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34-669: The Oued Zouzfana originates in the Atlas Mountains north of the town of Figuig , flows south past Figuig and Béni Ounif , then turns southwest through Taghit and finally to Igli , where it merges with the Oued Guir to form the Oued Saoura . Oued Zouzfana passes by jbel Sidi Youssef which is located to the south of Figuig. The inhabitants of Figuig still cultivate date palms. Sometimes there are floods of this river. This phenomenon, if we may call it that; Mainly because

68-633: 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 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

102-808: A river in Algeria is a stub . You can help Misplaced Pages by expanding it . 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 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

136-605: 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 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

170-527: Is a planet's "original" crust. It forms from solidification of a magma ocean. Toward the end of planetary accretion , the terrestrial planets likely had surfaces that were magma oceans. As these cooled, they solidified into crust. This crust was likely destroyed by large impacts and re-formed many times as the Era of Heavy Bombardment drew to a close. The nature of primary crust is still debated: its chemical, mineralogic, and physical properties are unknown, as are

204-495: Is debated. The anorthosite highlands of the Moon are primary crust, formed as plagioclase crystallized out of the Moon's initial magma ocean and floated to the top; however, it is unlikely that Earth followed a similar pattern, as the Moon was a water-less system and Earth had water. The Martian meteorite ALH84001 might represent primary crust of Mars; however, again, this is debated. Like Earth, Venus lacks primary crust, as

238-496: Is needed to create tertiary crust, and Earth is the only planet in the Solar System with plate tectonics. Earth's crust is a thin shell on the outside of Earth, accounting for less than 1% of Earth's volume. It is the top component of the lithosphere , a division of Earth's layers that includes the crust and the upper part of the mantle . The lithosphere is broken into tectonic plates that move, allowing heat to escape from

272-826: Is usually distinguished from the underlying mantle by its chemical makeup; however, in the case of icy satellites, it may be distinguished based on its phase (solid crust vs. liquid mantle). The crusts of Earth , Mercury , Venus , Mars , Io , the Moon and other planetary bodies formed via igneous processes and were later modified by erosion , impact cratering , volcanism, and sedimentation. Most terrestrial planets have fairly uniform crusts. Earth, however, has two distinct types: continental crust and oceanic crust . These two types have different chemical compositions and physical properties and were formed by different geological processes. Planetary geologists divide crust into three categories based on how and when it formed. This

306-610: 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 the Alleghenian orogeny . These mountains were formed when Africa and America collided and were once a chain rivaling today's Himalayas . Today,

340-575: 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

374-718: 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 the most striking features of the Atlas to geologists is the relative small amount of crustal thickening and tectonic shortening despite

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408-896: 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

442-421: The adiabatic rise of mantle causes partial melting. Tertiary crust is more chemically-modified than either primary or secondary. It can form in several ways: The only known example of tertiary crust is the continental crust of the Earth. It is unknown whether other terrestrial planets can be said to have tertiary crust, though the evidence so far suggests that they do not. This is likely because plate tectonics

476-820: 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

510-411: 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. Crust (geology) In geology , the crust is the outermost solid shell of a planet , dwarf planet , or natural satellite . It

544-645: 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

578-624: 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

612-517: The Oued Zouzfana is not always carrying water with large quantities, occurs even when there is no rain in the region, since the cause of the flood is far from Figuig and near East side of the Atlas Mountains . 30°29′11″N 2°18′18″W  /  30.4864°N 2.3050°W  / 30.4864; -2.3050 This article related to a river in Morocco is a stub . You can help Misplaced Pages by expanding it . This article related to

646-620: 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

680-423: The crust ranges between about 20 and 120 km. Crust on the far side of the Moon averages about 12 km thicker than that on the near side . Estimates of average thickness fall in the range from about 50 to 60 km. Most of this plagioclase-rich crust formed shortly after formation of the Moon, between about 4.5 and 4.3 billion years ago. Perhaps 10% or less of the crust consists of igneous rock added after

714-453: The entire planet has been repeatedly resurfaced and modified. Secondary crust is formed by partial melting of mostly silicate materials in the mantle, and so is usually basaltic in composition. This is the most common type of crust in the Solar System. Most of the surfaces of Mercury, Venus, Earth, and Mars comprise secondary crust, as do the lunar maria . On Earth secondary crust forms primarily at mid-ocean spreading centers , where

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748-462: 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), the mountain chains that today constitute the Atlas were uplifted, as the land masses of Europe and Africa collided at

782-463: The formation of the initial plagioclase-rich material. The best-characterized and most voluminous of these later additions are the mare basalts formed between about 3.9 and 3.2 billion years ago. Minor volcanism continued after 3.2 billion years, perhaps as recently as 1 billion years ago. There is no evidence of plate tectonics . Study of the Moon has established that a crust can form on a rocky planetary body significantly smaller than Earth. Although

816-595: 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

850-491: The igneous mechanisms that formed them. This is because it is difficult to study: none of Earth's primary crust has survived to today. Earth's high rates of erosion and crustal recycling from plate tectonics has destroyed all rocks older than about 4 billion years , including whatever primary crust Earth once had. However, geologists can glean information about primary crust by studying it on other terrestrial planets. Mercury's highlands might represent primary crust, though this

884-537: 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

918-416: The interior of Earth into space. A theoretical protoplanet named " Theia " is thought to have collided with the forming Earth, and part of the material ejected into space by the collision accreted to form the Moon. As the Moon formed, the outer part of it is thought to have been molten, a " lunar magma ocean ". Plagioclase feldspar crystallized in large amounts from this magma ocean and floated toward

952-506: 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

986-528: 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

1020-489: 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

1054-659: 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 a widespread extension of the Earth's crust that rifted and separated the continents mentioned above. This extension was responsible for

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1088-543: 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 the case of the Africa-Europe collision, it is clear that tectonic convergence is partially responsible for the formation of

1122-444: The surface. The cumulate rocks form much of the crust. The upper part of the crust probably averages about 88% plagioclase (near the lower limit of 90% defined for anorthosite ): the lower part of the crust may contain a higher percentage of ferromagnesian minerals such as the pyroxenes and olivine , but even that lower part probably averages about 78% plagioclase. The underlying mantle is denser and olivine-rich. The thickness of

1156-522: 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

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