The nature of Earth’s earliest crust and crustal processes remains enigmatic due to the almost complete lack of a rock record older than 4 billion years (Hadean Eon) and the scarcity of rocks between 4 and 3.6 billion years (Eoarchean Era). One unresolved question is when mobile-lid tectonics commenced. To study the Hadean, the only direct record is from the mineral zircon, but Hadean zircon is rarely found. In new research, scientists from Harvard...