Ancient zircons push plate tectonics to 3.3 billion years ago
New analyses of 3.3‑billion‑year‑old zircon crystals from Jack Hills in Western Australia suggest Earth already hosted more atmospheric oxygen (and possibly more water) than previously thought, and that tectonic plates may have been moving by about 3.3 billion years ago—implying early Earth had geologic processes that recycle key chemicals and could support life, though the findings are debated and require further verification.