The Generation and Compaction of Partially Molten Rock

作者：Dan McKenzie · 发表于：Journal of Petrology · 年份：1984 · DOI：10.1093/petrology/25.3.713 · 被引用次数：1900 · 研究领域：Geological and Geochemical Analysis、Mineral Processing and Grinding、Hydrocarbon exploration and reservoir analysis

The equations governing the movement of the melt and the matrix of a partially molten material are obtained from the conservation of mass, momentum, and energy using expressions from the theory of mixtures. The equations define a length scale δc called the compaction length, which depends only on the material properties of the melt and matrix. A number of simple solutions to the equations show that, if the porosity is initially constant, matrix compaction only occurs within a distance ∼δc of an impermeable boundary. Elsewhere the gravitational forces are supported by the viscous stresses resulting from the movement of melt, and no compaction occurs. The velocity necessary to prevent compaction is known as the minimum fluidization velocity. In all cases the compaction rate is controlled by the properties of the matrix. These results can only be applied to geological problems if the values of the permeability, bulk and shear viscosity of the matrix can be estimated. All three depend on the microscopic geometry of the melt, which is in turn controlled by the dihedral angle. The likely equilibrium network provides some guidance in estimating the order of magnitude of these constants, but is no substitute for good measurements, which are yet to be carried out. Partial melting by release of pressure at constant entropy is then examined as a means of produced melt within the earth. The principal results of geological interest are that a mean mantle temperature of 1350°C is capable o...