DRAINAGE EVOLUTION OF THE LOWER NARMADA VALLEY, WESTERN INDIA

Various tectonic disturbances from the Cretaceous to the present day have modified the geomorphic features of western India. Compression and extensional stresses generated by the northerly moving Indian plate, and its collision with the Eurasian plate, have brought about frequent changes in the drainage system and other features. Different segments that lie between several regional faults have encountered many upheavals and subsidences. During the major part of the Tertiary the tributaries of the Narmada, Mahi and other westerly flowing rivers had much larger catchment areas that extended to the north. The compressional stresses exerted during the Pliocene and Pleistocene epochs have shortened the basin of these rivers. The release of stresses during the Early Pleistocene is mainly responsible for the development of the present high-lands and lower surfaces. Based on structural studies, subsurface data, sedimentation in different basins and the area of provenance and movement of the Indian plate, the authors have suggested successive stages of the landform development in the lower reaches of the Narmada valley.