Wherever lithospheric plates move towards one another and meet, a convergent plate boundary is located. In areas where convergence occurs, volcanic activity, crust formation, and earthquakes occur. The overall outcome of two plates converging depends on the margin and plate type. There are only three convergent boundary types that exist.
Oceanic-continental convergences are created whenever an oceanic plate pushes into and moves underneath a continental plate. The continental plate that overrides the oceanic plate actually lifts up to create a mountain range. As the oceanic plate sinks, it slides into the newly formed trench, and smaller pieces break off. The pieces remain in place for years until generating earthquakes that lift up the land.
Oceanic-oceanic convergences occur when two oceanic plates meet and one oceanic plate is pushed underneath the other. During that process of subduction, a deep trench is formed. The Marianas Trench is an example of an oceanic-oceanic convergence. The southern end of the Marianas Trench plunges 11,000 meters into the earth's interior. Volcanoes also form as a result of an oceanic-oceanic convergence.
Continental-continental convergences are different from two oceanic plates meeting together. Continental crusts are too light to be carried down into a trench. As a result, neither plate is pushed underneath the other. The continental plates converge, buckle, and later compress to create tall mountain ranges on earth. The Himalayas are an example of a mountain range formed from continental-continental convergence.