Geologic models of subsurface sedimentray volumes

A method of using a three-dimensional, seismic image of a subsurface earth volume to construct a geological model that specifies the spatially-varying grain size distribution, porosity and permeability throughout the volume. The method is applied to soil volumes consisting of water-deposited clastic sedimentary deposits and involves, in one embodiment, (a) identifying the outline shapes of geological bodies in geological data; (b) using the outline shapes of the geological bodies to determine the spatially-varying grain size distribution in the bodies, guided by assumptions about the nature and behavior of the paleo flow that deposited the bodies; (c) determination of rock properties such as porosity and permeability of the geological bodies based on grain size distribution, mineralogy and cover history information.