Here's why:
* Active margins are where an oceanic plate subducts beneath a continental plate.
* Subduction causes the sinking plate to melt, generating magma.
* This magma rises to the surface and erupts, forming volcanoes.
* Over time, these volcanic eruptions can build up layers of lava and ash, creating volcanic mountains.
Examples of volcanic mountains formed at active continental margins include:
* The Andes Mountains in South America
* The Cascade Range in North America
* The Mount Fuji in Japan
While folded mountains can also occur at active margins, their formation is more common at convergent plate boundaries where two continental plates collide.
