| Abstract Submission No. | ABS-3.1-0149 |
| Title of Abstract | Influence of Trans-Yamuna Fault System on the active tectonics and Landscape Evolution in the NW Sub Himalaya |
| Authors | Satish Chandra Verma*, Prabha Pandey, Anand K. Pandey |
| Organisation | CSIR ¿ NGRI, AcSIR |
| Address | CSIR_NGRI Hyderabad, Telangana, India Pincode: 500007 E-mail: vschandra94@gmail.com |
| Country | India |
| Presentation | Poster |
| Abstract | Assessment of erosion proneness and active structural features is critical in tectonically dynamic regions, which can be effectively evaluated through morphotectonic analysis. The geomorphic indices capture the interaction between uplift and erosion that governs drainage basin dynamics and fluvial landscape. We investigate the influence of the tectonically active Trans-Yamuna Fault System (TYFS) on the NW Sub Himalayan. Unlike major intra-crustal structures such as the Himalayan Frontal Thrust (HFT) and Main Boundary Thrust (MBT), the TYFS affect the Lower Tertiary and pre-Tertiary sequence across the Main Boundary fault (MBF) and MBT, making it a structurally distinct tectonic unit. To quantify tectonic activity, geomorphic indices such as hypsometric integral (HI), stream-length gradient (SL), and basin asymmetry factor (AF), were derived from 30 m SRTM DEMs using ArcMap and MATLAB. Analysis of 20 sub-watersheds shows widespread evidence of uplift and erosion, with anomalous index values reflecting localized structural control. These results were integrated into an Index of Relative Active Tectonics (IRAT), allowing spatial assessment of deformation intensity. We used high-resolution remote sensing data (Cartosat, Google Earth), geomorphic expressions, including sag ponds, deflected streams, and steepened river profiles, aided by field observations reveal a dominant strike-slip deformation along TYFS. The TYFS was mapped by Ground Penetrating Radar (GPR) to a depth of 20-30 m, confirming the predominantly vertical geometry. Chronological constraints on the dislocated fluvial sequence were established through Optically Stimulated Luminescence (OSL) dating, which indicate fluvial aggradation and deformation during the Late Quaternary to Holocene. The integration of geomorphic indices, remote sensing, geophysical imaging, and geochronology provides a robust framework for identifying zones of active deformation in NW Sub Himalaya and role of neotectonics in shaping landscapes, which is important for seismic hazard assessment of the region. |
| Keywords | Trans-Yamuna Fault System, Neotectonics, Geomorphic Indices, Ground Penetrating Radar, OSL dating |