Geology Types of rock Sedimentary rock
 Sedimentary rock is rock that has been made from sediment. Sediment is all solid pieces of stuff that are moved by the wind, water, or glaciers. Sediment can be made from clay, sand, gravel and the bodies and shells of animals. The sediment gets dropped in a layer at the bottom of a river or sea. As the sediment piles up, the lowers layers get squashed together. Slowly they set hard into rock.