Mountains form as a result of disturbances in the Earth’s crust, erosion and volcanism. The most common way that mountains form is when the Earth’s tectonic plates collide. Tremendous forces cause places with a steep top to shape up to a peak or ridge.
According to geologists, most mountains are created from geological forces, heat and pressure. These elements produce changes and movements in the Earth’s crust. This is called plate tectonics, which is a theory that states that the Earth’s crust is divided into various rigid plates that move a few centimeters each year. Various geologic processes occur when these plates collide, resulting in a crustal uplift. Horizontal compression, which involves the deformation of crustal strata and causes folds or wrinkles, also triggers other geologic processes. For example, the Himalayas formed from the collision and compression of the Indian plate against the Eurasian plate.
Low mountains are typically formed through nontectonic processes and differential erosion. The shapes of mountains are affected by erosion through the combined effects of rain, wind and ice.
Another way that mountains form is through volcanic activities below the Earth’s surface. Magma cools and becomes hard rock when it rises to the surface. Eventually, it reveals a dome-shaped mountain when the softer rock above it erodes.