The oldest mineral record of terrestrial origin, a detrital zircon from the Jack Hills in the Yilgarn Craton of Western Australia has been dated to 4.4 billion years old.
The first 500 million years of Earth’s history, the Hadean eon - after Hades, Greek god of the underworld - was long believed to be a constantly violent and chaotic period, where volcanism and impacts with other bodies in the solar system meant a magmatic planetary surface.
These zircon crystals, formed only 150 million years after the origin of the Earth, seem to contradict the earlier notion of an extended period of a hellish Earth. Rather, they suggest the presence of liquid water, oceans and continental crust. So emerges a new picture of a cooler early Earth, one where life may have evolved much earlier than we had thought.
THE OLDEST KNOWN EARTHLY MATERIAL
4.4 Ga zirconium silicate in metasediments
Satellite view of the Jack Hills, Yilgarn Craton, Western Australia. Image courtesy of NASA.