Mountains are primarily formed at convergent plate boundaries, where tectonic plates collide. Here's a breakdown of how different types of convergent boundaries create mountains:

1. Oceanic-Continental Convergence:

* Process: A denser oceanic plate subducts (sinks) beneath a less dense continental plate.

* Mountains formed: Volcanic mountain ranges and folded mountains.

* Examples: The Andes Mountains in South America, the Cascade Range in North America.

2. Oceanic-Oceanic Convergence:

* Process: Two oceanic plates collide, and one subducts beneath the other.

* Mountains formed: Volcanic island arcs.

* Examples: The Mariana Islands in the Pacific Ocean, the Aleutian Islands in Alaska.

3. Continental-Continental Convergence:

* Process: Two continental plates collide. Neither plate is dense enough to subduct, so they buckle and fold.

* Mountains formed: Folded mountains and plateaus.

* Examples: The Himalayas in Asia, the Alps in Europe.

Note: While most mountains are formed at convergent boundaries, some mountains can also form at divergent boundaries, though these are less common.

Divergent Boundaries:

* Process: Plates move apart, creating space for magma to rise.

* Mountains formed: Mid-ocean ridges, volcanic mountains, and rift valleys.

* Examples: The Mid-Atlantic Ridge, the East African Rift Valley.