Tectonic control on distribution and evolution of ravines in the Lower Mahi Valley, Gujarat

All along the Lower Mahi Valley ravines form an important geomorphic unit. These have developed extensively in the Late Pleistocene continental sedime nts delimited by flat alluvial plains on one side and river channel on the other. The ravines are confined to all the three pediment, alluvial and est uarine zones. The intensity of these is more on the left bank compared to t he right and suggest a differential uplift of the horst block along basemen t faults. Morphologically, the ravines are divisible into two types: sharp crested, steep, deeply entrenched and gently sloping, with shallower depth and comparatively smaller in length. The directional analysis of ravine ori entations show that the higher order ravines trending NE-SW and NNE-SSW are related to neotectonic activity along older structural trends during Early Holocene. The smaller and gently sloping ravines showing varying trends ar e attributed to semi-arid and humid climate.