Development of Anisotropic Mobility During Two-phase Flow

This work presents a cross-scale formulation for the development of anisotropic melt mobility during coupled flow of viscous mantle matrix and magma. Deformation of the matrix flattens initially spherical melt pockets and initially cylindrical melt tubules perpendicular to the principal axes of tensile stress,leading to the formation of melt films. This work presents a theoretical formulation for the melt geometry under applied stress and tests it against experimental results. Frictional resistance at the melt-matrix interface is greatly modified due to the establishment of the anisotropic network of melt films. This work also derives an expression for the anisotropic resistance tensor corresponding to the shape change of melt tubules and pockets. Anisotropy of the resistance is modulated by the parameter β, the resistance enhancement factor. Establishment of an anisotropic resistance in an upwelling plume flow leads to strong melt segregation along the plume conduit.