Massive Undersea Volcanism May Explain Frequent Extinctions in Triassic Period
A team of geologists from China and Australia has found evidence that episodic eruptions from large marine igneous provinces (LIPs) caused repeated lower-order extinction events during the Triassic period.
Primitive earth. Image credit: Peter Sawyer / Smithsonian Institution.
“Mass extinctions are extremely catastrophic events on Earth,” said Dr Jian-Jun Fan and his colleague from Jilin University and Curtin University.
“Throughout Earth’s evolutionary history, numerous mass extinctions have occurred, with five major mass extinctions being particularly representative.”
“These extinctions reshaped the course of the evolution of life on Earth.”
“In addition to the five major mass extinctions, many frequent and lower-order extinctions also occurred on Earth, such as the Norian-Rhaetian extinction during the Triassic period.”
“Regarding the mechanisms triggering extinctions, the five major events have been relatively well studied. »
“However, the mechanisms triggering the frequent lower-order extinctions remain unclear.”
In the new study, the authors analyzed oceanic remains of islands, seamounts and plateaus from the Tibetan Plateau that trace the evolution of the Meso and Neo-Tethys oceans.
During the Triassic, three major episodes of marine LIPs formed 250-248, 233-231 and 210-208 million years ago.
By integrating the geological record of these LIP episodes with Triassic geological datasets, the researchers demonstrated a correlation between marine LIPs and at least four extinctions of marine biota, driven by the resulting anoxic-euxinic events.
“Marine LIPs account for half of the extinctions with an identifiable geological trigger during the Triassic,” the scientists said.
“This indicates that marine LIPs are a key driver of Triassic extinctions.”
“Eruptions of marine LIPs on Earth are common; however, evidence for ancient marine LIPs is likely significantly reduced by subduction during ocean basin closure.”
“This destruction makes these documents difficult to identify and, even when identified, difficult to interpret and date accurately. »
“Orogenic belts (i.e., remnants of ancient, extinct ocean basins) contain many unidentified “ghost” marine LIPs, and these marine LIP eruptions are likely a key driver of other Phanerozoic extinctions that were previously under-recognized in Earth system models.
The team’s article appears in the newspaper Geology.
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Fan of Jian Jun and others. Large marine igneous provinces: main factors of recurrent Triassic extinction. Geologypublished online January 20, 2026; doi: 10.1130/G53406.1
