Analysis of gases from hot springs in a frozen rift indicates the intrusion of gases originating from the Earth's mantle. Researchers estimate that this may be an early stage of a continental rift in South Africa.
A deep geological process may be developing beneath the surface of Zambia, which could change the face of the African continent in the distant future. A new study, published in the journal Frontiers in Earth Science, has found signs of active tectonic activity in the Kafue Rift region. The researchers identified an unusual helium isotope signature in hot springs in the area, which likely originates in the Earth's mantle. (Frontiers)
The possible meaning of the finding is that an early stage of a continental rift is developing beneath South Africa. Such a rift is an area where the Earth's crust is gradually stretching, weakening, and sinking. In some cases, such a process can stop after a while. In other cases, over millions of years, it may develop into a boundary between tectonic plates, and even contribute in the distant future to the opening of a new ocean.
The study does not claim that Africa is about to split apart anytime soon. These are very slow processes on a human scale. However, the mere detection of mantle-derived fluids and gases rising to the surface through deep cracks provides researchers with an important clue that the geological system in the region is not dormant.
Helium signature from the mantle
The researchers tested gases emitted from eight geothermal springs and wells in Zambia. Six of the samples were collected inside the suspected rift zone, and two more outside it. In the laboratory, the gases were tested for isotopes, that is, different versions of the same element, the ratios of which can indicate the source of the gas.
In this case, the key was helium. The ratio of helium isotopes originating in the atmosphere, the Earth's crust, and the mantle is not the same. The samples from the frozen rift region showed an isotopic ratio that does not fit with normal air and is also not well explained by a crustal source alone. According to the researchers, this indicates a significant contribution of helium originating in the mantle, that is, at a depth of tens to hundreds of kilometers below the surface.
Professor Mike Daly of the University of Oxford, one of the authors of the study, said that the helium signatures in the hot springs along the frozen rift indicate a direct connection with the Earth's mantle. He said such a connection indicates that the frozen rift's subduction boundary is active, and that the southwest African rift zone may also be active.
The researchers also compared the findings to the East African Rift System, a more familiar and geologically mature region. They say that the helium isotope ratios in the frozen rift are similar to those found in the East African Rift System, while springs outside the rift zone did not show the same signature.
A hidden rift thousands of kilometers long
The frozen rift is part of a larger rift system, about 2,500 kilometers long, stretching from Tanzania to Namibia. According to the researchers, it may have a broader geological connection to tectonic structures in the Atlantic Ocean. The area has attracted attention due to its unusual landscape, geothermal activity and abundance of hot springs, characteristics that could indicate a young rift system.
If the conclusions are confirmed in further studies, they may also have economic implications. Young rift systems may be linked to geothermal energy resources, as well as to underground reserves of helium and hydrogen. Both gases are important to modern industries: helium is used in scientific instruments, medicine, and the chip industry, among other things, and hydrogen is considered a potential resource in future energy systems.
However, the researchers are cautious about drawing far-reaching conclusions. Daly noted that the study is based on helium analyses from just one region within a system thousands of kilometers long. He said that more extensive follow-up studies are already underway to determine whether the signature found in Zambia represents a local phenomenon or part of a larger active system. (Frontiers)
The study adds to a broader understanding that continents are not permanent structures. They form, break apart, merge, and change shape over millions of years. If South Africa is indeed at the beginning of a new rifting process, it is a very early stage in an exceptionally long geological journey. For scientists, these subtle signs are important: they allow us to understand how a process begins that, in later stages, can reshape entire continents.
Short questions and answers:
Is Africa about to split up soon??
No. This is a very slow geological process that, if it continues, will develop over millions of years.
What did the researchers find in Zambia??
They found an unusual signature of helium isotopes in hot springs, indicating a source deep in the Earth's mantle.
Why is helium important in such research??
Helium isotope ratios can be used as a marker for the source of the gas. When they resemble signatures from the mantle, this may indicate deep cracks in the crust.
What is the possible economic significance??
Such areas may be associated with geothermal energy, helium, and hydrogen resources, but further studies are needed before assessing the economic potential.
Suggested internal links:
Plate tectonics, earthquakes, geology of Africa, geothermal energy, Earth's mantle
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There have been several times when the continents have converged together – because if America moves away from Europe, it must approach Asia on the other side in a big way. Why in a big way – because there is also a sideways movement. In another 200 million years, there will be a united continent again, but the puzzles will fall into place after Pangaea.
Why was there only one continent (Pangaea) in the distant past?
Most likely, several continents were formed.