Cosmic clocks in zircon reveal Australia’s ancient landscape history

Scientists read a “cosmic clock” in tiny zircon crystals to trace Australia’s ancient surface changes. By measuring cosmogenic krypton trapped in zircon from buried beach sands near the Nullarbor Plain, they estimate extremely slow erosion about 40 million years ago, revealing a long-stable landscape and explaining zircon-rich deposits. The approach provides a new long-term clock for Earth’s surface history and could illuminate landscape responses to major events like the rise of land plants, with implications for mineral wealth as well.