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Noble gases confirm plume-related mantle degassing beneath Southern Africa

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 asthe...

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Autores principales: 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.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6831580/
https://www.ncbi.nlm.nih.gov/pubmed/31690720
http://dx.doi.org/10.1038/s41467-019-12944-6
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author 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.
author_facet 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.
author_sort Gilfillan, S. M. V.
collection PubMed
description 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 CO(2) 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.
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spelling pubmed-68315802019-11-07 Noble gases confirm plume-related mantle degassing beneath Southern Africa 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. Nat Commun Article 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 CO(2) 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. Nature Publishing Group UK 2019-11-05 /pmc/articles/PMC6831580/ /pubmed/31690720 http://dx.doi.org/10.1038/s41467-019-12944-6 Text en © The Author(s) 2019 https://creativecommons.org/licenses/by/4.0/Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) .
spellingShingle Article
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.
Noble gases confirm plume-related mantle degassing beneath Southern Africa
title Noble gases confirm plume-related mantle degassing beneath Southern Africa
title_full Noble gases confirm plume-related mantle degassing beneath Southern Africa
title_fullStr Noble gases confirm plume-related mantle degassing beneath Southern Africa
title_full_unstemmed Noble gases confirm plume-related mantle degassing beneath Southern Africa
title_short Noble gases confirm plume-related mantle degassing beneath Southern Africa
title_sort noble gases confirm plume-related mantle degassing beneath southern africa
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6831580/
https://www.ncbi.nlm.nih.gov/pubmed/31690720
http://dx.doi.org/10.1038/s41467-019-12944-6
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