Geological science fiction refuted: A ‘cool’ new picture of early Earth.
The first 700 million years of Earth’s 4.5-billion-year existence are known as the Hadean period, after Hades, or, to shed the ancient Greek name,Those same zircon crystals also show that the modern oceans didn't exist in the Triassic and the Earth was half it's present diameter. Maybe now people can start to realize the mantle is also cold and therefore mantle convection is a myth.
That name seemed to fit with the common perception that the young Earth was a hot, dry, desolate landscape interspersed with seas of magma and inhospitable for life. Even if some organism had somehow popped into existence, the old story went, surely it would soon have been extinguished in the firestorm of one of the giant meteorites that slammed into the Earth when the young solar system was still crowded with debris.
Over the last decade, the mineralogical analysis of small hardy crystals known as zircons embedded in old Australian rocks has painted a picture of the Hadean period “completely inconsistent with this myth we made up,” said T Mark Harrison, a professor of geochemistry at the University of California, Los Angeles.