Here's why:
* Subduction Zones: The Andes are formed at a convergent plate boundary where the denser oceanic Nazca Plate is forced beneath the less dense continental South American Plate.
* Volcanic Activity: This subduction process leads to the creation of volcanoes along the Andes, as magma rises from the melting of the descending Nazca Plate.
* Mountain Building: The collision and compression of the plates also causes the uplift of the Andes, creating the towering mountain range.
