Chapter 16 Tectonics of the Cuddapah Basin and a model of its evolution: a review

Abstract

AbstractThe Proterozoic Cuddapah Basin of south India is one of the most important Purana basins of Peninsular India. It hosts the Cuddapah Supergroup and the Kurnool Group of rocks. The structure of the Cuddapah Basin reveals that it forms the frontal part of a larger fold–thrust belt, named the Cuddapah fold–thrust belt (CFTB). The CFTB formed in response to the amalgamation of the Prince Charles Mountains–Rayner Complex of Antarctica with the Krishna province of India during the formation of the Rodinia Supercontinent. The CFTB, bounded by the Nellore–Khammam schist belt and Eastern Ghats terrane in the east and Peninsular Gneissic complex of the Dharwar Craton to the west, includes two frontal thrusts and foreland of an orogen. The frontal Nallamalai thrust structurally separates the basin into two blocks – the eastern Nallamalai fold belt and the western foreland. A model of evolution of the CFTB has been proposed. The CFTB, forming the front-most segment of a larger orogen associated with the intercratonic deformation related to the formation of the Rodinia Supercontinent, is the result of fault-propagation folding, forming an overturned anticline–syncline pair at the tip of the propagating Velikonda thrust which later cuts through the common limb of the fold pair.