I have never been convinced that volcanic eruptions alone caused ANY previous extinctions. It is true that the ‘Trapps’ around the world – Deccan Traps in India, Siberia, North America, Central Atlantic Magmatic Province and a dozen or more others around the world. https://en.wikipedia.org/wiki/Flood_basalt#List_of_flood_basalts While I have no doubt they were a large contributor to many of the extinctions they are each associated with I do not buy the premise it was them alone that were the cause of ANY global extinctions. This article points to the morphology and deeper understanding of how that actually worked! GREAT STUFF.. 😊
The Siberian Traps, the scene of ancient volcanic eruptions 252 million years ago that led to a massive extinction of life on Earth. CCNY researchers Ellen Gales and Benjamin Black obtained samples for their study there. Photo credit: B. Black and L.T. Elkins-Tanton.
An emerging scientific consensus is that gases—in particular carbon gases–released by volcanic eruptions millions of years ago contributed to some of Earth’s greatest mass extinctions. But new research at The City College of New York suggests that that’s not the entire story.
“The key finding of our research is that carbon from massive, ancient volcanic eruptions does not line up well with the geochemical clues that tell us about how some of Earth’s most profound mass extinctions occurred,” said Benjamin Black, assistant professor in CCNY’s Division of Science, whose expertise includes effects of volcanism on climate and mass extinctions.
The study by Black with his M.S. in geology student Ellen Gales, the lead author, is entitled “Carbonatites as a record of the carbon isotope composition of large igneous province outgassing.” It appears in the current issue of the journal “Earth and Planetary Science Letters,” and is a product of Gales’ thesis work.
The new data does not rule out volcanism as the culprit in driving past mass extinctions, the article points out. But it does conclude that there must have been something extra at work.
“Ellen’s work is new in that scientists have previously guessed what the geochemical fingerprint of CO2 from these giant eruptions might be, but our findings are some of the first direct measurements of this fingerprint,” said Black.
“Our finding challenges the idea that carbon from this kind of eruption might be special, and therefore capable of easily matching changes in the carbon cycle during mass extinctions. It also helps us understand how volcanic eruptions move carbon—a key ingredient for life and climate—around inside the Earth and between the solid Earth and the atmosphere,” said Gales.