Silurian Rocks (IMAGE) Proceedings of the National Academy of Sciences Caption These are lower Silurian rocks of the Tures� Formation, Centrum S�, Kronprins Christian Land, North Greenland. Credit Jan Audun Rasmussen (Morslands Historiske Museum, Nyk�bing Mors, Denmark) 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.