Southern Africa is characterised by unusually elevated topography and abnormal heat flow, which have baffled scientists for decades.
Noble gase measurements now confirm plume-related mantle degassing beneath South Africa.
There are fields of methane bubbling off the coast of North Carolina as well as evidence of a hot magma mantle plume underneath Yellowstone National Park’s supervolcano hotspot. As well, Southern Africa is characterised by unusually elevated topography and abnormal heat flow, which have baffled scientists for decades.
Now a new study shows ‘the first evidence in support of upwelling deep mantle beneath Southern Africa, helping to explain the regions elevation and abnormal heat flow,’ after analysing the chemical composition of gases bubbling up from a deep earth crack in KwaZulu-Natal, South Africa.
The isotopic composition of the noble gases helium and neon present corresponds to the composition of the deep mantle, a rocky layer 1,000 kilometres below Earth’s surface.
Yes, geologists have been puzzled by the high relief and hotter than expected subsurface temperatures of the rocks beneath Southern Africa.
But this new science discovery clearly shows that CO2 gas at the surface is from a deep mantle plume (hotspot) and thus helps to explain the unusual landscape of South Africa. [Nature]