Earth’s crust was first formed at least 4.4 billion years ago, just 160 million years after the formation of our solar system, a new study in the journal Nature Geoscience has found. A time-line of the history of our planet places the formation of the Jack Hills zircon and a “cool early Earth” at 4.4 billion years, researchers said. With the help of a tiny fragment of zircon extracted from a remote rock outcrop in Australia, the picture of how our planet became habitable to life is coming into sharper focus.
An international team of researchers led by University of Wisconsin-Madison geoscience Professor John Valley reveals data that confirm the Earth’s crust first formed at least 4.4 billion years ago, just 160 million years after the formation of our solar system. The work shows that the time when our planet was a fiery ball covered in a magma ocean came earlier. “This confirms our view of how the Earth cooled and became habitable. This may also help us understand how other habitable planets would form,” said Valley.
The study confirms that zircon crystals from Western Australia’s Jack Hills region crystallised 4.4 billion years ago, building on earlier studies that used lead isotopes to date the Australian zircons and identify them as the oldest bits of the Earth’s crust. The microscopic zircon crystal used by Valley and his group is now confirmed to be the oldest known material of any kind formed on Earth.
- Varun Gandhi Under Attack Over Defence Deals: Here’s How
- This Diwali, Let Blind Students Brighten Up your Homes With Candles & Diyas
- CBI Files Supplementary Chargesheet In Sheena Bora Murder Case
- Soha Ali Khan And Vir Das Starrer 31st October Audience Reaction
- Sahara Chief Subrata Roy’s Parole Extended Till November 28
- Simple Tips To Secure Your Debit Card From Fraudsters
- New Zealand & India Team Being Welcomed In Chandigarh
- Mumbai Call Centre Scam: All You Need To Know
- Jammu Kashmir Chief Minister Mehbooba Mufti Appeals To Police: Here’s What She Said
- Shocker From Ahmedabad: Find Out What Happened
- Bigg Boss 10 Day 3 Review: Celebs Fail To Do Well in First Task
- Airtel Offers 10GB Data At Rs 259 For New 4G Smartphone Users
- Aamir Khan Starrer Dangal’s Trailer Launched: First Impressions
- TMC Supporters Attack BJP Leader Babul Supriyo
- Sri Lankan Navy Apprehends 20 Indian Fishermen
The study, according to Valley, strengthens the theory of a “cool early Earth,” where temperatures were low enough for liquid water, oceans and a hydrosphere not long after the planet’s crust congealed from a sea of molten rock. “The study reinforces our conclusion that Earth had a hydrosphere before 4.3 billion years ago,” and possibly life not long after, said Valley.
The study was conducted using a new technique called atom-probe tomography that, in conjunction with secondary ion mass spectrometry, permitted scientists to accurately establish the age and thermal history of the zircon by determining mass of individual atoms of lead in the sample. The clusters of lead atoms formed 1 billion years after crystallisation of the zircon, by which time the radioactive decay of uranium had formed the lead atoms that then diffused into clusters during reheating. “The zircon formed 4.4 billion years ago, and at 3.4 billion years, all the lead that existed at that time was concentrated in these hotspots,” Valley said.