Geomorphic Response of the Chenab River to Localized Active Tectonic Deformation: Implications from River Terraces

ABSTRACT The Chenab River traverses the northwestern Himalayan orogenic belt, extending across the Greater Himalaya, Lesser Himalaya, and the adjoining Foreland Plains. The Kishtwar Doda region also known as Chenab valley constitutes a tectonically dynamic domain, where geomorphic and stratigraphic signatures of Quaternary deformation, coupled with persistent seismic activity are prominent. Previous studies revealed the active tectonic deformation and ongoing seismic activities in this region but considerable gap still exists in estimating the rate of active tectonic processes. In this paper, we mapped the Quaternary landforms, particularly the river terraces along the Chenab River on the hanging wall of MCT between Baghliar in the south to Kishtwar in the north to describe the influence of active tectonic deformation and climate from geomorphic characteristic of the area. Our results indicate that both strath and fill terraces exist in this region showing interaction of climate and tectonics with significant localized active tectonic deformation towards Kishtwar. The dating of uplifted Pleistocene strath terraces through Optically Luminescence Dating (OSL) technique, revealed a long term incision of ~2.10mm/year during last 6.65±0.76k, ~2.40mm/year between 6.65±0.76ka to 17.47±1.93ka, and ~1.13mm/year between 17.47±1.93ka to 82.73±11.8ka time period. During this study we observed that in Domain-1 and Domain-2 the fill terraces are more prevalent whileas, in Domain-3\strath terraces are present. Based on the deformation of Late Pleistocene and Holocene strath river terraces in this region, we concluded that the deformation of strath terraces towards Kishtwar town is due to localized active tectonic structure i.e. Kishtwar Fault (KF).