We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Noble gases confirm plume-related mantle degassing beneath Southern Africa.
- Authors
Gilfillan, S. M. V.; Györe, D.; Flude, S.; Johnson, G.; Bond, C. E.; Hicks, N.; Lister, R.; Jones, D. G.; Kremer, Y.; Haszeldine, R. S.; Stuart, F. M.
- Abstract
Southern Africa is characterised by unusually elevated topography and abnormal heat flow. This can be explained by thermal perturbation of the mantle, but the origin of this is unclear. Geophysics has not detected a thermal anomaly in the upper mantle and there is no geochemical evidence of an asthenosphere mantle contribution to the Cenozoic volcanic record of the region. Here we show that natural CO2 seeps along the Ntlakwe-Bongwan fault within KwaZulu-Natal, South Africa, have C-He isotope systematics that support an origin from degassing mantle melts. Neon isotopes indicate that the melts originate from a deep mantle source that is similar to the mantle plume beneath Réunion, rather than the convecting upper mantle or sub-continental lithosphere. This confirms the existence of the Quathlamba mantle plume and importantly provides the first evidence in support of upwelling deep mantle beneath Southern Africa, helping to explain the regions elevation and abnormal heat flow. The elevation and high heat flow of Southern South Africa has controversially been attributed to a mantle plume. Here, the authors link degassed CO2 to a non-degassed mantle source rather than the convecting upper mantle, confirming plume-related mantle melting.
- Subjects
SOUTHERN Africa; NOBLE gases; PLUMES (Fluid dynamics); DEGASSING of metals; TOPOGRAPHY
- Publication
Nature Communications, 2019, Vol 10, Issue 1, p1
- ISSN
2041-1723
- Publication type
Article
- DOI
10.1038/s41467-019-12944-6