The Earth's lithosphere is composed of the CRUST and the upper mantle. The CRUST is the outermost layer of the Earth and is made up of solid rock. It is the thinnest layer of the Earth, ranging from 5 to 70 kilometers in thickness. The CRUST is divided into two types: oceanic CRUST and continental CRUST. Oceanic CRUST is denser and thinner than continental CRUST and is composed of basaltic rocks. Continental CRUST is thicker and less dense than oceanic CRUST and is composed of granitic rocks.