Here's how:

* Subduction Zones: At convergent boundaries, one tectonic plate (the denser oceanic plate) slides beneath another (the less dense continental plate) in a process called subduction.

* Magma Generation: As the oceanic plate descends, it melts due to the intense heat and pressure. This molten rock, or magma, rises to the surface.

* Volcanic Activity: The rising magma erupts through the Earth's crust, forming volcanoes. Over time, these eruptions can create a chain of volcanoes along the coast, forming a volcanic mountain range.

Examples:

* The Andes Mountains: This mountain range along the western coast of South America is a prime example. It's formed by the subduction of the Nazca Plate under the South American Plate.

* The Cascade Range: Located in the western United States, this range includes Mount Rainier, Mount Hood, and Mount St. Helens. It's formed by the subduction of the Juan de Fuca Plate under the North American Plate.

Other factors:

While convergent boundaries are the primary mechanism for forming volcanic mountain ranges near coastlines, other factors can influence their development:

* Hot Spots: Volcanic activity can also occur due to hot spots, which are areas within the Earth's mantle where unusually hot magma rises. These hot spots can create volcanic islands or mountain ranges even far from plate boundaries.

* Back-arc Basins: In some cases, volcanic activity can occur behind the arc of volcanoes formed at a convergent boundary. This can lead to the formation of basins and the creation of more volcanic features.

In conclusion, volcanic mountain ranges near coastlines primarily form at convergent plate boundaries, specifically subduction zones. However, other factors like hot spots and back-arc basins can also contribute to their formation.