Convergent plate borders are classified into three types: oceanic-oceanic boundaries, oceanic-continental boundaries, and continental-continental boundaries. Because of the density of the plates involved, each one is unique.
Oceanic-Oceanic Boundaries, When two of oceanic plates collide, the denser plate descends beneath the lighter plate, resulting in the formation of dark, heavy basaltic volcanic islands.
Oceanic-Continental Boundaries, When the oceanic and continental plates meet, the oceanic plate subducts, causing volcanic arcs to form on land. These volcanoes spew lava that contains chemical remnants of the continental crust through which they rise.
Continental-Continental Boundaries, Large slabs of crust collide at continental-continental convergent borders. As a result, relatively little subduction occurs since the majority of the rock is too light to be dragged very far down into the deep mantle.
