Delineating structural settings of Bhavani Complex; implication to multiple stages of deformations

Abstract

Detailed structural mapping in Bhavani Complex in the northern part of Southern Granulitic Terrain in Tamil Nadu, India was carried out. Structural characteristic features of multiples stages of deformations as subsequential events have occurred in the Bhavani Complex and they are well preserved in the lithologies such as gneisses, granulitic facies rocks, amphibolites, Banded Iron Formation and other metapelitic rocks. Based on these structural components, five stages of deformational events are recognized in the study area. The general trend and megascopic structures noted in the study area have resulted in identifying the three stages of later deformations (D₂, D₃ and D₄). Unlike these later deformation characters, most of the features of early-formed deformations D₀ and D₁ are obliterated due to the previously formed structural and metamorphic characters but some are preserved as overprint elements. Two major deformation activities among the different stages of deformation events can be identified based on the nature of kinematics of the formations in the terrain. They are strike-slip movements formed during Pan African regime and Dip-slip movement formed probably during the subduction processes.