for National Geographic News
Strange specimens of natural glass found in the Egyptian desert are products of a meteorite slamming into Earth between 100,000 and 200,000 years ago, scientists have concluded.
The glass—known locally as Dakhla glass—represents the first clear evidence of a meteorite striking an area populated by humans.
At the time of the impact, the Dakhla Oasis, located in the western part of modern-day Egypt, resembled the African savanna and was inhabited by early humans, according to archaeological evidence (see Egypt map.)
"This meteorite event would have been catastrophic for all living things," said Maxine Kleindienst, an anthropologist at the University of Toronto in Canada.
"Even a relatively small impact would have exterminated all life for [several] miles."
The origin of the glass had puzzled scientists since Kleindienst discovered it in 1987.
Some researchers had suggested the Stone Age glass may have been produced by burning vegetation or lightning strikes.
But a chemical analysis showed that the glass was created in temperatures so high that they could only have been the result of a meteorite impact.
Gordon Osinski, a geologist at the Canadian Space Agency in Saint-Hubert who conducted the analysis, found that the glass samples contain strands of molten quartz, a signature of meteorite impacts.
"We can now say for definite that they were caused by a meteorite impact," he said.
Osinski is the lead author of the paper detailing the findings, which was published online in ScienceDirect.
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