Russian and European geologists have discovered on the territory of Greenland in the vicinity of the city of Maniitsok the oldest crater on Earth with a diameter of 100 kilometers, which arose three billion years ago as a result of the fall of a 30 kilometer asteroid, according to an article published in the journal Earth and Planetary Science Letters.
“This unique discovery means that we can now study the consequences of the meteorite bombardment of the Earth in the form of a crater that formed a billion years earlier than previously thought possible. It took us three years to convince colleagues and the scientific community. The industrialists turned out to be more credulous - the Canadian company began to study the crater, trying to find deposits of nickel and platinum, already in 2011, said team leader Iain McDonald from Cardiff University (UK).
MacDonald and his colleagues, including the Russian scientist Boris Ivanov from the Institute of Dynamics of Geospheres of the Russian Academy of Sciences in Moscow, made this discovery during expeditions to the southern part of Greenland in 2010 and 2011.
According to the researchers, the crater was accidentally discovered by one of the authors of the article - geologist Adam Garde from the Geological Survey of Denmark and Greenland - in 2009, when he analyzed geological maps of the vicinity of the city of Maniitsok commissioned by one of the Danish mining companies.
Garde discovered strange anomalies in the structure of the rocks of the area, similar to the trail of a super-powerful meteorite impact. The scientist involved his colleagues from Russia, Great Britain and Sweden, who made two expeditions to the Maniitsok area and collected detailed data on the structure and other properties of the strange formation.
“The study process was similar to a detective story involving Sherlock Holmes. Gradually, we discarded all possible earth processes as impossible and realized that this anomaly is a giant trail from the impact of a meteorite,”MacDonald explained.
As the researchers note, the rocks at the site of the impact of the meteorite formed about three billion years ago. This respectful age of the crater explains why the crater lacks its usual bowl-like shape. Over the course of three billion years, Greenland has experienced several periods of mountain formation and glaciation, which destroyed all traces of the meteorite's fall, except for deformations in the rock caused by the shock wave.
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According to the calculations of geologists, this "scar" arose as a result of the collision of the Earth with an asteroid with a diameter of more than 30 kilometers. If this meteorite fell on the continent, it would leave a crater with a diameter of 500-600 kilometers, which is about twice as large as the previous record holder - Vredefort crater in South Africa. According to geologists, a celestial body of this size is capable of "vaporizing" a medium-sized state and wiping out all higher forms of life from the face of the Earth.
Scientists believe their discovery will help astrophysicists and planetary scientists better understand the conditions in which planets and meteorites were formed during the youth of the solar system.