Fold Mountains case study - Andes

Authors Avatar by margartiam (student)

Fold Mountain Case Study – The Andes

The Andes Mountains run the length of the West Coast of South America, rising in the North in Colombia and finishing in Chile and Argentina in the South.   They are world's longest mountain range running for over 7,000km and covering 6 countries. 

The mountains have been formed as a result of the convergence of the Nazca plate and the South American plate.  The heavier oceanic crust of the Nazca plate is pushed towards the South American plate, and because it is denser is subducted underneath.  The South American plate is less dense so sits on top of this subduction zone, but the rocks of the South American plate have been folded upwards and crumpled into Fold Mountains.  There are also Volcanoes and earthquakes along this destructive plate boundary - earthquakes caused by stresses building up as the 2 plates try to move past one another, and volcanoes caused by magma working its way up through vents in the Earth's crust.  This has created a sequence of volcanoes and Fold Mountains, rising up to 6962m at Aconcagua.  The trench (marking the boundary between the Nazca and South American plates) to the West of the Andes Mountains is called the Peru-Chile Trench, and reaches an incredible depth of 8066m under the sea level.

These areas are very hard to live in because of the physical geography.  The relief is very steep making farming difficult, and the high altitude makes breathing difficult.  The mountainous terrain makes it difficult to construct roads and railways to allow for communications.

Uses of the Andes


The mountain slopes of the Andes are used for a variety of farming practices.  The best land can be found on the valley floors, but an ingenious system of terraces dug into the valley sides and held up by retaining walls has been used to bring the lands on the valley sides into food production.  The flat terraces help to hold up water in a region where there are marked shortages. Most crops are grown in the lower areas and include soya, maize, rice and cotton. However, the main staple crop of the Andes is the potato, and there are hundreds of different varieties found in the mountains. 

Join now!

Most farming is subsistence, with the food grown for personal consumption, but there is some commercial farming.


Llamas are synonymous with the Andes. They are the pack animals, carrying irrigation and building materials into inhospitable and hard to reach areas for 100s of years. Ancient settlement of Machu Picchu relied on Llamas to transport materials and goods due to its remote location. Llamas are very well adapted to living in the harsh environment of the Andes. They have an unusual way of moving; they pace, which means that both legs on the same side rise together so they ...

This is a preview of the whole essay