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51-485: The Nevadaplano was a high plateau that is proposed to have covered parts of southwestern North America during the late Mesozoic and early Cenozoic , located in the present-day US states of Idaho , Nevada , Utah and possibly others. It most likely formed during the Cretaceous as a consequence of subduction dynamics and may have reached elevations of 3 kilometres (9,800 ft) and more, although its elevation

102-612: A sialic composition and reached thicknesses of 45–65 kilometres (28–40 mi). It consisted of metamorphic rocks that are now exposed as metamorphic core complexes such as in the Pequop Mountains of Nevada, as well as plutonic rocks including batholiths . Based on the fossils found in the Sheep Pass Formation , the Nevadaplano likely had a cold high-elevation climate. Located in the rain shadow of

153-645: A collapse and dismemberment of the Nevadaplano. Tectonic extension gave rise to the Basin and Range province and separated the Sierra Nevada-Great Valley block from the Nevadaplano, forming today's landscape. The existence of the Nevadaplano was proposed in 2004 by DeCelles and named after the Altiplano high plateau of South America. It is also known as the "Great Basin Altiplano". Unlike

204-553: A river was already there, though not necessarily on exactly the same course. Then, subterranean geological forces caused the land in that part of North America to gradually rise by about a centimeter per year for millions of years. An unusual balance occurred: the river that would become the Colorado River was able to erode into the crust of the Earth at a nearly equal rate to the uplift of the plateau. Now, millions of years later,

255-525: Is controversial. It was flanked on the west by the Sierra Nevada , which was traversed by various valleys that came down from the Nevadaplano. Closed basins and numerous volcanic calderas covered the relatively flat Nevadaplano; large volcanic eruptions distributed ignimbrites over the plateau and down the valleys draining it. During the Miocene , changes in the tectonic regime may have caused

306-566: Is divided into three main flat regions: the Bogotá savanna , the valleys of Ubaté and Chiquinquirá , and the valleys of Duitama and Sogamoso . The parallel Sierra of Andes delimit one of the world highest plateaux: the Altiplano , (Spanish for "high plain"), Andean Plateau or Bolivian Plateau. It lies in west-central South America, where the Andes are at their widest, is the most extensive area of high plateau on Earth outside of Tibet. The bulk of

357-422: Is present-day central Idaho in the north either to Sonora or southern Nevada in the south. It was a high plateau consisting of a peneplain and reached a width of 400–500 kilometres (250–310 mi). Isotope analysis indicates that the Nevadaplano stood at high elevations, probably higher than or comparable to the then- Sierra Nevada . The elevation of the Nevadaplano exceeded 3 kilometres (1.9 mi), but

408-663: Is present-day north-central Idaho to present-day Oregon and northern California, the Idaho River also from present-day north-central Idaho to the Green River basin and the California River from present-day southernmost California to the Uinta Basin. The northernmost among these rivers may have formed the northern boundary of the Nevadaplano. Some normal faulting took place within the Nevadaplano, along with

459-710: Is sometimes called the Roof of Africa due to its height and large area. Another example is the Highveld which is the portion of the South African inland plateau which has an altitude above approximately 1,500 metres, but below 2,100 metres, thus excluding the Lesotho mountain regions. It is home to some of the largest South African urban agglomerations . In Egypt are the Giza Plateau and Galala Mountain , which

510-545: Is the Scottish Highlands . Plateaus are classified according to their surrounding environment. The highest African plateau is the Ethiopian Highlands which cover the central part of Ethiopia. It forms the largest continuous area of its altitude in the continent, with little of its surface falling below 1,500 metres (4,921 ft), while the summits reach heights of up to 4,550 metres (14,928 ft). It

561-572: Is the home of more than 70 million people. The Western Plateau , part of the Australian Shield , is an ancient craton covering much of the continent's southwest, an area of some 700,000 square kilometres. It has an average elevation between 305 and 460 metres. The North Island Volcanic Plateau is an area of high land occupying much of the centre of the North Island of New Zealand, with volcanoes, lava plateaus, and crater lakes,

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612-895: The Deccan Plateau (≈1,900,000 km (730,000 sq mi), elevation 300–600 metres (980–1,970 ft)). A large plateau in North America is the Colorado Plateau , which covers about 337,000 km (130,000 sq mi) in Colorado , Arizona , New Mexico , and Utah . In northern Arizona and southern Utah the Colorado Plateau is bisected by the Colorado River and the Grand Canyon . This came to be over 10 million years ago,

663-727: The Laramide uplands, the Chusca erg or the Sevier fold-and-thrust belt were located east of the Nevadaplano. The boundary was located at a region corresponding to the present-day Wasatch , Santaquin and Canyon Ranges. A relatively short distance may have separated it there from the Western Interior Seaway . The region of what today is northern Nevada during the Oligocene may have been a gently tilted or closed plateau. To

714-546: The Middle Eocene in Colorado and Utah . An enormous gap (36.2 million years) in the fossil record occurs from the Late Eocene to Early Pleistocene . They can be taken by many fishing methods, including angling and gigging . Often, species such as Catostomus commersonii and Hypentelium nigricans are preferred for eating. They can be canned, smoked, or fried, but small incisions often must be made in

765-602: The Mogollon Highlands in the south through the Kingman Uplift into the Nevadaplano. There is some uncertainty in the drainage directions across the Nevadaplano, with some evidence interpreted as indicating that drainage divides shifted over time and that the divide between Nevada and Idaho was offset along a Neoproterozoic lineament. Among the reconstructed drainages are the Tyee and Princeton Rivers from what

816-494: The Ozarks they are a common food fish and a festival is held each year to celebrate them. The bigmouth buffalo, Ictiobus cyprinellus , can reach an age up to 127 years, making it the oldest known freshwater teleost by more than 50 years. The mouths of these fish are most commonly located on the underside of their head ( subterminal ), with thick, fleshy lips. Most species are less than 60 cm (2.0 ft) in length, but

867-682: The Yangtze , but the wild populations are under pressure from pollution, habitat destruction and hydroelectric dam projects. Some Catostomidae, especially those of Ictiobus and Moxostoma , are the subject of major recreational fisheries while most are the subject of at least limited recreational fisheries. Throughout much of their range species are considered to be rough fish . Suckers have historically been scapegoated for human environmental destruction and their impacts on popular fish species such as Pacific salmon and smallmouth bass . This has led to their widespread and unnecessary destruction at

918-614: The plate boundary between the Pacific Plate and the North American Plate . Presently, relic surfaces around the Middle Fork Feather River valley and the high elevations of the northern Basin and Range may be considered remnants of the Nevadaplano. The Nevadaplano was located in present-day Nevada and Utah , at the location of the present-day Great Basin , and may have extended from what

969-567: The " Roof of the World ", which is still being formed by the collisions of the Indo-Australian and Eurasian tectonic plates . The Tibetan Plateau covers approximately 2,500,000 km (970,000 sq mi), at about 5,000 m (16,000 ft) above sea level. The plateau is sufficiently high to reverse the Hadley cell convection cycles and to drive the monsoons of India towards

1020-631: The Altiplano lies within Bolivian and Peruvian territory while its southern parts lie in Chile. The Altiplano plateau hosts several cities like Puno, Oruro, El Alto and La Paz the administrative seat of Bolivia. Northeastern Altiplano is more humid than the Southwestern, the latter of which hosts several salares , or salt flats, due to its aridity. At the Bolivia-Peru border lies Lake Titicaca ,

1071-563: The Luning-Fencemaker fold-and-thrust belt may have formed the western boundary. It probably did not constitute a drainage divide ; various east–west trending valleys cut across the Sierra Nevada at that time. Presently filled with volcanic and sedimentary rocks, these valleys were 5–8 kilometres (3.1–5.0 mi) wide, 0.5–1.2 kilometres (0.31–0.75 mi) deep with flat and deeply weathered bottoms. Among these valleys are

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1122-541: The Nevadaplano and was tilted to the west along the Sierra Escarpment , beheading a number of westward-going drainages in the process. Former drainages of the Nevadaplano were buried by volcanic rocks and disrupted by tectonic processes. Farther east, the dismemberment of the drainages may have created suitable environments for the evolution of sucker fish. Miocene extension also created the well-known Basin and Range extension, probably triggered by changes in

1173-491: The Nevadaplano to California when the climate cooled during the Oligocene, founding the temperate forest communities of California. Conversely, the plateau might have impeded the migration of animals, although poor fossil preservation impedes a definitive determination of the fauna of the Nevadaplano. Evidence suggests that lakes and alluvial fans existed on the Nevadaplano, the Sheep Pass Formation constitutes

1224-536: The Nevadaplano with lahars , lava flows and volcanic sediments. In central Nevada and western Utah, at least 71 calderas located at high elevation erupted ignimbrites which propagated for over 200 kilometres (120 mi) westward and across former valleys in the Sierra Nevada, filling them in during the process. In particular, the 28.9 million year old Campbell Creek tuff covered an area of 55,000 square kilometres (21,000 sq mi) and propagated far east and west of its source area. The underlying crust had

1275-655: The Nine Hill and Soda Springs valleys in the Lake Tahoe region and the Stanislaus, Mokelumne and Cataract paleochannels in the Sonora Pass region. There is more evidence for paleovalleys in the northern Sierra Nevada than in the southern, which may either indicate that evidence of cross-Sierra drainage was removed in its southern sector or that the southern Sierra was higher than the central and northern Sierra at

1326-721: The North Rim of the Grand Canyon is at an elevation of about 2,450 m (8,040 ft) above sea level , and the South Rim of the Grand Canyon is about 2,150 m (7,050 ft) above sea level. At its deepest, the Colorado River is about 1,830 m (6,000 ft) below the level of the North Rim. Another high-altitude plateau in North America is the Mexican Plateau . With an area of 601,882 km (232,388 sq mi) and average height of 1,825 metres, it

1377-659: The Sevier orogen. Similar to the present-day Altiplano in South America , the combination of an arid climate , tectonic contraction, weak erosion and the accumulation of volcanic rocks both in and below the crust helped raise the Nevadaplano during the Cretaceous , when flat subduction was taking place. Later, its southern part was probably overprinted by the Laramide Orogeny when volcanism shifted far to

1428-546: The Sierra Nevada, it was dry, and therefore experienced only weak erosion. The rain shadow extended east of the Nevadaplano. However, precipitation was enough to cut large valleys into the Sierra Nevada, perhaps aided by the then-warm climate. Pulses of erosion may have occurred during Paleogene climate disturbances, such as the Paleocene–Eocene Thermal Maximum . Vegetation with temperate climate affinities like giant sequoias may have migrated from or through

1479-438: The collapse of the Nevadaplano. West of the Nevadaplano stood the Sierra Nevada , which was volcanically active until 80 million years ago and featured exposed batholiths from former volcanism. Its exact elevation at the time is unclear, with alternate models proposing either that it had already reached a height similar to today's Sierra Nevada or that it rose to present-day height in the Miocene and Pliocene . Alternatively,

1530-761: The crust. Tectonic plateaus are formed by tectonic plate movements which cause uplift, and are normally of a considerable size, and a fairly uniform altitude. Examples are the Deccan Plateau in India and the Meseta Central on the Iberian Peninsula . Plateaus can also be formed by the erosional processes of glaciers on mountain ranges, leaving them sitting between the mountain ranges. Water can also erode mountains and other landforms down into plateaus. Dissected plateaus are highly eroded plateaus cut by rivers and broken by deep narrow valleys. An example

1581-468: The disassembly of the Nevadaplano as well, including these where the Truckee Formation diatomites were emplaced in. High plateau Plateaus can be formed by a number of processes, including upwelling of volcanic magma, extrusion of lava, plate tectonics movements, and erosion by water and glaciers. Volcanic plateaus are produced by volcanic activity . The Columbia Plateau in

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1632-543: The east. The exact geologic evolution and character of the Nevadaplano is controversial, however, as is the notion that it was a geologically stable environment. The Nevadaplano underwent extensional tectonics during the Cenozoic , possibly in a multi-step process. An early stage may have occurred in the Eocene - Oligocene , toward the end of subduction , when the subducting slab steepened again and slab rollback decreased

1683-547: The exact value is controversial, as is whether it was flat or featured rugged topography. There is evidence of basins at its western margin, although the relief of the Nevadaplano is debated and was probably less than that of the Altiplano. The Nevadaplano probably drained to internal basins such as the Elko and Uinta Basins, the Western Interior Seaway and westward to the Pacific Ocean . A drainage divide extended from

1734-406: The exposure of core complexes , and generated isolated basins. This may have created regional basins in the late Cretaceous similar to those that lie in the present-day Altiplano - Puna region, and which include the Sheep Pass Formation basin and the long-lived Elko Basin. Lake sediments and volcanic rocks accumulated in these basins. The formation of these basins may have been an early stage of

1785-575: The flesh (termed "scoring") before frying to allow small internal bones to be palatable. Suckers were an important source of food for Indigenous Americans across the continent. Many fishing methods were employed with the most elaborate being stone fish traps constructed on spawning rivers, remnants of these traps can be seen today in Ahjumawi Lava Springs State Park where the Achomawi people trapped Sacramento suckers . In

1836-674: The gods" in the native tongue of the Pemon , the Indigenous people who inhabit the Gran Sabana . Tepuis can be considered minute plateaus and tend to be found as isolated entities rather than in connected ranges, which makes them the host of a unique array of endemic plant and animal species. Some of the most outstanding tepuis are Neblina , Autana , Auyan and Mount Roraima . They are typically composed of sheer blocks of Precambrian quartz arenite sandstone that rise abruptly from

1887-492: The jungle, giving rise to spectacular natural scenery. Auyán-tepui is the source of Angel Falls , the world's tallest waterfall . The Colombian capital city of Bogota sits on an Andean plateau known as the Altiplano Cundiboyacense roughly the size of Switzerland. Averaging a height of 2,600 m (8,500 ft) above sea level, this northern Andean plateau is situated in the country's eastern range and

1938-599: The largest lake in South America. [REDACTED] Media related to Plateaus at Wikimedia Commons Catostomidae See text The Catostomidae are the suckers of the order Cypriniformes , with about 78 species in this family of freshwater fishes . The Catostomidae are almost exclusively native to North America. The only exceptions are Catostomus catostomus , found in both North America and Russia, and Myxocyprinus asiaticus found only in China. In

1989-535: The largest species ( Ictiobus and Myxocyprinus ) can surpass 100 cm (3.3 ft). They are distinguished from related fish by having a long pharyngeal bone in the throat, containing a single row of teeth. Catostomids are most often found in rivers, but can be found in any freshwater environment. Their food ranges from detritus and bottom-dwelling organisms (such as crustaceans and worms), to surface insects, crayfish, small terrestrial vertebrates, and other fish. Catostomidae have been uncovered and dated to

2040-560: The later episode of east–west extension and northwestward shearing, which was underway by 16-17 million years ago and continues to a lesser extent today. That extension probably caused the high plateau to lose elevation. The heat flow from the Yellowstone hotspot and the addition of magmas into the crust are mechanisms that could have caused the collapse process. Also during the Miocene, the Sierra Nevada-Great Valley block separated from

2091-601: The most notable of which is the country's largest lake, Lake Taupō . The plateau stretches approximately 100 km east to west and 130 km north to south. The majority of the plateau is more than 600 metres above sea level. A tepui ( / ˈ t ɛ p w i / ), or tepuy ( Spanish: [teˈpuj] ), is a table-top mountain or mesa found in the Guiana Highlands of South America, especially in Venezuela and western Guyana . The word tepui means "house of

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2142-442: The north-western United States is an example. They may be formed by upwelling of volcanic magma or extrusion of lava. The underlining mechanism in forming plateaus from upwelling starts when magma rises from the mantle , causing the ground to swell upward. In this way, large, flat areas of rock are uplifted to form a plateau. For plateaus formed by extrusion, the rock is built up from lava spreading outward from cracks and weak areas in

2193-604: The present-day Andean Altiplano and Tibetan plateau , the Nevadaplano was dismembered during the Cenozoic and thus its structure and evolution are poorly understood. The Nevadaplano probably formed as part of either the Sevier or the Laramide Orogeny during the Mesozoic and persisted into the Paleogene . Its growth began either in the Cretaceous or the Jurassic , when significant tectonic shortening took place behind

2244-512: The remnants of such landforms. It is not clear however if the Sheep Pass lake system was at high elevation. Fossils of anurans , birds , bivalves , crustaceans , frogs , lizards , mammals , molluscs , ostracods and snakes have been found there, as well as evidence of algae , charophytes , plants and microbial mats . There are also traces of physical events such as debris flows , periodic desiccation and storms. Lakes formed during

2295-400: The south, the California River may have separated the Nevadaplano from an analogous high plateau to the south, called "Mexicoplano" or "Arizonaplano". The Colorado Plateau was either to the east of the Nevadaplano or else formed an integral part of the plateau. The San Juan Mountains region may have formed its own upland, the "Colorado-plano". During the Miocene, volcanic activity covered

2346-866: The south. The Deosai Plains in Pakistan are situated at an average elevation of 4,114 meters (13,497 ft) above sea level. They are considered to be the second highest plateaus in the world. Other major plateaus in Asia are: Najd on the Arabian Peninsula , elevation 762 to 1,525 m (2,500 to 5,003 ft), Armenian Highlands (≈400,000 km (150,000 sq mi), elevation 900–2,100 metres (3,000–6,900 ft)), Iranian Plateau (≈3,700,000 km (1,400,000 sq mi), elevation 300–1,500 metres (980–4,920 ft)), Anatolian Plateau , Mongolian Plateau (≈2,600,000 km (1,000,000 sq mi), elevation 1,000–1,500 metres (3,300–4,900 ft)), and

2397-416: The surrounding coastline through enormous glaciers . The polar ice cap is so massive that the echolocation measurements of ice thickness have shown that large areas are below sea level . But, as the ice melts, the land beneath will rebound through isostasy and ultimately rise above sea level. The largest and highest plateau in the world is the Tibetan Plateau , sometimes metaphorically described as

2448-400: The tectonic forces. At that time, volcanic activity swept southwestward, away from the volcanoes of central Nevada to the Sierra. This may have been accompanied by uplift that would have continued when the Yellowstone hotspot developed in the Miocene. The plateau overrode the heat source of the East Pacific Rise about 28 million years ago. By far the most significant stage of extension was

2499-406: The time of the Nevadaplano. Some of these rivers may have been large enough to allow sharks to reach Nevada. The rivers flowing through these valleys deposited the placer gold deposits of California, as part of intense westward sediment transport. On the eastern side, the proto- Platte and proto- Arkansas Rivers drained the Nevadaplano. There, the Arikaree Formation was deposited. Remnants of

2550-430: The west these relationships became even more important after the decline in salmon runs due to damming and habitat destruction , some groups of native people relied on seasonal sucker runs for a significant amount of their food until the 1950s. In China there is a significant aquaculture industry dedicated to raising Myxocyprinus asiaticus for food. Historically they were an important component of wild fisheries on

2601-467: Was once called Gallayat Plateaus, rising 3,300 ft above sea level. Another very large plateau is the icy Antarctic Plateau , which is sometimes referred to as the Polar Plateau or King Haakon VII Plateau, home to the geographic South Pole and the Amundsen–Scott South Pole Station , which covers most of East Antarctica where there are no known mountains but rather 3,000 m (9,800 ft) high of superficial ice and which spreads very slowly toward

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