The effects of clay conduction on the electrical behavior of shaly sandstones at low frequencies are analyzed by considering self-similar mixtures of conductive grains, as representative of these porous rocks. An essential step in this model is the representation of the surface conductivities of the clay platelets by an equivalent volume conductivity. Based on their pattern of occurence, the clays are treated either as a continuous coating over the sand grains or as individual detrital grains mixed with a nonconductive mineral matrix. In the first case, the solids are modeled as layered conducive particles, taken as spheres to a first approximation. In the secnd case, we generalize from the results of a three-component self-similar mixture of spherical particles. For linear approximations, the models are described by expressions quite similar to the frequently used Waxman-Smits and dual-water equations, but dependent upon the clay type, concentration, and its distribution in the rock. The models are written in terms of geometric parameters readily available from well-log measurements. The derived analytical expressions are successfully applied to describe a set of available experimental core and geophysical log data. The results clearly demonstrate the applicability of the equations to well-log interpretation, as a practical procedure for computing formation factors and shaliness of argillaceous sandstones.