The uppermost part of planet Earth, made up of continents and oceanic crust. The top of the Earth’s crust is home to humans and most of the living organisms that inhabit the Earth. The Earth’s crust, together with the upper part of the mantle, forms the lithosphere. It is divided into oceanic and continental crusts. The oceanic crust is thinner (3—10 km) and made up mostly of basaltic rocks, while the continental crust is thicker (30—50 km) and made up mostly of granitic rocks. It is fractured into lithospheric plates that float in a denser upper mantle. The entire crust makes up approximately 1 percent of the Earth’s volume.