Evaluating Neotectonic Imprints on the Banas and Mej Rivers: Insights from River Capture During the Late Quaternary Period

The Banas and Mej Rivers, situated in the tectonically active region of western India, exhibit distinct geomorphic evidence of neotectonic activity that has significantly influenced their drainage evolution. This study assesses neotectonic imprints on these river systems by analyzing morphological anomalies, river capture events, and associated fluvial adjustments during the Late Quaternary. A comprehensive morphotectonic analysis was conducted using remote sensing and GIS techniques, integrating various geomorphic indices to decipher the tectonic controls on basin evolution. The results reveal distinct drainage patterns and evidence of stream piracy, significantly influencing basin configurations. The Mej River exhibits a positive hypsometric curve and pronounced breaks in its longitudinal profile, indicative of active tectonic processes, in contrast to the relatively stable Banas River basin. Tectonic faulting, particularly along the Great Boundary Fault and the Banas Dislocation Zone during the Quaternary Period, has played a pivotal role in stream reorganization and basin migration, leading to the development of structural features such as half-grabens and horsts. Continuous fault movements have facilitated the piracy of portions of the Banas River basin by the Mej River, as reflected in the high asymmetry factor values, especially in the middle reaches of the Banas River. These tectonic processes have reactivated the Mej River basin’s topography, resulting in lateral shifting and compression within the Banas River’s middle section. The eastward tilt of the Banas River basin further signifies the influence of ongoing tectonic activity in the adjacent Mej River basin, with the potential for continued extension of the Mej River into the Banas River’s domain. The observed river capture events, particularly the encroachment of the Banas River basin by the Mej River, highlight the dynamic interplay between tectonics and fluvial systems, offering valuable insights into long-term landscape evolution in tectonically active regions.