Upper-mantle low-velocity zone structure beneath the Kaapvaal craton from S-wave receiver functions

Samantha E. Hansen, Andrew A. Nyblade, Jordi Julià, Paul H.G.M. Dirks, Raymond J. Durrheim

Research output: Contribution to journalArticle

39 Citations (Scopus)

Abstract

The southern African Plateau is marked by anomalously high elevations, reaching 1-2 km above sea level, and there is much debate as to whether this topography is compensated by a lower mantle source or by elevated temperatures in the upper mantle. In this study, we use S -wave receiver functions (SRFs) to estimate the lithospheric thickness and sublithospheric mantle velocity structure beneath the Kaapvaal craton, which forms the core of the Plateau. To fit the SRF data, a low-velocity zone (LVZ) is required below a ∼160-km-thick lithospheric lid, but the LVZ is no thicker than ∼90 km. Although the lid thickness obtained is thinner than that reported in previous SRF studies, neither the lid thickness nor the shear velocity decrease (∼4.5%) associated with the LVZ is anomalous compared to other cratonic environments. Therefore, we conclude that elevated temperatures in the sublithospheric upper mantle contribute little support to the high elevations in this region of southern Africa.

Original languageEnglish (US)
Pages (from-to)1021-1027
Number of pages7
JournalGeophysical Journal International
Volume178
Issue number2
DOIs
StatePublished - Aug 3 2009

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low velocity zone
cratons
low speed
S waves
craton
S-wave
upper mantle
Earth mantle
receivers
plateau
plateaus
lower mantle
velocity structure
mantle source
temperature
sea level
topography
mantle
Sea level
Topography

All Science Journal Classification (ASJC) codes

  • Geophysics
  • Geochemistry and Petrology

Cite this

Hansen, Samantha E. ; Nyblade, Andrew A. ; Julià, Jordi ; Dirks, Paul H.G.M. ; Durrheim, Raymond J. / Upper-mantle low-velocity zone structure beneath the Kaapvaal craton from S-wave receiver functions. In: Geophysical Journal International. 2009 ; Vol. 178, No. 2. pp. 1021-1027.
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Upper-mantle low-velocity zone structure beneath the Kaapvaal craton from S-wave receiver functions. / Hansen, Samantha E.; Nyblade, Andrew A.; Julià, Jordi; Dirks, Paul H.G.M.; Durrheim, Raymond J.

In: Geophysical Journal International, Vol. 178, No. 2, 03.08.2009, p. 1021-1027.

Research output: Contribution to journalArticle

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