Year: 2019
Type: article
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.
Source: Nature Communications
Language: English
Subfield: Geochemistry and Petrology
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $5,200
Awards: G1353267846, Fingerprinting captured CO2 using natural tracers: Determining CO2 fate and proving ownership, BGS Energy Systems and Basin Analysis, G4811044190, G5442153952, BGS Geoanalytics and Modelling, UK Carbon Capture and Storage Research Centre 2017 (UKCCSRC 2017), Improving Interpretation Outcomes: quantifying biases and designing workflows for better seismic interpretation, G7853178677, Applying natural tracer technologies in the environmental monitoring of unconventional gas extraction
OpenAlex ID: W2981653858