Unveiling Earth's Ancient Tectonic Secrets

New geochemical evidence from Earth's oldest-known rocks in Canada challenges previous models suggesting plate tectonics operated from the planet's early days. The study found no evidence of surface material recycling at 4.0 billion years ago, indicating subduction and plate recycling may not have been present at that time. However, a distinct shift in silicon and oxygen isotopes at 3.8 billion years ago suggests a possible change in Earth's geodynamics, potentially marking the onset of plate subduction. The findings shed light on the early history of tectonic activity on Earth.