Quick Facts:
1. When tectonic plates collide the sedimentary rocks that have built up between them are folded and forced upwards to form mountains 2. Fold mountains are found at destructive plate margins or where there used to be destructive plate margins, for example the west coast of North America 3. You get fold mountains where a continental plate and an oceanic plate collide, for example the Andes in South America 4. You can also get fold mountains where two continental plates collide, for example the Himalayas in Asia Humans use Fold Mountains areas for loads of things: Farming: Higher mountain slopes are not great for crowing crops but they are useful for grazing animals e.g. mountain goats. Lower slopes are used to grow crops. Steep slopes can be terraced as as form of way to make growing crops easier. Seen in the image just above. Mining: Fold mountains are a major source of metal ores, so there's a lot of mining that can be seen. the steep slopes mean access to the mines are difficult, so a zig-zag formation of roads have been carved out of the sides of some mountains to get to them. Forestry: Fold mountain ranges are a good environment to grow some types of trees e.g. conifers. They're grown on the steep valley slopes and are used for things like fuel, building materials, and to make things like paper and furniture. Hydro-Electric Power (HEP): steep sided mountains and high lakes (to store water) make fold mountains an ideal location for generating HEP. Tourism: Fold mountains have spectacular scenery, which attracts tourists. In winter, people visit to do sports like skiing, snowboarding and ice climbing. In summer, walkers come to enjoy the scenery. Tunnels have been drilled through some fold mountains to make straight, fast roads. This will also improve communications for tourists and people who live in the nearby areas. |
Case Studies:
Fold mountains are the most common type of mountain in the world. The soaring heights of the Himalayas, Andes, and Alps are all active fold mountains. The Himalayas stretch through the borders of China, Bhutan, Nepal, India, and Pakistan. The crust beneath the Himalaya, the most towering mountain range on Earth, is still the process of being compressed. Here, the Indian plate is colliding northward with the Eurasian plate. The Andes are the world’s longest mountain chain. They stretch along the entire west coast of South America, from Colombia in the north and through Ecuador, Peru, Bolivia, Chile, and Argentina to the south. Here, the dense oceanic crust of the Nazca and Antarctic plates is sub-ducting beneath the less-dense continental crust of the South American plate. The Andes are mostly being folded and uplifted from the thicker, less-dense rocks of the South American plate. The sedimentary and metamorphic rocks of the Andes are dotted by active and dormant volcanoes. The Alps roughly mark the top of the “boot” of the Italian Peninsula. The Alps stretch across Italy, Slovenia, Austria, Germany, Switzerland, Lichtenstein, Monaco, and France. Here, the tiny Adriatic plate is colliding with the much larger Eurasian plate to the north. The J-shaped Adriatic plate is a remnant of the African plate to the south, and today it carries the eastern Italian Peninsula as well as the entire Adriatic Sea. The Appalachians, stretching along North America’s east coast, are generally low-lying, gentle slopes. Millions of years ago, the Appalachians were taller than the Himalayas! Millions of years of erosion, however, have taken their toll. Today, some of the highest peaks of the Appalachians are less than a third of the height of Everest. The crust that is now the Appalachians began folding 480 million years ago, when the North American and African continental plates collided. Plate tectonics created this ancient mountain range, then called the Central Pangean Mountains . . . and plate tectonics tore it apart. As tectonic activity ripped apart the ancient supercontinent Pangea, the African, Eurasian, and North American plates drifted apart. The Appalachians are just one remnant of the Central Pangean Mountains. The Appalachians stretch from the province of Newfoundland, in southeastern Canada, through the southern state of Alabama in the U.S. |