On the beaches of Mauritius, zircons were found (a natural and very expensive gem, comparable in cost to sapphire), 2 billion years old. Scientists believe that these "wandering" zircons formed in granite rocks - fragments of an ancient microcontinent. About 85 million years ago, Madagascar began to separate from India, the ancient continent broke and went under water. It is likely that the Seychelles is also a tiny remnant of this continent.
Mauritius is an island state in East Africa, located 2 thousand kilometers from its shores, east of Madagascar. The state includes the islands of Mauritius (the largest) and Rodrigues, and many small islets. Scientists believe that this island was formed 9 million years ago from the cooled lava erupted by underwater volcanoes.
Despite the fact that the oldest of the island's basalts dates back to 8.9 million years BC, 20 zircons were recently found on the beaches, which are at least 660 million years old. And one of the crystals is approximately 2 billion years old!
These "stones" have an incredible level of resistance to external negative factors, and are usually radioactive due to impurities of rare elements. The high content of uranium in zircon makes it a convenient mineral for determining the age of rocks by the method of uranium-lead dating. Because of their chemical resistance, they are often used to study the geological past of our planet. How did such ancient breeds get to Mauritius?
It turns out that scientists have long suspected that volcanic islands may contain evidence of the existence of lost continents. This was the theory of the Norwegian scientist Yamthwaite, which he expressed in 1999. Yamtwaite, along with a group of like-minded people, decided to test their assumptions by going to Mauritius on a long expedition. A stay in tropical Mauritius "was very tempting for a Norwegian during a cold January," Yamtwaite admitted.
Mauritius was chosen for its volcanic origin. The island was formed from oceanic lava and was supposed to naturally contain zircon. If rocks with zircon are found and their age turns out to be more than 9 million years, then this will be proof of the real existence of the ancient continent.
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First, scientists broke rocks from Mauritius to extract zircon crystals from them. However, the crushing equipment contained zircon from other places, which did not allow us to speak with confidence about the purity of the experiment.
A few years later, geologists returned to Mauritius, and this time they began to take sand samples from the beaches. 20 samples of zircon of such a solid age were identified that there was no doubt that there is an ancient continent under Mauritius.
In the scientific journal Nature Geoscience, Yamthwaite published an article in which he described in detail his hypothesis and the evidence found for it.
Here it is: a long time ago on the site of Mauritius, between Madagascar and India, there was an ancient continent, which was confirmed by the analysis of the Earth's gravitational field. It turns out that under Mauritius there is an abnormal thickening of the earth's crust (25-30 km instead of the usual 5-10 km). This may be due to the presence of remnants of the supercontinent, nicknamed by the researchers - "Mauritia" (Mauritia).
Yamtwaite and his colleagues estimate that the lost microcontinent made up about one-fourth of today's Madagascar. In turn, Mauritius was once a small part of the much larger "supercontinent" Rodinia, which included India and Madagascar. Like prehistoric Atlantis, Mauritia disappeared underwater when India broke away from Madagascar about 85 million years ago.
Then volcanic activity took its toll, and volcanic islands rose in place of the submerged earth. Recent volcanic eruptions brought fragments of the crust to the surface and zircons "burst" from the parent rocks, falling into the sand. “As the lavas passed through the continental rocks towards the surface, they carried along with them some rocks containing zircon,” explains Yamtwaite.
These rocks may have split and melted due to the heat. However, a certain amount of zircon in the grains of sand remained and solidified during the eruption in the lava, which, sliding down, formed the rocky base of Mauritius.
Importantly, these unique stones were mined in hard-to-reach places in Mauritius. Therefore, the possibility that tourists bring them with them is excluded. There is a small chance that they were carried by the wind, but in theory, these fragments are too heavy for such a journey.
For this hypothesis, the scientist was criticized by many of his colleagues. Geologists began to demand from him some "outstanding proofs", believing that the author of the concept had not yet provided them.
Scientists are currently continuing their research, and for the "purity" of the experiment, they decided to choose new portions of sand for analysis, so that zircons that were accidentally stuck in crushing equipment after previous studies would not contaminate fresh samples. The nearest outcrop of the continental crust, where Mauritian zircons can still be found, is deep under water.
“It's far - many kilometers across the deep sea,” says Yamtwait. It may be necessary to search for sites using thermal imagers. Conol Mac Niokyle, a geologist at the University of Oxford, writes: "Obviously, the search will take a long time, since there is no local source of these zircons."
At the same time, Yamtwaite is optimistic and hopes to make new discoveries: "We know more about the topography of Mars than about the topography of the world's ocean floor, and therefore there may well be other dissected continents that are still awaiting discovery."