Encyclopedia of Astrobiology

Living Edition
| Editors: Muriel Gargaud, William M. Irvine, Ricardo Amils, Henderson James Cleaves, Daniele Pinti, José Cernicharo Quintanilla, Michel Viso

Mantle

Living reference work entry
DOI: https://doi.org/10.1007/978-3-642-27833-4_932-3

Definition

The mantle is the part of the Earth or of other planets between the crust and the core. On Earth, it is mainly composed of silicate minerals, whose nature changes depending on the pressure (or depth). In the upper mantle, between the base of the crust and the transition zone at about 660 km, the principal rock type is peridotite composed of olivine, orthopyroxene, clinopyroxene, and an aluminous phase (plagioclase, spinel, or garnet). In the lower mantle, these minerals convert to denser phases such as Mg- or Ca-perovskite and magnesiowüstite. The terrestrial mantle is solid except in shallow zones of partial melting beneath mid-ocean ridgesor in hot spots, and perhaps at the core-mantle boundary. The mantle convects at different scales, one manifested by the relative motion of lithospheric plates, the other by the upwelling of mantle plumes from the mantle-core boundary (D″ zone) or from the upper-to-lower mantle boundary at 660 km depth. The occurrence of mantle...

Keywords

Partial Melting Silicate Mineral Mantle Plume Plate Tectonic Thermodynamic Potential 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
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Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  1. 1.Maison des GéosciencesLGCA, Université J. FourierSt-Martin d’HèresFrance