Credit...Mark P. Witton/Science Source
The New York Times Trilobites column has an article about volcanic eruptions during the Triassic Period. Recently, a paper published in the Proceedings of the National Academy of Sciences describes striking evidence that volcanoes helped dinosaurs spread across the globe during the Triassic Period about 234 million years ago. It has long been debated what led to the dinosaurs' dominance during the Mesozoic Age. A team of researchers found evidence of intense volcanic activity in a lake deposit in northern China.
The researchers analyzed sediment and plant fossil evidence from a lake in Northern China and were able to match four intense phases of volcanic activity with the changes of the Carnian Pluvial Episode.
Previously, researchers had hypothesized that global carbon cycle changes during the episode were the result of major volcanic eruptions from what is now a mass of igneous rock found throughout western North America. The new study links the timing of the episode with four distinct peaks in mercury — a well-established indicator of volcanic activity — to carbon cycle shifts as well as rainfall, which led to local changes in the vegetation on land and in the lake.
“We’re often able to link volcanism to global warming, but our study is unusual in that we’ve also linked it to periods of intense rainfall,” said Jason Hilton, a paleobotanist at the University of Birmingham in England and a study co-author. “With each pulse of volcanism, we see an increase in plants adapted to wet and aquatic settings.”
Jing Lu, a researcher at the China University of Mining and Technology and also a co-author of the study, added that these eruptions “were powerful enough to drive evolutionary processes during the Triassic.”
