Geological characterization of weak cataclastic fault rocks with regards to the assessment of their geomechanical properties

A new quantitative method for the characterization of weak cataclastic faul t rocks (e.g. fault breccia, gouges) is presented. Applied to find correlat ions with geomechanical laboratory tests, the thin section and X-ray diffra ction analyses used for the method are on a similar scale. The method is sh own to be appropriate for the characterization of a large range of differen t types of weak cataclastic fault rocks (kakirites) and involves appraising their mineralogical composition and microstructural characteristics. The c orrelation of the geological and geomechanical properties of kakirites base d on this approach has shown promising results. The method could provide, i n the future, the required geological input data for a mathematical modelli ng of the geomechanical behaviour of cataclastic fault zones.