Cordilleras are mountains whose vast system occupies the western edge of the continent of North America. They stretched for about 7 thousand km. 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 the remaining mountain systems of our planet.
General characteristics of the Cordillera
Where are the mountains of the Cordillera? Mostly they are elongated in the submeridional direction. Within the five orotectonic belts of different ages, these mountains are formed. Cordillera have in their composition 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 here of many spectra of altitudinal zonation. Cordilleras are mountains formed at the junction between lithospheric plates. The border between them almost coincides with the coastline.
Composition Cordillera
The third part of the entire continent’s area is occupied by a mountain folded-block system. It has a width of 800-1600 km. Its structure includes mountain plateaus, intermountain basins, ridges, as well as volcanic plateaus and mountains. Young deformations, volcanism, denudations underwent the Cordillera, which determined their present appearance and masked many geological structures that appeared earlier. The mountain system is very heterogeneous both in the transverse and in the longitudinal direction.
Details on the structure of the Cordillera
Asymmetric is the structure of the surface of the mainland, where the Cordillera Mountains are located. They occupy the western part, the eastern part - low mountains and vast plains. The western part is located at an altitude of about 1700 meters, and the eastern - 200-300 m. 720 meters is the average height of the continent.
Cordilleras are mountains that comprise a number of mountain arcs that are stretched mainly in the direction from the northwest to the southeast. From Mackenzie, Brooks, Rocky Mountains consists of an eastern arc. An intermittent belt formed from internal plateaus and plateaus is located west of these ranges. 1-2 thousand meters is their height. Cordilleras are mountains that include the following plateaus and plateaus: the Yukon Plateau, the Columbian Plateau and the Plateau of British Columbia, the Great Basin, the Colorado Plateau, the plateau and the volcanic plateau of the Mexican Plateau (its inner part). For the most part, they are an alternation of hollows, ridges and flat dining surfaces.
The highest mountain
Cordillera from the western part are marked by the system of the highest ridges. This is the Aleutian Range, the ridge of the Aleutian Islands, the Alaskan Range. The latter reaches a height of 6193 meters. This is McKinley, pictured above the highest mountain. Cordillera is a system that also includes the Cascade Mountains in the western part, the Canadian Coastal Range, the Western Sierra Madre and Sierra Nevada, as well as the Transverse Volcanic Sierra with the Orisaba volcano (5700 meters) located here and others.
To the west of them the height decreases. Cordilleras are mountains that smoothly transition into the flat part of the mainland. It is occupied in the west by either bays (California, Puget Sound, Cook) or lowlands (California Valley, Willamette River Valley). This coast of the continent is formed by the ranges of St. Elijah, Chugachsky, Kenai, the island range of Canada, as well as the US Coastal ridges. The Cordillera chains south of the highlands of Mexico are bifurcated. 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 the Teuantepeci to the Colombian Andes.
What is the reason for the variety of mountain topography?
It is associated with different ages of land areas, as well as with the history of their development. The continent did not immediately form in its present form. The Cordillera mountains in their present form arose thanks to various processes that took place at different times on the continent.
For the Lavrentian Upland, marked by the most ancient geological structures, leveling surfaces are characteristic in the relief, the formation of which began at the beginning of the Paleozoic. The undulating surface of the present-day elevation was due to the varying resistance of the rocks to denudation, as well as the uneven tectonic movement. The lowering of the central part of the territory caused a quaternary glaciation, due to which hollows of the modern Hudson's Bay formed. In addition, under his influence, an accumulation of water-glacial and moraine deposits occurred, which formed the type of relief (moraine-hilly).
The Great and Central Plains are a type of stratum. Under the influence of denudation processes in different places, depending on the peculiarities of different rocks, cuest ridges (Great Lakes), stepped plateaus (Great Plains region), middle mountains and erosive low mountains (Washito, Ozark) were formed.
The relief of the Cordillera themselves is very complicated. The compression band of the earth's crust is crossed by numerous faults starting from the bottom of the ocean and ending on land. The mountain building process has not yet been completed. This is evidenced by volcanic eruptions (for example, Popocatepetl and Orisaba), 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. Cordillera is no exception. There are huge reserves of non-ferrous and ferrous metals. From non-metallic, oil can be distinguished, which is located in the intermontane troughs. Brown coal reserves are available in the region of the Rocky Mountains (their internal hollows).
Climate
Climate characteristics continue the description of the mountains. Cordilleras are on the path of airborne ocean masses. Because of this, the influence of the ocean is sharply weakening eastward. This climatic feature of the Cordillera is reflected in the soil and vegetation cover, the development of modern glaciation, and altitudinal zonation. The elongation from north to south of the mountain ranges determines the temperature differences in summer and winter. In winter, it ranges from -24 ° C (in the Alaska region) to +24 ° C (Mexico, the south of the country). In summer, the temperature reaches from +4 to +20 ° C.
Rainfall
The northwest has the highest rainfall. The fact is that this part of the Cordillera is located on the path of westerly winds blowing from the Pacific Ocean. The amount of precipitation here is approximately 3000 mm. The least moistened are tropical latitudes, since the airy ocean masses do not reach them. The low precipitation is also due to the cold current passing along the coast. The inner plateaus of the Cordillera are also not very moist. The mountains are located within the temperate, subarctic, tropical and subtropical climatic zones.
Rivers and Lakes Cordillera
A significant part of the western rivers of the continent originates precisely in the Cordillera. Mostly their food is snow and ice, in the summer there is a flood. These rivers are mountainous, swift. The largest of them are Colorado and Colombia. Glacial or volcanic origin are lakes Cordillera. Inland plateaus are saline shallow water bodies. These are the remains of large lakes that existed here for a long time, at the time of a humid climate.
Vegetable world
The flora of the Cordillera is very diverse. Coniferous forests with a peculiar appearance range up to 40 ° C. w. In terms of species composition, they are very rich. Spruce, cypress, fir, thuja (red cedar) are their typical representatives. The height of conifers reaches 80 meters. Between them there is practically no woody undergrowth. However, a variety of shrubs grow here in abundance. There are many mosses and ferns in the ground cover. In the coniferous forests, when moving south, sugar pine, white fir, and yellow pine begin to come across. The evergreen sequoia appears even farther south. As dryness increases, south of 42 ° C. sh., thickets of bushes replace forests. They are juniper, heather, and their height usually does not exceed two meters. Here you can sometimes find different types of evergreen oak. Climate humidity in the interior of the Cordillera is decreasing. They are characterized by dry forests, as well as areas of solyanka and wormwood deserts. The mountain slopes receiving rainfall are covered up to 1200 m by evergreen forests.
Animals in the Cordillera Mountains
Where the Cordillera Mountains are located, you can meet the grizzly brown bear - a large predator of the continent of North America. A baribal bear with long black fur lives in the southwest of this system. He exterminates cattle and spoils crops. There are also many lynxes, foxes, wolves. Arthropods, lizards, and snakes are often found in the southern regions of the mountains. In addition, a venomous toad 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 wildlife today.