Density change in upwelling mantle

Gravity modelling of the litho-asthenosphere system in regions involved in extensional tectonics requires an accurate estimation of the vertical density profile in the upwelling asthenosphere. To this end, the calculation of the variation of several parameters is needed, i.e., the degree of thermal anomaly in the asthenosphere, the amount of stretching, the thickness of the lithosphere before stretching, and the variation of melt fraction generated by adiabatic decompression. Therefore, knowledge of melt density and of the residual mantle rock composition is necessary in order to have the information to calculate the density of the uprising mantle. These calculations allow to partially solve the problem related to ambiguity of the gravity interpretation, and to provide information about the structural features of the upwelling mantle.