The Theory of Plate Tectonics. Earth’s Internal Layers The crust varies in thickness (4-60 km) oxygen, silicon, magnesium and iron The mantle (2885 km)
Processes that shape the planet.. Earth’s Internal Layers The crust (oxygen, silicon, magnesium and iron) The mantle (silicon & oxygen) Outer core (iron.
Processes that shape the planet.
The Theory of Plate Tectonics
