Domino Effect: Geologists Unravel Age-Old Mystery of Oceanic Volcanism and Plate Tectonics
Kyiv • UNN
New research explains the presence of continental chemical materials on volcanic islands by suggesting that continents are slowly being peeled away from below by Earth's tectonic forces. This material is then transported far away, enriching the oceanic mantle and fueling volcanism.
Geologists have unraveled an age-old mystery of oceanic volcanism and plate tectonics, related to the presence of continental chemical materials on volcanic islands located far out in the oceans. This is reported in a Science Alert article, according to UNN.
Details
It is noted that according to modeling and chemical analysis conducted by the University of Southampton, these complex mechanisms arise when continents slowly delaminate from below by Earth's tectonic forces, far from their tectonic boundaries. As continental plates split and drift apart, the hot upper mantle strips them at their roots. This washed-out material is then transported far away, where it enriches the oceanic mantle and fuels volcanism for ages.
We have known for decades that parts of the mantle beneath the oceans appear strangely contaminated, as if pieces of ancient continents somehow ended up there.
The publication indicates that previous hypotheses regarding continental material found on oceanic islands focused on two main sources: oceanic sediments recycled at plate boundaries, and columns of hot rock known as deep mantle plumes.
Thus, some volcanic regions show few signs of crustal recycling, while others are too cold and shallow to be driven by deep mantle plumes.
The new study offers an alternative explanation: continents not only split at the surface, they also delaminate at depths of 150 to 200 km.
We found that the mantle continues to experience the effects of continental breakup long after the continents themselves have separated. The system doesn't shut down when a new oceanic basin forms - the mantle continues to move, reorganize, and transport enriched material far from its origin.
Scientists summarize that the breakup of continents is like a domino effect, initiating long-lasting disturbances deep within the Earth's interior, linking the fate of continental roots to unexpected geological activity worldwide.
Recall
Scientists have discovered traces of an ancient continent that broke away from Australia more than 150 million years ago and was long thought to be lost.