up Until now no one had noticed, but right under the feet of the inhabitants of the south of Europe, including the Iberian Peninsula, sleep the remains of an old continent . One that sank a long time ago in the depths of the Earth, and whose history, 250 million years later, it has been rebuilt step by step by a team of geologists from the universities of Utrecht, Oslo and the Institute of Geophysics ETH, in Zurich.
The only visible remains of this lost continent, known as Great Adria , are the limestone rocks, which can be found in the mountain chains of southern Europe. The researchers, who just published their work in the journal Gondwana Research, they believe that these rocks began their existence as marine sediments, to later be "scraped" from the surface of the earth's crust and elevated to their current positions due to the collisions of the tectonic plates. For this reason, both the original size as the shape and the history of this land mass disappeared has been very difficult to reconstruct. In his article, the geologists explain that a large part of it was, for millions of years, the bottom of ancient tropical seas shallow.A violent history
For starters, says Douwe van Hinsbergen, University of Utrecht, and first author of the article, Great Adria had a history of "violent and complicated." In fact, separated from the southern supercontinent Gondwana , which included what is now Africa, South America, Australia, Antarctica, the indian subcontinent and the Arabian Peninsula, makes a whopping 240 million years ago. And from that moment began to advance towards the north.
The researchers believe that about 140 million years ago Great Adria was a mass of earth the size of Greenland , covered in large part by a light tropical sea, where the sediments were accumulated slowly to become rocks.
later, between 100 and 120 million years ago, hit with that today is Europe, being shattered and being pushed beneath the continent. Only a small part of the rocks of Great Adria, torn out of the earth's crust during the collision, managed to stay on the surface of the Earth so that the geologists had the occasion of discovering it.30 countries
The study, in addition, had to face an additional complication: the Big rocks Adria are scattered throughout more than 30 countries, ranging from a strip of the iberian peninsula to Iran. And in the same way that the rocks, also the data on its history have been scattered and have a result, explains van Hinsbergen, very difficult to collect.
finally, until less than a decade ago geologists have not provided the sophisticated software needed to perform reconstructions as complex as this. "The Mediterranean region", explains van Hinsbergen - it is simply disaster geological . Everything is bent, broken, and stacked".
to conduct their study, the team of researchers spent ten years collecting information about the ages of the rock samples of Great Adria, as well as the direction of the magnetic fields trapped in them. And they probably managed to identify not only when, but where those rocks had been formed.
In this way, the researchers realized that, at the same time progressed towards the north, Grand Adria turned in counter-clockwise , pushing and scraping to your step other tectonic plates. In the end, came the collision with Europe. And although this occurred at speeds of no more than 3 or 4 cm per year, the shock shattered completely the bark of Great Adria, about 100 km thick, sending most of it to the depths of the earth's mantle and just below the south of the european continent. Some parts of this lost continent are, in effect, more than 1,500 km of depth .Updated Date: 27 September 2019, 08:03