Geochemists have successfully deployed a novel dating technique using Calcium-48 isotopic chronometry to resolve longstanding debates over the age of early hominin sites. The study, appearing in Science Advances, focused on volcanic ash layers surrounding Acheulean stone tools found in the East African Rift Valley. By measuring the decay of Calcium isotopes, researchers achieved a precision window of less than 5,000 years, pushing the timeline of tool production back to 1.9 million years ago.
This refined methodology allows archaeologists to create a high-resolution timeline of human evolution, linking specific tool-making breakthroughs to precise environmental shifts. The use of Calcium-48 is expected to become a new gold standard in dating Paleolithic artifacts that were previously difficult to pin down using traditional carbon-14 or argon-argon methods.