In this section, we focus on how plate tectonics causes the formation of mountains on Earth. The theory of plate tectonics explains how mountains form on Earth. When two plates of similar density and containing continental crust collide and converge at a convergent boundary, the crust within the plates folds, crumbles, thickens, and rises to cause the uplift of Earth’s surface. This process is called mountain building (or orogeny). Note that mountains can also form at divergent plate boundaries due to a different mechanism that will not be explored here. During this mountain-building process, rock undergoes significant stress leading to geological hazards such as earthquakes and landslides. The stress on rocks can also lead to the formation of unique geological structures such as folds, faults, and foliations. In this section, we will also focus on the Himalaya, the Andes, and the Appalachian Mountain ranges.

The video below demonstrates a simple experimental model to help visualize and explain mountain building at a convergent boundary.