Morphotectonic and lithostratigraphic analysis of intermontane Karewa Basin of Kashmir Himalayas, India

Abstract

Morpho-tectonic study plays an important role in deciphering the effects of tectonic activity in the geomorphic evolution of the drainage basins. Romushi watershed forms one of the major watersheds of the intermontane Karewa Basin of Kashmir Valley. The Karewa sediments are characterized by glacio-fluvio-lacustrine deposits capped by the aeolian loess. The geomorphic, morphometric and lithostratigraphic studies of these cap deposits have been carried out to elucidate the effect of tectonics on the geomorphic evolution of Romushi Watershed. Geomorphic mapping was carried out using GPS measurements, DEM at 30m resolution, Topographic Position Index (TPI) model, topographic maps, LANDSAT TM Imagery and field data. Morphometric and morphotectonic analyses in GIS environment were used to calculate various geomorphic indices (Mountain Front Sinuosity Index, Bifurcation Ratio, Asymmetry Factor, River Profile, etc). These indices reveal that the tectonic uplift observed in the region due to Himalayan orogeny coupled with mass movement and aeolian deposition have dominated the landscape evolution of intermontane Karewa Basin of Kashmir throughout the Late Quaternary Period. Additional data from lithostratigraphic measurements were analyzed to understand the geomorphic evolution of intermontane Karewa Basin. The data revealed that the basin has experienced differential uplift and erosion rates from time to time in the geological past. This was corroborated by the results from the morphometric and morphotectonic analysis.