New evidence suggests volcanoes caused biggest mass extinction ever: Mercury found in ancient rock around the world supports theory that eruptions caused 'Great Dying' 252 million years ago. -- ScienceDaily

New evidence suggests volcanoes caused biggest mass extinction ever: Mercury found in ancient rock around the world supports theory that eruptions caused 'Great Dying' 252 million years ago. -- ScienceDaily: Researchers say mercury buried in ancient rock provides the strongest evidence yet that volcanoes caused the biggest mass extinction in the history of the Earth. The extinction 252 million years ago was so dramatic and widespread that scientists call it 'the Great Dying.' The catastrophe killed off more than 95 percent of life on Earth over the course of hundreds of thousands of years.