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89-747: The northeastern part of Colombia is characterized by its wavy plains, called Llanos Orientales , as part of the bigger Llanos that extend into Venezuela. The landscape is similar to a savanna and is poor in trees. It is located between the Eastern Ranges of the Colombian Andes in the west, the Vaupés Arch in the south and the Guiana Shield in the east. Geologically, the Llanos Basin underlies this typical landscape of

178-655: A canopy 8 to 20 meters high, and include Inga spp., Combretum frangulifolium , Gustavia augusta , Pterocarpus sp., Pterocarpus dubius , Spondias mombin , and Copaifera pubiflora . Semi-deciduous forests occur above flood level, and form a canopy 12 to 15 meters high. Common trees include Tabebuia billbergii , Godmania aesculifolia , Cassia moschata , Spondias mombin, Copaifera pubiflora, Bourreria cumanensis , Cordia spp., Bursera simaruba , Cochlospermum vitifolium , Hura crepitans , and Acacia glomerosa . "Matorrales" are deciduous and semi-deciduous shrublands 5 to 8 meters high which cover large areas in

267-535: A hectare. During the rainy season from May to October, parts of the Llanos can flood up to a meter. This turns some savannass and grasslands into temporary wetlands , comparable to the Pantanal of central South America. This flooding also creates habitat for water birds and other wildlife. These seasonally flooded grasslands and savannas, known as llano bajo, typically have richer soils. They are characterized by

356-555: A higher potential for larger, high-magnitude earthquakes in the future. The mountain range is also a source of shallow intraplate earthquakes within the South American Plate. The largest such earthquake (as of 2024) struck Peru in 1947 and measured M s   7.5. In the Peruvian Andes, these earthquakes display normal ( 1946 ), strike-slip (1976), and reverse ( 1969 , 1983) mechanisms. The Amazonian Craton

445-566: A joint ice stream network. The Andes' dendritic glacier arms, components of valley glaciers, were up to 112.5 km (69.9 mi) long and over 1,250 m (4,101 ft) thick, and spanned a vertical distance of 5,150 m (16,896 ft). The climatic glacier snowline (ELA) was lowered from 4,600 m (15,092 ft) to 3,200 m (10,499 ft) at glacial times. The Andean region cuts across several natural and floristic regions, due to its extension, from Caribbean Venezuela to cold, windy, and wet Cape Horn passing through

534-746: A lowland that extends mostly east and west. The Llanos are bounded on the west and northwest by the Andes , and on the north by the Venezuelan Coastal Range . The Guiana Highlands are to the southeast, and the Negro-Branco moist forests are to the southwest. To the east the Orinoco wetlands and Orinoco Delta swamp forests occupy the Orinoco Delta . The Llanos' main river is the Orinoco , which runs from west to east through

623-594: A north–south axis of cultural influences. A long series of cultural development culminated in the expansion of the Inca civilization and Inca Empire in the central Andes during the 15th century. The Incas formed this civilization through imperialistic militarism as well as careful and meticulous governmental management. The government sponsored the construction of aqueducts and roads in addition to pre-existing installations. Some of these constructions still exist today. Devastated by European diseases and by civil war ,

712-711: A series of bends or oroclines . The Bolivian Orocline is a seaward-concave bending in the coast of South America and the Andes Mountains at about 18° S. At this point, the orientation of the Andes turns from northwest in Peru to south in Chile and Argentina . The Andean segments north and south of the Orocline have been rotated 15° counter-clockwise to 20° clockwise respectively. The Bolivian Orocline area overlaps with

801-634: A typical location for calc-alkalic and subduction volcanism, the Andean Volcanic Belt has a large range of volcano-tectonic settings, such as rift systems, extensional zones, transpressional faults , subduction of mid-ocean ridges , and seamount chains apart from a large range of crustal thicknesses and magma ascent paths, and different amount of crustal assimilations. The Andes Mountains host large ore and salt deposits, and some of their eastern fold and thrust belts act as traps for commercially exploitable amounts of hydrocarbons . In

890-536: A whole glacier in the ablation area or in the accumulation area . In the high Andes of Central Chile and Mendoza Province , rock glaciers are larger and more common than glaciers; this is due to the high exposure to solar radiation . In these regions, glaciers occur typically at higher altitudes than rock glaciers. The lowest active rock glaciers occur at 900 m a.s.l. in Aconcagua . Though precipitation increases with height, there are semiarid conditions in

979-780: A zone of volcanic activity that encompasses the Pacific rim of the Americas as well as the Asia-Pacific region. The Andes are the result of tectonic plate processes extending during the Mesozoic and Tertiary eras, caused by the subduction of oceanic crust beneath the South American Plate as the Nazca Plate and South American Plate converge. These processes were accelerated by the effects of climate. As

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1068-561: Is a result of the subduction of the Nazca Plate and Antarctic Plate underneath the South American Plate. The belt is subdivided into four main volcanic zones that are separated from each other by volcanic gaps. The volcanoes of the belt are diverse in terms of activity style, products, and morphology. While some differences can be explained by which volcanic zone a volcano belongs to, there are significant differences inside volcanic zones and even between neighboring volcanoes. Despite being

1157-551: Is actively underthrusted beneath the sub-Andes region of Peru, producing thrust faults. In Colombia, Ecuador, and Peru, thrust faulting occurs along the sub-Andes due in response to compression brought on by subduction, while in the high Andes, normal faulting occurs in response to gravitational forces. In the extreme south, a major transform fault separates Tierra del Fuego from the small Scotia Plate . The Andes range has many active volcanoes distributed in four volcanic zones separated by areas of inactivity. The Andean volcanism

1246-841: Is formed by the foothills ( Piedemonte ) of the Eastern Cordillera Basin , the sedimentary basin covering the Eastern Ranges of the Colombian Andes . The basin is bound to the west by the Eastern Frontal Fault System , a 921.4 kilometres (572.5 mi) long fault system connecting the North Andes and South American Plates and thus the Eastern Cordillera Basin and the Llanos Basin. The fault system has an average strike of 042.1±19, but this orientation varies greatly along its course. The 1827 , 1834 , 1917 , 1967 , 1995 , and 2008 earthquakes were all caused by fault movement as part of

1335-471: Is natural, or the result of clearing which began during the Incan period. Regardless, in modern times , the clearance has accelerated, and the trees are now considered highly endangered , with some believing that as little as 10% of the original woodland remains. The Andes are rich in fauna: With almost 1,000 species, of which roughly 2/3 are endemic to the region, the Andes are the most important region in

1424-1647: Is the largest city of all Andean countries. It is the seat of the Andean Community of Nations . La Paz , Bolivia 's seat of government, is the highest capital city in the world, at an elevation of approximately 3,650 m (11,975 ft). Parts of the La Paz conurbation, including the city of El Alto , extend up to 4,200 m (13,780 ft). Other cities in or near the Andes include Bariloche , Catamarca , Jujuy , Mendoza , Salta , San Juan , Tucumán , and Ushuaia in Argentina; Calama and Rancagua in Chile; Cochabamba , Oruro , Potosí , Sucre , Tarija , and Yacuiba in Bolivia; Arequipa , Cajamarca , Cusco , Huancayo , Huánuco , Huaraz , Juliaca , and Puno in Peru; Ambato , Cuenca , Ibarra , Latacunga , Loja , Riobamba , and Tulcán in Ecuador; Armenia , Cúcuta , Bucaramanga , Duitama , Ibagué , Ipiales , Manizales , Palmira , Pasto , Pereira , Popayán , Sogamoso , Tunja , and Villavicencio in Colombia; and Barquisimeto , La Grita , Mérida , San Cristóbal , Tovar, Trujillo , and Valera in Venezuela. The cities of Caracas , Valencia , and Maracay are in

1513-404: The 2010 Maule earthquake (M8.8), the 2015 Illapel earthquake (M8.2), and the 1960 Valdivia earthquake (M9.5), which as of 2024 was the strongest ever recorded on seismometers. The amount, magnitude, and type of seismic activity varies greatly along the subduction zone. These differences are due to a wide range of factors, including friction between the plates, angle of subduction, buoyancy of

1602-682: The Americas and Antarctica . The etymology of the word Andes has been debated. The majority consensus is that it derives from the Quechua word anti "east" as in Antisuyu (Quechua for "east region"), one of the four regions of the Inca Empire . The term cordillera comes from the Spanish word cordel "rope" and is used as a descriptive name for several contiguous sections of

1691-456: The Andean cock-of-the-rock , while mixed-species flocks dominated by tanagers and furnariids are commonly seen—in contrast to several vocal but typically- cryptic species of wrens , tapaculos , and antpittas . A number of species such as the royal cinclodes and white-browed tit-spinetail are associated with Polylepis , and consequently also threatened . The Andes Mountains form

1780-592: The Caribbean Sea off the coast of Venezuela, were formerly thought to represent the submerged peaks of the extreme northern edge of the Andes range, but ongoing geological studies indicate that such a simplification does not do justice to the complex tectonic boundary between the South American and Caribbean plates . The Andes are an orogenic belt of mountains along the Pacific Ring of Fire ,

1869-535: The Cenozoic . Tectonic forces above the subduction zone along the entire west coast of South America where the Nazca Plate and a part of the Antarctic Plate are sliding beneath the South American Plate continue to produce an ongoing orogenic event resulting in minor to major earthquakes and volcanic eruptions to this day. Many high-magnitude earthquakes have been recorded in the region, such as

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1958-661: The Cesar-Ranchería Basin farther northwest of the Llanos Basin. The units found in the Llanos Basin pertain to the Farallones Group and comprise the Valle del Guatiquía Red Beds , Pipiral Shale and the Gutiérrez Sandstone . The Llanos Basin is the most prolific hydrocarbon basin of Colombia, hosting well-known petroleum deposits as Caño Limón , Rubiales and other fields. Nine of

2047-694: The Tropical Andes , the Dry Andes , and the Wet Andes . The Andes are the highest mountain range which is outside of Asia . The range's highest peak, Argentina's Aconcagua , rises to an elevation of about 6,961 m (22,838 ft) above sea level. The peak of Chimborazo in the Ecuadorian Andes is farther from the Earth's center than any other location on the Earth's surface, due to

2136-506: The Venezuelan Coastal Range , which is a debatable extension of the Andes at the northern extremity of South America. Cities and large towns are connected with asphalt -paved roads, while smaller towns are often connected by dirt roads, which may require a four-wheel-drive vehicle. The rough terrain has historically put the costs of building highways and railroads that cross the Andes out of reach of most neighboring countries, even with modern civil engineering practices. For example,

2225-674: The War of the Pacific between Chile and the allied Bolivia and Peru, in a diplomatic deal to keep Peru out of the war. The Chilean Army and Chilean Navy defeated the combined forces of Bolivia and Peru, and Chile took over Bolivia's only province on the Pacific Coast, some land from Peru that was returned to Peru decades later. Bolivia has been completely landlocked ever since. It mostly uses seaports in eastern Argentina and Uruguay for international trade because its diplomatic relations with Chile have been suspended since 1978. Because of

2314-602: The equatorial bulge resulting from the Earth's rotation . The world's highest volcanoes are in the Andes, including Ojos del Salado on the Chile-Argentina border, which rises to 6,893 m (22,615 ft). The Andes are also part of the American Cordillera , a chain of mountain ranges ( cordillera ) that consists of an almost continuous sequence of mountain ranges that form the western "backbone" of

2403-517: The longest continental mountain range in the world, forming a continuous highland along the western edge of South America . The range is 8,900 km (5,530 mi) long and 200 to 700 km (124 to 435 mi) wide (widest between 18°S and 20°S latitude ) and has an average height of about 4,000 m (13,123 ft). The Andes extend from South to North through seven South American countries: Argentina , Chile , Bolivia , Peru , Ecuador , Colombia , and Venezuela . Along their length,

2492-594: The lowland paca ( Cuniculus paca ), agoutis ( Dasyprocta spp.), and Brazilian porcupine ( Coendou prehensilis ), and large cats like the puma ( Puma concolor ), jaguar ( Panthera onca ), and ocelot ( Leopardus pardalis ). The endangered giant otter ( Pteronura brasiliensis ) lives along the Orinoco and its tributaries. Some of the largest jaguars in the world are found in the Llanos, with average weights of over 100 kg (220 lb) for males. The Llanos long-nosed armadillo ( Dasypus sabanicola ) and

2581-483: The rodent order, inhabit the Andes' alpine regions. The Andean condor , the largest bird of its kind in the Western Hemisphere , occurs throughout much of the Andes but generally in very low densities. Other animals found in the relatively open habitats of the high Andes include the huemul , cougar , foxes in the genus Pseudalopex , and, for birds, certain species of tinamous (notably members of

2670-703: The 1,000-kilometer-wide (620 mi) Drake Passage lie the mountains of the Antarctic Peninsula south of the Scotia Plate , which appear to be a continuation of the Andes chain. The far east regions of the Andes experience a series of changes resulting from the Andean orogeny. Parts of the Sunsás Orogen in Amazonian craton disappeared from the surface of the earth, being overridden by

2759-652: The African grass Melinis minutiflora , and now cover large areas. Agriculture, particularly rice and maize, now cover extensive areas, including rice fields in former seasonal wetlands. In Los Llanos, the governments of Venezuela and Colombia had developed a strong oil and gas industry in the zones of Arauca, Casanare, Guárico, Anzoátegui, Apure and Monagas. The Orinoco Belt , entirely in Venezuelan territory, consists of large deposits of extra heavy crude ( oil sands ). The Orinoco belt oil sands are known to be one of

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2848-469: The Andean peoples are those of the Quechua and Aymara language families. Woodbine Parish and Joseph Barclay Pentland surveyed a large part of the Bolivian Andes from 1826 to 1827. In modern times, the largest cities in the Andes are Bogotá , with a metropolitan population of over ten million, and Santiago , Medellín , Cali , and Quito . Lima is a coastal city adjacent to the Andes and

2937-405: The Andes are tobacco and potatoes . The high-altitude Polylepis forests and woodlands are found in the Andean areas of Colombia , Ecuador , Peru , Bolivia , and Chile . These trees, by locals referred to as Queñua, Yagual, and other names, can be found at altitudes of 4,500 m (14,760 ft) above sea level. It remains unclear if the patchy distribution of these forests and woodlands

3026-510: The Andes are split into several ranges, separated by intermediate depressions . The Andes are the location of several high plateaus —some of which host major cities such as Quito , Bogotá , Cali , Arequipa , Medellín , Bucaramanga , Sucre , Mérida , El Alto , and La Paz . The Altiplano Plateau is the world's second highest after the Tibetan Plateau . These ranges are in turn grouped into three major divisions based on climate:

3115-521: The Andes end at the Pacific Ocean , although the Peru-Chile trench can be considered their ultimate western limit. From a geographical approach, the Andes are considered to have their western boundaries marked by the appearance of coastal lowlands and less-rugged topography. The Andes also contain large quantities of iron ore located in many mountains within the range. The Andean orogen has

3204-462: The Andes such as the Incas have practiced irrigation techniques for over 6,000 years. Because of the mountain slopes, terracing has been a common practice. Terracing, however, was only extensively employed after Incan imperial expansions to fuel their expanding realm. The potato holds a very important role as an internally-consumed staple crop. Maize was also an important crop for these people, and

3293-526: The Andes varies greatly depending on latitude, altitude, and proximity to the sea. Temperature, atmospheric pressure, and humidity decrease in higher elevations. The southern section is rainy and cool, while the central section is dry. The northern Andes are typically rainy and warm, with an average temperature of 18 °C (64 °F) in Colombia . The climate is known to change drastically in rather short distances. Rainforests exist just kilometers away from

3382-542: The Andes, as well as the entire Andean range, and the combined mountain chain along the western part of the North and South American continents. The Andes can be divided into three sections: At the northern end of the Andes, the separate Sierra Nevada de Santa Marta range is often, but not always, treated as part of the Northern Andes. The Leeward Antilles islands Aruba , Bonaire , and Curaçao , which lie in

3471-524: The Andes. The Sierras de Córdoba , where the effects of the ancient Pampean orogeny can be observed, owe their modern uplift and relief to the Andean orogeny in the Tertiary . Further south in southern Patagonia , the onset of the Andean orogeny caused the Magallanes Basin to evolve from being an extensional back-arc basin in the Mesozoic to being a compressional foreland basin in

3560-491: The Incas were defeated in 1532 by an alliance composed of tens of thousands of allies from nations they had subjugated (e.g. Huancas , Chachapoyas , Cañaris ) and a small army of 180 Spaniards led by Francisco Pizarro . One of the few Inca sites the Spanish never found in their conquest was Machu Picchu , which lay hidden on a peak on the eastern edge of the Andes where they descend to the Amazon. The main surviving languages of

3649-518: The Llanos Basin are: Mining activities in the Llanos Basin are restricted to certain areas, resulting in less conflicts, more common with indigenous peoples in the Amazonian part of Colombia. In San José del Guaviare platinum is mined. Compared to many fossiliferous formations in Colombia, the Llanos Basin has been lean in fossil content. Most of the basin stratigraphy is only known from wells. Paleozoic outcrops surrounding and perforating

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3738-429: The Llanos Basin has provided many fossil flora. Llanos The Llanos ( Spanish Los Llanos , "The Plains"; Spanish pronunciation: [los ˈʝanos] ) is a vast tropical grassland plain situated to the east of the Andes in Colombia and Venezuela , in northwestern South America. It is an ecoregion of the tropical and subtropical grasslands, savannas, and shrublands biome . The Llanos occupy

3827-476: The Llanos Basin ranges, depending on the definition from either Jurassic or Paleozoic to recent. The basement is formed by the westernmost extensions of the Guiana Shield . Remnants of these Precambrian formations are found as inselbergs in the far east of Colombia ( Cerros de Mavecure ), in the Serranía de la Macarena to the southwest of the basin and in the tepuis of the Serranía de Chiribiquete to

3916-720: The Llanos Basin. During the Andean orogenic phase, the paleotemperatures in the basin dropped considerably; in the Baja Guajira area from 115 °C (239 °F) in the Early Miocene to 70 °C (158 °F) in the Late Miocene. In the Late Miocene to Pliocene, the major faults to the southwest of the Cocinetas Basin, the Oca and Bucaramanga-Santa Marta Faults were tectonically active. The stratigraphy of

4005-566: The Llanos. An area where transport occurs mostly by small boats along the many rivers and the "buses of the Llanos", the Douglas DC-3 planes. The basin covers an area of 96,000 square kilometres (37,000 sq mi) and contains a stratigraphic column from the Paleozoic to recent. Several of the formations in the basins are source rocks ( Gachetá , Los Cuervos , Carbonera C8 ), reservoir rocks ( Mirador , Barco , Guadalupe and

4094-478: The Patagonian Orocline. The western rim of the South American Plate has been the place of several pre-Andean orogenies since at least the late Proterozoic and early Paleozoic , when several terranes and microcontinents collided and amalgamated with the ancient cratons of eastern South America, by then the South American part of Gondwana . The formation of the modern Andes began with

4183-520: The Venezuelan llanos, and is also widespread in the Colombian llanos. Grasses of genus Trachypogon are predominant, and species include Trachypogon plumosus , T. vestitus , Axonopus canescens , A. anceps , Andropogon selloanus , Aristida spp., Leptocoryphium lanatum , Paspalum carinatum , Sporobolus indicus , and S. cubensis , and sedges in the genera Rhynchospora and Bulbostylis . Shrubs and herbs are most commonly legumes in

4272-592: The area of the maximum width of the Altiplano Plateau , and according to Isacks (1988) the Orocline is related to crustal shortening . The specific point at 18° S where the coastline bends is known as the Arica Elbow. Further south lies the Maipo Orocline, a more subtle orocline between 30° S and 38°S with a seaward-concave break in the trend at 33° S. Near the southern tip of the Andes lies

4361-427: The border with Venezuela. Major concerns in the basin for the production of petroleum are biodegradation , hydrocarbon migration , fault seal capacity and water flow. The Llanos Basin is crossed by numerous rivers, all belonging to the Orinoco watershed . From north to south: Among other species, Lynch's swamp frog ( Pseudopaludicola llanera ) is endemic to the Llanos, with the species epithet referring to

4450-1108: The central Venezuelan llanos, and may be a form of secondary vegetation in areas that were formerly dry deciduous forest. Typical shrubs are Bourreria cumanensis , Randia aculeata , Godmania aesculifolia , Pereskia guamacho , Prosopis spp., Xylosma benthamii , Erytroxylum sp., and Cereus hexagonus . Mammals of the grassland and savanna include white-tailed deer ( Odocoileus virginianus ), giant anteater ( Myrmecophaga tridactyla ), capybara ( Hydrochoerus hydrochaeris ), giant armadillo ( Priodontes maximus ), Eastern cottontail ( Sylvilagus floridanus ), Alston's cotton rat ( Sigmodon alstoni ), Hispid cotton rat ( S. hispidus ), Zygodontomys brevicauda , and Oecomys bicolor . The gallery forests are home to more diverse large and medium-sized mammals, including collared peccary ( Tayassu tajacu ), white-lipped peccary ( T. pecari ), South American tapir ( Tapirus terrestris ), white-tailed deer, red brocket ( Mazama americana ), wedge-capped capuchin ( Cebus olivaceus ), Venezuelan red howler ( Alouatta seniculus ), large rodents like

4539-428: The cowhands that took care of the herds, and had some cultural similarities with the gauchos of the Pampas or the vaqueros of Spanish and Mexican Texas . Decades of extensive cattle raising has altered the ecology of the Llanos. Grasslands and savannas are frequently burned to make them more suitable for grazing and eliminate trees and shrubs. Non-native grasses have been introduced for cattle fodder, including

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4628-399: The dry climate that reduced the disturbing actions of meteoric water . The dry climate in the central western Andes has also led to the creation of extensive saltpeter deposits which were extensively mined until the invention of synthetic nitrates . Yet another result of the dry climate are the salars of Atacama and Uyuni , the former being the largest source of lithium and the latter

4717-478: The dry season (winter) possible and allows the cultivation of frost-resistant vegetable crops like onion and carrot . The Andes rose to fame for their mineral wealth during the Spanish conquest of South America . Although Andean Amerindian peoples crafted ceremonial jewelry of gold and other metals, the mineralizations of the Andes were first mined on a large scale after the Spanish arrival. Potosí in present-day Bolivia and Cerro de Pasco in Peru were among

4806-436: The ecoregion and forms part of the border between Colombia and Venezuela. The Orinoco is the major river system of Venezuela. The ecoregion has a tropical savanna climate that grades into a tropical monsoon climate in the Colombian Llanos. Rainfall is highly seasonal, with a rainy season from April to November, and a dry season between December and March. The wettest months are typically June and July. Rainfall varies across

4895-477: The ecoregion's wetlands. Indigenous peoples of the Llanos include the Guahibo in the western Llanos of Colombia and Venezuela, and the Yaruro in the eastern Llanos in Venezuela. The primary economic activity in the Llanos since the Spanish colonial era is the herding of millions of cattle. An 1856 watercolor by Manuel María Paz depicts sparsely populated open grazing lands with cattle and palm trees. The term llanero ("plainsman") became synonymous with

4984-494: The ecoregion, from up to 3,000 millimetres (120 in) per year in the southwest, 1,200 to 1,600 millimetres (47 to 63 in) in Apure State, and 800 to 1,200 millimetres (31 to 47 in) per year in the Llanos of Monagas State in the northeast. Mean annual temperature is 27 °C or 80.6 °F, and the average monthly temperature varies little throughout the year; the lowest-temperature months (June, July, December, and January) are only 2 °C or 3.6 °F cooler than

5073-501: The establishment of the century-long Inca Empire . This all changed in the 16th century, when the Spanish conquistadors colonized the mountains in advance of the mining economy. In the tide of anti-imperialist nationalism, the Andes became the scene of a series of independence wars in the 19th century, when rebel forces swept through the region to overthrow Spanish colonial rule. Since then, many former Spanish territories have become five independent Andean states. The climate in

5162-519: The events of the Triassic , when Pangaea began the breakup that resulted in developing several rifts . The development continued through the Jurassic Period. It was during the Cretaceous Period that the Andes began to take their present form, by the uplifting , faulting , and folding of sedimentary and metamorphic rocks of the ancient cratons to the east. The rise of the Andes has not been constant, as different regions have had different degrees of tectonic stress, uplift, and erosion . Across

5251-423: The extreme in the slopes near the virtually-lifeless Atacama Desert. About 30,000 species of vascular plants live in the Andes, with roughly half being endemic to the region, surpassing the diversity of any other hotspot . The small tree Cinchona pubescens , a source of quinine which is used to treat malaria , is found widely in the Andes as far south as Bolivia. Other important crops that originated from

5340-401: The forelands of the Atacama Desert , some of the largest porphyry copper mineralizations occur, making Chile and Peru the first- and second-largest exporters of copper in the world. Porphyry copper in the western slopes of the Andes has been generated by hydrothermal fluids (mostly water) during the cooling of plutons or volcanic systems. The porphyry mineralization further benefited from

5429-417: The genera Mimosa , Cassia , Desmodium , Eriosema , Galactia , Indigofera , Phaseolus , Stylosanthes , Tephrosia , and Zornia . The trees manteco ( Byrsonima crassifolia ), chaparro ( Curatella americana ), and alcornoque ( Bowdichia virgilioides ) are the most common, growing either as scattered trees or in woodland patches known as matas which range in area from 12 meters in diameter up to

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5518-555: The genus Nothoprocta ), Andean goose , giant coot , flamingos (mainly associated with hypersaline lakes), lesser rhea , Andean flicker , diademed sandpiper-plover , miners , sierra-finches and diuca-finches . Lake Titicaca hosts several endemics, among them the highly endangered Titicaca flightless grebe and Titicaca water frog . A few species of hummingbirds , notably some hillstars , can be seen at altitudes above 4,000 m (13,100 ft), but far higher diversities can be found at lower altitudes, especially in

5607-447: The glaciers were over ten times longer. On the east side of this section of the Mendozina Andes, they flowed down to 2,060 m (6,759 ft) and on the west side to about 1,220 m (4,003 ft) above sea level. The massifs of Aconcagua (6,961 m (22,838 ft)), Tupungato (6,550 m (21,490 ft)), and Nevado Juncal (6,110 m (20,046 ft)) are tens of kilometres away from each other and were connected by

5696-425: The grass Paspalum fasciculatum . Trees include the palm Copernicia tectorum and gallery forest species. Gallery forests include evergreen seasonally flooded forests, and semi-deciduous forests on higher ground. Morichales are seasonally flooded forests characterized by the moriche palm ( Mauritia flexuosa ). Vegas are seasonally flooded evergreen forests found along the Orinoco and its tributaries. Trees form

5785-599: The hottest months. The plant communities in the Llanos include open grasslands, savannas with scattered trees or clumps of trees, and small areas of forest, typically gallery forests along rivers and streams. There are seasonally flooded grasslands and savannas ( llano bajo ) and grasslands and savannas that remain dry throughout the year ( llano alto ). The llano alto grasslands and savannas are characterized by grasses and shrubs 30–100 cm high, forming tussocks 10 to 30 cm apart. Soils are typically sandy and nutrient-poor. Llano alto covers approximately two-thirds of

5874-453: The humid Andean forests (" cloud forests ") growing on slopes in Colombia, Ecuador, Peru, Bolivia, and far northwestern Argentina. These forest-types, which includes the Yungas and parts of the Chocó, are very rich in flora and fauna, although few large mammals exist, exceptions being the threatened mountain tapir , spectacled bear , and yellow-tailed woolly monkey . Birds of humid Andean forests include mountain toucans , quetzals , and

5963-467: The hyperarid Atacama Desert . Rainforests and tropical dry forests used to encircle much of the northern Andes but are now greatly diminished , especially in the Chocó and inter-Andean valleys of Colombia. Opposite the humid Andean slopes are the relatively dry Andean slopes in most of western Peru, Chile, and Argentina. Along with several Interandean Valles , they are typically dominated by deciduous woodland, shrub and xeric vegetation, reaching

6052-439: The larger glaciers descend to sea level. The Andes of Chile and Argentina can be divided into two climatic and glaciological zones: the Dry Andes and the Wet Andes . Since the Dry Andes extend from the latitudes of the Atacama Desert to the area of the Maule River , precipitation is more sporadic, and there are strong temperature oscillations. The line of equilibrium may shift drastically over short periods of time, leaving

6141-1016: The largest, behind that of the Athabasca Oil Sands in Alberta , Canada. Venezuela's non-conventional oil deposits of about 1,200 billion barrels (1.9 × 10  m ), found primarily in the Orinoco oil sands, are estimated to approximately equal the world's reserves of conventional oil. A 2017 assessment found that 105,323 km², or 28%, of the ecoregion, is in protected areas. Protected areas include Aguaro-Guariquito National Park (5,857.5 km²), Cinaruco-Capanaparo National Park (5,843.68 km²), Tortuga Arrau Reserve (98.56 km²), and Caño Guaritico Wildlife Refuge (93.0 km²) in Venezuela, and El Tuparro National Natural Park (5,549.08 km²) in Colombia. 6°49′23.2″N 67°38′57.4″W  /  6.823111°N 67.649278°W  / 6.823111; -67.649278 Andes The Andes ( / ˈ æ n d iː z / AN -deez ), Andes Mountains or Andean Mountain Range ( Spanish : Cordillera de los Andes ; Quechua : Anti ) are

6230-432: The main crossover of the Andes between Argentina and Chile is still accomplished through the Paso Internacional Los Libertadores . Only recently have the ends of some highways that came rather close to one another from the east and the west been connected. Much of the transportation of passengers is done via aircraft. However, there is one railroad that connects Chile with Peru via the Andes, and there are others that make

6319-445: The nearly-7,000-metre (22,966 ft) highest mountains of the Andes. This dry steppe climate is considered to be typical of the subtropical position at 32–34° S. The valley bottoms have no woods, just dwarf scrub. The largest glaciers, for example the Plomo Glacier and the Horcones Glaciers, do not even reach 10 km (6.2 mi) in length and have only insignificant ice thickness. At glacial times, however, c. 20,000 years ago,

6408-479: The plains. Also the whip scorpion Mastigoproctus colombianus is reported from the Llanos Basin. The country of Colombia spreads out over six tectonic plates , clockwise from north: The Llanos Basin is situated entirely on the South American Plate , bordering the North Andean Block or North Andean microplate in the west. The basin is one of three Colombian basins on the South American Plate, to

6497-723: The planar geography have provided fossils dating back to the Cambrian ; the Duda and Ariarí Formations . Several fossiliferous formations of contemporaneous depositional environments have provided many unique fossils indicative of paleoclimatic conditions; turtle fossils were described from Los Cuervos in the Cesar-Ranchería Basin, and the Mirador Formation in the Catatumbo Basin direct northwest of

6586-402: The rainy season (summer), part of the rangeland is used for cropping (mainly potatoes, barley, broad beans, and wheat). Irrigation is helpful in advancing the sowing data of the summer crops, which guarantees an early yield in periods of food shortage. Also, by early sowing, maize can be cultivated higher up in the mountains (up to 3,800 m (12,500 ft)). In addition, it makes cropping in

6675-460: The same connection via southern Bolivia. There are multiple highways in Bolivia that cross the Andes. Some of these were built during a period of war between Bolivia and Paraguay , in order to transport Bolivian troops and their supplies to the war front in the lowlands of southeastern Bolivia and western Paraguay. For decades, Chile claimed ownership of land on the eastern side of the Andes. However, these claims were given up in about 1870 during

6764-550: The short-tailed opossum Monodelphis orinoci are endemic to the Llanos. The Llanos' wetlands supports around 70 species of water birds , including the scarlet ibis . A large portion of the distribution of the sharp-tailed ibis ( Cercibis oxycerca ) and white-bearded flycatcher ( Phelpsia inornata ) is in the Llanos. Native reptiles include the Orinoco crocodile ( Crocodylus intermedius ), spectacled caiman ( Caiman crocodilus ), Green anaconda ( Eunectes murinus ), and Arrau turtle ( Podocnemis expansa ), which live in

6853-721: The snow-covered peak of Cotopaxi . The mountains have a large effect on the temperatures of nearby areas. The snow line depends on the location. It is between 4,500 and 4,800 m (14,764 and 15,748 ft) in the tropical Ecuadorian, Colombian, Venezuelan, and northern Peruvian Andes, rising to 4,800–5,200 m (15,748–17,060 ft) in the drier mountains of southern Peru and northern Chile south to about 30°S before descending to 4,500 m (14,760 ft) on Aconcagua at 32°S , 2,000 m (6,600 ft) at 40°S , 500 m (1,640 ft) at 50°S , and only 300 m (980 ft) in Tierra del Fuego at 55°S ; from 50°S, several of

6942-751: The south the Caguán-Putumayo Basin and to the southeast the Vaupés-Amazonas Basin . The northern boundary of the Llanos Basin is formed by the Colombia-Venezuela border where the basin grades into the Barinas-Apure Basin on the Venezuelan side. The Catatumbo Basin , representing the Colombian portion of the larger Maracaibo Basin borders the Llanos Basin in the northwest and the western boundary

7031-606: The southeast. The Proterozoic crystalline rocks are overlain by metamorphosed sedimentary and igneous rocks ranging in age from Cambrian to Devonian . Younger and contemporaneous Paleozoic deposits are only found in the subsurface and in regional correlative units as the Floresta and Cuche Formations of the Altiplano Cundiboyacense to the direct northwest and the Río Cachirí Group of

7120-526: The subducting plate, rate of subduction, and hydration value of the mantle material. The highest rate of seismic activity is observed in the central portion of the boundary, between 33°S and 35°S. In this area, the angle of subduction is very low, meaning the subducting plate is nearly horizontal. Studies of mantle hydration across the subduction zone have shown a correlation between increased material hydration and lower-magnitude, more-frequent seismic activity. Zones exhibiting dehydration instead are thought to have

7209-637: The subduction of the Nazca Plate and the Antarctic Plate . To the east, the Andes range is bounded by several sedimentary basins , such as the Orinoco Basin , the Amazon Basin , the Madre de Dios Basin, and the Gran Chaco , that separate the Andes from the ancient cratons in eastern South America. In the south, the Andes share a long boundary with the former Patagonia Terrane . To the west,

7298-556: The system. The tectonic history of the Llanos Basin, a foreland basin formed on top of Mesozoic rift basins , Paleozoic metasediments and Precambrian basement underlain by continental crust , goes back to the Early Jurassic . The Andean orogeny , represented by the tectonic uplift of the Colombian Eastern Ranges and its northern extension, the Serranía del Perijá , caused tilting and uplift in

7387-452: The tortuous terrain in places, villages and towns in the mountains—to which travel via motorized vehicles is of little use—are still located in the high Andes of Chile, Bolivia, Peru, and Ecuador . Locally, the relatives of the camel , the llama , and the alpaca continue to carry out important uses as pack animals, but this use has generally diminished in modern times. Donkeys , mules , and horses are also useful. The ancient peoples of

7476-539: The twenty most producing oil fields of Colombia are situated in the Llanos Basin. Based on data released in March 2018, Colombia is the 21st oil producer in the world. Daily production dropped in 2017 to 854.121 thousand barrels per day (135.7944 × 10 ^  m/d). In 2016, twenty oilfields produced 66% of all oil of Colombia, listed below in bold. The total proven reserves of Colombia were 1,665.489 million barrels (264.7916 × 10 ^  m) in 2016. Major oil fields in

7565-510: The uneven numbered members of Carbonera). Seals are formed by the shaly intervals (even numbered) of the Carbonera Formation, Los Cuervos, and León . The basin is the main petroleum producing basin of Colombia, with four of the nations biggest oil fields located in the Llanos Basin. Major fields are Rubiales , Colombia's biggest and most recent giant discovery sealed by a complex of hydrodynamic processes , and Caño Limón , at

7654-477: The uplift of the Andes created a rain shadow on the western fringes of Chile, ocean currents and prevailing winds carried moisture away from the Chilean coast. This caused some areas of the subduction zone to be sediment-starved, causing excess friction and an increased rate of compressed coastal uplift. The main cause of the rise of the Andes is the compression of the western rim of the South American Plate due to

7743-642: The world for amphibians . The diversity of animals in the Andes is high, with almost 600 species of mammals (13% endemic), more than 1,700 species of birds (about 1/3 endemic), more than 600 species of reptiles (about 45% endemic), and almost 400 species of fish (about 1/3 endemic). The vicuña and guanaco can be found living in the Altiplano , while the closely related domesticated llama and alpaca are widely kept by locals as pack animals and for their meat and wool . The crepuscular (active during dawn and dusk) chinchillas , two threatened members of

7832-470: The world's largest reserve of the element. Early Mesozoic and Neogene plutonism in Bolivia's Cordillera Central created the Bolivian tin belt as well as the famous, now-mostly-depleted, deposits of Cerro Rico de Potosí . The Andes Mountains, initially inhabited by hunter-gatherers , experienced the development of agriculture and the rise of politically centralized civilizations , which culminated in

7921-408: Was used for the production of chicha , important to Andean native people. Currently, tobacco , cotton , and coffee are the main export crops. Coca , despite eradication programs in some countries, remains an important crop for legal local use in a mildly stimulating herbal tea , and illegally for the production of cocaine . In unirrigated land, pasture is the most common type of land use. In

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