Scientists Reveal Hidden Mantle Threat: How Earth’s Continents Might Splinter from Within

The hidden chemistry inside the Earth has a big impact on how continents are shaped. A recent study from the Guangzhou Institute of Geochemistry found that carbon, often trapped deep in the mantle, can either strengthen ancient land or cause it to collapse. By using high-pressure experiments and studying deep diamonds, researchers discovered a surprising link between carbon and continent stability.

When oceanic plates sink into the mantle through a process called subduction, the carbon-rich materials don’t just vanish. Instead, at depths of up to 660 kilometers, they transform in ways that can either stabilize or weaken the land above. A key factor is the mantle’s "redox state," which describes its ability to gain or lose electrons.

Professor Yu Wang, the lead author of the study, explained that in reduced, cooler conditions, carbon solidifies into diamonds and iron-rich minerals, helping to hold cratons (the stable cores of continents) together. In contrast, in hotter, oxidized areas, the carbon creates volatile melts that can weaken and destabilize the continental structure.

For instance, cooler mantle regions allow carbon materials to turn into diamonds over time, creating a strong foundation for continents. Research shows that areas like the Amazonia Craton are prime examples. Here, diamonds contain minerals that only form under specific high-pressure conditions, indicating a stable environment that has preserved the continent’s integrity for millions of years.

On the other hand, the Kaapvaal Craton in southern Africa tells a different story. This region has weakened due to oxidized carbon-rich melts interacting with its base, leading to instability and geological upheaval. Diamonds found in this area show distinct mineral patterns, revealing their different origins.

These trends highlight how important the redox state of the mantle is for the fate of continents. Recent findings indicate that as the Earth continues to evolve, the balance of these chemical processes will be crucial in shaping our planet.

Overall, diamonds act as time capsules that help us understand the Earth’s past. The composition of the minerals within them reveals not just the conditions they experienced but also the chemical environment in the mantle. This research not only enriches our knowledge of geology but also inspires new questions about how the Earth continues to adapt and change.

For more detailed scientific insights, you can read the complete study published in Science Advances.

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