3.3-Billion-Year-Old Crystals Reveal Earth’s Hidden Tectonic Past

A new study reveals surprising clues about the beginnings of subduction on Earth. The Hadean Eon, which lasted from 4.6 to 4.0 billion years ago, is still the least understood period in Earth’s past. It began with the birth of the planet and was quickly marked by a giant impact with a Mars-sized object. This [...]