The mantle is the mostly solid bulk of Earths interior, which lies between Earths dense, super-heated core and its thin outer layer, the crust. The mantle is composed of silicate rocky material with an average thickness of 2,886 kilometers (1,793 miles) and makes up 84% of the Earth by volume, compared to 15% in the core and the remainder being taken up by the crust. The major elements that make up the mantle are oxygen, silicon, and magnesium, which together account for more than 88% of the mantles composition. Other elements found in the mantle include iron, aluminum, calcium, sodium, and potassium.