Long‐term, deep‐mantle support of the Ethiopia‐Yemen Plateau. Issue 2 (29th February 2016)

• Record Type: Journal Article
• Authors: Sembroni, Andrea; Faccenna, Claudio; Becker, Thorsten W.; Molin, Paola; Abebe, Bekele
• Is Part Of: Tectonics. Volume 35:Issue 2(2016)
• Page Start: 469
• Page End: 488
• Publication Date: 2016-02-29
• Subjects: mantle plume -- continental flood basalts -- dynamic topography -- flexural isostasy -- Ethiopia; Geology, Structural -- Periodicals; 551.8
• DOI: 10.1002/2015TC004000
• Languages: English
• ISSNs: 0278-7407

Abstract

Abstract: Ethiopia is a key site to investigate the interactions between mantle dynamics and surface processes because of the presence of the Main Ethiopian Rift (MER), Cenozoic continental flood basalt volcanism, and plateau uplift. The role of mantle plumes in causing Ethiopia's flood basalts and tectonics has been commonly accepted. However, the location and number of plumes and their impact on surface uplift are still uncertain. Here we present new constraints on the geological and topographic evolution of the Ethiopian Plateau (NW Ethiopia) prior to and after the emplacement of the large flood basalts (40–20 Ma). Using geological information and topographic reconstructions, we show that the large topographic dome that we see today is a long‐term feature, already present prior to the emplacement of the flood basalts. We also infer that large‐scale doming operated even after the emplacement of the flood basalts. Using a comparison with the present‐day topographic setting, we show that an important component of the topography has been and is presently represented by a residual, nonisostatic, dynamic contribution. We conclude that the growth of the Ethiopian Plateau is a long‐term, probably still active, dynamically supported process. Our arguments provide constraints on the processes leading to the formation of one of the largest igneous plateaus on Earth. Key Points: Reconstruction of the topographic evolution of the Ethiopian Plateau The present‐day topographic dome is a long‐term feature present since the Oligocene Much of the topography has been and is dynamically sustained