The Atlas Mountains is a mountain range across the northwestern stretch of Africa extending
about 2,500 km through Algeria, Morocco and Tunisia. The highest peak is Toubkal, with
an elevation of 4,165 metres 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 have been 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, the Barbary Leopard, the Barbary stag, Barbary Sheep, the Barbary Lion, the
Atlas Mountain Badger, the North African Elephant, the African Aurochs, 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 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 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, 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 and/or a continental collision. 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. Natural resources
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. Subranges of the Atlas Mountains
The range can be divided into four general regions:
Tell Atlas. Saharan Atlas.
Aurès Mountains. Middle Atlas, High Atlas, and Anti-Atlas.
Middle Atlas range
The Middle Atlas is a portion of the Atlas mountain range lying completely in Morocco.
The Middle Atlas is the westernmost of three Atlas Mountains chains that define a large,
plateaued basin extending eastward into Algeria. South of the Middle Atlas and separated by
the Moulouya and Oum Er-Rbia rivers, the High Atlas stretches for 700 kilometres with a
succession of peaks among which ten reach above 4,000 metres. North of the Middle Atlas
and separated by the Sebou River, the Rif mountains are an extension of the Baetic Cordillera
in the south of Spain. High 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. 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.
On the heights of Ouarzazate the massif is cut through by the Draa valley which opens
southward. Here, water runs in some places, forming clear basins. It is mainly inhabited
by Berber people, who live in small villages and cultivate the high plains of 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 the area are Ouarzazate, Tahanaoute, Amizmiz, Imlil,
Tin Mal and Ijoukak. Anti-Atlas ranges
The Anti-Atlas extends from the Atlantic Ocean in the southwest of Morocco toward the northeast
to the heights of Ouarzazate and further east to the city of Tafilalt. 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 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.
Saharan Atlas range
The Saharan Atlas of Algeria is the eastern portion of the Atlas mountain range. Though
not as high as the Grand Atlas, they are far more imposing than the Tell Atlas range that
runs to the north of them and closer to the coast. The highest peak in the range is the
2,236 m high Djebel Aissa. They mark 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.
Tell Atlas range
The Tell Atlas is a mountain chain over 1,500 kilometres in length, belonging to the Atlas
mountain ranges and stretching from Morocco, through Algeria to Tunisia. It parallels the
Mediterranean coast. Together with the Saharan Atlas to the south it forms the northernmost
of two more or less parallel ranges which gradually approach one another towards the
east, merging in Eastern Algeria. At the western ends at the Middle Atlas range in Morocco.
The area immediately to the south of this range is the high plateau of the Hautes Plaines,
with lakes in the wet season and salt flats in the dry.
Aurès mountain range
The Aurès Mountains of Algeria and Tunisia are the farthest eastern portion of the Atlas
mountain range. The Aurès natural region is named after the range.
See also Capsian culture
North Africa References and notes
^ http:www.britannica.comtopicBerber ^ UAB.es Potential field modelling of the
Atlas lithosphere ^ UAB.es Crustal structure under the central
High Atlas Mountains from geological and gravity data, P. Ayarza, et al., 2005, Tectonophysics,
400, 67-84 ^ Des Montagnes du Sarho aux dunes de Merzouga
^ Algeria - Ethnic Groups and Languages