What isotopes reveal about ancient cratons with Dr Eric Vandenberg

Where Anthony sees crystals and Holly sees a rock, Dr Eric Vandenberg sees atoms, and specifically, Eric counts the neutrons. Eric is a postdoc at the Adelaide University and part of the ARC Training Centre for Critical Resources for the Future, and he shrinks the solid Earth down to the subatomic scale to answer some of geology's biggest questions: how the first continents formed, how plate tectonics got started, and how the rarest metal deposits on the planet came to be. ⚛️ What even is an isotope? Same element, different number of neutrons. But some isotopes are "radiogenic" and quietly decay over geological time (hello, beta and alpha decay), and why anything heavier than lead is inherently unstable. ⏳ The gold standard for dating rocks: why uranium and thorium love hiding inside zircon crystals, why lead doesn't, and how that mismatch lets geologists measure the exact age of a rock - this is geochronology in a nutshell. 🪨 The Pilbara: older than almost anything left on Earth. A craton stretching from 3.6 to 2.8 billion years old, closer in age to the formation of the planet than to today, and one of the best-preserved windows we have into Earth's earliest crust. 🌋 Earth vs Venus: why Earth is the only planet in the solar system with true plate tectonics, what a "stagnant lid" planet like Venus looks like instead, and the decades-old scientific debate over exactly when Earth made the switch. ⛏️ From ancient cratons to critical minerals: How isotope geochemistry traces the journey of gold, copper, nickel and platinum from sulfides deep in the mantle into the porphyry and IOCG deposits we mine today, without needing the impossibly hot magmas of the early Earth. A huge thank you to the Centre for Critical Resources for the Future for supporting this episode. 🔗 Find us at thegeoco.com.au 📸 Instagram & TikTok: @thegeoco 📰 Sign up to our newsletter: thegeoco.substack.com GeoCo connects to you from the traditional country of the Kaurna people of the Adelaide Plains, South Australia. We pay our respects to their Elders past, present, and emerging.