Displacement-length scaling of brittle faults in ductile shear

► We describe the development of triclinic flanking structures along elliptical faults. ► Initial orientations of the faults influence the development of the final structures. ► Brittle deformation along the faults occurs during ductile flow of the host rocks. ► The faults record nearly ideal elliptical displacement profiles. ► The faults record the largest known ratio of maximum displacement versus distance.