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39-682: Drâa-Tafilalet is situated in the Atlas Mountains of Morocco. Its main watersheds are that of the Draa River in the west and the Ziz River , which irrigates the Tafilalt oasis, in the east. Drâa-Tafilalet borders five other Moroccan regions: Souss-Massa to the southwest, Marrakech-Safi to the west, Béni Mellal-Khénifra to the northwest, Fès-Meknès to the north, and Oriental to the northeast. It also borders two of Algeria 's provinces , Tindouf in

78-407: A terrane was accreted to the edge of the continent. Any of this material may be folded, refolded and metamorphosed. New igneous rock may freshly intrude into the crust from underneath, or may form underplating , where the new igneous rock forms a layer on the underside of the crust. The majority of continental crust on the planet is around 1 to 3 billion years old, and it is theorised that there

117-453: A weak zone on which the harder (stronger) limestone cover was able to move over the hard basement, making the distinction between basement and cover even more pronounced. In Andean geology the basement refers to the Proterozoic , Paleozoic and early Mesozoic ( Triassic to Jurassic ) rock units as the basement to the late Mesozoic and Cenozoic Andean sequences developed following

156-473: A plate of oceanic crust is subducted beneath an overriding plate of oceanic crust, as the underthrusting crust melts, it causes an upwelling of magma that can cause volcanism along the subduction front on the overriding plate. This produces an oceanic volcanic arc , like Japan . This volcanism causes metamorphism , introduces igneous intrusions , and thickens the crust by depositing additional layers of extrusive igneous rock from volcanoes. This tends to make

195-516: A relatively thin veneer, but can be more than 5 kilometres (3 mi) thick. The basement rock of the crust can be 32–48 kilometres (20–30 mi) thick or more. The basement rock can be located under layers of sedimentary rock, or be visible at the surface. Basement rock is visible, for example, at the bottom of the Grand Canyon , consisting of 1.7- to 2-billion-year-old granite ( Zoroaster Granite ) and schist ( Vishnu Schist ). The Vishnu Schist

234-527: A widespread extension of the Earth's crust that rifted and separated the continents mentioned above. This extension was responsible for the formation of many thick intracontinental sedimentary basins including the present Atlas. Most of the rocks forming the surface of the present High Atlas were deposited under the ocean at that time. In the Paleogene and Neogene Periods (~66 million to ~1.8 million years ago),

273-587: Is believed to be highly metamorphosed igneous rocks and shale , from basalt , mud and clay laid from volcanic eruptions, and the granite is the result of magma intrusions into the Vishnu Schist. An extensive cross section of sedimentary rocks laid down on top of it through the ages is visible as well. The basement rocks of the continental crust tend to be much older than the oceanic crust. The oceanic crust can be from 0–340 million years in age, with an average age of 64 million years. Continental crust

312-495: Is older because continental crust is light and thick enough so it is not subducted, while oceanic crust is periodically subducted and replaced at subduction and oceanic rifting areas. The basement rocks are often highly metamorphosed and complex, and are usually crystalline . They may consist of many different types of rock – volcanic, intrusive igneous and metamorphic. They may also contain ophiolites , which are fragments of oceanic crust that became wedged between plates when

351-413: Is the thick foundation of ancient, and oldest, metamorphic and igneous rock that forms the crust of continents , often in the form of granite . Basement rock is contrasted to overlying sedimentary rocks which are laid down on top of the basement rocks after the continent was formed, such as sandstone and limestone . The sedimentary rocks which may be deposited on top of the basement usually form

390-691: The Alleghenian orogeny . These mountains were formed when Africa and America collided and were once a chain rivaling today's Himalayas . Today, the remains of this chain can be seen in the Fall Line region in the Eastern United States . Some remnants can also be found in the later formed Appalachians in North America. A second phase took place during the Mesozoic Era (before ~66 My). It consisted of

429-615: The Atlantic Ocean in the southwest of Morocco toward the northeast to the heights of Ouarzazate and further east to the city of Tafilalt (altogether a distance of approximately 500 kilometres or 300 miles). In the south it borders the Sahara . The easternmost point of the anti-Atlas is the Jbel Saghro range and its northern boundary is flanked by sections of the High Atlas range . It includes

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468-493: The Atlantic Ocean ; the name "Atlantic" is derived from the mountain range, which stretches around 2,500 km (1,600 mi) through Morocco , Algeria and Tunisia . The range's highest peak is Toubkal , which is in central Morocco, with an elevation of 4,167 metres (13,671 ft). The Atlas Mountains are primarily inhabited by Berber populations. The terms for 'mountain' are Adrar and adras in some Berber languages , and these terms are believed to be cognates of

507-846: The Mediterranean coast and joins with the Saharan Atlas in Eastern Algeria and Tunisia. The highest summit of the Tell Atlas is the 2,308 m (7,572 ft) Lalla Khadidja in the Djurdjura range of Kabylia . The western end of the Tell Atlas merges with the Middle Atlas range in Morocco. The area immediately to the south of the Tell Atlas is the high plateau of the Hautes Plaines , with lakes in

546-486: The World Heritage Site Aït Benhaddou , are popular tourist attractions. Traditional arts and crafts such as the pottery of Tamegroute and the rugs of Taznakht are also significant to the local economy. The largest towns in the region, Errachidia and Ouarzazate, are linked together by National Route 10 . The Draa valley is served by National Route 9 which also links Ouarzazate with Marrakesh to

585-576: The toponym Atlas . The mountains are home to a number of animals and plants which are mostly found within Africa but some of which can be found in Europe. Many of these species are endangered and a few are already extinct . The weather is generally cool but summers are sunny, and the average temperature there is 25 °C. The Atlas Mountains have earned a reputation as a trekkers’ den, attracting adventurers year-round. The basement rock of most of Africa

624-849: The Atlas mountain range. It covers parts of Algeria and Tunisia . The Aurès natural region is named after the range. Flora in the mountains include the Atlas cedar , evergreen oak and many semi-evergreen oaks such as the Algerian oak . Animals that live in the area include the Barbary macaque (misnamed as the Barbary ape), Barbary leopard , Barbary stag , Barbary sheep , Atlas Mountain badger , Cuvier's gazelle , North African boar , striped hyena , Red fox , northern bald ibis , Algerian nuthatch , dipper , and Atlas mountain viper . Many animals used to inhabit

663-463: The Atlas mountains such as the Atlas bear , North African elephant , North African aurochs , bubal hartebeest and Atlas wild ass , but these subspecies are all extinct. Barbary lions are currently extinct in the wild, but descendants exist in captivity. Basement rock In geology , basement and crystalline basement are crystalline rocks lying above the mantle and beneath all other rocks and sediments. They are sometimes exposed at

702-619: The Djebel Siroua, a massif of volcanic origin with the highest summit of the range at 3,304 m. The Jebel Bani is a much lower range running along the southern side of the Anti Atlas. The High Atlas in central Morocco rises in the west at the Atlantic coast and stretches in an eastern direction to the Moroccan-Algerian border. It has several peaks over 4,000 m (13,000 ft), including

741-490: The Earth's continents being accreted into one giant supercontinent . Most continents, such as Asia, Africa and Europe, include several continental cratons, as they were formed by the accretion of many smaller continents. In European geology , the basement generally refers to rocks older than the Variscan orogeny . On top of this older basement Permian evaporites and Mesozoic limestones were deposited. The evaporites formed

780-606: The High Atlas, crossing Algeria from the Moroccan border and into Tunisia. The Aures Mountains are often presented as being the easternmost part of the Saharan Atlas. Though not as high as the High Atlas, they reach similar altitudes as the Tell Atlas range that runs to the north of them and closer to the coast. The highest peak in the range, outside of the Aures Mountains, is the 2,236 m (7,336 ft) high Djebel Aissa. They mark

819-603: The area are Ouarzazate , Tahannaout , Amizmiz , Imlil , Tin Mal and Ijoukak . The Middle Atlas is completely in Morocco and is the northernmost of its three main Atlas ranges. The range lies north of the High Atlas, separated by the Moulouya and Oum Er-Rbia rivers, and south of the Rif mountains, separated by the Sebou River . To the west are the main coastal plains of Morocco with many of

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858-645: The case of the Africa-Europe collision, it is clear that tectonic convergence is partially responsible for the formation of the High Atlas , as well as for the closure of the Strait of Gibraltar and the formation of the Alps and the Pyrenees . However, there is a lack of evidence for the nature of the subduction in the Atlas region, or for the thickening of the Earth's crust generally associated with continental collisions. One of

897-416: The crust thicker and less dense, making it immune to subduction. Oceanic crust can be subducted, while continental crust cannot. Eventually, the subduction of the underthrusting oceanic crust can bring the volcanic arc close to a continent, with which it may collide. When this happens, instead of being subducted, it is accreted to the edge of the continent and becomes part of it. Thin strips or fragments of

936-511: The edge of the continent. There are exceptions, however, such as exotic terranes . Exotic terranes are pieces of other continents that have broken off from their original parent continent and have become accreted to a different continent. Continents can consist of several continental cratons – blocks of crust built around an initial original core of continents – that gradually grew and expanded as additional newly created terranes were added to their edges. For instance, Pangea consisted of most of

975-578: The highest summit in North Africa, Toubkal (4,167 m or 13,671 ft), and further east Ighil m'Goun (4,071 m or 13,356 ft), the second major summit of the range. At the Atlantic and to the southwest, the range drops abruptly and makes a transition to the coast and the Anti-Atlas range. To the north, in the direction of Marrakesh , the range descends less abruptly. On the heights of Ouarzazate

1014-501: The major cities and, to the east, the high barren plateau that lies between the Saharan and Tell Atlas. The high point of the range is the jbel Bou Naceur (3340 m). The Middle Atlas experiences more rain than the ranges to the south, making it an important water catchment for the coastal plains and important for biodiversity. It is home to the majority of the world's population of Barbary macaque . The Saharan Atlas of Algeria runs east of

1053-515: The massif is cut through by the Draa Valley which opens southward. It is mainly inhabited by Berber people, who live in small villages and cultivate the high plains of the Ourika Valley . Near Barrage Cavagnac there is a hydroelectric dam that has created the artificial lake Lalla Takerkoust . The lake serves also as a source for fish for the local fishermen. The largest villages and towns of

1092-670: The most striking features of the Atlas to geologists is the relative small amount of crustal thickening and tectonic shortening despite the important altitude of the mountain range. Recent studies suggest that deep processes rooted in the Earth's mantle may have contributed to the uplift of the High and Middle Atlas. The Atlas are rich in natural resources . There are deposits of iron ore , lead ore , copper , silver , mercury , rock salt , phosphate , marble , anthracite coal and natural gas among other resources. The range can be divided into four general regions: The Anti-Atlas extends from

1131-466: The mountain chains that today constitute the Atlas were uplifted, as the land masses of Europe and Africa collided at the southern end of the Iberian Peninsula . Such convergent tectonic boundaries occur where two plates slide towards each other forming a subduction zone (if one plate moves underneath the other), and/or a continental collision (when the two plates contain continental crust ). In

1170-482: The northern edge of the Sahara Desert . The mountains see some rainfall and are better suited to agriculture than the plateau region to the north. Today, most of the population of the region are Berbers ( Imazighen ). The Tell Atlas is a mountain chain over 1,500 kilometres (900 mi) in length, belonging to the Atlas mountain ranges and stretching from Eastern Morocco to Tunisia, and through Algeria. It parallels

1209-671: The northwest. National Route 13 runs along the Ziz valley and links Errachidia with Meknes to the north. Ouarzazate has the busiest airport in the region; the airports at Errachidia and Zagora also have commercial service. Atlas Mountains The Atlas Mountains are a mountain range in the Maghreb in North Africa . It separates the Sahara Desert from the Mediterranean Sea and

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1248-703: The onset of subduction along the western margin of the South American Plate . When discussing the Trans-Mexican Volcanic Belt of Mexico the basement include Proterozoic, Paleozoic and Mesozoic age rocks for the Oaxaquia, the Mixteco and the Guerrero terranes respectively. The term basement is used mostly in disciplines of geology like basin geology , sedimentology and petroleum geology in which

1287-468: The region on 13 October 2015. He was succeeded by Mohamed Benribag in 2017. Drâa-Tafilalet comprises five provinces: Agriculture and pastoralism have traditionally been major economic activities in the region, but they have been adversely impacted in recent years by increasing desertification . There is a filmmaking industry concentrated in the Ouarzazate area. The fortified towns in the area, such as

1326-627: The south and Béchar in the southeast. Drâa-Tafilalet was formed in September 2015 by integrating the provinces of Errachidia and Midelt in Meknès-Tafilalet region with three provinces of the Souss-Massa-Drâa region. Lahbib Choubani of the Justice and Development Party was elected as the regional council's first president on 14 September 2015. Mohamed Fanid was appointed governor ( wali ) of

1365-525: The surface, but often they are buried under miles of rock and sediment. The basement rocks lie below a sedimentary platform or cover, or more generally any rock below sedimentary rocks or sedimentary basins that are metamorphic or igneous in origin. In the same way, the sediments or sedimentary rocks on top of the basement can be called a "cover" or "sedimentary cover". Crustal rocks are modified several times before they become basement, and these transitions alter their composition. Basement rock

1404-414: The underthrusting oceanic plate may also remain attached to the edge of the continent so that they are wedged and tilted between the converging plates, creating ophiolites . In this manner, continents can grow over time as new terranes are accreted to their edges, and so continents can be composed of a complex quilt of terranes of varying ages. As such, the basement rock can become younger going closer to

1443-511: The wet season and salt flats in the dry. The eastern half of the Tell Atlas has the most humid climate of North Africa, with annual precipitation reaching well above 1,000 mm (39 in), and sometimes over 1,500 mm (59 in) like in the Collo Peninsula or near Ain Draham . An important amount of snow falls on the summits in winter. The Aurès Mountains are the easternmost portion of

1482-562: Was at least one period of rapid expansion and accretion to the continents during the Precambrian. Much of the basement rock may have originally been oceanic crust, but it was highly metamorphosed and converted into continental crust . It is possible for oceanic crust to be subducted down into the Earth's mantle , at subduction fronts, where oceanic crust is being pushed down into the mantle by an overriding plate of oceanic or continental crust. When

1521-739: Was formed during the Precambrian supereon and is much older than the Atlas Mountains lying on the continent. The Atlas was formed during three subsequent phases of Earth's geology. The first tectonic deformation phase involves only the Anti-Atlas , which was formed in the Paleozoic Era (~300 million years ago) as the result of continental collisions . North America , Europe and Africa were connected millions of years ago. The Anti-Atlas Mountains are believed to have originally been formed as part of

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