New Research Shows The Oldest Meteorite Crater On Earth Isn't Actually A Crater
In 2012, scientists identified what they believed was a remnant of a three billion-year-old meteorite crater in the Archean Maniitsoq structure in Greenland. During fieldwork in the same location, a team of scientists from the University of Waterloo has found that the region's features are inconsistent with an impact crater. According to the lead scientist on the project, Chris Yakymchuk, the area's zircon crystalline rocks are like "little time capsules."
He said they preserve ancient damage caused by shockwaves resulting from a meteorite impact and that the team had found no such damage in the rocks. Yakymchuk also notes that there are multiple places where rocks melted and recrystallizing deep in the Earth. During a meteorite impact, that process, called metamorphism, would happen almost immediately. The researchers found that in that particular area of Greenland, the process occurred 40 million years later than the earlier group proposed.
The team says it was there to explore the area for potential mineral exploration. A close examination of the area and data collected since 2012 allowed them to conclude the features were inconsistent with a meteorite impact. Yakymchuk says the team was disappointed that they weren't working in a structure that resulted from a meteorite impacting the Earth 3 billion years ago but notes that the understanding of the Earth's ancient history always evolves.
The team's findings provide scientific data for resource companies and Greenlandic prospectors to find new mineral resources. It's unclear what sort of minerals the team was prospecting for at the time. Yakymchuk worked with a team of international scientists from Canada, Australia, Denmark, Greenland, and the UK.