Scientists have discovered new evidence suggesting that a tectonic plate boundary could be forming beneath parts of southern Africa, potentially marking the early stages of the continent slowly splitting apart over millions of years.
Researchers studying geothermal springs in Zambia found unusual helium and carbon isotope signatures that indicate deep mantle material is rising through cracks in the Earth’s crust along the Kafue Rift, a region considered part of the larger Southwest African Rift System.
The findings, published in Frontiers in Earth Science, suggest that the rift may already have broken through the Earth’s crust and connected directly to the mantle below a major geological milestone in the formation of a new tectonic boundary.
Ancient Rift System Showing Signs of Activity
The Kafue Rift forms part of a vast 2,500-kilometre-long chain of rifts stretching from Tanzania to Namibia. Scientists say the system could eventually evolve into a major continental divide similar to the well-known East African Rift System.
According to Mike Daly from the University of Oxford, the discovery provides evidence that tectonic forces are actively reshaping the region beneath southern Africa.
“The hot springs along the Kafue Rift have helium isotope signatures indicating a direct connection with the Earth’s mantle,” Daly said. “This suggests the fault boundary is active and may represent an early stage of continental break-up.”
What Scientists Found
Researchers collected gas samples from eight geothermal springs and wells across Zambia, including six within the suspected rift zone. Laboratory analysis revealed unusually high levels of mantle derived helium isotopes, similar to those observed in the active East African Rift System.
The samples also contained carbon dioxide signatures consistent with gases rising from deep within the Earth’s mantle rather than from the atmosphere or shallow crustal rocks.
Scientists say this combination strongly suggests that fractures linked to the rift have penetrated through the crust, allowing mantle fluids to escape to the surface.
Could Africa Split Apart?
While the process would take millions of years, scientists believe the Southwest African Rift System may eventually develop into a full tectonic plate boundary capable of dividing parts of Africa.
The East African Rift has long been viewed as the continent’s most likely future break up zone. However, researchers say the Southwest African Rift may possess geological weaknesses that make continental separation easier in this region.
Daly explained that surrounding mid ocean ridges tend to resist tectonic extension across much of Africa, but natural weaknesses in the crust along the Southwest African Rift could lower the threshold needed for continental break-up.
Still, researchers cautioned that the study represents an early stage of investigation, and more extensive geological surveys are already underway.
Potential Energy Opportunities
Beyond its geological significance, the discovery could also have economic implications for the region.
Early-stage rift zones often contain valuable geothermal resources as well as underground reserves of helium and hydrogen gases. Scientists say future exploration could support renewable energy projects and industrial development across parts of southern Africa.
Researchers noted that geothermal systems in the Kafue Rift may eventually provide sustainable energy opportunities for local communities while also advancing scientific understanding of how continents slowly reshape over Earth’s history.