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The Atlas Mountains is a mountain range which stretches across northwestern Africa extending about through Algeria, Morocco and Tunisia. The highest peak is Jebel Toubkal, with an elevation of in southwestern Morocco. The Atlas ranges separate the Mediterranean and Atlantic coastlines from the Sahara Desert. The population of the Atlas Mountains is mainly Berbers. The terms for 'mountain' in some Berber languages are ''adrar'' and ''adras'', believed to be cognate with the toponym. The mountains are home to a number of plant and animal species unique in Africa, often more like those of Europe; many of them are endangered and some have already gone extinct. Examples include the Barbary macaque, the Atlas bear (Africa's only species of bear; now extinct), the Barbary leopard, the Barbary stag, Barbary sheep, the Barbary lion (extinct in the wild), the Atlas Mountain badger, the North African elephant (extinct), the North African aurochs (extinct), Cuvier's gazelle, the Northern bald ibis, dippers, the Atlas mountain viper, the Atlas cedar, the European black pine, and the Algerian oak. ==Geology== The basement rock of most of Africa was formed in the Precambrian and is much older than the Atlas Mountains lying in Africa. The Atlas formed during three subsequent phases of earth's history. 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 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) and consisted of 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. Finally, in the Paleogene and Neogene Periods (~66 million to ~1.8 million years ago), the mountain chains that today comprise 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 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. In fact, one of 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.〔(UAB.es ) Potential field modelling of the Atlas lithosphere〕〔(UAB.es ) ''Crustal structure under the central High Atlas Mountains (Morocco) from geological and gravity data'', P. Ayarza, et al., 2005, Tectonophysics, 400, 67-84〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Atlas Mountains」の詳細全文を読む スポンサード リンク
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