Tectonic plates collide at convergent plate boundaries. This module shows the processes through which continents split to make new divergent plate boundaries and how earth"s ocean basins are formed. Differentiate the three types of convergent margins and associated landforms. Convergent margins are places where two plates collide. When two tectonic plates with oceanic crust converge on each other, the denser of the two plates begins to subduct under the other. The density of a plate is related to its age. As oceanic curst is pushed away from a mid ocean ridge, it cools and thickens, and become metamorphosed by circulating hydrothermal fluids, increasing its overall density. As the subducting slab of oceanic crust descends into the mantle, it triggers melting and magma production, resulting in the formation of a volcanic arc in the overriding plate above. The mariana trench is the deepest feature on planet earth and marks the point where the.