Earth consist of large number of mountains. Large portion of earth’s surface is make up with mountains. The mountains are classified into four according to the mode of formation.
1. Fold Mountains
- The mountains formed by the movement of the earth whenstresses developed in the Earth’s crust.
- Due to these stresses compressive forces are developed causes the uplifting of the center
- The up folded part part is called anticline and down folded part is called syncline.
- The mountains of Himalayas, Rockies, Alps etc are formed due to the compressional forces.
- These fold mountains are also called mountains of elevation
- These fold mountains contains active volcanoes except Himalayas
2. Block Mountains
- When the Earth’s crust cracks faulting occurs, which causes the lengthening or shortening of the earth’s crust
- The movement of generate tensional forces that pulls the crust and faults are developed
- Thus the standing up mountains became the block or block mountains called as horst.
- The tension causes the formation of rift valley or graben.
- The Black forest of Rhineland is an example of block mountain.
3. Volcanic Mountains
- It is a mountain or hill of conical shape in which molten lava is ejected from the Earth’s crust.
- They are common in the Circum Pacific belt, Mount Fuji is an example.
- It consist of solid ,liquid and gaseous materials.
- The rising of lava is due to endogenic force
4. Residual Mountain
- The mountains formed due to denudation ie formed by the wearing of the earth’s surface by moving water or wind.
- The height of the land will be decreased by the eroding agent.
- These may also formed by the plateau which have been eroded by the rivers or by eroding high mountains.