A close look at tree rings (IMAGE) American Geophysical Union Caption A thin section of a very well-preserved piece of Picea (spruce) driftwood. The tree’s anatomical details allowed Hole to identify and trace it. Credit Georgia Hole 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.