Partial melting - changing the chemistry of the planet

'Partial melting; simple process, huge global impact' - one of the many activities in our plate tectonics series. This activity explains how partial melting, coupled with plate tectonics, has changed the chemistry of our planet.

Each time that partial melting takes place during different stages of the plate tectonic cycle, materials with different chemical and physical makeup are formed. The starting point for these processes is the mantle, where the most abundant elements are oxygen, silicon, magnesium and iron in that order. However the Earth’s crust contains much more silicon and oxygen and much less magnesium and iron than the mantle. How this happens is explained in this activity.
This is one of many innovative plate tectonics activities to be found on the ELI website. Other ideas are listed in teaching strategies.