Shale rocks, Mackenzie mountains, Canada. (IMAGE) University of Oxford Caption Shale rocks high up in the remote Mackenzie mountains Canada, which contain lots of rock organic carbon and are hotspots of CO2 release. Image credit: Robert Hilton. Credit Robert Hilton. Usage Restrictions The image can be used if credited. 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.