GCSE Plate margins

Inner Core

A dense sphere of solid iron and nickel at the center of Earth

Shield Volcano

A wide gentle sloping volcano made of layers of lava and formed by quiet eruptions.

Ocean ridge

Created at a divergent boundary where the ocean plates spread apart. Magma rises out to form underwater mountains.

Ocean Trench

Deep valley in the ocean floor that forms along a subduction zone

Continental crust

Granitic part of the Earth's crust that makes up the continents. Continental crust is also called sial because it consists largely of silica and aluminum and averages about 40km thick

Composite volcano

Tall, cone-shaped volcano in which layers of lava alternate with layers of ash

Subduction

The PROCESS when one plate is pushed underneath another plate

Mantle

The layer of the earth between the crust and the core, molten in parts

Convection current

The movement of magma in the mantle caused by heating of the material

Crust

The outer, solid layer of the Earth

Fold mountains

These are mountains formed as the plates move together and folds are formed as the the layers are squeezed horizontally.

Oceanic crust

Thin, more dense than continental crust, subducting crust

Destructive plate margin

Where 2 plates collide and one plate sinks under another, destroying the oceanic crust

Conservative plate margin

Where 2 plates slide alongside each other at different speeds, stick slip occurs which causes earthquakes

Plate Margin

Where the two plates meet

Constructive Plate margin

Where the two plates move apart making new crust

Pacific ring of fire

Zone of crustal instability, volcanism, and earthquakes in the Pacific region.