A new plate boundary is forming in Zambia, and it’s not subtle. Instead of seismic activity, the telltale sign comes from hot spring water.
Researchers have discovered gases escaping from deep within the Earth at these springs, especially along the Kafue Rift, a crack in Zambia’s crust. They suspect this rift might still be active, and this study provides the evidence.
Led by Mike Daly, a professor at the University of Oxford, a team sampled gases from eight geothermal wells in the region. Six wells were within the rift zone, while two were on stable ground. They collected bubbling gas and sealed it in copper tubes for analysis.
The team analyzed these samples for helium isotopes and other elements. Helium isotopes can reveal where gases originate. Earth’s mantle holds a rare type of helium, while the crust has a different version from radioactive decay. The ratio of these isotopes helps identify the gas’s source.
Results showed a distinct signature indicating that gases were rising from rocks 25 to 100 miles below the surface. This evidence establishes a connection between Kafue’s springs and the Earth’s mantle.
In terms of comparison, the Kafue Rift’s gases mirrored samples from the East African Rift, an older rift known for its active volcanoes and deep valleys. Zambia’s rift appears to be in a much earlier stage, with no volcanoes yet.
If the Kafue Rift continues to develop, it could lead to a new plate boundary, potentially splitting Africa. The Southwest African Rift stretches about 1,550 miles, suggesting that this is part of a larger geological process.
Research shows that as rifts begin to form, they can produce geothermal energy and valuable gases like helium and hydrogen. Zambia is already exploring geothermal energy along the Kafue Rift. Helium is in high demand for medical devices and technology; hydrogen is gaining attention as a clean fuel. Early-stage rifts like this one might become prime spots for these resources.
This study fills a critical gap in understanding the Kafue Rift’s activity. The findings hint at dynamic geological processes at work, prompting further research along the Southwest African Rift System.
Daly warns that while this study sheds light on one area, more fieldwork is necessary across the rift, particularly in neighboring Botswana and Namibia. Anticipating results from these areas this year, the discussions around Africa’s geological future are evolving. Historically, East Africa has been the focus, but Zambia is now a strong contender for the next significant plate boundary formation.
The full study is published in the journal Frontiers in Earth Science.
Stay updated on this fascinating development as research unfolds!
