Earth’s oldest rocks were formed by meteorites

The oldest rocks on Earth may have formed in an apocalyptically fiery barrage of meteorites that melted the planet’s crust more than four billion years ago, geologists report.
Analysis of four-billion-year-old silica-rich rocks from the Acasta River in Canada by researchers from Western Australia’s Curtin University, published in the journal Nature Geoscience, found that they probably formed at high temperatures and at a surprisingly shallow depth.