Plate Margins

Question 1

Continental crust

Answer 1

• Thick but dense
• Cooled quickly
• 30 - 50 km
• Old
• Can’t be destroyed

Question 2

Destructive plate boundary

Answer 2

Where an oceanic plate meets a continental plate they are moving towards each other.
The DENSER plate (oceanic) is SUB-DUCTED beneath the less dense (continental) plate
Pressure builds and can cause earthquakes

Question 3

Constructive

Answer 3

Where two oceanic plates are moving apart from each other
Magma rises
As it cools, forms a new oceanic crust
Volcanos are formed as magma fills the gap

Question 4

Conservative

Answer 4

As plates slide past each other, friction between them causes earthquakes (no volcanoes)

Question 5

What causes destructive plates

Answer 5

Convection currents cause destructive plate boundaries

Question 6

Collision plate boundary

Answer 6

When two continental plates are moving towards each other

The plates are not dense enough so the plates buckle and form fold mountains they have powerful earthquakes

Question 7

Oceanic crust

Answer 7

• Thin but dense
• Sinks into the mantel
• 5 - 10 km thick
• Oldest is 180 million year old
• Destroyed at destructive plate margins

Question 8

Formation of a fold mountain (COLLISION plate boundary)

Answer 8

• Eroded sediment is deposited on the ocean floor and layers up (sedimentary rock)
• Rocks crumble as a result of pressure
• Plates are not dense enough to sub duct
• Buckle forming a fold mountain
• Fold mountains have anticlines + synclines

Question 9

Formation of a fold mountain (DESTRUCTIVE plate boundary)

Answer 9

• Eroded sediment is deposited on the ocean floor and layers up (sedimentary rock)
• Rocks crumble as a result of pressure
• Fold mountains form at subduction zones
• An ocean trench has very deep sea
• Fold mountains have anticlines + synclines