Atlas Mountains

Atlas Mountains
	Jbel Toubkal in Toubkal National Park in the High Atlas
Countries	Morocco, Algeria, Tunisia
Highest point	Jbel Toubkal
- elevation	4,167 meters (13,671 feet)
	Location of the Atlas Mountains (colored red) across North Africa

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The Atlas Mountains (Arabic: جبال الأطلس ) are a series of mountain peaks that run along the northwestern portion of the African continent, extending through modern day Morocco, Algeria, and Tunisia. The terrain of the Atlas Mountain range is particularly difficult to cross due to its extrememly high peaks, reaching a towering 4,167 meters (13,671 ft) at its high point Jbel Toubkal in southwestern Morocco. Other notable peaks are slightly smaller, particualrly mountain M'Goun, which measures 4071 meters. The difficult terrain of the Atlas Mountain Range extends 1,500 miles, and for this reason the range served in the past to geographically seperate the northern coastline of Africa from the Saharan desert. While the range has been passable for many centuries, evidence of the historical divide is still present in cultural and societal differences on opposite sides of the range. The region is rich in iron ore, lead ore, copper, silver, mercury, rock salt, phosphate, marble, anthracite coal and natural gas among other resources.

For ease of discussion and study the Atlas Mountain Range is commonly divided into six seperate ranges: Middle Atlas, High Atlas, Anti-Atlas, Tell Atlas, Saharan Atlas, and the Aurès Mountains.

Geology

File:Atlas-Mountains-Labeled-3.jpg

Map showing the location of the Atlas Mountains across North Africa

While much of the bedrock ofraced to the African continent was formed in the early Precambrian Era, the foundation of the Atlas Mountain range was formed much later. The beginnings of the Atlas range can be traced to three disctinct stages:

Over 80 million years ago, the first phase of Atlas Mountain formation began. This stage consisted of a series of continental collisions between African and Eurasian plates. The collisions forced layers of limestone and sandstone up from the earth, effectively forming the first level of the mountain range. In the section of the Atlas Range termed the High Atlas the continental collisions resulted in extremely high outcroppings of stone. In other areas, such as the Anti-Atlas, only small outcroppings resulted.

In the second stage of geological development the earth's crust significantly expanded, resulting in a seperation of many pervious continental formations. When the continents broke apart, many sedmentary basins were formed, including the Atlas Mountain Range.

The tectonic boundary.

The first 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 in the eastern United States. Some remnants can also be found in the later formed Appalachians in North America.

The last stage of geological development was marked by a massive continental collision between the southern end of the Iberian peninsula and the European plate. However, this continental collision was remarkable different that the first stage of development. When the mountains were first being formed the collisions between continents pushed excess material upwards, forming a mountain ridge along the line of collision. In the the continental collisions that took place in the third stage of development geologists are divided as to whether this type of collision took place. While the most probable method of geological formations involved continental plates sliding over one another, there is very little evidentiary support for this hypothesis. On the other hand, there is also little support for a violent, rock-spewing collision. Geologists are often suprised by how little evidence crust thickening or plate shortening is found in the region. A new theory claims that processes deep within the earth's mantle may have contributed to the development of the Atlas mountain range. [1]^{[citation needed]} Recent studies suggest that deep processes rooted in the Earth's mantle may have contributed to the uplift of the High and Middle Atlas.[2]

Seismic activity

While the Atlas Range owns its formation to the shifting of the earth, the ramifications of living on a fault line have had a marked impact on the civilizations that call the Atlas their home. The city of Blida, located in the center of the Tell Atlas range, suffered a fatal blow in the 19th century from a strong earthquake. The city of 265,000 inhabitants was completely destoryed. A similiar instance occurred in 1980, when a 7.3 magnitude Richter Scale quake rocked the small city of Ech Cheliff. The city suffered 5,000 fatalies in the earthquake.

Atlas Range Subdivisions

The range can be divided into six general regions:

Middle Atlas
High Atlas
Anti-Atlas
Tell Atlas
Saharan Atlas
Aurès Mountains.

Middle Atlas range

Located in the central portion of Morocco, the Middle Atlas Range lies north of the High Atlas and west of the Tell Atlas, stretching for 700 km. Overall, it is distinguished by a high average peak height, with many individual mountains reaching altitudes upwards of 8,000 feet. The highest peak for this section of the Atlas Mountain range is Jbel Bou Naceur, which measures 3340 meters. It is a common site for hikers and adventures looking to explore the beauty of the Atlas Range. One of the attractions of the Middle Atlas is it pleasant environment, as much of the range is covered by green plant growth and recieves a large annual percentage of rainfall. In fact, the Middle Atlas hosts a ski resort in the town of Ifrane, an unusual occurance in northern Africa that takes advantage of annual snowfall to attract tourists and sportspeople.

The Middle Atlas snowfall and rain provides a valuable source of water for the region. Precipitation is naturally collected at four major locations:

The basin of Sebou: discharging to the Atlantic Ocean.
The basin of Oum Errabiaa: discharging to the Atlantic Ocean.
The basin of Bouregreg: discharging to the Atlantic Ocean.
The basin of Moulouya: drains to both the Middle and the High Atlas, as well as the Mediterranean Sea.

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. In this chaos of rocks the contrasts are astonishing: 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.

Dades-Tal (a Kasbah) in the High Atlas

The range includes Jbel Toubkal, which at 4,167 m 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's climatic influences, which are particularly pronounced in the summer, from the more Mediterranean climate to the north, resulting in dramatic changes in temperature across the range. In the higher elevations in the range snow falls regularly, allowing winter sports. Snow lasts well into late spring in the High Atlas, mostly on the northern faces of the range.

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.

Panoramic picture of the artificial lake of Lala Takerkoust near Barrage Cavagnac, with the hydroelectric dam (extreme right)

Near Barrage Cavagnac, there is a hydroelectric dam that has created the artificial lake Lala Takerkoust. The lake serves also as a source for fish for the local fishermen.

The largest villages and towns of the area are Tahanaoute, Amizmiz, Asni, Tin Mal, Ijoukak, and Oukaïmden.

Anti-Atlas ranges

The Anti-Atlas range is found in Morocco, where it lies between a large plateau and an extensive plain. This section of the Atlas mountain range is most extreme western border, reaching all the way to the Moroccan shores of the Atlantic Ocean. In total the Anti-Atlas range spans for approximately 500 km, and contains many peaks that exceed 6,000 feet in altitude.

Geologically, the Anti-Atlas is distingushed by a large concentration of grantite boulders that form a breathtaking visual effect. It also boasts silicia rich soil that has become compacted to form access routes through the range. The rock structures in the Anti-Atlas date from the Pre-Cambrian period, a fact which makes than older than the formations found to the north west in the High Atlas.

Tell Atlas range

Main article: Tell Atlas

Panoramic view of typical Berber village (Morocco - High Atlas Mountains).

The Tell Atlas is a mountain chain over 1,500 kilometers 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 high plateau, with lakes in the wet season and salt flats in the dry.

Saharan Atlas range

Main article: Saharan Atlas

The Saharan Atlas of Algeria is the eastern portion of the Atlas mountain range. 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 tallest peak in the range is the 2236 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.

Aurès mountain range

Main article: Aurès Mountains

The Aurès Mountains of Algeria and Tunisia are the furthest eastern portion of the Atlas mountain range.

References and notes

Britannica Retrieved October 3, 2007.
Davies, Claude. Climbing in the Moroccan Anti-Atlas: Tafroute and Jebel El Kest. 2004: Cicerone Press. ISBN 1852844124
Smith, Karl. Trekking in the Atlas Mountains. 2Rev Ed edition. 2004: Cicerone Press. ISBN 1852844213
McGuiness,Justin. Footprint Marrakesh & the High Atlas Handbook. 2001: Footprint Handbooks. ISBN 1903471125

External links

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