CONVERGING PLATES: OCEANIC/CONTINENTAL and OCEANIC/OCEANIC
As new crust is formed by diverging plates, old crust must be "destroyed" where plates converge. Where a plate of oceanic crust converges with a plate of continental crust, the denser oceanic crust will move under the continental crust. This process is called subduction. It is through this process that mountains and volcanoes are formed as the continental crust is compressed and lifted, while subducted oceanic crust is melted and recycled to the surface. (see figures 2). The west coast of North and South America are examples of this process. Where two oceanic crusts converge, the older (more dense) crust will subduct under the newer (less dense) one, which leads to volcanic ring islands being formed (Japanese Islands, see figure 3).