Influence of dihedral angle on the seismic velocities in partially molten rocks

This article reports the influence of dihedral angle in a partially molten aggregate on its effective elastic properties using theoretical techniques. For a given mineral assemblage, dihedral angles can vary widely depending on the composition of the melt. Our results indicate that wetting melts with low dihedral angles have a lower fraction of intergranular contact area, contiguity, reducing the effective elastic moduli. An important consequence of this effect is that the seismic signature of an aggregate with a small volume fraction of a wetting melt will be similar to that of an aggregate containing a larger volume fraction of less wetting melt. Inferring the extent of melting in seismic ultralow velocity zones, therefore, needs to incorporate the influence of melt composition via the influence of dihedral angle.