An international team of geoscientists journeyed to northeastern Oregon, where massive volcanism has been linked with climate warming 16 million years ago. For their study, the scientists zeroed in the Wallowa Mountains, which are laced with enormous sheets of flat magmatic dikes, created when molten rock flowed into cracks and solidified. Credit: Benjamin Black/Rutgers University Volcanoes have played a role in mass extinctions at multiple times in our planet’s geologic history.  Exactly how they kill off everything is dependent on the rapidity with which they erupt. If the eruptions...