Assessing Quaternary reactivation of the Main Central thrust zone (central Nepal Himalaya): New thermochronologic data and numerical modeling

Abstract

Research Article| August 01, 2009 Assessing Quaternary reactivation of the Main Central thrust zone (central Nepal Himalaya): New thermochronologic data and numerical modeling Xavier Robert; Xavier Robert 1Laboratoire de Géodynamique des Chaînes Alpines, Université Joseph Fourrier, CNRS, Grenoble, France Search for other works by this author on: GSW Google Scholar Peter van der Beek; Peter van der Beek 1Laboratoire de Géodynamique des Chaînes Alpines, Université Joseph Fourrier, CNRS, Grenoble, France Search for other works by this author on: GSW Google Scholar Jean Braun; Jean Braun 2Géosciences Rennes, Université de Rennes 1, Rennes, France Search for other works by this author on: GSW Google Scholar Claire Perry; Claire Perry 1Laboratoire de Géodynamique des Chaînes Alpines, Université Joseph Fourrier, CNRS, Grenoble, France2Géosciences Rennes, Université de Rennes 1, Rennes, France *Current address: GEOTOP, Université du Québec à Montréal, Montréal QC H3C 3P8, Canada. Search for other works by this author on: GSW Google Scholar Matthieu Dubille; Matthieu Dubille 1Laboratoire de Géodynamique des Chaînes Alpines, Université Joseph Fourrier, CNRS, Grenoble, France Search for other works by this author on: GSW Google Scholar Jean-Louis Mugnier Jean-Louis Mugnier 1Laboratoire de Géodynamique des Chaînes Alpines, Université Joseph Fourrier, CNRS, Grenoble, France Search for other works by this author on: GSW Google Scholar Geology (2009) 37 (8): 731–734. https://doi.org/10.1130/G25736A.1 Article history received: 07 Jan 2009 rev-recd: 30 Mar 2009 accepted: 02 Apr 2009 first online: 03 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Xavier Robert, Peter van der Beek, Jean Braun, Claire Perry, Matthieu Dubille, Jean-Louis Mugnier; Assessing Quaternary reactivation of the Main Central thrust zone (central Nepal Himalaya): New thermochronologic data and numerical modeling. Geology 2009;; 37 (8): 731–734. doi: https://doi.org/10.1130/G25736A.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract We study the recent dynamics of the central Nepal Himalaya, focusing on possible reactivation of the footwall of the Main Central thrust, which is marked by an abrupt topographic transition. Different tectonic mechanisms, such as overthrusting of a major crustal ramp, underplating, or out-of-sequence thrusting, have been suggested to explain the morphology and exhumation patterns in this area. We present 25 new apatite fission-track ages collected along a north-south transect in central Nepal, as well as two age-elevation profiles. Ages are consistently younger than 3 Ma old in the Main Central thrust zone and increase continuously to 4–6 Ma old in the south. No jump in apatite fission-track ages is observed across the topographic transition. Apparent exhumation rates from age-elevation relationships vary from 0.46 +0.13/−0.09 km/Ma in the Palung granite south of Kathmandu to 4.4 +4.8/−1.5 km/Ma in the Main Central thrust zone; the latter rate is probably overestimated by a factor of two due to topographic effects. As shown by a new numerical model, these strongly varying exhumation rates can be explained by overthrusting of a crustal ramp, which exerts a primary control on age patterns, and do not require out-of-sequence reactivation of thrusts in the Main Central thrust zone. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.