30-09-2010, 04:46 PM
|
 | HALAKU KHAN | | Join Date: Jul 2010 Location: PAKISTAN Age: 41
Posts: 373
Contact Number: +923007970483 Program / Discipline: Mass Communication Class Roll Number: 32456 | |
 Mountains Around The World
Mountains Around The World
Around 40 million years ago, the Australian-Indian plate was drifting northwards towards the Eurasian plate. Ancient rock on the sea floor between them was gradually pushed upwards to form the beginnings of the Himalayas and the Tibetan plateau. Eventually the Indian plate moved under the Eurasian plate, pushing up the mountains further still.
Mountains around the World
Image Credit
Mountains around the World
Image Credit
A mountain is defined as an upward projection of the Earth’s surface with an altitude of at least 600m (1968 ft). Most major mountain ranges from where two of the Earth’s plates push together, which is also where most volcanoes occur. The process that produced mountains are collectively called orogenesis, from ‘oros’ meaning mountain, and ‘genesis’, to come into being. There are three types of mountain – fold, fault-block, and volcanic. Weathering and erosion, especially by glaciers, gradually break up a range and create individual peaks. Individual mountains that are not part of a range are known as monarchs.
The Andes
Image Credit
The range is one of the youngest. It began forming 4.5 million years ago.
The Andes run almost the entire length of South America. The system is divided into two parallel ranges; the older eastern range: the Cordillera Oriental, and the younger, western range, the Cordillera Occidental. They are separated by a high-altitude plateau called the Altiplano. Types of Mountains  Image Credit Fold Mountains form where layers of folded rock are pushed upwards along the edge of a continental plate as two plates collide. Most mountains formed this way, including the Alps, Himalayas and Appalachians.  Image Credit Fault-Block Mountains are formed by the displacement of rock along a fault in the Earth’s crust. The Sierra Nevada in California, the Grand Tetons in Wyoming, and the mountains along the East African Rift Valley formed this way. Old and New  
Last edited by .BZU.; 01-10-2010 at 01:10 AM.
Reason: links removed from othersites
|