Structure of the Earth
The four main layers of the Earth are:
Crust, Mantle, Outer Core, Inner Core
You also have the upper crust as an extra.
All the layers of the Earth have different temperatures and densities. The crust is solid rock and is the thinnest layer. The mantle is semi-molten due to its high temperature so convection currents occur. Hot lava rises to the surface, cools down and sticks to the crust. The cool magma starts to sink and pulls the crust along with it because the magma is stuck to the crust.
Destructive Plate Margin
1. Plates move towards each other. (One Oceanic and one Continental)
2. The heavier oceanic plates sinks beneath the lighter continental plate.
3. Plates rubbing cause severe earthquakes.
4. Friction is created and heat from the mantle melts the oceanic rock from the plate.
5. Pressure builds and magma rises.
6. There is a violent volcanic eruption.
Constructive Plate Margin
1. Plates move away from each other. (two oceanic plates)
2. Magma rises.
3. Magma cools to form new oceanic crust.
4. New mountain ranges form under the sea.
5. Mountain tops break surface as islands.
6. Movement causes earthquakes.
Collision Plate Margin(Zone)
1. Plates move towards each other. (two continental plates)
2. They crash into each other as neither will sink below the other (same density)
3. The pressure causes rocks to fold and bend.
4. Rocks are pushed upwards to form fold mountains.
5. Movement causes severe earthquakes.
6. No Volcanic activity.
Consevative plate margin
1. Two plates try to slide past each other. (it doesn't matter which ones!)
2. Plates get stuck.
3. Huge amounts of pressure build up.
4. Pressure release causes violent earthquakes.
5 Plates move on a few millimetres.
6. No volcanic activity.