Volcanism in Rocks

At https://phys.org/print444408979.html … new evidence that volcanism drove the Late Devonian extinctions. Perhaps this title should be stood up on its head – new evidence that the Late Devonian extinction event involved volcanism (with the caveat that it is not known what caused volcanism to come into play). It is otherwise an enjoyable read on an event dated 370 million years ago (one of the Big Five). It is said to have killed 80 per cent of species, including the Devonian coral reef system. It seems the presence of mercury is an indicator of volcanism.