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Tuesday, July 10, 2012

The oldest crater on Earth is in Greenland


European Geologists have found the oldest impact crater on Earth in the city of Maniitsog (Greenland). This is a crater 100 kilometers in diameter caused by the fall of an asteroid 3,000 million years ago. Experts suspected the existence of the crater since 2009, when the Geological Survey of Denmark and Greenland, examining a geological map of the surrounding Maniitsoq, discovered strange anomalies in the structure of the local rocks, caused by the impact of a giant meteor .

Then conducted further studies and new expeditions in Greenland with Russian experts, English and Swedish, in 2010 and 2011, and has now been confirmed that the data obtained in the area corresponding to the oldest impact crater on the planet . The author of the work, Iain McDonald, stated that "this discovery can only study the effects of meteoric bombardment of the planet that occurred billions of years earlier than previously believed. " The impact caused the crater occurred about 3,000 million years, as can be inferred from the absence of the "cup", the usual form of the craters. Moreover, the calculations allowed us to conclude that the asteroid that struck Earth was more than 30 kilometers . In this sense, the study points out that 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. McDonald explained that this crater has been "hiding" under long periods of glaciers and mountain building that Greenland has lived for 3,000 million years now . "The ice erased all traces of the fall of the meteorite , except in rock deformation caused by the shock wave that is now allowed this discovery, "concludes the researcher.

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