The crust is of two different types. One is the continental crust (under the land) and the other is the oceanic crust (under the ocean). The continental crust is thicker, 30 km (20 mi) to 50 km (30 mi) thick. It is mostly made of less dense, more felsic rocks, such as granite. The oceanic crust is thinner, 5 km (3 mi) to 10 km (6 mi) thick. It is made of denser, more mafic rocks, such as basalt.