Researchers have identified a previously unknown source of volcanic lava at Earth’s extreme depths, in the transition zone between the upper and lower mantle.
In the Bermuda Islands, geologists have found evidence of volcanic material from the transition zone, between 400 and 650km below the Earth’s surface.
A source of volcanic lava at an unprecedented depth has just been discovered by scientists.
“We hope this data shows that the volcano is a mantle formation, an outburst from the deeper mantle like the one in Hawaii,” said geologist Esteban Gazel of Cornell University. This is the first time we have found a clear indication from the transition zone deep in the Earth’s mantle that volcanoes can form in this way.”
Hawaiian volcanoes originate at depths between 200 and 400km. But Bermuda’s volcano originates much deeper, in an area rich in water, crystals and molten rock.
Geologists found this evidence in a core sample drilled in Bermuda in 1972. It is more than 700 meters long and it is essentially a timeline of the geological history of the area. As matter is deposited, it forms a layer in the rock, and researchers can study it to reconstruct past events.
The researchers analyzed the rock sample, looking for isotopes, trace elements, evidence of water and volatiles, hoping their results will show that the volcano is a volcano from the mantle. above.
“I first suspected that Bermuda’s volcanic past was very special when I sampled the core and noticed that diverse textures and mineralogy were preserved in different lava flows. We quickly confirmed it. find the abundance in trace element compositions. .