ancient asteroid impacts helped create Earth's continents

How Earth got its crust: Researchers find ancient asteroid impacts formed gigantic pools of molten rocks that eventually formed Earth's continents Occurred more than 3.8bn years ago, in a time period called the Hadean eon Giant pools were tens of kilometres thick, and thousands in diameter Say Earth at the time resembled the surface of the moon 

By Mark Prigg For Dailymail.com

Published: 00:14 GMT, 1 February 2019 | Updated: 00:14 GMT, 1 February 2019

View
comments

Scientists have revealed how Earth may have got its crust.

Before it split into the continents we know today, it was formed from gigantic pools of molten rock caused by asteroids bombarding the planet, researchers say.

It occurred more than 3.8 billion years ago, in a time period called the Hadean eon, and the giant pools were tens of kilometres thick, and thousands of kilometres in diameter.

More than 3.8 billion years ago, in a time period called the Hadean eon, and the giant pools were tens of kilometres thick, and thousands of kilometres in diameter.

More than 3.8 billion years ago, in a time period called the Hadean eon, and the giant pools were tens of kilometres thick, and thousands of kilometres in diameter.

At the time, most of these surface rocks on Earth were basalts, and the asteroid impacts produced large pools of superheated impact melt of such composition. 

'If you want to get an idea of what the surface of Earth looked like at that time, you can just look at the surface of the Moon which is covered by a vast amount of large impact craters,' says Professor Rais Latypov from the School of Geosciences of the University of the Witwatersrand in South Africa.

However, ressearchers are still baffled by exactly how the ancient, giant melt sheets became the 'protocontinents'. 

One theory is that, on cooling, they may have crystallized back into a similar type of rock, wiht asteroid playing no part.  

An alternative model suggests that these sheets may undergo large-scale chemical change to produce layered magmatic intrusions, such as the Bushveld Complex in South Africa.

Before it split into the continents we know today, Earth's crust was formed from gigantic pools of molten rock caused by asteroids bombarding the planet, researchers say.

Before it split into the continents we know today, Earth's crust was formed from gigantic pools of molten rock caused by asteroids bombarding the planet, researchers say.

In this scenario, asteroid impacts may have played an important role in producing various igneous rocks in the early Earth's crust and therefore they may have contributed to its chemical evolution.

By studying the younger impact melt sheet of the Sudbury Igneous Complex (SIC) in Canada, researchers found that ancient asteroid impacts were capable of producing various rock types from the earlier Earth's

read more from dailymail.....

Get the latest news delivered to your inbox

Follow us on social media networks

NEXT Technology Zuckerberg says he wants strict European-style privacy laws — but some ...