Mountains
Mountains are some of the Earth’s most dramatic landforms. They are formed by powerful forces deep within the planet, mainly caused by the movement of tectonic plates. Mountain ranges can take millions of years to form and continue to change as plates move, collide, and pull apart.
How Mountains Are Formed
Most mountains form as a result of tectonic plate movement. When plates interact, the Earth’s crust can be pushed upwards, folded, fractured, or built up by volcanic activity. The way a mountain forms depends on the type of plate boundary involved.
Fold Mountains (Collision of Plates)
Fold mountains form when two continental plates move towards each other. Because continental crust is buoyant, neither plate sinks beneath the other. Instead, the crust crumples and folds upwards, creating large mountain ranges.
The Himalayas are a famous example. They formed when the Indian Plate collided with the Eurasian Plate. This collision is still happening today, causing the mountains to slowly rise and making the region prone to earthquakes.
Fault-Block Mountains (Crust Breaking and Lifting)
Fault-block mountains form when the Earth’s crust is stretched and fractured. Large blocks of crust move up or down along faults, creating steep-sided mountains and valleys.
An example of fault-block mountains can be found in parts of the western United States, such as the Sierra Nevada. These mountains formed as blocks of crust were uplifted while surrounding land dropped down.
Volcanic Mountains
Volcanic mountains form when magma rises through the Earth’s crust and erupts at the surface. Over time, repeated eruptions build up layers of lava and ash, creating mountains.
Many volcanic mountains are found at destructive plate boundaries or hotspots. Mount Fuji in Japan and Mount Etna in Italy are well-known examples. These mountains are often steep-sided and can be dangerous due to explosive eruptions.
