Neotectonic response of the Godavari and Kaddam rivers in Andhra Pradesh, India: Implications to quaternary reactivation of old fracture system

摘要

A field and imagery based study at the eastern margin of the Deccan Volcanic Province (DVP), and in the Precambrian terrain of Adilabad and Karimnagar districts of Andhra Pradesh, India display a striking response of the Godavari and Kaddam rivers to Kaddam lineament-fault fracture (KLF) system. Brittle to ductile deformations within the Precambrian formations indicate its antiquity, while the continuity of Kaddam lineament over DVP suggests its Tertiary reactivation. The morpho-tectonic response of the Godavari and Kaddam rivers in this area depict southward tilt of the fault block west of Kaddam fault during Quaternary. In the given set-up we postulate a greater role of crustal loading of the Deccan traps, and its rapid erosional unloading during Late Cenozoic intensified monsoon conditions as one of the causative factors for the above neotectonic response demanding further detailed work on the KLF and elsewhere in the peripheral regions of DVP encountered by active faults and old fractures.