The myth of Atlantis has just been revived. They discovered rocks from submerged microcontinents between 200 and 3.2 billion years ago
An island in the Atlantic, which was a mighty military power, and which the ocean waters swallowed. Atlantis. It exists only in Plato’s texts. What if it wasn’t a myth?
An international team of scientists, led by the University of Grenada (UGR), has discovered evidence of several microcontinents that existed between 200 and 3.2 billion years ago, and that are submerged at the bottom of the Central Atlantic Ocean. His work, published in the journal Petrology, revived the ancient legend of Atlantis, described by Plato 2,300 years ago, which has captivated the imagination of many generations throughout history.
The geochronology team led by Fernando Bea and Pilar González Montero, professors of Mineralogy and Petrology at the University of Granada, found that oceanic rocks dredged from the bottom of the Central Atlantic with ages less than 2-3 million years old contained zircon minerals inherited from rocks. much older continental rocks, aged between 200 and 3.2 billion years.
These discoveries took place in the vicinity of the mid-Atlantic Ridge, the great mountain range that is the backbone of the ocean. So far from other places where attempts have traditionally been made to locate Atlantis, especially on the Greek island of Santorini, partially destroyed 3,600 years ago during a volcanic eruption.
the time capsule
The mineral zircon can be considered a ‘time capsule’ containing information encoded in the isotopic composition of the elements that form it. Zircon can crystallize containing appreciable amounts of the radioactive elements Thorium and Uranium which decompose into various isotopes of lead. The ratio between each radiogenic daughter (Lead isotopes) and its radioactive parent (Thorium and Uranium isotopes) allows us to calculate with great precision the age of crystallization of the mineral.
In addition, zircon contains oxygen, which is the most abundant element in the Earth’s crust and mantle. Oxygen has two natural isotopes of masses 16 and 18 which, due to their large relative mass difference, are easily fractionated from each other. Thus, continental rocks tend to have more 18O than mantle rocks.
A fragment of dismembered continent
“Because oxygen diffuses very rapidly, the fact that ancient zircons found in modern ocean floor rocks retain their clearly continental isotopic composition indicates that they spent very little time within mantle magmas and suggests that they were extracted from a continental crust that was fragmenting when it was invaded by the mantle magmas that produce oceanic crust – the UGR researchers point out -. In short, we are convinced that it is a fragment of a continent that was dismembered in the middle of the Atlantic Ocean.”
UGR scientists point out that the date when this breakup of the continent took place is given by the ages of magmatic zircons that coexist with ancient zircons. “The analyzes carried out in the SHRIMP-IBERSIMS laboratory of the UGR showed ages of up to 600,000 years, but we cannot rule out even younger ages; Therefore, there may have been one or several microcontinents populated by hominids, if we take into account that Homo antecessor roamed Europe 900,000 years ago,” the authors point out.
“This age of 600,000 years for the destruction of the Atlantic microcontinents is a maximum estimate. There is no evidence to rule out that it could have occurred in more recent times, such that the catastrophe would have been recorded in the legends and myths of homo sapiens. This would require finding recent oceanic rocks (less than 10,000 years old) that also contain zircons inherited from an ancient continent. We hope that ongoing studies can clarify the unknown”, concludes Fernando Bea.
Bibliographic reference:
Bortnikov, N., Silant’ev, SA, Bea F., Montero, Zinger, T., Skolotnev, S., and Sharkov, E., 2022. Multiple melting of a heterogeneous mantle and episodic accretion of oceanic crust in a spreading Zone: U-Pb Zircon Age and Hf-O Isotope Evidence from a Mid-Atlantic Ridge Ocean Core Complex. Petrology 30, 1-24.