Primary assessment on the poly deformational regime of Kadavur Structural Complex, Tamil Nadu, India.

Kadavur Anorthosite Complex (KAC) is well known massif type anorthosite emplaced into the Kadavur Structural Complex (KSC). This study focuses on the preliminary structural characterization of the quartzites and associated rocks which form the skeletal structure of the complex. Simultaneously the available weathered met sedimentary rocks exhibiting the residual structural characters were also taken into consideration for better understanding of the structure. Quartzite is the major rock type seen in Kadavur area which encircles the Kadavur basin thus forming a circular ridges and hence it is known as Kadavur basin among the geologist. This body and structure is a significant structural feature in Southern Granulitic Terrain (SGT). These quartzite and quartz schists exhibit vertical to sub-vertical bedding plane which is composed of compositional banding. At some points these beds show a distinct down dip lineation, caused by slipping of beds during deformation of the rock. This lineation may indicate the axis of the fold structure standing on edge or plunging very steeply. On this assumption, these circular groups of quartzite ridges are interpreted as the limbs of a large anticlinal structure plunging almost vertically to the west. Another possible interpretation would be that these quartzite ridges form the outer rim of a synclinal depression with an indefinite trend. The Kadavur complex has suffered four phases of folding where the intersection of F1 & F2 axial plane gives rise to interference pattern of shape.