Integrating geomorphic and tectonic signals: A multi-parameter evaluation of active deformation in the Zanskar Shear Zone, Northwest Himalaya, India

This study investigates the tectono-geomorphic signatures of the NE-dipping Zanskar Shear Zone (ZSZ)—a structurally complex and tectonically dynamic segment of the Himalayan hinterland. Utilizing high-resolution remote sensing datasets, GIS-based morphometric analyses, and systematic field validation, we conducted a detailed spatial assessment of 32 drainage basins distributed along both sides of the Doda River. In this analysis, six key geomorphic indices were computed to quantify relative tectonic activity, estimate uplift rates, and delineate zones of active deformation within the Doda Valley (DV). A multi-parametric classification based on the Index of Active Tectonics (IAT) categorizes 35% of the basins as highly active and 65% as moderately active, reflecting spatial heterogeneity in crustal deformation. Highly active basins are characterized by steep hypsometric gradients, deeply incised valleys, linear mountain fronts, prominent faceted spurs, and wine-glass valley morphologies. These landforms collectively reflect persistent tectonic uplift and fault-controlled incision, indicative of an actively deforming landscape influenced by structural complexities and localized strain accumulation. In contrast, moderately active basins exhibit a dynamic equilibrium between tectonic uplift and denudational processes, modulated by faulting, glacial incision, freeze—thaw cycles, and sediment flux. This interpretation is further supported by a strong inverse correlation (R² = 0.85) between Smf and Vf, with a bivariate relationship yielding an estimated uplift rate of ~0.5 mm/yr in the DV. The spatial correspondence between morphometric anomalies and mapped tectonic lineaments underscores the dominant role of ongoing crustal deformation in shaping basin-scale geomorphic patterns and modulating surface processes. The NW—SE-trending ZSZ, dipping ~20° NE, emerges as a major crustal-scale structure governing regional uplift and landscape evolution, exhibiting recent tectonic characteristics akin to those of the Main Central Thrust. Collectively, these findings highlight the ZSZ as a key driver of tectono-geomorphic evolution, providing new insights into the active deformation mechanisms operating within this segment of the orogenic belt.