Science glossary film: Continental crust

The uppermost layer of the Earth that forms the continents and coastal sea floor, sitting on top of a layer of denser rock called the mantle. It's composed mainly of granite, and ranges from 10 to 70 kilometers in thickness. It is created and destroyed very slowly by various geological processes – the oldest known rocks in the crust are about 4 billion years old.

It's composed mainly of granite, and ranges from 10 to 70 kilometres in thickness. It is created and destroyed very slowly by various geological processes – the oldest known rocks in the crust are about 4 billion years old.