Plate tectonics

 Topic 2:Types of plate margins and plate movements

• Diverging/ constructive plate margins: when two plates are moving away from each other

Features of constructive

• A gap/space is created.

• Due to heat and pressure, magma flows up to fill the gap.

• When magma cools down and solidifies it creates new landforms

(form new crust/land)

• Converging/ destructive plate margins: when two plates move towards each other and collide (leads to earthquakes and volcanic eruption)

Features of destructive plate margins

When oceanic and continental meet,

• the heavier, denser oceanic crust is forced down into mantle at subduction zone (area where oceanic plate is forced down).

• Heat and pressure/friction from mantle cause the oceanic crust to melt into magma.

• Molten material forced up through cracks (deep sea trenches) to form volcanic eruption.

• Earthquakes are common here

• Conservative/transform plate margins: it is when plates slide slowly past each other in

opposite direction or in the same direction but one plate is moving faster than the other.

Features of conservative

•Plates sliding past each other.

• The edges of the two plates are not smooth

• Therefore, the plates stick to each other and pressure builds up.

• When pressure is released it creates severe earthquake.

• No volcanic eruptions.

• Land forms such as San Andreas fault in USA is formed at conservative plate margin e.g. North American and Pacific plates.

Examples of plates margins/ movement