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a rigid block of crust and upper mantle rock.


the outer layer of the Earth.


the layer of the planet Earth beneath the crust and outside of the core.


the center-most part of Earth.


an opening in Earth's crust through which molten lava, ash and gases are ejected.


molten rock beneath the Earth's surface (*found inside a volcano).


molten rock that issues from a volcano (*liquid that flows on the outside of a volcano).

Plate tectonics

when the plates of Earth's crust move to form landforms such as mountains and trenches.

Pangea theory

the idea that the Earth originally consisted of one large super-continent (one piece of land).

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