Oceanic-continent convergence: When the two different types of plates converge, subduction occurs where the denser oceanic plate goes beneath the continental plate. The entire region of subduction is called the subduction zone. The subducting oceanic plate causes melting in the Earth’s mantle, creating volcanoes. The resulting volcanoes are known as the continental arc. Felsic (viscous) magma at a continental arc cools to form large structures of igneous rock called batholiths, which may eventually become mountain ranges.
Oceanic-oceanic convergence: This type of convergence also results in subduction and subduction zones. These subduction zones create continental arcs known as island arcs. Subduction zones that are no longer active are ocean trenches. These trenches mark the place where an ocean plate is pushed down. The plate that gets pushed up forms volcanoes. When these volcanoes erupt, islands form.
Continental-continental convergence: Continental crust is too buoyant to subduct, therefore when two continental plates collide they go up, forming mountain ranges. The stress the two plates experience form many metamorphic rocks. Because of the stress, earthquakes are also common in areas where there are a lot of mountains.