ICSE Class 9 Answered

Fold Mountains are caused due to large scale movements taking place inside the Earth’s crust. These movements are caused due to various factors like movements in the mantle, expansion and contraction of some parts of the Earth etc. These are horizontal movements. Fold mountains are formed when two tectonic plates move towards each other leading to the folding of the layers of the Earth. The up folds are called anticlines and the down folds are called synclines.

Block Mountains are formed when two tectonic plates move away from each other causing cracks on the surface of the Earth. When parallel cracks or faults occur, the strip of land or the block of land between them may be raised resulting in the formation of block mountains. The upward block is called a horst.