Banded iron formations (IMAGE) University of Southampton Caption Banded iron formations studied by the authors showing the alternation between iron-rich (red) and silica-rick (white) layers. Credit University of Southampton 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.