Appraisal of Active Tectonics: An Insight from the Morphotectonic Study of Drainage Basins and OSL Dating in the Kangra Area, Himachal Pradesh

Abstract

A morphotectonic investigation of the drainage basins and an estimation of the rate of upliftment have been conducted in the vicinity of Palampur, located in the Kangra district of Himachal Pradesh. The assessment utilized the geomorphic index of active tectonics (IAT) and the Optically Stimulated Luminescence (OSL) dating technique. The study area is situated within the epicentral zone of the 1905 Kangra earthquake and is drained by three significant perennial tributaries of the Beas river, namely Baner, Neogal, and Awa. To evaluate the tectonic influence on these drainage basins, Digital Elevation Model (DEM) data with a resolution of 30m, Survey of India toposheets, and Google Earth images were processed using ArcGIS and Global Mapper software. The findings of this investigation indicate that the drainage basins have been impacted by tectonic activity, resulting in the formation of asymmetrical, elongated basins with deep V-shaped valleys and active mountain fronts. The hypsometric integral values derived from the study suggest that these basins have reached an equilibrium stage. Originating from elevations exceeding 4500m in the Dhauladhar range, these rivers, like other Himalayan rivers, partake in active downcutting and erosional processes, as observed in the presence of terraces. By employing the OSL dating technique, the terraces of the Neogal river were dated, enabling the calculation of an upliftment rate ranging from 0.6 ± 0.03 mm/year to 1.7 ± 0.1 mm/year for the area.