Mountains are an outcome of the movements of the Earth’s crust, which is the Earth’s outer layer. The Earth’s crust consists of six massive slabs referred to as tectonic plates, which are always moving a few centimeters annually. Two tectonic plates moving against each other cause the thickening and deformation of the crust and land mass is forced upwards to form mountains. Over time, mountains are subjected to erosion from elements such as the wind, ice, and rain, causing their surfaces to be younger than the rocks which initially formed them. Depending on the tectonic forces at work, different types of mountains are formed.
Mountains take millions of years to form. Huge movements deep in the centre of the Earth slowly push rocks into mountain shapes. Some mountains, like the Urals in Russia, started to form about 250 million years ago.
The Earth’s surface is like a rocky jigsaw.
The outer layer of the Earth is made from giant pieces of rock called plates which lie on top of boiling hot, runny rock called ‘magma’. The plates move about a thumb’s length each year, but we can’t feel them moving. When the plates push into or pull away from each other, rock is forced upwards forming a mountain. This aerial view shows a fault in Tibet in Asia. The Kunlun fault is 1,500 km long. It can be seen running from left to right. Lines of vegetation are shown in red.
Some mountains are still growing!
Some plates that collided millions of years ago are still pushing together, and causing the land to rise upwards. The Himalayas in Asia grow about six centimetres each year. Soft soil above the Asian plate is rising because it is being pushed by the stronger Indian plate.
Geologists study mountain rocks.
Geologists are scientists. They study rock layers and the ways that rocks form. Bu examining rocks, they are able to work out how a mountain formed and even how old it is! Geologists use a range of tools, from hammers and chisels to drills, satellites and computer technology.
Picture Credit : Google