Valleys and mountain ranges form through a process called tectonic activity. It involves the movement and collision of large pieces of the Earth's crust called tectonic plates. As these plates collide, they can push against each other, causing Earth's crust to buckle and fold, forming mountain ranges. At the same time, they can also create fault lines, where the Earth's crust breaks and slips, leading to the formation of valleys. Over millions of years, these processes of plate movement, folding, and faulting shape the landscape and create the vast mountain ranges and deep valleys we see today.
