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The oldest crystal on Earth: Scientists say zircon formed in the craters left by violent asteroid im
The oldest crystal on Earth: Scientists say zircon formed in the craters left by violent asteroid impacts that hit our young planet
By Ellie Zolfagharifard For Dailymail.com
Published: 18:05 EST, 28 April 2016 | Updated: 18:33 EST, 28 April 2016
The very oldest pieces of rock on Earth - zircon crystals - are likely to have formed in the craters left by violent asteroids.
This contradicts the previous belief that they were created by Earth's plate tectonics shortly after it formed.
The discovery was made by scientists who studied zircons in the Sudbury impact crater in Ontario, and found them to be no different from an ancient set.
Rocks that formed over the course of Earth's history allow geologists to infer things such as when water first appeared on the planet, how our climate has varied, and even where life came from.
But, scientists can only go back in time so far, as the only material we have from the very early Earth comes in the form of tiny, naturally occurring zircon crystals.
The origin of these crystals, which are around the width of a human hair and more than four billion years old, has become a matter of major debate.
More:
http://www.dailymail.co.uk/sciencetech/article-3564649/The-oldest-crystal-Earth-Scientists-say-zircon-formed-craters-left-violent-asteroid-impacts-hit-young-planet.html#ixzz47fiMwytO
