From the depths of Bermuda, a determined geological mystery offers new insights into the history of the Earth.
This has nothing to do with the famous Triangle, where some say the boats are lost, nor with the beaches and sand of the archipelago that attract tourists from all over the world.
The key is below, hundreds of kilometers deep, under even the limestone layers that form the soil.
There died a volcano that disappeared about 30 million years ago.
But this is not a volcano.
According to a group of scientists led by the Estonian geologist Esteban Gazel, it was created in a way it has never seen on our planet.
The study, published in the journal Nature, guarantees that the volcano on which the Bermuda is located originates from the mantle transition area, a layer rich in water, crystals and rocks, merging between 440 and 660 km below the earth's crust. on the ground.
Gazel, Professor of Atmospheric Science and Earth Sciences at Cornell University, USA.
Gazel argues that so far geologists have believed that volcanoes are formed in two ways:
- As a result of the tectonic plate movement.
- When the so-called mantle feathers (a type of narrow columns of mantle material) were erected to create hot spots in the earth's crust.
"Now we find that the minerals that form under the transition zone of the mantle of the Earth can penetrate the surface and form volcanoes," says Gasel.
How did you come to this discovery?
According to Gazel, a drill was made in the 1970s to pass Bermuda's limestone layer and take deep Bermuda samples, which have been preserved for decades at a university in Nova Scotia (Canada).
After asking for several permissions, the geologist and his team had access to them for analysis.
"Then we found that the contained minerals had enough water to form in the transition zone," he says.
How important is this?
According to the researcher, the discovery, in addition to confirming the volcanic origin of Bermuda or the new way of forming volcanoes, reveals the importance of the less-known layer of the Earth.
"The study helps to understand that the transitional zone is a layer of essential importance for the evolution of planet Earth, where magma and chemical processes are produced," he adds.
The geologist confirms that this layer is in itself a "volcano reservoir", but also a "unique" source of water.
"There is water that forms at least three oceans," he says.
But this in itself is not good news for the lack of water on our planet.
"Of course, it is not in liquid form, but in the structure of minerals, ie minerals have water in their molecules," he explains.