A Martian Mineral History (IMAGE) Brown University Caption The large dark area right of center on the hemisphere view of Mars is Syrtis Major. The map shows the presence of water-bearing clay minerals identified by OMEGA data. Blue indicates small amounts and orange-red indicates large amounts. Credit European Space Agency 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.