Final answer:
Mountain building occurs due to the collision of tectonic plates, resulting in the formation of mountain ranges like the Himalayas and the Appalachian/Caledonide Mountains.
Step-by-step explanation:
Mountain Building Examples
Mountain building occurs when two tectonic plates collide, pushing against each other under great pressure. One example of mountain building is the formation of the Himalayas, which resulted from the collision between the African and Eurasian plates.
Another example is the Appalachian/Caledonide Mountains, which formed during three separate tectonic events over a period of 220 million years. These events were the Taconic, Acadian, and Alleghenian orogenies.