Tectonic geomorphology of the Mahi river basin, western India

Neotectonic activity along pre-quaternary tectonic trends has played a majo r role in the evolution of Mahi drainage basin. The Mahi basin is controlle d by NE-SW and WNW-ESE Aravalli trend in the uplands and by NNW-SSE Tertiar y basement faults in the distal part. Lineament analysis shows three struct ural trends in the area which are related to major regional tectonic trends . Stream orientations indicate that the NNE-SSW and NNW-SSE trends represen t lineaments which were active during the youngest tectonic phase. The NE-S W and WNW-ESE trends are slightly older. The evolution of overall configura tion of the basin is attributable to neotectonic activity along WNW-ESE and NE-SW trends which have been modified by a later phase of tectonic activit y along NNW-SSE trend. Morphotectonic analysis has been helpful in assessin g the relative degree of tectonic activity in the different geomorphic zone s of the Mahi river basin. An increasing degree of tectonic activity toward s the NE conforming to the northeastward extension of the Aravalli range wh ere the central axis of the range lies, has been indicated.