Valleys and mountain ranges form through a process called tectonic activity. The Earth's crust is made up of several large plates that move slowly over time. When tectonic plates collide, they can create intense pressure, causing the crust to fold and buckle. This folding results in the formation of mountain ranges. Additionally, as the crust is compressed, it can also fracture and create deep, elongated depressions called valleys. Other factors such as erosion by water and ice can further shape these landscapes over time.
