Sept. GSA Today cover (image) Geological Society of America Caption This image shows actively growing, subtidal stromatolites north of Carbla Point, Shark Bay, Western Australia. The individual build-ups are separated by areas of rippled, bare sand. The sand is not overgrown by microbial mat because the grains are in constant motion by waves and tidal currents. Photo by Stan Awramik. Credit Stanley Awramik for GSA Today. Usage Restrictions With credit as noted. 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.