A team of international researchers, including specialists from the University of Southampton and the University of Potsdam, has proposed a fresh perspective on an age-old geophysical puzzle: the detection of continental rock fragments in remote areas of oceanic volcanoes. The results of their study are detailed in the journal Nature Geoscience. The central element of the new interpretation lies in the concept of the gradual separation of the lower layers of continents. According to the data obtained, the stretching process of continental plates leads to hot material in the upper mantle affecting their base, initiating a process termed “mantle waves.” “These slow-moving disturbances at depths of 150 to 200 kilometers can tear off pieces of continental crust and transport them over enormous distances,” explains the lead author of the study, Thomas Gernon. He clarified that the unusual “contamination” of certain mantle zones beneath the oceans has long puzzled geologists, as accepted models, including subduction or mantle plumes, could not fully explain the recorded chemical anomalies. A co-author of the project, Sascha Brune, emphasized that mantle processes continue to bear the imprints of continental breakup long after the actual rift event. “This mechanism continues to transport the enriched substrate even after a new oceanic basin has already formed,” he added. An underwater volcanic massif in the Indian Ocean, formed after the breakup of the supercontinent Gondwana, serves as additional evidence supporting this hypothesis. The absence of mantle plumes and the observed attenuation of volcanic activity in this specific area are entirely consistent with the proposed model. The scientists believe that the identified mantle waves may have the potential to explain a whole range of other geological phenomena, from eruptions of diamond-bearing rocks to the formation of Earth’s grandest topographical structures.
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