The uppermost layer of the Earth is called the crust. It is a thin, solid layer that varies in thickness from about 5 to 70 kilometers. The crust is made up of different types of rocks, including continental crust and oceanic crust. Continental crust is thicker and less dense than oceanic crust. It is made up of a variety of rocks, including granite, sandstone, and limestone. Oceanic crust is thinner and denser than continental crust. It is made up of a type of rock called basalt.