Traces of ancient seafloor cataclysms turn up in the Himalayas

Amazing stuff!

"High on the Tibetan Plateau, geologists have identified slivers of twisted and folded lava they say are the relics of immense volcanic eruptions more than 200 million years ago, on the floor of a vanished sea. The discovery provides a culprit for previously unexplained marine extinctions.

Such supereruptions, which can spew millions of cubic kilometers of magma and last for millions of years, have been linked with some of the largest mass extinctions in Earth’s history. Called large igneous provinces, they are easy to recognize when they occur on land because the lava plateaus they leave behind stick around for eons. However, because oceanic crust gets recycled relatively quickly back into the mantle, the evidence for marine supereruptions has mostly vanished. By identifying the landlocked traces of two vanished supereruptions, the new study ... fills out the history of these cataclysms—and adds to the evidence that oceanic supereruptions have shaped the history of life more than once thought. ..."

From the abstract:

"The trigger for frequent extinctions during the Phanerozoic remains a persistent and unresolved frontier issue in Earth sciences.

We present a detailed analysis of oceanic island, seamount, and plateau remnants in the Tibetan Plateau that trace the evolution of the Meso- and Neo-Tethys oceans, incorporating new and published data.

During the Triassic, three major episodes of marine large igneous provinces (LIPs) formed at 250−248 Ma, 233−231 Ma, and 210−208 Ma. By integrating geological records of these LIP episodes with Triassic geological data sets, we demonstrate a correlation between marine LIPs and at least four extinctions in marine biota, driven by the resultant anoxic-euxinic events.

Consequently, marine LIPs emerge as a primary driver of recurrent mass extinctions. Numerous previously unexplained extinctions throughout Earth’s history may potentially result from currently unidentified components of marine LIPs occurring as fragments within orogenic belts."

Traces of ancient seafloor cataclysms turn up in the Himalayas | Science | AAAS "Vast undersea eruptions may be undercounted source of extinctions through Earth’s history"

Key Drivers of Recurrent Extinction in the Triassic "New study in Geology links massive undersea volcanism to repeated marine extinctions"

Marine large igneous provinces: Key drivers of Triassic recurrent extinction (open access)