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
International Association for Engineering Geology and the Environment International Association for Engineering Geology and the Environment The International Association for Engineering Geology and the Environment (), formerly International Association for Engineering Geology, also known as IAEG (), is an international scientific society which was founded in 1964. It is affiliated with the International Union of Geological Sciences (IUGS) and has 3,798 members and 59 national groups all over the world. The association aims to promote and encourage the advancement of engineering geology through technological activities and research. At the same time it strives to improve teaching and training in engineering geology, and to collect, evaluate and disseminate the