Geography of South America
According to Countryaah, as of 2021, there are a total of twelve countries in South America. Along the west side of South America rises the Andes, a continuation south of the Cordillarians in North America. Like these, the Andes consist of a complex of several parallel chains which in some places are joined together in solid. The chains reach an average of 4,000–5,000 m above sea level. Of the peaks, Aconcagua (6,962 m above sea level) is highest. The chains are separated by valleys such as the valley of the Magdalena River in the north and the large north-southbound central valley in Chile or by high plateaus such as Altiplano (southeastern Peru and western Bolivia) with South America’s largest lake Titicaca (3,812 m above sea level). Large salt lakes occur on the plateaus. The largest is Salar de Uyuni, about 9 000 km2. Volcanoes are common except in the far south, and many are active. Earthquakes often occur and cause large breeds and landslides in the steep terrain. Glaciers and glacial erosion forms the highest parts of the Andes. In the south, glaciers reach all the way down to the sea. The west side of the southern Andes is characterized by fjord coast and archipelagos. On the west side of the central Andes lies the Atacama Desert.
In northern South America, the highlands of Guyana reach almost 3,000 meters above sea level. in the central part and 3 014 meters above sea level. in Pico da Neblina in the southwest. The highland, which is an urban area, otherwise consists of a series of low mountains (below 1,000 m above sea level) with wooded lowlands in between. As in the Brazilian highlands, which is also an urban area, plains with single domed inselbergs are common. The Brazilian Highlands is highest in the east and south-east and reaches almost 3,000 m above sea level in Serra do Mar. Steep slopes reach all the way to the coast, for example. Rio de Janeiro. In the south, the paranabalas form plateaus at different levels. There are several waterfalls in the area, e.g. in the river Iguaçú. Sloping layers of sedimentary rocks form cuestic landscapes within the highlands. The drainage mainly takes place against the Paraguay – Paraná lowlands and the Amazon basin; The São Francisco River in a deep cut valley in the Northeast is an exception.
Between the highlands, the Amazon basin is spreading, mostly below 200 m above sea level. Alluvial material forms a pleasant terrain. Orinoco’s lowland between the Andes and the Guyanese highlands is a rolling plain, made up of alluvial material. It rarely reaches over 300 meters above sea level. and is an offshoot of the Amazon basin. Paraguay-Paranás lowlands start in the north in the flat Pantanal, during the rainy season a swamp, and turn south in Pampas, a plain which, however, rises from about 20 m above sea level. at Buenos Aires to 500 m asl. at the Andes. Patagonia, farthest to the south, consists of a series of plateaus that rise from east to west to about 1,000 m above sea level. at the Andes.
|Countries||Important rivers||Largest lake|
|Argentina||Salado del Norte, Paraná, Bermejo-Desaguadero-Salado, Uruguya, Colorado, Rio Negro||Argentino, Viedma|
|Bolivia||Mamoré, Beni||Lake Titicaca|
|Brazil||Amazon River, Paraná, Sâo Francisco||Patos, Mirim, Mangueira, Araruma|
|Ecuador||Napo, Bobonazo, Guayas||Lake San Pablo|
|Paraguay||Paraná, Paraguay, Pilcomayo||Ypoa|
|Peru||Ucayali, Marañón||Lake Titicaca|
|Suriname||Suriname||van Blommestein lake|
|Uruguay||Río Negro, Río Uruguay||Embalse del Río Negro (artificial)|
|Venezuela||Orinoco River||Lake Maracaibo, Lake Valencia|
Soil and soils
Three different types of geological regions can be discerned in South America’s bedrock: cratons ; ancient continent parts that have been relatively stable and not exposed to mountain range formation or extensive deformation since Proterozoic (more than 570 million years ago); sedimentation pools, i.e. depressions or streams in the earth’s crust where thick deposits of sediment have been deposited and a complex of parallel mountain ranges, the Andes, along the west coast. Volcanic activity during Jurassic and Cretaceous (about 208–65 million years before today) has resulted in extensive plateau base salts, e.g. the up to 1,800 m thick paranabal salts in Brazil.
South America has mainly been built around the Guyanese shield and the Brazilian shield, which form the bedrock in much of Brazil and northeastern South America. These bedrock shields consist of rocks formed during the Precambrian (older than about 570 million years), mainly granites, gneisses, mica slates and green stones. The shields have arisen through at least five mountain range formations (orogenesis), with new crustaceans being gradually added to the continent. The oldest known mountain range formation occurred during the archaeological period, over 3,000 million years ago. The youngest mountain range formation took place from the end of the Precambrian (to the beginning of Ordovician (about 700-480 million years ago)) and particularly affected the eastern part of the Brazilian shield. The mountain chains (orogens) that build up the shields are today degraded.
In many areas, the shields are covered by flat sedimentary rocks from Ordovician to Tertiary (about 470–2 million years before today). These rocks build up so-called platforms, which together with the shields form cratons. The thickest bearing sequences have been deposited in sedimentation basins formed by vertical movements in the earth’s crust, often for a very long time. Larger pools include the Amazon Basin, the Paranaíba Basin and the Paraná Basin. From carbon to the end of the Triassic (about 363–208 million years ago), so-called gondola deposits were deposited, which are dominated by continental sandstones and shales. Gondwan inventory sequences are found in Brazil, Paraguay, Uruguay and Argentina. They can be rich in fossil vertebrates and plants, e.g. genus Glossopteris. The lower parts of the gondola storage sequences often contain glacial deposits, e.g. trust, from carbon (about 363-290 million years before today). The spread of these glacial deposits shows that icings covered the southeastern parts of South America (including the Falkland Islands) during this period. Traces of icing have also been found in silur (about 439-409 million years before today).
During the Paleozoic period (about 570–245 million years ago), the western continent border followed approximately the eastern edge of the Andes. Westwards, thousands of meters of thick warehouses were set aside. Through continental movements, mountain range formation and fusion with microcontinents, South America expanded to the west. One of the microcontinents that was annexed to South America in the Middle to Younger Paleozoic (about 430–370 million years ago) is Patagonia.
For many million years, South America belonged to the giant continent Gondwana. During the Jurassic period (about 208–146 million years before today), Gondwana began to split, but it was only during Cretaceous (about 146–65 million years before present) that the South Atlantic was formed when Africa separated from South America. Through the movement westwards, South America collided with the seabed, the Nazca plate, in the west. From the compressed material, continental crust was now created in the form of a mountain chain system, the Andes, along the west side of the continent. The Andes have been in formation for more than 600 million years, but the real and not yet completed development of the mountain range complex began during the Alpine orogenesis about 200 million years ago. Weathering products from the Andes have given rise to large amounts of sediment deposited east of the mountain range.
South America has significant assets of almost all metals. In the urban areas there are iron, manganese, tungsten, titanium, gold, lead and zinc ores. The Carajás Mountains (Brazil) are thought to have the world’s largest iron ore reserve, about 18 billion tonnes of 66 percent ore, along with large deposits of copper, manganese, nickel, gold and bauxite. Significant bauxite resources are also found in Guyana and Suriname. In the Andes, besides alloy metals, tin, gold and silver, there are very large reserves of porphyry copper. Chile and Peru together have about 25% of the world’s copper reserves. Gold is found as wash basins in several areas of the Amazon basin. Similarly, there is tin in Rondônia in Brazil.
Of non-metals, there are larger resources of phosphate, nitrate, mainly Chilean salts, and salt in South America’s dry areas.
According to Abbreviationfinder, energy resources are dominated by oil (Venezuela, the Amazon lowlands in Colombia, Ecuador and Peru and Argentina). Larger reserves of natural gas are found in Venezuela and Argentina. Oil sands occur in Venezuela. South America has comparatively small assets of coal (Colombia, Brazil). The known uranium resources are also small, only about 5% of the world (Brazil, Peru and Argentina). Hydropower potential is great, especially in the tributaries of the Amazon River from the Brazilian highlands. The world’s largest hydropower plant Itaipú (12,870 MW) is located in the Paraná River, which flows south from the Brazilian highlands.
The freshwater is insufficient in both South America’s dry areas and in most metropolitan regions, where pollution is also a major problem. The tropical rainforest, together with savannas (mainly Brazil) and temperate grasslands (Argentina), are the most economically important but partially over-exploited natural vegetation types. The previously extensive araucaria forests (which give the wood species parana pine) are largely cut away. The temperate forests in southern Chile are being harvested at a rapid rate. In the Amazon lowlands, the northwest and forests of Guyana are largely untouched. Otherwise, the rainforests are being degraded to provide space for primarily settler agriculture and livestock farming (meat animals) alongside large logging for firewood, timber and pulp. The temperate grasslands (Pampas) have been transformed into agricultural and livestock areas. Loose soil here forms the basis for the cultivated soil. Most of South America’s cultivated soils are otherwise weathering soils that form the basis for meager lateritic soils. Laterite crusts are common as a result of soil degradation in areas with lateritic soils. In the Andes, the often good alluvial soils are important. South America has among the world’s most economically important but over-exploited fishing waters off Peru and Chile.