A new study published in the journal Nature Communications sheds new light on the birth of what could be the youngest ocean on the planet: the Red Sea, now one of the most geologically active areas on the planet and a unique natural laboratory for understanding how oceans form and the mechanisms that govern continental drift.
The research, conducted in collaboration with the Saudi Geological Survey, involved several institutions: the National Research Council with the Institute of Marine Sciences in Bologna (CNR-ISMAR) and the Institute of Environmental Geology and Geoengineering in Rome Montelibretti (CNR-IGAG), the Department of Earth and Environmental Sciences at the University of Pavia, the Department of Earth Sciences at the University of Florence, and the Department of Physics and Geology at the University of Perugia.
The study focused on magmatic rocks (gabbros and basaltic dikes) from the Tihama Asir complex in southern Saudi Arabia, which formed during the initial stages of the opening of the Red Sea about 25 million years ago: the aim was to understand the role of deep magmatism in the processes of continental crust rupture and the subsequent formation of an ocean basin.
The results reveal that the magmas, generated by the partial melting of the asthenosphere—the portion of the Earth’s mantle beneath the crust that behaves plastically—interacted with ancient portions of the lower crust before accumulating in more superficial magma chambers, with minimal contamination from the upper crust. This process—triggered by the combination of the rise of the deep mantle through the hot Afar plume and the extensional tectonic forces induced by subduction along the Zagros chain in Iran—led to a thermal weakening of the lower crust, promoting its deep deformation and allowing the asthenosphere to rise in place of the continental lithospheric mantle.
It has thus been demonstrated that magmatism can not only promote the fragmentation of continents, but can also hinder it by delaying the onset of new oceanic crust formation. In particular, as in the case studied, magma can temporarily thicken the continental crust during thinning, helping to absorb the extension through continuous intrusions of dikes. In other words, the birth of an ocean may be a slower and more complex process than previously thought.
“The Red Sea is a window onto the processes that, millions of years ago, gave rise to the other oceans on Earth,” explains Marco Ligi of CNR-ISMAR, who coordinated the research together with his colleagues Alessio Sanfilippo of the University of Pavia and Sandro Conticelli of the University of Florence. “Understanding its evolution also means improving our knowledge of geothermal resources, tectonic dynamics, and even faunal migrations, including that of hominids out of Africa.”
The study represents an important step in understanding the deep geological processes that shape our planet, offering a model that can also be applied to other contexts of continental rifting on planet Earth and, consequently, in other similar planetary contexts.
Our insight into the deep workings of the planet we live on, the only one we can observe and analyze directly, allows us to build bridges toward understanding the universe, the evolution of planets, and, above all, the origin of life and the mechanisms by which it can spread and colonize other potentially habitable worlds like Earth.
Fact sheet
Who: Institute of Marine Sciences of the National Research Council in Bologna (Cnr-Ismar); Institute of Environmental Geology and Geoengineering of the National Research Council in Rome Montelibretti (Cnr-Igag); Department of Earth and Environmental Sciences of the University of Pavia; Department of Earth Sciences of the University of Florence; Department of Physics and Geology of the University of Perugia
What:, Sanfilippo, A., Ligi, M., Avanzinelli, R. et al. Magmatic underplating and crustal intrusions accommodate extension during Red Sea continental rifting. Nat Commun 16, 6488 (2025). https://doi.org/10.1038/s41467-025-61598-0, link: https://www.nature.com/articles/s41467-025-61598-0
Info: Marco Ligi, Cnr-Ismar, marco.ligi@bo.ismar.cnr.it
