Quaternary International xxx (xxxx) xxx Please cite this article as: Mahesh Thakur, Quaternary International, https://doi.org/10.1016/j.quaint.2020.07.014 Available online 25 August 2020 1040-6182/© 2020 Elsevier Ltd and INQUA. All rights reserved. Geological and geomorphic evidences of neotectonic activity along the Himalayan Frontal Thrust, Nahan Salient, NW Himalaya, India Mahesh Thakur a, * , Gurvinder Singh a , Javed N. Malik b a Centre of Advanced Study in Geology, Panjab University, Sector 14, Chandigarh, 160014, India b Department of Earth Sciences, IIT Kanpur, Kanpur, 208016, Uttar Pradesh, India A R T I C L E INFO Keywords: Himalayan frontal thrust Retreated scarp Fault-propagating-fold Active fault scarp ABSTRACT In this paper, we report geomorphic signatures of neotectonic activity identifed from the area around Nahan Salient along Himalayan Frontal Thrust (HFT), using remote sensing and feld investigations. We document two newly discovered exposures of HFT fault zone and active fault traces along the mountain front at Khetpurali, Nahan Salient, NW Himalaya, India. We demonstrate that HFT fault zone at Khetpurali is not blind, instead it is exposed at the surface along with highly deformed, folded strata in the hanging wall and its geometry is quite variable with the possibility of along strike-segmentation. The geometry of fold and various deformational features preserved in the hanging wall indicate a process of fault-propagation-fold. This is in contrast to the previous observation of fault-bent-folding within the Nahan Salient. Two-three levels of river terraces are pre- served and truncated in the hanging wall, along with the active fault scarps which are linked to uplift along HFT fault zone. The Khetpurali Anticline (KA), is a fault-propagating-fold formed due to displacement and shortening along HFT which dips 30 ◦ towards north and strike WNW-ESE. The uplift (U) along the KA is calculated to be ~73 m and accommodated 7.3% shortening of the original length, before the fault tip truncated the fold. Various deformational structures have been identifed within the hanging wall around-tip damage zone of ~80 m perpendicular to HFT fault zone and in the core of KA. Northwest of Khetpurali, a south-facing hogback structure ~100 m high is formed due to erosion of forelimb of the anticline. At Khetpurali, tectonic control due to folding of strata and uplift of river terraces is evident as the Dudhgarh River forms V-shaped profle near the thrust, compared to the wide foodplain before and after crossing the HFT fault zone. Along strike segmentation of HFT and associated anticlines is observed as the surface trace of HFT is offset at Khetpurali, Trilokpur, and Sabilpur due to the strike-slip faults. The study reveals that HFT has been truncated by tear faults and has different subsurface geometries in study area which may have implication on seismic hazard in the Nahan Salient where three thrusts; Himalayan Frrontal Thrust (HFT), Nahan Thrust (NT) and Main Boundary Fault (MBF) are located at relatively shorter distance of ~6 km as compared to the surrounding recesses. 1. Introduction The process of collision between Indian and Eurasia plates started at around 40–50 Ma (Najman et al., 2010; Bouilhol et al., 2013) and is continuing till today at a convergence rate of 40–50 mm/yr (Patriat and Achache, 1984; Bettinelli et al., 2006, Minister and Jordan, 1978). Due to the collision, four major north-dipping thrusts have been produced in the Himalayan domain from north to south: Indus-Tsangpo Suture Zone (ITSZ), the Main Central Thrust (MCT), the Main Boundary Thrust (MBT) and the Himalayan Frontal Thrust (HFT) along with the evolving Himalayan foreland basin (Gansser, 1964; Valdiya, 1998; Hodges, 2000; Pearson and DeCelles, 2005; Yin, 2006: Bhattacharyya and Mitra, 2009; Matin and Mukul, 2010; Mitra et al., 2010). The dynamics of this collision controls the topography, structures, distribution of earthquakes and active faults in the Himalaya. Various geological studies have been conducted in the foothills of frontal Himalaya to understand the convergence, slip rates, paleoearthquakes and active faulting (e.g., Wesnousky et al., 1999; Malik and Nakata, 2003; Thakur, 2004; Lav´ e et al., 2005; Malik et al., 2008, 2010a, 2010b, 2015, 2016, 2017; Kumar et al., 2001, 2006, 2010; Philip et al., 2009; Philip et al., 2011; Kuma- hara and Jayangondaperumal, 2013; Sapkota et al., 2013; Yule et al., 2006; Bollinger et al., 2014, 2016; Jayangondaperumal et al., 2017; * Corresponding author. E-mail address: mahesh09@gmail.com (M. Thakur). Contents lists available at ScienceDirect Quaternary International journal homepage: www.elsevier.com/locate/quaint https://doi.org/10.1016/j.quaint.2020.07.014 Received 20 May 2020; Received in revised form 1 July 2020; Accepted 10 July 2020