text: You tend to get big pushed up mountain chains where 2 continental plates are converging, subduction zone volcanism where you've got 1 plate being subducted beneath another (the subducting plate causes partial melting in the mantle and this magma pushes up through the plate above), mid-ocean ridge system where oceanic crust is being pulled apart (if you can find a map which shows sea topography as well as land topography you can have a look at the mid-ocean ridge system - it's pretty amazing, shows the outlines of the plates pretty well, too), and you also get continental rifting and volcanoes where continental crust is being pulled apart, like in Africa.