Formation of Fold Mountains
Fold mountains form along both destructive and collision plate boundaries.
- They form when two plates with landmasses on them move towards each other.
- The plates push layers of accumulated sediment in the sea into folds between them.
- This becomes a fold mountain range.
- Most fold mountains continue to grow as the plates constantly move.
- Examples: the Himalayas (Asia), Rockies (USA), Andes (South America), Alps (Europe)
This video explains how tectonic activity forms moutain ranges
Human effect of Fold Mountain Ranges
There are both positive and negative effects for the people living in these mountain ranges.
Tourism is a positive effect with hill walking, attractive scenery, river rafting, and climbing attracting people. However, building tourist facilities such as hotels and restaurants is difficult due to the lack of flat land. Skiing is a popular tourist activity in winter e.g. in the Alps and Rockies.
Tourism can have negative impacts on the local environment and people. There can be a constant threat of avalanches in winter which have to be monitored with huge amounts of money being spent to combat the avalanche threat, especially where many tourists use the mountains. Tourists also bring congestion, litter and pollution problems.
This video shows a model of an avalanche is created using flour and powdered potato in layers to represent the different types of snow fall during a season. The layers slip past each other when disturbed by an object, a process that is analogous to using a lubricant to reduce the friction between two surfaces.
Farming is the main primary activity but often only cattle and sheep rearing is possible due to the very cold, wet climate, the altitude and steepness of the slopes. Agricultural machinery is difficult to use and there is a very short growing season. In mountains such as the Andes and Himalayas, terraces (steps) have been cut into the hillsides to allow crops such as vines and fruit to be grown.
Forestry is a key economic activity with the planting and harvesting of trees e.g. in the Alps. There are times, however, when forestry can be damaging e.g. in the Himalayas local people and logging companies have cut down large numbers of trees causing large-scale deforestation which leads to problems of soil erosion and flooding.