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S-WAVE VELOCITY STRUCTURE OF THE CRUST AND UPPER MANTLE BENEATH KENYA IN COMPARISON TO TANZANIA AND ETHIOPIA: IMPLICATIONS FOR THE FORMATION OF THE EAST AFRICAN AND ETHIOPIAN PLATEAUS

2009; Geological Society of South Africa; Volume: 112; Issue: 3-4 Linguagem: Inglês

10.2113/gssajg.112.3-4.241

1996-8590

M. T. Dugda, A. Nyblade, Jordi Julià,

Geological and Geochemical Analysis

Research Article| December 01, 2009 S-WAVE VELOCITY STRUCTURE OF THE CRUST AND UPPER MANTLE BENEATH KENYA IN COMPARISON TO TANZANIA AND ETHIOPIA: IMPLICATIONS FOR THE FORMATION OF THE EAST AFRICAN AND ETHIOPIAN PLATEAUS M.T. DUGDA; M.T. DUGDA Department of Physics, North Carolina A&T State University, Greensboro, North Carolina, United States of America, e-mail: mtdugda@ncat.edu Search for other works by this author on: GSW Google Scholar A.A. NYBLADE; A.A. NYBLADE Department of Geosciences, Pennsylvania State University, University Park, Pennsylvania, United States of America, e-mail: andy@geosc.psu.edu; jjulia@geosc.psu.edu Search for other works by this author on: GSW Google Scholar J. JULIÀ J. JULIÀ Department of Geosciences, Pennsylvania State University, University Park, Pennsylvania, United States of America, e-mail: andy@geosc.psu.edu; jjulia@geosc.psu.edu Search for other works by this author on: GSW Google Scholar Author and Article Information M.T. DUGDA Department of Physics, North Carolina A&T State University, Greensboro, North Carolina, United States of America, e-mail: mtdugda@ncat.edu A.A. NYBLADE Department of Geosciences, Pennsylvania State University, University Park, Pennsylvania, United States of America, e-mail: andy@geosc.psu.edu; jjulia@geosc.psu.edu J. JULIÀ Department of Geosciences, Pennsylvania State University, University Park, Pennsylvania, United States of America, e-mail: andy@geosc.psu.edu; jjulia@geosc.psu.edu Publisher: Geological Society of South Africa First Online: 09 Mar 2017 Online ISSN: 1996-8590 Print ISSN: 1012-0750 © 2009 Geological Society of South Africa South African Journal of Geology (2009) 112 (3-4): 241–250. https://doi.org/10.2113/gssajg.112.3-4.241 Article history First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation M.T. DUGDA, A.A. NYBLADE, J. JULIÀ; S-WAVE VELOCITY STRUCTURE OF THE CRUST AND UPPER MANTLE BENEATH KENYA IN COMPARISON TO TANZANIA AND ETHIOPIA: IMPLICATIONS FOR THE FORMATION OF THE EAST AFRICAN AND ETHIOPIAN PLATEAUS. South African Journal of Geology 2009;; 112 (3-4): 241–250. doi: https://doi.org/10.2113/gssajg.112.3-4.241 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 SocietySouth African Journal of Geology Search Advanced Search Abstract New estimates of the S-wave velocity structure of the crust and upper mantle beneath the Kenya Rift and surrounding Kenya Highlands have been obtained by jointly inverting P wave receiver functions and Rayleigh wave phase and group velocities. The joint inversion was performed for seven broadband seismic stations, five that were part of the Kenya broadband seismic experiment and two belonging to the Global Seismic Network. 1-D S-wave velocity models obtained from the inversions have been compared to similar models for Tanzania and Ethiopia to identify differences in lithospheric structure beneath the East African and Ethiopian Plateaus. The S-wave velocity structure of the upper mantle to at least 100 to 150 km depth beneath the Kenya Highlands is similar to structure under the East African Plateau in Tanzania. It therefore appears that the plateau lithosphere under the Kenya Highlands has not been affected thermally to any greater extent than the plateau lithosphere beneath Tanzania. Under the Kenya Rift, however, the lithosphere has been substantially modified. S-wave velocities at depths of 80 to 150 km beneath the rift are 8 to 10% lower compared to under the Kenya Highlands, which may be a sufficiently large change to indicate the presence of partial melt.There is little similarity between the plateau lithosphere in East Africa and Ethiopia. The lithosphere under the Ethiopian Plateau is thin, extending to a depth of no more than about 80 to 90 km depth, compared to 100 to 150 km beneath Tanzania and the Kenya Highlands. The maximum S-wave velocity in the lithosphere is also very low, reaching only to 4.2 to 4.3 km/s, compared to 4.6 to 4.7 km/s beneath Tanzania and the Kenya Highlands. These differences indicate that the buoyant support for the plateau elevation in East Africa, including the Kenya Highlands, resides at deeper depths in the mantle than beneath the Ethiopian Plateau. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.