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GCSE Physical Geography > Plate Margins > Flashcards

Flashcards in Plate Margins Deck (9)
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1

Continental crust

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

2

Destructive plate boundary

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

3

Constructive

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

4

Conservative

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

5

What causes destructive plates

Convection currents cause destructive plate boundaries

6

Collision plate boundary

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

7

Oceanic crust

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

8

Formation of a fold mountain (COLLISION plate boundary)

- 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

9

Formation of a fold mountain (DESTRUCTIVE plate boundary)

- 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