Embers of an Ancient Inferno Pinpoint The Worst Extinction in Earth's History - ScienceAlert

A new analysis of mercury isotopes has provided evidence that a quarter of a billion years ago, far-flung places in Earth's Southern Hemisphere were blanketed with debris from volcanic eruptions in Siberia.

Also, many studies of this mass extinction event have focused on sites from the Northern Hemisphere, making it difficult to understand the impact of volcanism on the underside of Earth.

This is significant because mounting evidence suggests the Great Dying was not a single deathly event, but multiple extinction episodes that occurred in waves over a hundred thousand years.

At the time of the Great Dying, the basins were united in one supercontinent called Pangaea, but are now separated by roughly 10,000 kilometers (6,200 miles) and the Indian ocean.

Their work aligns with signals from sulfur isotopes coinciding with the Great Dying, and also builds on past research which suggests mass extinctions started occurring on land up to 600,000 years before marine life sucked in its last few breaths.

"That suggests that the event itself wasn't just one big whammy that happened instantaneously," explains Christopher Fielding, another geologist at the University of Connecticut.