Mantle (geology) Mantle (geology) The mantle is a layer inside a planetary body bounded below by a core and above by a crust. Mantles are made of rock or ices, and are generally the largest and most massive layer of the planetary body. Mantles are characteristic of planetary bodies that have undergone differentiation by density. All terrestrial planets (including Earth), a number of asteroids, and some planetary moons have mantles. The Earth's mantle is a layer of silicate rock between the crust and the outer core. Its mass of 4.01 × 10 kg is 67% the mass of the Earth. It has
International Association for Engineering Geology and the Environment of and the development of measures for prevention or remediation of geologic hazards. Engineering geology embraces: the definition of geomorphology, structure, stratigraphy, lithology and groundwater conditions of geological formations; the characterization of the mineralogical, physico-geomechanical, chemical and hydraulic properties of all earth materials involved in construction, resource recovery and environmental change; the assessment of the mechanical and hydrologic behaviour of soil and rock masses; the prediction of changes to the above properties with time; the determination of the parameters to be considered in the stability analysis of engineering works and of earth masses; and the improvement and maintenance of the