Climatic forcing of erosion, landscape, and tectonics in the Bhutan Himalayas

Abstract

Research Article| October 01, 2006 Climatic forcing of erosion, landscape, and tectonics in the Bhutan Himalayas Djordje Grujic; Djordje Grujic 1Department of Earth Sciences, Dalhousie University, Halifax B3H 4J1, Canada Search for other works by this author on: GSW Google Scholar Isabelle Coutand; Isabelle Coutand 2Université de Lille I, UMR 8110, 59655 Villeneuve d'Ascq Cedex, France Search for other works by this author on: GSW Google Scholar Bodo Bookhagen; Bodo Bookhagen 3Institute for Crustal Studies, University of California–Santa Barbara, Santa Barbara, California 93106, USA Search for other works by this author on: GSW Google Scholar Stéphane Bonnet; Stéphane Bonnet 4Université de Rennes 1, Géosciences Rennes, 35042 Rennes Cedex, France Search for other works by this author on: GSW Google Scholar Ann Blythe; Ann Blythe 5Department of Earth Sciences, University of Southern California, Los Angeles, California 90089, USA Search for other works by this author on: GSW Google Scholar Chris Duncan Chris Duncan 6Department of Geosciences, University of Massachusetts, Amherst, Massachusetts 01003, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Djordje Grujic 1Department of Earth Sciences, Dalhousie University, Halifax B3H 4J1, Canada Isabelle Coutand 2Université de Lille I, UMR 8110, 59655 Villeneuve d'Ascq Cedex, France Bodo Bookhagen 3Institute for Crustal Studies, University of California–Santa Barbara, Santa Barbara, California 93106, USA Stéphane Bonnet 4Université de Rennes 1, Géosciences Rennes, 35042 Rennes Cedex, France Ann Blythe 5Department of Earth Sciences, University of Southern California, Los Angeles, California 90089, USA Chris Duncan 6Department of Geosciences, University of Massachusetts, Amherst, Massachusetts 01003, USA Publisher: Geological Society of America Received: 05 Jan 2006 Revision Received: 25 Apr 2006 Accepted: 01 May 2006 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2006) 34 (10): 801–804. https://doi.org/10.1130/G22648.1 Article history Received: 05 Jan 2006 Revision Received: 25 Apr 2006 Accepted: 01 May 2006 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Djordje Grujic, Isabelle Coutand, Bodo Bookhagen, Stéphane Bonnet, Ann Blythe, Chris Duncan; Climatic forcing of erosion, landscape, and tectonics in the Bhutan Himalayas. Geology 2006;; 34 (10): 801–804. doi: https://doi.org/10.1130/G22648.1 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 A fundamental objective in studies of climate-erosion-tectonics coupling is to document convincing correlation between observable indicators of these processes on the scale of a mountain range. The eastern Himalayas are a unique range to quantify the contribution of tectonics and climate to long-term erosion rates, because uniform and steady tectonics have persisted for several million years, while monsoonal precipitation patterns have varied in space and time. Specifically, the rise of the Shillong plateau, the only orographic barrier in the Himalayan foreland, has reduced the mean annual precipitation downwind in the eastern Bhutan Himalaya at the Miocene-Pliocene transition. Apatite fission-track (AFT) analyses of 45 bedrock samples from an E-W transect along Bhutan indicate faster long-term erosion rates outside of the rain shadow in the west (1.0–1.8 mm/yr) than inside of it in the east (0.55–0.85 mm/yr). Furthermore, an AFT vertical profile in the latter segment reveals a deceleration in erosion rates sometime after 5.9 Ma. In this drier segment of Bhutan, there are remnants of a relict landscape formed under a wetter climate that has not yet equilibrated to the present climatic conditions. Uplift and preservation of the paleolandscape are a result of a climate-induced decrease in erosion rates, rather than of an increase in rock uplift rate. This study documents not only a compelling spatial correlation between long-term erosion and precipitation rates, but also a climatically driven erosion-rate change on the scale of the eastern Himalayas, a change that, in turn, likely influences that region's recent tectonic evolution. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.