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36-574: Ourika Valley is a valley in the Moroccan High Atlas along the Ourika River . It is located around 30 km from Marrakech , and is essentially populated by Berber people speaking Shilha . Despite its proximity to Marrakech, it is still considered a relatively well-preserved valley, by its very nature a and traditional mountain way of life. Ourika is the name of one of the most famous tribes, written by Ibn Khaldoun . Setti-Fatma

72-595: A gothic cathedral . Among the summits at a height of 1,600 m (5,200 ft) height lies the Kasbah of Telouet on the road to Marrakech . The canyons and ravines of the Dadès and the Todra are also points of interest. Canyon A canyon (from Spanish : cañón ; archaic British English spelling: cañon ), gorge or chasm , is a deep cleft between escarpments or cliffs resulting from weathering and

108-593: A ksar ( Maghribi Arabic : قـصـر , romanized :  qṣer , fortified village) still in use. The ksar is widely used in the film industry. At approximately mid-range, the Amesfrane Rock Wall rises some 1,650 feet (500 m) from a dry riverbed wadi . The formation is composed of rounded columns patterned with horizontal ridges that occurred as a result of erosion, which caused travellers to nickname it "the Cathedral", for its resemblance to

144-579: Is actually 1 km wider than the Grand Canyon, making it the widest canyon in the world. Some canyons have notable cultural significance. Evidence of archaic humans has been discovered in Africa's Olduvai Gorge . In the southwestern United States, canyons are important archeologically because of the many cliff-dwellings built in such areas, largely by the ancient Pueblo people who were their first inhabitants. The following list contains only

180-435: Is characterized by a folded domain that is dominated by NE-SW striking structural highs or ridges separating elongated and wide synclines filled by Early and Middle Jurassic sediments. Subordinate NW-SE trending structural highs bounding equal-trend synclines are also present. Cretaceous and later syntectonic Tertiary units are also locally present (e.g., Miocene-Pliocene La Cathédrale conglomerates and sandstones). During

216-676: Is occasionally used in the United Kingdom . In South Africa, kloof (in Krantzkloof Nature Reserve ) is used along with canyon (as in Blyde River Canyon ) and gorge (in Oribi Gorge ). Most canyons were formed by a process of long-time erosion from a plateau or table-land level. The cliffs form because harder rock strata that are resistant to erosion and weathering remain exposed on

252-477: Is separated from the central and eastern High Atlas by the Paleozoic Massif , an area of pre-Mesozoic basement exposures located south of Marrakesh. The central and eastern High Atlas basin developed as a multiphase rift system opened toward the east by two major rift episodes occurring during Middle-Late Triassic and Early Jurassic (late Sinemurian and Pliensbachian . At present, the central High Atlas

288-599: Is similarly imprecise, especially if one includes mountain canyons, as well as canyons cut through relatively flat plateaus (which have a somewhat well-defined rim elevation). The Yarlung Tsangpo Grand Canyon (or Tsangpo Canyon), along the Yarlung Tsangpo River in Tibet , is regarded by some as the deepest canyon on Earth at 5,500 metres (18,000 ft). It is slightly longer than the Grand Canyon in

324-598: Is soluble to a certain extent, cave systems form in the rock. When a cave system collapses, a canyon is left, as in the Mendip Hills in Somerset and Yorkshire Dales in Yorkshire , England. A box canyon is a small canyon that is generally shorter and narrower than a river canyon, with steep walls on three sides, allowing access and egress only through the mouth of the canyon. Box canyons were frequently used in

360-644: Is the Fish River Canyon in Namibia . In August 2013, the discovery of Greenland 's Grand Canyon was reported, based on the analysis of data from Operation IceBridge . It is located under an ice sheet. At 750 kilometres (470 mi) long, it is believed to be the longest canyon in the world. Despite not being quite as deep or long as the Grand Canyon, the Capertee Valley in Australia

396-707: Is the highest in the range and lies in Toubkal National Park . The range serves as a weather system barrier in Morocco running east–west and separating the Sahara from the Mediterranean and continental zones to the north and west. In the higher elevations of the massif, snow falls regularly, allowing winter sports . Snow lasts well into late spring in the High Atlas, mostly on the northern faces of

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432-570: Is the last small town (or douar ) which is accessible by the paved route. It is the departure point for many excursions to the nearby mountains. The most prized and most easy hike consists of mounting the length of a mountain torrent in order to discover the cascades. It is a little village (or douar ) without great architectural interest. It is however the center of the weekly traditional market (or souk ), taking place every Monday (or tnine in Arabic ). High Atlas The High Atlas rises in

468-560: The Azilal Formation developed in the margins of the central High Atlas basin, whereas the basin axis was occupied by a mixed carbonate-siliciclastic platform system prograding eastward to basinal deposits. This mixed system progressively graded to an extensive shallow water carbonate platform of the Anoual Formation , Bajocian to early Bathonian in age that is recognized throughout the central High Atlas. Finally,

504-537: The Toarcian and Bathonian deposits of this range, respectively. In 2023, a fossil of a hybodontiform Strophodus was collected from the Bajocian deposits of High Atlas. It's the oldest Gondwanan specimen of this genus at the time of discovery. The new species was named Strophodus atlasensis , after the mountain range where its holotype was found. At the foot of the High Atlas one finds Aït Benhaddou ,

540-569: The Triassic , the central High Atlas extensional basin was characterized by the synrift deposition of red beds and localized evaporites capped by extensive basaltic lava flows . Following the Triassic red bed deposition, marine conditions prevailed during the Early and Middle Jurassic resulting in the development of carbonate and mixed depositional systems. The Jurassic Atlas basin was open to

576-461: The United States , place names generally use canyon in the southwest (due to their proximity to Spanish-speaking Mexico ) and gorge in the northeast (which is closer to French Canada ), with the rest of the country graduating between these two according to geography. In Canada , a gorge is usually narrow while a ravine is more open and often wooded. The military-derived word defile

612-403: The erosive activity of a river over geologic time scales . Rivers have a natural tendency to cut through underlying surfaces, eventually wearing away rock layers as sediments are removed downstream. A river bed will gradually reach a baseline elevation, which is the same elevation as the body of water into which the river drains. The processes of weathering and erosion will form canyons when

648-642: The seabed of the continental slope are referred to as submarine canyons . Unlike canyons on land, submarine canyons are thought to be formed by turbidity currents and landslides . The word canyon is Spanish in origin ( cañón , pronounced [kaˈɲon] ), with the same meaning. The word canyon is generally used in North America , while the words gorge and ravine (French in origin) are used in Europe and Oceania , though gorge and ravine are also used in some parts of North America. In

684-835: The tectonic inversion of the Late Triassic to Middle Jurassic rift basin during the Cenozoic convergence between the African and Eurasian Plates . The Moroccan Atlas is formed by the ENE-WSW-striking High Atlas and the NE-SW-trending Middle Atlas. The former is divided into three segments named western, central, and eastern High Atlas. The western High Atlas was part of the Atlantic Jurassic passive margin and

720-460: The western United States as convenient corrals, with their entrances fenced. The definition of "largest canyon" is imprecise, because a canyon can be large by its depth, its length, or the total area of the canyon system. Also, the inaccessibility of the major canyons in the Himalaya contributes to their not being regarded as candidates for the biggest canyon. The definition of "deepest canyon"

756-596: The United States, with an average depth of 1,600 metres (5,200 ft) and a volume of 4.17 trillion cubic metres (147 trillion cubic feet), is one of the world's largest canyons. It was among the 28 finalists of the New 7 Wonders of Nature worldwide poll. (Some referred to it as one of the seven natural wonders of the world .) The largest canyon in Europe is Tara River Canyon . The largest canyon in Africa

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792-627: The United States. Others consider the Kali Gandaki Gorge in midwest Nepal to be the deepest canyon, with a 6,400-metre (21,000 ft) difference between the level of the river and the peaks surrounding it. Vying for the deepest canyon in the Americas is the Cotahuasi Canyon and Colca Canyon , in southern Peru. Both have been measured at over 3,500 metres (11,500 ft) deep. The Grand Canyon of northern Arizona in

828-480: The basin. Pliensbachian carbonate platforms preferentially developed in the margins basin and in synsedimentary structural highs, promoting abrupt transitions in the marine sedimentary record from shallow water to basinal facies. Global anoxia during the latest Pliensbachian and the earliest Toarcian occurred in close association with regional drowning of the lower Liassic platforms and localized deposition of basinal marls. From Toarcian times, carbonate platforms of

864-746: The canyon walls, in a process known as frost wedging. Canyon walls are often formed of resistant sandstones or granite . Sometimes large rivers run through canyons as the result of gradual geological uplift. These are called entrenched rivers , because they are unable to easily alter their course. In the United States, the Colorado River in the Southwest and the Snake River in the Northwest are two examples of tectonic uplift . Canyons often form in areas of limestone rock. As limestone

900-605: The community and their living system. There are two types of Alpine Climates in the High Atlas: In the west lies the oldest portion of the range. Its high point is the Jbel Toubkal, which is visible from the city of Marrakech . Jbel Toubkal lies in the Toubkal national park, which was created in 1942. The massif consists of Jurassic and Cretaceous formations notched by deep erosion-carved valleys. This part of

936-438: The contrasting landscapes are similar to Colorado in the United States , with high plateaux, gorges and box canyons , and peaks sometimes splintered by erosion. Several peaks in this area exceed 4,000 m (13,000 ft), with Jbel Mgoun at 4068 m being the highest peak in this part of the High Atlas. The area is populated by Berbers . The eastern part of the High Atlas forms vast plateaux at high altitude which provide

972-677: The discovery of the bones of a dinosaur called ' Atlasaurus ', which populated Morocco 180 million years ago. This dinosaur is also named Tazoudasaurus , after the name of the village of Tazouda , where it was discovered. The creature, about 15 metres (49 feet) long, is postulated to be an ancestor of the Sauropoda found in America. Until 140 million years ago, the African and American continents were connected. The Atlas Mountains define an ENE-WSW trending intracontinental belt, resulting from

1008-499: The east (western Tethys realm) with Paleozoic provenance areas located toward the west and south. Liassic sedimentary systems evolved from extensive peritidal shallow water carbonate platforms ( Hettangian -lower Sinemurian ) that progressively backstepped toward the basin margins, to more localized platform development flanking the depocenters (Sinemurian). Normal faulting and block tilting increased notably during Pliensbachian times, resulting in north to south compartmentalization of

1044-526: The headwaters for the Moulouya River . It extends from the town of Khenifra . This portion of the range includes the solid mass of the Tamlelt whose northern edge is occupied by its higher peaks, such Jbel Ayachi at 3,747 m (12,293 ft). The altitude falls towards the east where the mountains join the pre-Saharan zone. This massif became an internationally famous paleontological site after

1080-568: The middle Dogger to Lower Cretaceous red beds record the sedimentation of continental to shallow marine transitional deposits that characterize the central High Atlas domain. Fully marine environmental conditions and platform carbonate deposits, which locally crop out in the margins of the Atlas System, dominated between Aptian and Cenomanian times. Fossils of Mesozoic animals are known from High Atlas. Remains of sauropod dinosaurs Tazoudasaurus and Atlasaurus were found in

1116-769: The range includes the Ourika Valley , which is the only location in the High Atlas where the endangered primate , the Barbary macaque , Macaca sylvanus , is found; however, this primate is also found in parts of the Middle Atlas and the Rif , as well as parts of Algeria . The Ourika Valley is also a location where a diverse flora was recorded as early as the 19th century. A solid chalk mass morphologically dominated by tabular zones reaching an altitude of 2,500 m (8,200 ft) extends from Azilal to Ouarzazate. Here,

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1152-566: The range. On the Western High Atlas, there is Oukaïmeden , one of three main ski stations in Morocco. The High Atlas forms the basins for a multiplicity of river systems. The majority of the year-round rivers flow to the north, providing the basis for the settlements there. A number of wadis and seasonal rivers terminate in the deserts to the south and plateaux to the east of the mountains. The High-Atlas Mountains are inhabited by Berbers, who live from agriculture and pastoralism in

1188-1075: The river's headwaters and estuary are at significantly different elevations, particularly through regions where softer rock layers are intermingled with harder layers more resistant to weathering. A canyon may also refer to a rift between two mountain peaks, such as those in ranges including the Rocky Mountains , the Alps , the Himalayas or the Andes . Usually, a river or stream carves out such splits between mountains. Examples of mountain-type canyons are Provo Canyon in Utah or Yosemite Valley in California's Sierra Nevada . Canyons within mountains, or gorges that have an opening on only one side, are called box canyons. Slot canyons are very narrow canyons that often have smooth walls. Steep-sided valleys in

1224-456: The valley walls. Canyons are much more common in arid areas than in wet areas because physical weathering has a more localized effect in arid zones. The wind and water from the river combine to erode and cut away less resistant materials such as shales . The freezing and expansion of water also serves to help form canyons. Water seeps into cracks between the rocks and freezes, pushing the rocks apart and eventually causing large chunks to break off

1260-610: The valleys. In the steppe zone of the High-Atlas, where precipitations are low, the locals created a smart technique in managing the low precipitations and the weak soil. They turn the rather semi-arid lands into fertile valleys called locally by Agdal (garden in Berber). This technique has intrigued many Western agriculturalists, in which they were impressed by the high efficiency of this agricultural system. Many scientists, particularly French scientists, make yearly expeditions to observe

1296-659: The west at the Atlantic Ocean and stretches in an eastern direction to the Moroccan- Algerian border. At the Atlantic and to the southwest the range drops abruptly and makes an impressive transition to the coast and the Anti-Atlas range. To the north, in the direction of Marrakech , the range descends less abruptly. The range includes Jbel Toubkal , which at 4,167 m (2.589 miles; 13,671 ft)

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