X-ray fluorescence maps (IMAGE) Proceedings of the National Academy of Sciences Caption X-ray fluorescence maps showing the distribution of iron (red) and lead (blue) in red ink. Credit Marine Cotte and Thomas Christiansen Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.