Describe the differences between the oceanic and continental crust.

The oceanic crust is generally younger than the continental crust as it is less than 200 million years old and can also be renewed or destroyed at plate boundaries. For example, the oceanic crust which forms Iceland is only 1 million years old. The oceanic crust is also denser, being made out of basalt, compared to the continental crust which is made of granite. As a result, the oceanic crust can sink beneath the continental crust at constructive plate margins and also be destroyed at subduction plate margins.