Abundance of the chemical elements in the Sun and outer planets is similar to that in the universe. Due to solar heating, the elements of Earth and the inner rocky planets of the Solar System have undergone an additional depletion of volatile hydrogen, helium, neon, nitrogen, and carbon (which volatilizes as methane). The crust, mantle, and core of the Earth show evidence of chemical segregation plus some sequestration by density. Lighter silicates of aluminum are found in the crust, with more magnesium silicate in the mantle, while metallic iron and nickel compose the core. The abundance of elements in specialized environments, such as atmospheres, or
Journey to the Centre of the Earth (album) titled "Return to the Centre of the Earth". The story follows a group of adventurers who attempt to follow the previous expedition to the Earth's centre as discovered by Saknussemm. In 2002, Wakeman released the 8-CD compilation box set "Treasure Chest" which contained the previously unreleased first half of the second concert at the Royal Festival Hall. The recording was presumed to have been wiped, but a rough mix was accidentally discovered on a poorly conditioned and mislabelled tape initially used as a guide for the mastering, and was digitally remastered. The CD also contained Hemmings record narration in five