Timing of East African Rift development in southern Ethiopia: Implication for mantle plume activity and evolution of topography

Abstract

Research Article| February 01, 2008 Timing of East African Rift development in southern Ethiopia: Implication for mantle plume activity and evolution of topography Raphaël Pik; Raphaël Pik 1Centre de Recherches Pétrographiques et Géochimiques, CRPG, CNRS-UPR 2300, BP 20, 54501 Vandoeuvre-Lès-Nancy Cedex, France Search for other works by this author on: GSW Google Scholar Bernard Marty; Bernard Marty 1Centre de Recherches Pétrographiques et Géochimiques, CRPG, CNRS-UPR 2300, BP 20, 54501 Vandoeuvre-Lès-Nancy Cedex, France Search for other works by this author on: GSW Google Scholar Jean Carignan; Jean Carignan 1Centre de Recherches Pétrographiques et Géochimiques, CRPG, CNRS-UPR 2300, BP 20, 54501 Vandoeuvre-Lès-Nancy Cedex, France Search for other works by this author on: GSW Google Scholar Gezahegn Yirgu; Gezahegn Yirgu 2Addis Ababa University, Geology and Geophysics Department, P.O. Box 1176, Addis Ababa, Ethiopia Search for other works by this author on: GSW Google Scholar Teklewold Ayalew Teklewold Ayalew 2Addis Ababa University, Geology and Geophysics Department, P.O. Box 1176, Addis Ababa, Ethiopia Search for other works by this author on: GSW Google Scholar Author and Article Information Raphaël Pik 1Centre de Recherches Pétrographiques et Géochimiques, CRPG, CNRS-UPR 2300, BP 20, 54501 Vandoeuvre-Lès-Nancy Cedex, France Bernard Marty 1Centre de Recherches Pétrographiques et Géochimiques, CRPG, CNRS-UPR 2300, BP 20, 54501 Vandoeuvre-Lès-Nancy Cedex, France Jean Carignan 1Centre de Recherches Pétrographiques et Géochimiques, CRPG, CNRS-UPR 2300, BP 20, 54501 Vandoeuvre-Lès-Nancy Cedex, France Gezahegn Yirgu 2Addis Ababa University, Geology and Geophysics Department, P.O. Box 1176, Addis Ababa, Ethiopia Teklewold Ayalew 2Addis Ababa University, Geology and Geophysics Department, P.O. Box 1176, Addis Ababa, Ethiopia Publisher: Geological Society of America Received: 29 Jun 2007 Revision Received: 12 Oct 2007 Accepted: 15 Oct 2007 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 The Geological Society of America, Inc. Geology (2008) 36 (2): 167–170. https://doi.org/10.1130/G24233A.1 Article history Received: 29 Jun 2007 Revision Received: 12 Oct 2007 Accepted: 15 Oct 2007 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Tools Icon Tools Get Permissions Search Site Citation Raphaël Pik, Bernard Marty, Jean Carignan, Gezahegn Yirgu, Teklewold Ayalew; Timing of East African Rift development in southern Ethiopia: Implication for mantle plume activity and evolution of topography. Geology 2008;; 36 (2): 167–170. doi: https://doi.org/10.1130/G24233A.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 Accurate determination of rifting chronology and associated uplift is crucial to understanding the evolution of the East African Rift System (EARS) and for identifying the significance of mantle plumes during continental breakup. This investigation of rift-related cooling along a major fault scarp in southern Ethiopia, using (U-Th)/He thermochronometry, shows that rifting started not before 20 Ma. Therefore, there is an absence of significant rift activity synchronous with the earliest volcanics of the EARS, which are Eocene in age. In contrast, this initial magmatic episode, which preceded the main flood basalts and rifting events by 15–20 Ma, is attributed to convective instabilities above the rising Afar mantle plume. A detailed spatial and temporal quantification of uplift and denudation along this rift shoulder shows that rift development in southern Ethiopia has been continuous since initiation in the Miocene. This direct evidence of denudation is inconsistent with the hypothesis that massive Plio-Pleistocene rifting and associated uplift occurred in this part of the EARS and could have triggered recent aridification. To the contrary, our study rather supports a major contribution of plume-related doming for creation of topographical barriers in the Ethiopian province. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.