BIROn - Birkbeck Institutional Research Online

    Imaging lithospheric discontinuities beneath the Northern East African Rift using S -to-P receiver functions

    Lavayssière, A. and Rychert, C. and Harmon, N. and Keir, D. and Hammond, James O.S. and Kendall, J.-M. and Doubre, C. and Leroy, S. (2018) Imaging lithospheric discontinuities beneath the Northern East African Rift using S -to-P receiver functions. Geochemistry, Geophysics, Geosystems , ISSN 1525-2027.

    [img]
    Preview
    Text
    25009.pdf - Published Version of Record
    Available under License Creative Commons Attribution.

    Download (4MB) | Preview
    [img] Text
    24011.pdf - Author's Accepted Manuscript
    Restricted to Repository staff only

    Download (1MB)

    Abstract

    Imaging the lithosphere is key to understand mechanisms of extension as rifting progresses. Continental rifting results in a combination of mechanical stretching and thinning of the lithosphere, decompression upwelling, heating, sometimes partial melting of the asthenosphere, and potentially partial melting of the mantle lithosphere. The northern East African Rift system is an ideal locale to study these processes as it exposes the transition from tectonically active continental rifting to incipient seafloor spreading. Here we use S‐to‐P receiver functions to image the lithospheric structure beneath the northernmost East African Rift system where it forms a triple junction between the Main Ethiopian rift, the Red Sea rift, and the Gulf of Aden rift. We image the Moho at 31 ± 6 km beneath the Ethiopian plateau. The crust is 28 ± 3 km thick beneath the Main Ethiopian rift and thins to 23 ± 2 km in northern Afar. We identify a negative phase, a velocity decrease with depth, at 67 ± 3 km depth beneath the Ethiopian plateau, likely associated with the lithosphere‐asthenosphere boundary (LAB), and a lack of a LAB phase beneath the rift. Using observations and waveform modeling, we show that the LAB phase beneath the plateau is likely defined by a small amount of partial melt. The lack of a LAB phase beneath the rift suggests melt percolation through the base of the lithosphere beneath the northernmost East African Rift system.

    Metadata

    Item Type: Article
    Keyword(s) / Subject(s): Geochemistry and Petrology, Geophysics
    School: School of Science > Earth and Planetary Sciences
    SWORD Depositor: Mr Joe Tenant
    Depositing User: James Hammond
    Date Deposited: 29 Nov 2018 08:09
    Last Modified: 16 Feb 2021 01:14
    URI: https://eprints.bbk.ac.uk/id/eprint/25009

    Statistics

    Downloads
    Activity Overview
    185Downloads
    72Hits

    Additional statistics are available via IRStats2.

    Archive Staff Only (login required)

    Edit/View Item Edit/View Item