Radiometric ages of laterites and constraints on long-term denudation rates in West Africa

Abstract

Research Article| February 01, 2003 Radiometric ages of laterites and constraints on long-term denudation rates in West Africa Yanni Gunnell Yanni Gunnell 1Laboratoire de Géographie Physique, CNRS-UMR 8591, 1 Place A. Briand, 92120 Meudon, France Search for other works by this author on: GSW Google Scholar Author and Article Information Yanni Gunnell 1Laboratoire de Géographie Physique, CNRS-UMR 8591, 1 Place A. Briand, 92120 Meudon, France Publisher: Geological Society of America Received: 14 Jun 2002 Revision Received: 05 Oct 2002 Accepted: 12 Oct 2002 First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2003) 31 (2): 131–134. https://doi.org/10.1130/0091-7613(2003)031<0131:RAOLAC>2.0.CO;2 Article history Received: 14 Jun 2002 Revision Received: 05 Oct 2002 Accepted: 12 Oct 2002 First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Yanni Gunnell; Radiometric ages of laterites and constraints on long-term denudation rates in West Africa. Geology 2003;; 31 (2): 131–134. doi: https://doi.org/10.1130/0091-7613(2003)031<0131:RAOLAC>2.0.CO;2 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 In stable cratonic regions, most tropical weathering mantles evolve over long time scales and record long-term environmental change. They may therefore also reflect tectonism and its denudation-related signals detected through apatite fission-track thermochronology, cosmogenic radionuclide dating, and the age bracketing of laterites by 40Ar/39Ar dating of potassium- and manganese-rich oxides. Based on an existing Cenozoic pedimentation model for the West African craton, this study uses the three combined radiometric methods to define rates of Cenozoic denudation. Denudation rates of <2 m/m.y. on the lateritic plateaus, in comparison to rates of 7–13 m/m.y. adjacent to them, fit ages of 45–50 Ma for late stages of bauxite development and 24–25 Ma for one phase of lateritization. Together, they support the theory implicit in the landscape model that depths of denudation in cratonic interiors are equal to, or not significantly greater than, existing elevation differences between lateritic landforms. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.