Plate boundary

Types and description of each plate boundary (examples given)

constructive

Occurs when plates move apart. Volcanoes are formed as magma wells up to fill the gap, and eventually new crust is formed

example (Iceland)

Destructive

When oceanic and continental plates move towards each other. The heavier, denser oceanic plate is forced under the continental plate. As it sinks below the continental plate the oceanic plate melts due to friction in the subduction zone. The crust becomes molten called magma

example (Andes - South America)

Collision

This is when two continental plates collide. Neither plate is forced under the other, therefore both are forced up and form fold mountains

example (Himalayas - Nepal)

Conservative

Occurs where plates side past each other in opposite directions, or in the same direction but at different speeds. Friction is eventually overcome and the plates slip past each other in a sudden movement. The shockwaves create an earthquake.

example (San Andreas fault - California USA)