Wanderlust World Wanderlust World The Andes formed from the subduction of the Nazca Plate beneath the South American Plate. As the Nazca Plate moves eastward, it melts, producing magma that rises to form volcanoes, building the range. The process continues today.
The Cascades formed similarly from the subduction of the Juan de Fuca Plate beneath the North American Plate. Ongoing subduction fuels volcanic activity and mountain growth.