New research led by iCRAG Deputy Director Prof. Balz Kamber has found that the very oldest pieces of rock on Earth—zircon crystals—are likely to have formed in the craters left by violent asteroid impacts that peppered our nascent planet, rather than via plate tectonics as was previously believed.
In the summer of 2014, with the support of the Irish Reseach Council (IRC) and Science Foundation Ireland (SFI), the team collected thousands of zircons from the Sudbury impact crater, Ontario, Canada – the best preserved large impact crater on Earth and the planet’s second oldest confirmed crater at almost two billion years old.
Read more at: http://geology.gsapubs.org/content/early/2016/04/27/G37898.1