What is a Destructive Plate Margin?

This is when a Oceanic plate collides with a Continental plate. The Oceanic plate is forced under the Continental plate as because its heavier. It Subducts. As the plate sinks into the mantle or Lithosphere, it melts to become magma. This newly formed magma, along with the other magma in the mantle builds pressure below the Crust. It then escapes by going through the weakness in the rock and becomes a Composite Volcano.