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
Delamination (geology) xenoliths found within the crust in the region support the metamorphic phase change associated with the density inversion in the lower crust. It is possible that the Sierra Nevada is the only place on Earth where dense material is currently being removed from the crust. Delamination (geology) In geophysics, delamination refers to the loss and sinking (foundering) of the portion of the lowermost lithosphere from the tectonic plate to which it was attached. The outer portion of the Earth is divided into an upper, lithosphere layer and a lower, asthenosphere layer. The lithosphere layer is composed of two parts, an