Argon-argon dating refines date of Vesuvius eruption

Scientists improved the precision of argon-argon dating by calibrating it against the 79 CE eruption of Mount Vesuvius. Analysis of pumice from Oplontis yielded an age of 1,946 years with 0.4% accuracy and 0.7% precision, twice as precise as previous estimates.

• Minerals from Oplontis dated to 1,946 years ago
• Method achieves 0.4% accuracy and 0.7% precision
• August 24, 79 CE eruption date confirmed within two months
• Method will help calibrate radiocarbon dating of materials younger than 55,000 years