A new full-3D balanced restoration technique for geological structures is used to estimate the strain tensor and to define fractured zones applying failure criteria. This approach based on the elastic solid theory of continuous media gives the tensor of deformations. In simple cases such as thin plates this new approach is in agreement with results predicted by the theory. Strain tensor invariants (dilatation coefficient principal strains etc.) coupled with mechanical properties of rock types are used to characterize the distribution of fracture orientations. The method is applied on the Split Mountain.