A crater 100 kilometers in diameter caused by the fall of an asteroid or comet makes 3 billion years ago, was discovered by European geologists near the city of Maniitsog in Greenland .
The crater , caused by a celestial body 30 km in diameter, is the oldest on Earth .“This discovery only to study the effects of meteoric bombardment of the planet that occurred billions of years earlier than previously thought,” said Iain McDonald, University of Csrdiff, who directs the study.
“We need three years to convince the scientific community to undertake such a study.Entrepreneurs were the first to react. Organized exploration of the crater in 2011, hoping to find deposits of nickel and platinum, “he added.
After several expeditions to Greenland in 2010 and 2011, McDonald and Boris Ivanov, expert from an institute of the Academy of Sciences of Russia, made such a discovery.
The geologist Adam Garde, the Geological Survey of Denmark and Greenland, was the first to assume the existence of a crater at the site in 2009. While examining a geological map around Maniitsoq, discovered strange anomalies in the structure of the local rocks, caused apparently by the impact of a giant meteor .
The study of this phenomenon were included scientists from Russia, Britain and Sweden. Two expeditions were organized, during which were discarded alternative explanations for these anomalies and confirmed the impact of a giant meteor .
That event occurred about three billion years. This explains the absence of the cup, as usual of craters . During such a long time, Greenland experienced several periods of glaciation and mountain building, which erased all traces of the meteorite, except in rock deformation caused by the shock wave.
The calculations allowed us to conclude that it was an asteroid more than 30 kilometers. Such a body falling on a continent, would have caused a funnel up to 600 kilometers in diameter, or twice the Vredefort crater in South Africa.