Bruce Runnegar quartzite unage (IMAGE) University of California - Los Angeles Caption Quartzite with traces of burrowing animals. The scale is marked in centimeters. Credit Stefan Bengtson/Swedish Museum of Natural History Usage Restrictions Use is permitted with proper credit attribution. 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.