Formation and erosion of holocene alluvial fans along the narmada-son fault near Rajpipla in lower Narmada basin, Western India

Abstract

Five alluvial fans have been recognised along the Narmada-Son Fault near Rajpipla in the Lower Narmada basin. These have been studied in their proximal, medial and distal parts. Lithofacies characteristics and facies associations indicate debris flows and sheet flood flows as the major processes responsible for aggradation of these fans. The fans have coalesced and formed a fault-bound geomorphic surface during Early Holocene. Sedimentation in an alluvial fan environment during the Early Holocene is not yet known from this part of Western India. Prolonged subsidence along Narmada-Son Fault and two other faults along the Narmada river and its tributary Karjan, have provided ideal site for the accumulation of fan deposits. These alluvial fans suggest differential movement along the Narmada-Son Fault and a humid climate during Early Holocene.