International Journal of Earth Sciences

, Volume 99, Issue 7, pp 1545–1557 | Cite as

Crustal thinning beneath the Rwenzori region, Albertine rift, Uganda, from receiver-function analysis

  • Ingo Wölbern
  • G. Rümpker
  • A. Schumann
  • A. Muwanga
Original Paper

Abstract

The Rwenzori mountains in western Uganda, with a maximum elevation of more than 5,000 m, are located within the Albertine rift valley. We have deployed a temporary seismic network on the Ugandan side of the mountain range to study the seismic velocity structure of the crust and upper mantle beneath this section of the rift. We present results from a receiver-function study revealing a simple crustal structure along the eastern rift flank with a more or less uniform crustal thickness of about 30 km. The complexity of inner-crustal structures increases drastically within the Rwenzori block. We apply different inversion techniques to obtain reliable results for the thickness of the crust. The observations expose a significantly thinner crust beneath the Rwenzori range with thickness values ranging from about 20–28 km beneath northern and central parts of the mountains. Our study therefore indicates the absence of a crustal root beneath the Rwenzori block. Beneath the Lake Edward and Lake George basins we detect the top of a layer of significantly reduced S-wave velocity at 15 km depth. This low-velocity layer may be attributed to the presence of partial melt beneath a region of recent volcanic activity.

Keywords

East African Rift System Rwenzori mountains Receiver functions Lithosphere Crust 

Supplementary material

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Supplemental Fig. 9. (GIF 82.8 kb)

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Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  • Ingo Wölbern
    • 1
  • G. Rümpker
    • 1
  • A. Schumann
    • 2
  • A. Muwanga
    • 2
  1. 1.Institute of GeosciencesGoethe University FrankfurtFrankfurt am MainGermany
  2. 2.Department of GeologyMakerere University KampalaKampalaUganda

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