Constrictive deformation in transpressional regime: field evidence from the Cauvery Shear Zone, Southern Granulite Terrain, India

The paper describes a typical field example of rarely preserved complex structural patterns related to constrictional strain from the deeply eroded central part of the Neoproterozoic crustal-scale Cauvery shear zone system, southern India. The area exposes intense migmatisation and a distinctive map pattern of a broad domal structure with complex strain patterns. The field features such as interfering fold structures, extreme hinge line variation, domes and basins, highly asymmetrical and amoeboid shape structures, geometry of foliation trajectories and radial stretching lineations could be related to a single phase of D2–M2 constrictive deformation. Our observations suggest a close spatial and temporal relationship between transpressive deformation, deep crustal melting, assent of granite magmas and migmatisation synchronous with D2–M2.