Thomas Algeo, University of Cincinnati (IMAGE) University of Cincinnati Caption University of Cincinnati geology professor Thomas Algeo said a spike in mercury found in 252-million-year-old rock at a dozen locations around the world is evidence that volcanic eruptions caused a mass extinction that wiped out most of life on Earth during the Permian Period. Credit Joseph Fuqua II/UC Creative Services Usage Restrictions None 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.