Did the Earth have a crust since its birth? Or did it form through time? Lots of debates have stormed the issue, but, all left several open ends. Scientists have come up with another evidence to suggest that earth had a crust. These are the tiny zircon crystals dug up from ancient Australian deposits. They are claimed to have been formed right after the birth of the planet. So, the finding suggests that early on, Earth had a cool crust much like that of today’s. And that too could have harbored life!
Stephen Mojzsis of the University of Colorado informed that though most remnants of the very early crust, formed more than 4 billion years ago, are gone, little zircon crystals have survived. They say that most remnants of the very early crust were recycled as part of the steady ongoing process known as plate tectonics. The key to this finding was a rare metal element known as hafnium. It is found with the zircons. “This is one of the few Earth materials that we know of that is capable of surviving recycling of the crust,” Mojzsis said Reuters in a telephone interview.