What happens when the crust touches the earth well what happens is that is makes a Earthquake and after the earthquake everything is destroyed by it. What is the Earths crust (according to the text) is composed of a great variety of igneous, metamorphic, and sedimentary rocks. The crust is underlain by the mantle. The upper part of the mantle is composed mostly of peridotite a rock denser. The crust is made out of rock containing silicon iron magnesium oxygen and other minerals. What is the mantle made out the mantle is made out of basically the same thing the crust is made out of. the mantle is mostly made out of oxygen silicon aluminum iron calcium sodium potassium and magnesium. The outer core is made out of liquid iron nickel. the inner core is made out of the same thing but no water there is iron and some nickel