The electrical coupling coefficients in rocks are widely used in oil, gas and mineral prospecting. Examples include downhole resistivity and spontaneous potential measurements as well as surface gophysical self-potential profiling. Interpretation of the measurements in terms of microscopic rock properties requires a detailed knowledge of the mechanisms of ion transport in pore networks. Inhomogeneities in geologic membranes can arise as a result of intimate mixing, sedimentation and diagenesis of mixtures of minerals or in the form of organic surface coatings such as kerogen in shales. These inhomogeneities may significantly alter the membrane properties of the rock. No systematic study has been undertaken to investigate this dependence. It is the objective of this project to obtain a better understanding of the nature of electro- chemical-kinetic coupling in these inhomogeneous systems.
