Sydney: Earth's oldest evolved rocks are the consequence of asteroids colliding with the planet 4 billion years ago,an Australian research released on Tuesday revealed. The study by the Curtin University suggests that the rocks, part of the Acasta Gneiss Complex in northwest Canada, are the result of asteroids smashing into the Earth and melting its crust, allowing evolved, or granitic, rocks to form, reports Xinhua news agency.
What led scientists to suggest that they were formed in this way was first, the composition of the rocks is different from the those typical of the Earth’s ancient crust. “The only known evolved rocks from the Hadean eon are those in northwest Canada, which have chemical compositions clearly distinct from those that dominate ancient continental crust worldwide, suggesting they were formed in a different way,” research co-author professor Phil Bland said. (IANS)