10 km. The eugeosyncline is composed of volcanogenic and volcanogenic-sedimentary strata with a thickness of about 15 km. In Late Jurassic time, the mesozoids of Canada and the USA underwent folding, and in Early Cretaceous time granitoids were intruded into them. Within the Sierra Madre Occidental and the California Peninsula, folding and orogenic processes occurred in Late Cretaceous - Paleocene times (Laramides), and the intrusion of granites dates back to the Late Cretaceous - Oligocene.

To the west of the Mesozoid on the Alaska Peninsula and in the Coast Ranges of California and Oregon, as well as in southern Central America, the Cenozoic geosynclinal system extends. It is folded powerfully (up to 25 km) strata of volcanic and sedimentary rocks of the Upper Jurassic, Cretaceous and Cenozoic. These areas are characterized by volcanism, high seismicity and intense modern tectonic movements. In the north of the Pacific Ocean, geosyncline structures include the Aleutian, and in the south, the Central American deep-sea trench; The formation of a deep trough in the Gulf of California is associated with the development of a geosyncline.

In the Pre-Cordilleran foredeep (Canada) and in young depressions (Alaska, California) there are oil deposits, in the mesozoids of the Rocky Mountains, Sierra Nevada and Sierra Madre - ores of gold, tungsten, copper, molybdenum (see Climax) , polymetals, in the Cenozoic structures of the Coastal Ranges - mercury, as well as coal, etc.

N. A. Bogdanov.

Relief. The eastern belt is characterized by both large arched massifs dissected by river valleys (Brooks Range, Mount Mackenzie, Canadian Rockies and Sierra Madre Oriental) and short anticlinal ridges formed in the area of marginal platform structures (US Rocky Mountains).

The relief of the inner belt includes high plateaus (Yukon, Stikine, etc.), which are a combination of large flat-topped massifs and wide basins crossed by river valleys; lava plateaus (Fraser, Columbian, Mexican), deeply cut by river canyons; semi-buried highlands (Great Basin), which have a folded base brought to the surface in the form of short numerous ridges surrounded by extensive depressions, as well as deeply dissected plateaus (Colorado Plateau, etc.), which are an area of platform structures involved in the Cordillera mountain belt.

The Pacific ridge belt is characterized by large anticlinal ridges with outcrops of intrusive rocks in the axial part (Alaska Ridge); Massive, significant ridges-batholiths (Sierra Nevada, Coast Range) are also close to this type. Another type is volcanic ridges that have a folded base, complicated by a series of volcanoes planted on it, including active ones. In the belt of longitudinal depressions, accumulative lowlands (Great California Valley) have become widespread. The belt of coastal chains is most characterized by low, weakly dissected ridges that form straight shores.

In the northern part of K.S.A. (north of 40-49° N) both ancient glacial (troughs, cirques, terminal moraine ridges, loess, outwash and lacustrine plains) and modern nival landforms (kurums) are widespread. , mountain terraces, etc.), confined to the most high levels mountains (Alaskan Range, Rocky Mountains). In areas that were not subject to glaciation (interior Alaska), thermokarst and polygonal landforms associated with the distribution of rocks and soils are widely represented. In the rest of the C.S.A., water-erosion forms predominate: valley dissection in the most humid areas (Canadian Cordillera), table forms and canyons in arid areas (Colorado Plateau, Columbia Plateau). Desert areas (Great Basin, Mexican Highlands) are characterized by denudation and aeolian forms.

Climate. The northern part of K.S.A. is located in the Arctic (Brooks Range) and subarctic ( most of Alaska), territory up to 40° N. w. - V temperate zone, to the south - in the subtropical, the California Peninsula and the Mexican Highlands - in the tropical. On the slopes facing the Pacific Ocean, the climate is predominantly mild, oceanic (at the latitude of San Francisco - Mediterranean), in the interior regions - continental. On the Yukon Plateau average temperature January about -30 °C, July 15 °C. In the Great Basin, winters experience temperatures down to -17°C, and summer temperatures often exceed 40°C (absolute maximum 57°C). In July, the highest temperatures are observed in the intermountain valleys of the South (32 °C in the lower reaches of the Colorado River), the lowest in the highlands of Southern Alaska (8 °C in the Chugach Mountains and the St. Elias Massif). Humidification is extremely uneven. In the temperate zone, the extreme west is best moistened; in the tropical zone, the extreme east is best moistened. The interior plateaus receive the least amount of precipitation. On the southern ranges of Alaska, annual precipitation is 3000-4000 mm, on the coast of British Columbia - up to 2500 mm, on the US inland plateau it drops to 400-200 mm. The Mojave Desert receives only 50 precipitation. mm in year. To the south-east Mexican Highlands precipitation increases to 2000 mm. The greatest thickness of snow cover (up to 150 cm and more) is observed in southern Alaska (Chugach, St. Elias, Wrangel mountains), as well as on the Coast Range and in the Columbia Mountains of Canada.

Glaciation. Large differences in the latitudinal and altitudinal position of the K.S.A., as well as a sharp difference in the moisture content of the territory, led to the uneven development of modern glaciation. Lowest (300-450 m) the snow line is located on the Pacific slope of the mountains of Southern Alaska, in some places falling to ocean level. On the northern slopes of the Chugach and St. Elijah mountains the snow line is at an altitude of 1800-1900 m, on the Alaska Range - from 1350-1500 m(southern slope) up to 2250-2400 m(northern slope). The area of modern glaciation here reaches 52 thousand. km 2. In the Brooks Range and the Mackenzie Mountains, glaciation develops only on the highest peaks. To the south the snow line rises to 1500-1800 m in the Coast Range and until 2250 m - in the Columbia Mountains of Canada. As a result, the glaciated area of inland Alaska and the Canadian Cordillera is only 15 thousand hectares. km 2. In the US proper, the snow limit rises to 2500-3000 m in the Cascade and Rocky Mountains, up to 4,000 m more than that in the Sierra Nevada, up to 4500 m and more - in Mexico. The area of modern glaciation in the United States is estimated at 0.5-0.6 thousand. km 2, in Mexico - 0.011 thousand. km 2. All main types of glaciers are represented in K.S.A.: extensive ice fields and caps, washed glaciers (Depont Glacier in the Coast Range), foothill glaciers, or foot glaciers (Malaspina), valley glaciers (Hubbard, length 145 km in the Coast Range), cortical and short hanging glaciers, mostly disappearing (Sierra Nevada). Star-shaped glaciers form on volcanic peaks, sending out numerous glacial streams (there are more than 40 streams on Mount Rainier).

Rivers and lakes. Within the K.S.A. lie the sources of many river systems of the mainland: Yukon, Peace River - Mackenzie, Saskatchewan - Nelson, Missouri - Mississippi, Colorado, Columbia, Fraser. Since the main watershed is the eastern mountain belt, most of the precipitation that falls within the K.S.A. flows to the west, into the Pacific Ocean. North 45-50° N. w. on the Pacific coast, the rivers are fed predominantly by snow with a clearly defined spring flood. In the south it predominates rain power with a winter maximum on the Pacific coast and a spring-summer maximum in the interior regions. In the southern part of K.S.A., significant territories have no flow into the ocean and are irrigated mainly by short-term watercourses ending in endorheic salt lakes (the largest of them is the Great Salt Lake). In the north there are numerous fresh lakes of glacial-tectonic and dammed origin (Atlin, Kootenay, Okanagan, and others).

The deepest mountain rivers, having a large fall and being regulated by lakes, have enormous hydroelectric potential and are widely used for electricity and irrigation. On the river Colombia has identified more than 10 sites suitable for the construction of hydroelectric power stations, and some of them have already been used (Grand Coulee, Te Dals, etc.).

Natural areas. Due to the significant height along the entire length of the K.S.A., the altitudinal zonation of natural landscapes is clearly expressed. At the same time, the strike of mountain ranges in a 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 largest changes in landscapes are associated with the latitudinal position of the mountain system, with its transition from the subarctic zone to the temperate, subtropical and tropical. There are 4 main natural area: Northwestern, Canadian Cordillera, US Cordillera and Mexican Cordillera.

The northwestern region, or Alaskan Cordillera, covers most of the state of Alaska and the Yukon Plateau in northwestern Canada. In the south, high mountain ranges with thick glaciers predominate; the rest of the territory is dominated by plateaus. The climate is subarctic, south coast- moderate. With the exception of the coast of the Gulf of Alaska, permafrost is developed everywhere. The range of altitudinal zones is represented by foothill light forests (forest-tundra) in river valleys and mountain tundra on high plateaus. On the western coast, subarctic meadows are developed, on the southern Pacific slopes there are belts of tall coniferous forests of hemlock and thuja (the so-called coastal forest), subalpine woodlands, replaced at the peaks by alpine meadows and glaciers. The tundra is home to reindeer, arctic foxes, polar hares, and lemmings. The forests are home to elk, grizzly bear, wolf, fox and other predators. Lots of birds. The bulk of the population and cities are concentrated on the southern coast.

The Canadian Cordillera is the narrowest part of the mountain belt, including the southeastern coast of Alaska and partially extending into the United States (up to 44° N). The relief is dominated by high mountain ranges with a wide development of ancient glacial forms and modern glaciation. The climate is temperate, from humid to dry. The range of vertical belts includes steppes on the bottoms of intermountain valleys, pine forest-steppe on high plateaus, mountain coniferous forests of fir, spruce, red cedar, balsam pine on slopes where podzolic brown forest and mountain forest soils are developed, subalpine coniferous woodlands and alpine meadows on mountain meadow and skeletal soils in the apical part. The Pacific slopes are occupied by tall forests of Douglas fir, Sitka spruce, hemlock and thuja, coming here from the southern regions of Alaska. There are many different animals found in mountain forests: reindeer wapiti, moose, caribou, grizzly bear; there are wolves, foxes, wolverines, lynxes, pumas, Mountain sheep. Fur-bearing animals include marten, ermine, mink, nutria, and muskrat. The population is concentrated mainly in the south, in coastal cities (Vancouver). The steppe lands of the valleys are cultivated, the forest-steppe plateaus are used as pastures.

The US Cordillera, or Southern Cordillera, corresponds to the widest part of the mountain belt and has a wide variety of natural conditions. High forested ridges covered with snowfields and glaciers are directly adjacent to vast, drainless desert plateaus. The climate is subtropical, Mediterranean on the coast, and arid in the interior. On the slopes of high ridges (the Front Range, Sierra Nevada) belts of mountain pine forests (American spruce, larch), coniferous subalpine woodlands and alpine meadows are developed. The Low Coast Ranges are covered with mountain pine forests, groves of old-growth redwood forests, and evergreen hardleaf shrubs (chapparral). The western slopes of this part of the Cordillera are rich in forest resources, but in the 19th and especially in the 20th centuries. forests were heavily cut down and suffered due to frequent fires, and the area under them was significantly reduced (Sitka spruce, Douglas fir, etc., which survived in small quantities on the Pacific coast, were especially affected). Vast spaces of the internal plateau are occupied by wormwood and shrubby semi-deserts and deserts, while low ridges are occupied by pine and pine-juniper woodlands. In areas developed by humans, large animals have either been destroyed or are on the verge of destruction. Bison have been almost completely exterminated, and pronghorn antelope is rare. The rich fauna is preserved only in nature reserves (Yellowstone national park, Yosemite National Park, etc.). In semi-desert areas, rodents, snakes, lizards, and scorpions are common. The population is concentrated near the Pacific coast, where large cities are located (Los Angeles, San Francisco). In the river valleys there are tracts of irrigated land used for subtropical fruit crops. Subtropical woodlands and shrub deserts are used as pastures.

Mexican Cordillera. Includes the Mexican Highlands and the California Peninsula. The relief is dominated by high plateaus and highlands, in places highly dissected (Sierra Madre Occidental). Characterized by high seismicity. The climate is tropical, mostly dry. On the windward slopes, low-growing thorny forests (at the foot) and deciduous tropical forests (at the tops) are developed. In the interior parts there are shrubby creosote and high-mountain succulent deserts, cactus-acacia savannas and mountain coniferous-hard-leaved forests. Among the animals found in deserts and semi-deserts are cougar, pronghorn antelope, meadow wolf, or coyote, many hares, voles and other rodents. The forests are home to black bear, lynx and other predators. Monkeys, tapirs, and jaguar are found in tropical forests. The majority of the population is concentrated on the Mesa Central plateau, where the main cities of Mexico are located (Mexico City, Guadalajara, San Luis Potosí), and on the Gulf Coast (the ports of Tampico, Veracruz). Significant tracts of land in the south are used for plantations of tropical crops and grain crops.

Lit.: Ignatiev G.M., North America, M., 1965; Relief of the Earth, M., 1967; Vitvitsky G.N., Climates of North America, M., 1953; King F.B., Geological Development of North America, trans. from English, M., 1961; Bostock N. S., Physiography of the Canadian Cordillera, Ottawa, 1948; Landscapes of Alaska, Los Ang., 1958; Tamayo J. L., Geografia general de Mexico, 2 ed., v. 1-4, Mex., 1962; Thornbury W. D., Regional geomorphology of the United States, N.Y., 1965.

A. V. Antipova, G. M. Ignatiev.

Cordillera
Aconcagua
Mountains of North America
Location:	North and South (Andes) Americas
Highest point:	McKinley (6193 m) and Aconcagua (6962 m)
Coordinates:	63°4′10″N 151°0′26″W and 32°39′20″S, 70°00′57″W

Cordillera, the largest mountain system on the globe, stretching along the western edges of the Northern and South America, from 66° N (Alaska) to 56° S. w. (Terra del Fuego).

The length is more than 18 thousand km, the width is up to 1600 km in North America and up to 900 km in South America. Located in the territory of [Canada, USA, Mexico, Central American countries, Venezuela, Colombia, Ecuador, Peru, Bolivia, Argentina and Chile.

Almost along their entire length they are a watershed between the basins of the Atlantic and Pacific oceans, as well as a sharply pronounced climatic boundary. Second only to the Himalayas and mountain systems in height Central Asia. The highest peaks of the Cordillera: in North America - Mount McKinley (6193 m), in South America - Mount Aconcagua (6960 m).

The entire Cordillera system is divided into 2 parts - North American Cordillera, and the Cordillera of South America, or the Andes.

The main mountain-building processes that gave rise to the Cordillera began in North America in Jurassic period, in the South - at the end of the Cretaceous and took place in close connection with the formation of mountain systems on other continents (Alpine folding). The formation of the Cordillera has not yet ended, as evidenced by frequent earthquakes and intense volcanism (more than 80 active volcanoes). Important role Quaternary glaciation also played a role in the formation of the Cordillera relief, especially north of 44° N. and south of 40° S.

The Cordilleras lie in all geographical zones (except for the subantarctic and Antarctic) and are distinguished by a wide variety of landscapes and pronounced altitudinal zones. The snow line in Alaska is at an altitude of 600 m, on Tierra del Fuego - 500-700 m, in Bolivia and Southern Peru it rises to 6000-6500 m. In the northwestern part of the Cordillera of North America and in the southeastern Andes, glaciers descend to ocean level, in the hot zone they cover only the highest peaks. The total area of glaciation is about 90 thousand km 2 (in the Cordillera of North America - 67 thousand km 2, in the Andes - about 20 thousand km 2).

Literature

Geographical encyclopedic Dictionary, M., 1986.

North American Cordilleras - Northern part the Cordillera mountain system, stretching along the Pacific coast of the mainland for nine thousand kilometers, and spreading over more than one and a half thousand kilometers in width. They start with , them southern border- the valley of the Mexican Balsas River, separating North and Central America, to the south are the Sierra Madre Southern mountains, belonging to the Cordillera of Central America, which pass into the Andes, forming the longest mountain system on Earth, more than 18 thousand km long.
These mountains cross the territory of three countries in North America: the USA (from Alaska to California), Canada and Mexico.
The history of the formation of the North American Cordillera is incredibly complex, primarily due to the large area of this object and the significant duration of its formation: for example, the age of the rocks of the vast Colorado Plateau and the eastern ranges of the Rocky Mountains is about 2.4 billion years. The process of formation of the Cordillera of North America is still in an active phase, earthquakes are not uncommon here, and volcanic eruptions also occur.
In the configuration of this part of the Cordillera, three longitudinal mountain belts are clearly visible.
The eastern one, also known as the belt with the Elbert peak, is a chain of high massive ridges. In the east it is limited by a sharp ledge, which is the border of the piedmont plateaus (Arctic Plateau, Great Plains), and in the west it is limited by deep tectonic depressions called the “Rocky Mountain Ditch”, or by the valleys of large rivers like the Rio Grande. The southernmost section of the eastern belt forms the Sierra Madre Oriental, about 4 km high.
The inner belt is enclosed between the eastern belt and the western belt of the Pacific ridges. In Alaska these are vast tectonic depressions occupied by river valleys and alternating with relatively low mountain ranges; in Canada there are numerous high plateaus 2.5 km high; within the United States and Mexico proper there are high mountain ranges and volcanic plateaus.
The western (Pacific) belt, which includes the highest ridges, consists of a belt of Pacific ridges, a belt of intermountain depressions and a belt of coastal chains. The Pacific ridge belt includes the Alaska Range with the highest point of the entire continent - the peak of Denali. Part of the western belt are large mountains - the Cascades, the Sierra Nevada and the Transverse Volcanic Sierra. Most of the peaks of the local mountains are cones of active and extinct volcanoes 4 km high and higher, the most famous being Rainier, Orizaba, Popocatepetl and Nevada de Colima.
Sedimentary rocks accumulated in depressions between mountain ranges for a long time, as a result, huge deposits of various minerals were formed throughout the Cordillera of North America, and metal ores were formed in the thickness of the mountains. In the Canadian Pre-Cordilleran foredeep and in depressions in Alaska and California there are oil deposits, in the Rocky Mountains, Sierra Nevada and Sierra Madre - ores of gold, tungsten, copper, molybdenum, base metals, in the Coast Ranges - mercury and everywhere - deposits of stone coal
Glaciers occupy almost 70 thousand km 2, most are located in the mountains of Alaska, among them the Bering stands out - the largest mountain glacier in North America (some glaciologists believe that in the whole world).
The Cordillera contains the sources and headwaters of many major rivers in North America: Yukon, Saskatchewan, Missouri, Columbia, Colorado, Rio Grande. There are lakes, many of them salty, the most famous being Bolshoye Solenoye.
The Cordillera of North America is the northern part of the Cordillera mountain system, stretching along the western edge of North America and in Central America.
The length of the Cordillera of North America is large, which explains the noticeable difference in landscapes, depending on the latitudinal position of the mountain system.
The natural landscapes of the Cordillera of North America throughout their entire length, due to their significant altitude, have a pronounced altitudinal zonation, which is in many ways typical of such large mountainous regions.
The North American Cordillera zone is divided into four main natural regions: the Northwestern Cordillera, the Canadian Cordillera, the US Cordillera and the Mexican Cordillera.
The Northwestern (Alaska Cordillera) occupies most of the American and Canadian Yukon Plateau. Here is the kingdom of high mountain ranges with powerful glaciation, the climate ranges from arctic to temperate. Vegetation is poor because everywhere -permafrost. On the slopes of the mountains there is mountain tundra, and higher up there are glaciers, in the valleys of freezing rivers there is forest-tundra, on the west coast - which is warmer - subarctic meadows and coastal coniferous forests appear. Reindeer, arctic fox, polar hare, and lemming live in the tundra. The forest is the habitat of the grizzly bear, wolf, and fox. A lot of birds.
People settled only on the coast, where all the cities and towns are located.
The population is engaged in fishing, hunting fur-bearing animals and extracting the most valuable minerals (gold, oil), since the export of others is too expensive.
The Canadian Cordillera, which partially extends into the United States, is the narrowest part of the mountain belt. There are many mountain ranges and glaciers, but the climate is milder - temperate, humid. Steppes appear in river valleys, and thickets of mountain coniferous forests appear on the plateau: fir, spruce, red cedar, balsam pine. The fauna becomes more diverse, moose, wolverine, lynx, puma, mountain sheep, fur-bearing animals appear: marten, ermine, mink, nutria, muskrat.
The local population is residents of large port cities like Vancouver, as well as farmers: the steppes are plowed, forest-steppe plateaus are used as pastures.
The US Cordillera is the widest part of these mountains, so there is a greater variety of natural conditions. High, forested ridges with glaciers lie close to vast desert plateaus. The climate is subtropical, and on the coast it is Mediterranean; in the inland areas, where moisture no longer reaches from the ocean, it is arid. On the slopes of the Front Range and Sierra Nevada there are mountain pine forests; the lower Coast Ranges are covered with groves of relict sequoia and hard-leaved shrubs - chapparral. But the forests in the west have been largely cut down or burned in forest fires - also due to human fault.
Where people have settled, large animals have either been destroyed or are on the verge of destruction: for example, the bison has been almost completely destroyed. Rich wildlife is preserved only in very large nature reserves, such as Yellowstone and Yosemite National Parks.
The bulk of the population is concentrated along the Pacific coast, where the large cities of Los Angeles and San Francisco are located.
The Mexican Cordillera is the Mexican Highlands and the California Peninsula. The climate is tropical, very dry, vegetation is poor, with the exception of tropical forests on the mountain slopes. Pronghorn antelope, coyote, monkeys, and jaguar live here. Most of the population lives in and around Mexico City or in port cities.

general information

Location: western North America.

Mountain ranges: eastern belt (Brooks, Richardson, Mackenzie, Sawatch, San Juan, Frontline, Uintah, Sierra Madre Oriental), inner belt (Kilbuck, Kuskokwim, Ray, Cassiar, Omineca, Columbian, Yukon Plateau, Stikine, Fraser, Snake, Great Basin, Colorado and Mexican Highlands), western (Alaskan, Aleutian, Coastal, Sierra Nevada, Transverse Volcanic Sierra, Sierra Vizcaino, St. Elias Massif, Cascade and Chugach Mountains).

Plateaus, highlands and plateaus: Yukon, Fraser, Columbian, Colorado, Mexican.

Administrative affiliation: USA, Canada, Mexico.
Large cities: Mexico City - 8,851,080 people. (2010), Los Angeles - 3,928,864 people. (2014), San Francisco - 852,469 people. (2014), Vancouver (Canada) - 2,313,328 people. (2011).
Languages: English, French, Indian dialects.

Ethnic composition: whites, African Americans, indigenous peoples.
Religions: Christianity (many branches and directions), Judaism, Islam.

Currency: Canadian dollar, US dollar, Mexican peso.

Large rivers (headwaters and headwaters): Yukon, Peace, Athabasca, Mackenzie, Saskatchewan, Missouri, Columbia, Colorado, Rio Grande, Fraser.

Large lakes: Bolshoye Solenoye, Tahoe.

Numbers

Length: more than 9000 km.

Maximum width: in Alaska - 1100-1200 km, in Canada - up to 800 km, in the US proper - about 1600 km, in Mexico - up to 1000 km.

Highest point: Mount Denali (Pacific belt, 6144 m).

Other peaks: Mount (5951 m), Volcano Orizaba (5700 m), Volcano Popocatepetl (5452 m), Mount Whitney (4418 m), Mount Elbert (4399 m), Volcano Rainier (4392 m), Volcano Nevado de Colima (4265 m), Mount Marques Baker (4016 m), Mount Waddington (4042 m), Yliamna Volcano (3075 m).

Glaciers: area - about 67 thousand km 2.

Climate and weather

In the north - arctic and subarctic, to the south - temperate, in the south - from subtropical to tropical. On the eastern (Pacific) slopes - soft, oceanic to Mediterranean, in the interior - continental.

Average January temperature: in the north -30°С, in the south -17°С.
Average temperature in July: in the north +15°С, in the south up to +30°С.

Average annual precipitation: on the southern ridges of Alaska - 3000-4000 mm, on the coast of British Columbia - up to 2500 mm, on the internal plateau of the USA - up to 400-200 mm, in the Mojave Desert - 50 mm per year.

Relative humidity: from 70-80% in the north to 50-60% in the south.

Economy

Minerals: oil, natural gas, hard and brown coal, manganese, gold, silver, tungsten, copper, molybdenum, mercury, uranium, vanadium, limestone, granite, marble.
Industry: mining, metallurgy, heavy and transport engineering, chemical, food.

Agriculture: in the north - reindeer husbandry, in temperate zone- grains and large cattle, in the south - citrus fruits.

Service sector: tourism, transport, trade.

Attractions

■ Natural: national parks Yellowstone, Yosemite, Glacier, Sequoia, Rocky Mountain, Grand Canyon (all - USA), Jasper, Banff, Yoho, Nahanni, Kootenay, Waterton Lakes, Garibaldi Provincial Park (all - Canada).

Curious facts

■ In general, the Cordillera is the longest mountain system on the globe, located along the western coast of South and North America. The total length is about 18 thousand km, the width on average is about 1000 km. The Cordilleras are located on the territory of 9 countries, starting with the USA and Canada in the north and ending with Chile in the far south.
■ The world's largest mountain glacier, the Bering Glacier, is located in the Nugach Mountains in Alaska, its length is 203 km, and its area is about 5800 km 2. The glacier was named in honor of the Russian explorer Vitus Bering (1681-1741). The glacier is only 10 km from the coast of the Gulf of Alaska. As a result of a global increase in air temperature over the past 100 years, the glacier has shrunk by 12 km, reducing its mass, which put pressure on the earth’s crust and restrained seismic activity. As a result, the number of earthquakes in Alaska has increased dramatically.
■ Near the western (Pacific) belt of the Cordillera of North America characteristic feature: intermountain longitudinal depressions are not only lowlands like the Great California Valley, but also large sea bays and straits, like Cook Inlet and Shelikhov Strait, flooded sea water when sea levels rise.
■ In the Cordillera of North America there are all the main types of glaciers: large ice fields and caps, washed glaciers (Depont Glacier in the Coast Range), foothill glaciers or foothill glaciers (Malaspina), valley glaciers (Hubbard), ridge and short hanging glaciers, mostly disappearing (Sierra Nevada), and star-shaped glaciers are formed on the volcanic peaks, so named because numerous glacial streams depart from them (there are several dozen of them on Mount Rainier alone).
■ The Mackenzie Mountains in Canada were named in memory of Alexander Mackenzie (1822-1892), Canada's second prime minister. He carried out a number of important reforms, but his government fell in 1878, when an economic crisis began in Canada, so strong that, with all his authority, Mackenzie was unable to overcome it.
■ Sequoiadendron groves, or mammoth trees, on a narrow strip of the western slope of the Sierra Nevada, including in Sequoia National Park, are the most massive trees in the world: each one contains up to 1500 m 2 of wood.
■ In 1799-1867. Mount McKinley ( modern name Denali) was the highest point of the Russian Empire, but in 1867 it was sold to the United States along with all of Alaska.
■ Most of the most famous volcanic eruptions in the United States involve volcanoes in the Cascade Mountains, including the 1914–1915 eruption of Lassen Peak. and the 1980 eruption of Mount St. Helens.

The Cordilleras are mountains, a huge system of which occupies the western edge of the continent of North America. They stretch for about 7 thousand km. The Cordilleras are mountains characterized by a wide variety of natural conditions. They are characterized by a number of features, and this determines their uniqueness among other mountain systems on our planet.

General characteristics of the Cordillera

Where are the Cordillera Mountains? They are predominantly elongated in the submeridional direction. These mountains were formed within five orotectonic belts of different ages. The Cordilleras have a significant proportion of highlands (2.5-3 thousand or more meters above sea level). They have active volcanism and high seismicity. The large extent of these mountains from north to south has led to the presence of many spectra of altitudinal zones. Cordilleras are mountains formed at the junction between lithospheric plates. The border between them almost coincides with the coastline.

Composition of the Cordilleras

A third of the area of the entire continent is occupied by a mountain fold-block system. It has a width of 800-1600 km. It consists of mountain plateaus, intermountain basins, ridges, as well as volcanic plateaus and mountains. The Cordillera underwent young deformations, volcanism, and denudations, which determined their current appearance and masked many geological structures that appeared earlier. The mountain system is very heterogeneous both in the transverse and longitudinal directions.

The highest mountain

The cordillera on the western part is marked by a system of the highest ridges. These are the Aleutian Range, the Aleutian Islands, and the Alaska Range. The latter reaches a height of 6193 meters. This is McKinley, shown in the photo above the most high mountain. The Cordillera is a system that also includes in the western part the Cascade Mountains, the Coast Range of Canada, the Sierra Madre Occidental and the Sierra Nevada, as well as the Transverse Volcanic Sierra with the area located here (5700 meters), etc.

To the west of them the height decreases. Cordilleras are mountains that smoothly turn into a flat part of the mainland. It is occupied in the west by either Puget Sound, Cook) or lowlands (California Valley, Willamette River Valley). This coast of the continent is formed by the St. Elias, Chugach, Kenai, and Canadian Island Ranges, as well as the US Coast Ranges. The Cordillera chains bifurcate south of the Mexican Highlands. One of them deviates to the east, forming the islands of the West Indies and underwater ridges, after which it passes into the Venezuelan Andes. The second half stretches across the Isthmus of Panama and Tehuantepec to the Colombian Andes.

What is the reason for the diversity of mountain topography?

It is associated with the different ages of land areas, as well as with the history of their development. The continent did not immediately form into its present form. The Cordillera Mountains in their present form arose due to various processes that occurred at different times on the continent.

For the Laurentian Upland, marked by the most ancient geological structures, the relief is characterized by leveling surfaces, the formation of which began at the beginning of the Paleozoic. The undulating surface of the modern upland was determined by the different resistance of rocks to denudation, as well as uneven tectonic movement. The subsidence of the central part of the territory caused the cover Quaternary glaciation, due to which the depressions of the modern one were formed. In addition, under its influence, the accumulation of hydroglacial and moraine sediments occurred, which formed the type of relief (moraine-hilly).

They are large and belong to the formation type. Under the influence of denudation processes in various places, depending on the occurrence of various rocks, cuesta ridges (Great Lakes), stepped plateaus (Great Plains region), middle mountains and erosive lowlands (Washita, Ozarks) were formed.

The terrain of the Cordillera itself is very complex. The compression zone of the earth's crust is crossed by numerous faults, starting from the ocean floor and ending on land. The mountain-building process has not yet been completed. This is evidenced by volcanic eruptions (for example, Popocatepetl and Orizaba), as well as strong earthquakes that occur here from time to time.

Minerals

As you know, many different minerals can be found where there are mountains. The Cordillera is no exception. There are huge reserves of non-ferrous and ferrous metal ores here. Among the non-metallic ones, oil can be distinguished, which is located in intermountain troughs. Brown coal reserves are found in the Rocky Mountains (their inland basins).

Climate

We will continue our description of the mountains with climate characteristics. The Cordilleras are located on the path of oceanic air masses. Because of this, the influence of the ocean sharply weakens in the eastern direction. This climatic feature of the Cordillera is reflected in the soil and vegetation cover, the development of modern glaciation, and altitudinal zonation. The elongation of mountain ranges from north to south determines the differences in temperatures in summer and winter. In winter it ranges from -24 °C (in the Alaska region) to +24 °C (Mexico, south of the country). In summer the temperature reaches from +4 to +20 °C.

Precipitation

The northwest receives the highest rainfall. The fact is that this part of the Cordillera is located in the path of the westerly winds blowing from the Pacific Ocean. The amount of precipitation here is approximately 3000 mm. Tropical latitudes are the least humidified, since oceanic air masses do not reach them. The low amount of precipitation is also explained by the cold current passing near the coast. The interior plateaus of the Cordillera are also not very wet. The mountains are located within the temperate, subarctic, tropical and subtropical climate zones.

Rivers and lakes of the Cordillera

A significant part of the continent's western rivers originates in the Cordillera. Their food mainly comes from snow and glaciers, with floods occurring in the summer. These rivers are mountainous and swift. The largest of them are Colorado and Columbia. The lakes of the Cordillera are of glacial or volcanic origin. On the interior plateaus there are saline shallow water bodies. These are the remains of those who existed here long ago, during the times humid climate, large lakes.

Vegetable world

Very diverse vegetable world Cordillera. Coniferous forests with a unique appearance are located up to 40° N. w. They are very rich in species composition. Spruce, cypress, fir, thuja (red cedar) are their typical representatives. The height of coniferous trees reaches 80 meters. There is practically no woody undergrowth between them. However, a variety of shrubs grow here in abundance. There are a lot of mosses and ferns in the ground cover. In coniferous forests, as you move south, you begin to come across sugar pine, white fir, and yellow pine. Evergreen sequoia appears even further south. As dryness increases, south of 42° N. sh., thickets of bushes are replaced by forests. They are juniper, heather, and their height usually does not exceed two meters. Here you can sometimes find different types evergreen oak. The climate humidity in the interior regions of the Cordillera decreases. They are characterized by dry forests, as well as areas of saltwort and wormwood deserts. The mountain slopes receiving precipitation are covered with evergreen forests up to a height of 1200 m.

Animals living in the Cordillera mountains

Where the Cordillera mountains are located, you can meet a brown grizzly bear - large predator continent of North America. having long black fur, lives in the southwest of this system. It destroys livestock and spoils crops. There are also many lynxes, foxes, and wolves. In the southern regions of the mountains, arthropods, lizards, and snakes are often found. In addition, the poisonous tooth lives here - the only legless poisonous lizard. Large animals in places where people live are either destroyed or are extremely rare. Bison and pronghorn (a rare antelope) are preserved only thanks to national programs in North America. Only in nature reserves can one observe a rich fauna today.

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

Relief. The Cordillera of North America is the largest mountainous region of the continent and is represented by a system of high-mountain linear ridges, mountain ranges and extensive denudation surfaces. 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 defined: eastern, internal and western.

The eastern belt, or the belt of the Rocky Mountains, is represented by a chain of high massive mountain ranges, mostly serving as a watershed between the basins of the Pacific, Atlantic and Northern rivers Arctic Oceans. In the east, the belt abruptly ends at the foothill plateaus (Arctic, Great Plains), in the west it is in some places limited by deep tectonic depressions (“Rocky Mountain Ditch”) or valleys of large rivers (Rio Grande), and in some places it gradually turns into mountain ranges and plateaus. In Alaska, the Rocky Mountain belt includes the Brooks Range, 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. The northern part of the belt is dominated by peaked block-folded massifs with alpine landforms, large glacial fields, cirques, cirques, and trough valleys. In the Canadian Rockies, narrow linear ridges and longitudinal valleys are common. They are bordered to the west by the Columbia Mountains. Between 45° and 32° north latitude, the eastern belt reaches its greatest width and is represented by the Rocky Mountains in the USA (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 (so-called basins, parks). The highest are the Peredovaya ridges (height up to 4345 m), Wind River (up to 4207 m), Uinta Mountains (up to 4123 m), Absaroka (up to 4009 m). The high-mountain massifs in the area of development of batholiths in Idaho (for example, the Lost River ridge, height up to 3859 m) stand out in sharp forms. The southern part of the eastern belt is represented by the Sierra Madre Oriental ridge (height up to 4054 m).

The inner belt, or the 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) with a height of 750-1800 m, deeply dissected by river valleys. In the interior of Alaska, extensive tectonic depressions occupied by river valleys alternate with flat-topped mountain ranges 1500-1700 m high (Mounts Kilbak, Kuskokuim, Ray). In Canada, this belt is narrow; in many places it is interrupted by the Skeena, Cassiar, and Omineka mountain ranges (heights up to 2469 m). Volcanic plateaus are common (for example, Fraser, Columbia Plateau, Yellowstone). In the United States 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 Pacific ridges borders the interior plateaus of the Cordillera of North America on the west and includes the Alaska Range (up to 6194 m high, Mount McKinley is the highest point of the North American continent), the Wrangel Mountains (up to 5005 m, Mount Bona) and the St. Elias Mountains ( 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 stretch the Sierra Nevada, Sierra Madre Occidental, Transverse Volcanic Sierra ranges with the volcanoes Orizaba (height 5610 m), Popocatepetl (5465 m), Iztaccihuatl (5230 m), etc. To the south of the tectonic basin of the Balsas River are the Sierra Madre Sud. , Sierra Madre (height up to 4220 m, Tajumulco volcano is the highest point of Central America), Central volcanic Cordillera with volcanoes Poas (2704 m), Irazu (3432 m), etc.; in the southern narrowed part of the continent there are two arcs of uplifts of the Isthmus of Panama - the folded ridges of San Blas and Serrania del Daria (height up to 1875 m). The westernmost chain of Pacific ridges includes the Aleutian Islands, Aleutian Range, Chugach Mountains (elevation up to 4016 m, Mount Marcus Baker), a series of coastal mountainous islands (Kodiak Island, 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 Cordillera of North America (north of 40-49° north latitude), ancient glacial (troughs, cirques, terminal moraine ridges, loess, outwash and lacustrine plains) and modern nival landforms (kurums, mountain terraces, etc.) are widespread. confined to the highest levels of mountains (Alaska Range, Rocky Mountains). In areas not subject to glaciation (interior Alaska) and in the Arctic Lowland, thermokarst and polygonal forms are widely represented. In the rest of the Cordillera of North America, water-erosive forms predominate: valley dissection in the most humid areas (Canadian Cordillera), table forms and canyons in arid areas (Colorado Plateau, Columbia Plateau). Desert areas (Great Basin, Mexican Highlands) are characterized by denudation and aeolian landforms.

Geological structure and minerals. Tectonically, the Cordillera of North America is a huge fold-cover mountain structure in the northern part of the East Pacific Mobile Belt. They experienced several phases of folding: Antler (Late Devonian; 370-330 million years ago), Sonoma (late Permian - Middle Triassic; 250-235 million years ago), Nevada (Late Jurassic; 150-140 million years ago), Sevier ( end of the Early Cretaceous; 110-100 million years ago) and Laramie (Cretaceous-Paleogene boundary; 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: external (eastern) and internal (western). The outer mega-zone includes the Brooks Range in the north, the Rocky Mountains in the central part, and the Sierra Madre Oriental range in the south. In its main part (Rocky Mountains), the mega-zone is underlain by the Early Precambrian crystalline basement of the North American platform located to the east (the distribution 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 deformation during the Laramie folding phase. Within the Brooks and Sierra Madre Oriental ranges, the mega-zone is superimposed on the Paleozoic fold structures of the Inuit and Ouachita-Marathon systems, respectively; its development here is limited to the Mesozoic. The outer mega-zone is formed mainly by shelf carbonate and terrigenous sediments of the former passive margin of the North American continent, which form a system of tectonic nappes, torn from the basement and moved to the northeast and east (in the Brooks Range - to the north). In the western part of the Rocky Mountains, Upper Proterozoic predominantly clastic rocks with covers of basalts and horizons of glacial sediments (tillites), accumulated during the rifting stage that preceded the formation of the passive margin of the ancient North American continent, are widespread. The outer mega-zone reaches its greatest width in the USA, which is due to the involvement of a large section of the North American platform in the Laramie deformations. In the north of the deformed section of the platform, a series of differently oriented foundation uplifts arose, which were pushed over the areas separating them. deep depressions, filled with Cretaceous and Paleocene deposits. In the southern half of the area (Colorado Plateau), a large block of basement was uplifted, bounded on the east by the linear uplifts of the Southern Rockies and the young Rio Grande rift. In Mexico, the easternmost part of the outer mega-zone underwent folding during the Miocene. In front of the thrust front of the Cordillera of North America, there is a chain of foredeeps (filled with Cretaceous-Cenozoic molasse), which include the following 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 extremely complex internal structure with numerous zones of melange, thrusts and strike-slip faults, resulting from deformations that began in the Permian and culminated in the Cretaceous. The mega-zone is a so-called collage (mosaic) of terranes that 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 different 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 (possibly more than a thousand) kilometers.

After the end of the main deformations, intermountain troughs filled with Cretaceous and/or Cenozoic molasse were superimposed on the fold-thrust structure of the Cordillera of North America in places, for example, the Central Valley trough in California, Bowser in Canada, and a number of troughs in the west of Alaska. The underthrust (subduction) of the Pacific lithosphere 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 Sierra Madre Occidental range, and the formation of still active volcanoes Aleutian island arc, Aleutian and Alaskan ranges, Cascade Mountains, Trans-Mexican volcanic belt. To the east, the introduction 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, basaltic volcanism intensely manifested itself in the rear of the Cascade Mountains, creating the Columbia Plateau. The Cenozoic became an era of rifting, when an extensive polyrift system (the Basins and Ranges zone) arose in the central part of the orogen with the thickness of the earth's crust and lithosphere reduced to 30 km or less, the Rio Grande rift and the Gulf of California rift, which continues on the continent, were formed.

The southern part of the Cordillera of North America (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 its Pacific part, preserves high mobility with the manifestation of intense seismicity, which is associated with processes occurring at the border of the transition of the North American continent - the Pacific Ocean: the underthrust (subduction) of the Pacific lithospheric plate under the North American in the Aleutian deep-sea trench and along the coast of Washington and Oregon (USA); horizontal sliding of the Pacific Plate along the North American along the Queen Charlotte and San Andreas shear zones; the subduction 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 fade: the western, southern and eastern peripheries of the Great Basin and the Rio Grande Rift are seismic.

The subsoil of the Cordillera of North America is rich in minerals. Copper-molybdenum-porphyry deposits are typical. 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 Range, the gold-silver zone of the Great Basin, the uranium-bearing block of the Colorado Plateau, the Front Range zone with deposits of molybdenum and gold-silver ores, etc. There are known deposits of iron, lead, zinc, nickel ores, as well as bauxite, phosphorite, barite, fluorite, etc. Deposits of oil and natural combustible gas, coal, rock and potassium salts, and natural borates are confined to the strip of foredeeps and intermountain troughs and depressions .

Climate. The northern regions of the Cordillera of North America are located in the Arctic (Brooks Range) and subarctic (most of Alaska, northern Canada) zones, the territory up to 42° north latitude on the coast (in the inner zone up to 37° north latitude) is 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 subequatorial belt. On the slopes facing the Pacific Ocean, almost all climate types are characterized by relatively mild oceanic features, while inland areas are characterized by sharper, continental features. Altitudinal climate zones are observed everywhere. In the northern part of the Cordillera of North America on the coast, winters are rainy and mild, summers are cool and damp, with frequent fogs. Average January temperatures range from 0 to -5°C south of the Alaska Range, varying to -30°C (absolute minimum -62°C) on the Yukon Plateau; Average temperatures in July are approximately the same - about 15°C. The annual precipitation in southern Alaska (Chugach, St. Elijah, Wrangel mountains) is 3000-4000 mm (snow cover up to 150 cm or more), in the Yukon Plateau area - 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 precipitation amount on the western slopes of the Coast Range is 6000 mm, on the internal plateaus it decreases to 200-400 mm. In the Rocky Mountains, winters often experience frosts down to -30°C (absolute minimum -54°C), summers are sunny and dry, with an average July temperature of 19-20°C. 600-1200 mm of precipitation falls annually.

In the subtropical zone in the southern part of the Cordillera of the United States 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 regions it is dry continental. Average temperatures increase as you move inland 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, Death Valley). On the coast, winter is rainy; annual precipitation decreases from north to south from 2000 to 350 mm. The inner zone has dry, hot summers and relatively cold, moderately humid winters. Precipitation is 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°C, the warmest (May) are 20°C, in the southern part they are 21-23°C and 26-27°C, respectively. In the western and central regions In the northern part, the annual precipitation is 100-200 mm and increases to the south to 500 mm. 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 average annual temperatures 26-27°C. In the mountains at an altitude of 3800 m, temperatures drop to 6°C; on the constantly wet Atlantic slopes, 2000-4000 mm of precipitation falls per year. In the eastern part, tropical hurricanes are frequent, bringing heavy rainfall and having destructive power.

Glaciation. The area of modern glaciation in the Cordillera of North America is 67 thousand km2. Large differences in the latitude and altitude of the North American Cordillera, as well as a sharp difference in the moisture content of the territory, caused the uneven development of glaciation. The lowest (300-450 m) snow line is located on the Pacific slope of the mountains of Southern Alaska, in some places dropping to ocean level. On the northern slopes of the Chugach and St. Elias mountains, the snow line 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 km 2. In the Brooks Range and Mackenzie Mountains, glaciation develops only on the highest peaks. To the south, the snow line runs at an altitude of 1500-1800 m in the Coast Range and up to 2250 m in the Columbia Mountains. The total area of glaciation in the interior of Alaska and the Canadian Cordillera is only 15 thousand km 2. In the United States, the snow line to the south rises to 2500-3000 m in the Cascade and Rocky Mountains, to 4000 m or more in the Sierra Nevada, 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. The Cordillera of North America contains all the major types of glaciers: extensive ice fields and caps, foothill glaciers, or foothill glaciers (for example, Malaspina), valley glaciers (for example, Hubbard in the Coast Range), ravines and short hanging glaciers, mostly disappearing (Sierra -Nevada). Star-shaped glaciers form on volcanic peaks with numerous glacial flows (for example, on Mount Rainier).

Surface waters. Within the Cordillera of North America are the sources of many river systems of the mainland: Yukon, Peace - Mackenzie, Saskatchewan - Nelson, Missouri - Mississippi, Columbia, Fraser, Colorado, Rio Grande. The main watershed between the Pacific and Atlantic oceans is the eastern mountain belt, so the rivers of the Pacific Ocean basin are the deepest. To the north of 45-50° north latitude, the rivers are fed by glaciers and snow with a clearly defined spring flood. In the south, rain feeding predominates with a winter maximum on the Pacific coast and a spring-summer maximum in the interior regions. In the southern part of the Cordillera of North America, large areas do not drain into the ocean and are irrigated primarily by streams ending in endorheic salt lakes (the largest of them is the Great Salt Lake). In the north there are numerous fresh lakes of glacial-tectonic origin (Atlin, Kootenay, Okanagan, etc.), in the south - of tectonic origin (Chapala, Nicaragua). The rivers of the Cordillera of North America have enormous hydroelectric potential and are widely used for electricity and irrigation. Large reservoirs were built on the Yukon, Columbia, Colorado and other rivers.

Types of landscapes. Due to the significant altitude throughout the Cordillera of North America, the altitudinal zonation of natural landscapes is clearly expressed. At the same time, the strike of mountain ranges in a 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 largest changes in landscapes are associated with the latitudinal position of the mountain system, with its transition from the subarctic zone to the temperate, subtropical, tropical and subequatorial zone. In the northern part of the Cordillera there are the Cordillera of Alaska and Canada, in the southern part - the Cordillera of the USA, Mexico and Central America.

Alaskan Cordillera. With the exception of the Gulf of Alaska coast, permafrost is widespread throughout the Alaska Cordillera. The range of altitudinal zones is represented by foothill open forests (forest-tundra) in river valleys and mountain tundra on high plateaus and slopes of ridges in northern Alaska. On the southwestern coast, subarctic oceanic meadows (reed grass, pike, sedges, forbs) on gley soils and cryozems are developed; on the slopes of the Aleutian Range from a height of 200-300 m there is shrub tundra. On the southern slopes of the Alaska Range, forests rise almost to the snow line. Dense coniferous forests of Sitka spruce are widespread, with western hemlock and Nootka cypress (red cedar) mixed in on the slopes of the Kenai, Chugach, and Wrangel mountains. In the river valleys that flow into Cook Inlet (such as Matanuska), the land is partially used for agriculture.

Cordilleras of Canada. The Pacific slopes up to an altitude 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 pseudohemlock yew. Engelmann spruce and alpine fir grow higher above, and subalpine coniferous woodlands are common. The soils change from mountain brown taiga to mountain podzolic. In the interior regions north of 53° north latitude, taiga forests of white, black spruce and fir (balsam, great, etc.) on podzolic soils are common; to the south (as evaporation increases) forests of pine (yellow, lodgepole) are found on gray forests soils give way to 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 range of landscapes of the Columbia Mountains includes steppes, montane coniferous forests of giant fir, Weymouth pine, Douglas fir, white and red spruce, red cedar, balsam pine on podzolic-brown montane forest soils, and subalpine meadows. The ridges of the Rocky Mountains up to an altitude of 1800-2400 m are covered with dense mountain taiga forests of white spruce, balsam fir, banks pine and white birch; higher up, alpine tundra, snowfields, glaciers are developed, and subalpine meadows appear in the northern part.

In forested areas, forestry landscapes make up a significant proportion. IN southern parts wide intermountain basins - arable and pasture landscapes. Secondary pine forests after fires and logging are widespread.

The US Cordillera has a unique diversity of natural landscapes. The western slopes of the Pacific ridges and the Rocky Mountains are characterized by the most complex altitudinal structure. On the slopes of high ridges (Advanced, Sierra Nevada) belts of mountain pine forests (yellow pine, lodgepole pine, sugar pine, edible pine), mountain spruce-fir forests, coniferous subalpine woodlands and alpine meadows are developed. In the drier southern regions of the Rocky Mountains, a steppe-forest-meadow type of altitudinal zone is developed. On the slopes descending to the Great Plains, mountain steppes give way to pine forests, and at an altitude of 1800-2200 m - spruce-fir (Douglas fir, Engelmann spruce) forests. The lower parts of the mountain ranges, facing the deserts of the interior plateaus, are occupied by areas of grassland of grama, seline, mesquite grass, scrub oak, juniper, mesquite shrub and succulents. The gentle western slope of the Sierra Nevada up to an altitude of 2800 m is covered with mixed forests dominated by yellow pine, Douglas fir, oak (giant sequoia, or “mammoth tree” is found as an admixture), and higher up - 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 Coast Ranges there are mixed forests with Douglas-fir, thuja, western hemlock, and cypress on acidic mountain brown soils. The southern part of the ridges is characterized by summer-dry mixed hard-leaved forests of pines, Douglas fir, evergreen oak, and strawberry tree on mountain brown soils. In northwestern California, near the Pacific coast, groves of evergreen sequoia have been preserved. On the slopes of the southernmost ridges, which receive 250-350 mm of precipitation per year, chaparral is widespread - a formation of dry-loving shrubby evergreen oaks with an admixture of acacia and sumac on gray-brown soils. The internal plateaus are occupied by wormwood semi-deserts and deserts; in the eastern, more humid part, dry steppes of grama and bison grass on chestnut soils are developed. On the Columbia Plateau there are typical grass steppes on ordinary chernozems. In the Great Basin, mid-mountain ridges covered with pine woodlands and depressions occupied by wormwood semi-deserts with the participation of quinoa, a garden tree, alternate mosaically. In subtropical regions, the vegetation cover is dominated by creosote bush, acacia, mesquite tree, cacti (prickly pear, echinocactus, columnar cactus cereus, agaves, yucca). The soils are predominantly brown desert-steppe, gray soils, solonchaks and solonetzes (in basins), and mountain-brown. The Colorado Plateau is home to forest-steppe subtropical vegetation - pines and acacias, junipers and creosote bushes, Mexican succulents, and cereals. In the southern part of the inland highlands, exotic features of desert landscapes are given by picturesque weathering of sandstones in the form of arches and pedestals.

Most of the forests in the Coast Ranges have been cleared, and agricultural and residential landscapes dominate. 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. In the southeastern and southern regions, wet forest landscapes predominate. The rest of the territory is dominated by succulent and shrub (with creosote bush) deserts and semi-deserts. The Mexican highlands are the richest genetic center of endemic Mexican flora, there are about 500 species of cacti, 140 species of agaves, several species of yucca. The windward slopes of the peripheral ridges at the foot are occupied by low-growing thorny forests and open forests of caesalpinia (including quebracho), acacia, mimosa and mesquite on brown-red soils. South of 22° north latitude, on the southeastern windward slopes of the Eastern Sierra Madre and on the southern slopes of the Transverse Volcanic Sierra, up to an altitude of 600-1000 m, permanently moist evergreen tropical forests grow with an abundance of ficus, palm trees, and tree ferns on yellow ferrallitic soils. The forests are distinguished by an exceptionally rich species composition of woody plants: mahogany (mahogany, or kaoba), 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, willow, sambucus, ostia with tree ferns and podocarpus in the lower tier dominate. The trees are entwined with vines and epiphytes of 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 leeward slopes of volcanoes are covered with seasonally wet, winter-dry deciduous evergreen forests of diverse species composition. The forests contain up to 100 species of tree species, including cordia, carapa, cedrela, mahogany, enterolobium, chimenea, andir, chlorophore, and calophyllum brasiliensis. Dry, low-growing deciduous and semi-deciduous tropical forests grow in the arid inland basins of the southern Mexican Highlands. Widespread species include cedrela, burcera, morning glory, ceiba cotton tree, pseudobombax, and cordia. In the northwest of the Mexican Highlands and 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 pastoralism and irrigated agriculture. On the plains and foothills, large areas of forest are cleared for plantations of sugar cane, bananas, cocoa, coffee and tropical fruits, and in dry areas - cotton and agave.

In the Cordillera of Central America, the forest-meadow type of altitudinal zone is clearly expressed. Oceanic tropical and subequatorial moist and moderately moist forests predominate on the abundantly moist northeastern slopes and seasonally moist forests on the leeward southwestern slopes. In the mid-mountain zone on the slopes there are mixed evergreen-deciduous and coniferous forests on siallitic yellow-brown soils. Savannas and woodlands are common in basins and 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, ficus, bamboo, trees with valuable wood, rubber plants on ferrsiallite and allite red-yellow soils. Biological diversity forest formations are enormous; there are about 5,000 species of vascular plants. The most common tree species are mahogany, achras, brazimum, paleto, allspice, breadfruit, ampelosera, mazaquilla, cordia, brazilian calophyllum, castilla, Amazonian terminalia. At an altitude of about 2000 m, “fog forests” appear of beeches, lindens with thickets of tree ferns and bamboos. Alpine meadows are developed on high ridges and volcanoes. The monsoon-prone Pacific plains and lowlands of the extreme south of Central America are covered with deciduous evergreen forests (tambelnia, morning glory, bombax). In low areas and gentle slopes of mountains, plantations of coffee, bananas, sugar cane, etc. predominate.

Environmental issues and protected natural areas. The adverse consequences of human economic activity occur over a large area of the Cordillera of North America and are associated with intensive use natural resources, primarily forest, mineral, soil, water. In the southern Cordillera of Canada and the western United States, forests have been heavily logged since the 2nd half of the 20th century. Plantings of Sitka spruce, Douglas fir, and sequoia were especially affected. In the south of the Coast Range and the Columbia Mountains, in the Cascade Mountains, clearings occupy not only flat, but also steeply sloped areas. Deforestation, fires, shooting of animals and loss of their habitats, high recreational pressures create an unfavorable ecological situation in a number of areas of the Cordillera of North America. Accelerated erosion is evident in large areas. There is contamination of water sources with pesticides and nitrates. In Mexico, the rate of deforestation is 0.8% per year, and the highest erosion rate is observed in the Cordillera of North America. Are being cut down valuable species trees: cedrela, caoba, or mahogany, quebracho, ceiba, campeche tree, Brazilian calophyllum, pine, sacred fir. A serious problem associated with deforestation and oil pollution of the coastal waters of the Gulf of Mexico is the preservation of mangrove ecosystems. In the state of Arizona (USA), as well as in the basin of Mexico City (Mexico), groundwater depletion is observed.

The largest and most famous protected natural areas in the Cordillera of North America are Denali, Gates of the Arctic, Katmai, and Lake Clark national parks (USA); biosphere reserve Montes Azules, national parks Nevado de Toluca, Tepozteco, Popocatepetl-Iztaccihuatl, Pico de Orizaba (Mexico). The World Heritage List includes parks and reserves of Mount Wrangel and Mount St. Elijah, Kluane, Glacier Bay, Waterton-Glacier International Peace Park (all in the USA and Canada), parks of the Canadian Rockies (Canada), Yellowstone National Park, Olympic, Grand Canyon, Redwood, Yosemite (USA), Mariposa-Monarca Biosphere Reserve (Mexico), Rio Platano National Parks (Honduras), Darien, Coiba (Panama), Talamanca - La Amistad (World Biosphere Project, Costa Rica and Panama), protected area of Guanacaste (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. Mech., 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 S. M. Mesozoic evolution of exotic terranes and marginal seas, Western North America // Marine Geology. 1991. Vol. 102; Golubchikov Yu. N. Geography of mountain 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. Kondratyeva; V. E. Khain (geological structure and minerals).

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