Drilling for Shale Gas (IMAGE) European Geosciences Union Caption Tower in Pennsylvania, USA, for drilling into the Marcellus Shale Formation for natural gas. (Source: https://commons.wikimedia.org/wiki/File%3AUpper_Fairfield_Township_gas_well_2a.JPG; License: CC-BY) Credit Ruhrfisch Usage Restrictions CC-BY 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.