Banded iron formation (IMAGE) University of Oxford Caption An example of the 3.7 billion year old banded iron formation that is found in the northeastern part of the Isua Supracrustal Belt. Credit: Claire Nichols. Credit Claire Nichols. Usage Restrictions The image can be used for editorial purposes ONLY and must be credited. It must NOT be sold on to third parties. License Original 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.