The lithosphere (literally, the “stone sphere”) is the surface and rigid part material whose the stars are made telluric S, of which the Ground, Mars, Venus, Mercure, etc It is divided into a certain number of tectonic plates, on Earth.

The lithosphere is consisted of the crust and the surface part of the higher coat. The lower limit of the lithosphere (i.e. limit between the higher coat rigid and the higher coat ductile) is with the Isotherme where the Olivine (mineral largely dominating in the coat) reached its Point melting: in the neighborhoods of 1200 °C. This depth varies almost 0 km on the level of the oceanic dorsal , with more than 200 km under the old continents. Because of fusion very partial of minerals constituting it (between 1 and 5%), the materials become less viscous and it occurs a transport of heat by Convection in the asthenosphere, whereas it is done by conduction in the lithosphere.

The transformation of a rigid coat in the lithosphere, in a more deformable coat (ductile) in the Asthenosphere, is responsible for a reduction the speed and a marked attenuation of the seismic waves P and S on the level of the “Low velocity zone”.

The lithosphere can be animated movements of Divergence or movements of Convergence. The movements of divergence translate a distance of two plates one compared to the other on the level of a dorsal . Convergence, a bringing together of the two plates. Convergence can be a subduction, a plate passes below an other, or a collision, the two plates enters in collision (formation of the mountains). The quantity of lithosphere on the surface of the Earth is always the same one, this being with the movements of convergence and divergence, which are compensated.