Associated with plate tectonics is the process which in the Pacific is known as the ring of fire. As the oceanic plates are subducted under the continental plates volcanic mountain chains are formed. The subducting oceanic plate is melted as it descends deeper into the Earth’s crust under the edges of the over-riding continental plates. This hot melted oceanic material is lighter or more buoyant than the denser continental plate. Thus the molten material from the subducting oceanic plate rises through fissures or faults in the overlying continental plate and eventually emerges onto the surface of the continental plate. This process forms the volcanoes which ring the perimeter of the Pacific Ocean basin.