geography unit 1 H - restless earth

Ocean Plates are denser and newer than continental plates, which are thicker, older and cannot be renewed.

Plates float on the mantle and are made up of slabs called tectonic plates and form the earth’s crust. The cracks where these plates meet are called plate margins.

Convection currents which are found in the mantle cause the plates above them to move around and crash into, slide along or move away from each other. Convection currents are caused by radioactive decay in rocks. This releases heat, causing the molten rock in the mantle to move.

• Continental crust is less dense and thus forces the oceanic crust underneath it
• this forms a deep oceanic trench
• The oceanic plate is melted in the subduction zone
• Molten rock also rises which…