The OPA material has been intensively studied by a variety of multiple scale and non-destructive 3-D X-ray CT investigations, following a consequent top-down approach to identify specific regions of interest. According to the mechanical experiment, it has been observed that the shear failure is located in a clay-rich area. Within the intersecting area of the two main fractures, a so called mylonitic zone with a particle reduction was observed on the open shear failure using CT and SEM techniques.

This study improves our understanding of the evolution of pores in shales for modelling transport properties. 3-D microscopy on early and postmature Posidonia Shales showed similar porosities and pore size distributions. Large isolated pore clusters are within carbonates and clay minerals. Pores form during maturation in the postmature-matrix-filling organic matter. Modelled permeabilities are lowest perpendicular to bedding. They decrease with increasing maturity and are comparable to experimental data.