Plate Tectonics: Geography AQA: GCSE (9:1)

Plate Tectonics

A theory stating that the earth's surface is broken into plates that move.

Plate Margins

The place where tectonic plates meet and the earth is particularly unstable

Crust

The thin and solid outermost layer of the Earth above the mantle

Mantle

The largest layer of the earth between the crust and the core which is made up of semi-molten rock which is constantly moved by convection currents.

Outer Core

A layer of molten iron and nickel that surrounds the inner core of Earth

Inner Core

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

Convection Current

A circular current of molten magma in the mantle caused due to the difference in temperatures within the mantle.

Magma

Molten rock beneath the earth's surface

Lava

Magma that reaches Earth's surface

Constructive Plate Margin

A plate margin where two plates are moving apart

Destructive Plate Margin

A plate margin where two plates are moving towards each other resulting in one denser plate sinking beneath the other.

Collision Plate Margin

Two continental plates collide. Neither plate is forced under the other, and so both are forced up and form fold mountains

Conservative Plate Margin

Tectonic plate margin where two tectonic plates slide past each other.

Continental Crust

The relatively thick but less dense part of the earth's crust that forms the large landmasses. It is generally older and more complex than the oceanic crust.

Oceanic Crust

Thinner, more dense, younger crust making ocean floor

Subduction Zone

In tectonic plates, the site at which an oceanic plate is sliding under a continental plate.