Cave Gallery (IMAGE) Geological Society of America Caption Dimitri Laurent explores a typical gallery in the Nébélé Cave, that was formed by sulfuric acid speleogenesis. You can see a deep notch that indicates the former presence of a river, and sodium sulfate on the left that is produced from weathering by sulfuric acid (credit: Christophe Durlet). Credit Christophe Durlet Usage Restrictions Credit must be given to the creator. Only noncommercial uses of the work are permitted. License CC BY-NC 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.