destructive plate boundary

contains destructive plate boundary activity otherwise known as a convergent plate boundary, oceanic plate and continental plate definitions, collision margin

destructive plate boundary is where a denser, thinner oceanic plate (plates which carry ocean on top, they cover the ocean floor and are primarily built of basalt.) is subducted under a lighter, thicker oceanic plate (the plate which carries land). when the oceanic plate sinks into the mantle, it melts to form magma. the pressure of the magma is built up beneath the earths surface, then the magma escapes through weaknesses in the rock and rises up through a composite volcano. The volcanic eruptions are often violent, with lots of steam, gas and ash.

However, if two continental plates collide in a destructive plate boundary, neither can sink and so the land buckles upwards to form fold mountains. This is called a collision margin. Earthquakes can occur at collision margins.