Wed Jan 15 13:51:23 UTC 2025: ## Earth’s Mantle Split Reveals Secrets of Supercontinents

**Perth, Australia** – A new study published in *Nature Geoscience* reveals a fundamental division in Earth’s mantle, mirroring the geological history of supercontinents. Researchers from Curtin University have found that the mantle is effectively split into two distinct domains, separated by the Pacific Ring of Fire, a region reflecting the formation and breakup of the supercontinent Pangaea.

The “African domain,” encompassing most of Earth’s landmass, exhibits a significantly greater diversity of elements and isotopes than the “Pacific domain,” which primarily underlies the Pacific Ocean. This disparity, according to lead researcher Luc Doucet, is a direct consequence of the formation and breakup of the supercontinents Rodinia and Pangaea over the past billion years.

Both Rodinia and Pangaea formed predominantly over the present-day African domain. As oceans closed during their formation, subduction – the process of oceanic crust sinking beneath continental crust – transported continental rock and its associated elements and isotopes deep into the mantle. This process intensified as the supercontinents assembled, concentrating these materials beneath their vast landmasses.

Even after Pangaea’s breakup, its geochemical signature remains detectable in both shallow and deep mantle regions. This conclusion is based on an analysis of 3,983 magma samples from mid-ocean ridges, providing crucial insights into the link between surface processes and deep Earth activity.

The researchers suggest that the two large low-shear velocity provinces (LLSVPs), or “mantle blobs,” one beneath the Pacific and the other beneath the African domain, also play a role in this geochemical division.

“Understanding these mantle dynamics,” Doucet explains, “is crucial not only for identifying potential concentrations of valuable materials like rare earth elements, but also for comprehending the planet’s unique plate tectonic system, which cycles essential elements for life between the Earth’s interior and surface.” The study highlights the importance of plate tectonics in sustaining life on Earth, a process unique to our planet.

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