Fabric evolution during the deformation of chalk

The consolidation and shear deformation behaviour of a single outcrop chalk is described in phenomenological terms based on the interpretation of laboratory deformation experiments. Studies of the fabrics of the deformed materials are then used to validate the interpretations. Chalk behaviour is strongly influenced by the progressive destruction of its intact fabric: showing at shear failure, a transition from discrete fractures at low consolidation stres ses where the fabric remains intact, to a pervasive cataclasis at high consolidation stresses where the fabric has become substantially disaggregated. This bulk response to deformation can be described using a rheological framework based on conventional soil mechanics.