Seismic evidence for a deep upper mantle thermal anomaly beneath East Africa

A. A. Nyblade, T. J. Owens, H. Gurrola, J. Ritsema, C. A. Langston

Research output: Contribution to journalArticle

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Abstract

Upper mantle seismic velocity variations beneath northern Tanzania coupled with the structure of the 410 and 660 km discontinuities reveal a 200-400-km-wide thermal anomaly extending into but not necessarily through the transition zone beneath the eastern branch of the East African rift system. This finding is not easily explained by small-scale mantle convection induced by passive stretching of the lithosphere or by a broad thermal upwelling extending from the lower mantle into the upper mantle, but it can be attributed to a mantle plume, provided that a plume head is present under the lithospheric keel of the Tanzania craton. A plume interpretation for the deep thermal anomaly is supported by evidence for mantle having the geochemical characteristics of a plume at >150 km depth beneath northern Tanzania.

Original languageEnglish (US)
Pages (from-to)599-602
Number of pages4
JournalGeology
Volume28
Issue number7
DOIs
StatePublished - Jan 1 2000

All Science Journal Classification (ASJC) codes

  • Geology

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