Tiny zircon crystals are revealing that Earth’s earliest history may have included surprisingly complex tectonic activity. Earth today is built around recycling. Old crust sinks, melts, and returns as new rock. A new zircon study suggests that kind of cycling may have started shockingly early, in some places, when the planet was still in its [...]from SciTechDaily https://ift.tt/vzXVF9M
