The lithosphere (crust) reacts with the atmosphere and the hydrosphere; it has a more varied composition than the mantle or the core
A unique feature in the development of the Earth's crust is as a result of its reaction with the gases and water which escaped from the centre of the Earth by volcanic activity. Interactions with air and water can chemically alter existing rocks and partially or wholly separate their individual components, to produce a range of different sedimentary rocks, sediments and soils at the surface of the lithosphere.
Why does the lithosphere have a more varied composition than the mantle or the core?