Continental flood basalts drive Phanerozoic extinctions

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Although the causes of the five largest mass extinctions remain controversial, geochronological improvements have revealed an apparent correlation between large igneous provinces (LIPs) and periods of Phanerozoic faunal turnover. This paper establishes that this relationship is unlikely to occur by chance and defines an eruptive rate threshold, above which known continental LIPs correlate with large extinctions. Continental LIPs also have an approximately linear relationship between their eruptive rate and extinction magnitude. It is difficult to attribute the causality of any one extreme event like an extinction with certainty, but there is an overall correlation between continental LIPs and extinction events that warrants consideration.

See also the Dartmouth News story by Harini Barath!

Abstract:
Refinements of the geological timescale driven by the increasing precision and accuracy of radiometric dating have revealed an apparent correlation between large igneous provinces (LIPs) and intervals of Phanerozoic faunal turnover that has been much discussed at a qualitative level. However, the extent to which such correlations are likely to occur by chance has yet to be quantitatively tested, and other kill mechanisms have been suggested for many mass extinctions. Here, we show that the degree of temporal correlation between continental LIPs and faunal turnover in the Phanerozoic is unlikely to occur by chance, suggesting a causal relationship linking extinctions and continental flood basalts. The relationship is stronger for LIPs with higher estimated eruptive rates and for stage boundaries with higher extinction magnitudes. This suggests LIP magma degassing as a primary kill mechanism for mass extinctions and other intervals of faunal turnover, which may be related to CO2, SO2, Cl, and F release. Our results suggest continental LIPs as a major, direct driver of extinctions throughout the Phanerozoic.

Suggested citation:
Green, T., Renne, P.R., & Keller, C.B. (2022). Continental flood basalts drive Phanerozoic extinctions. Proceedings of the National Academy of Sciences 119 (38), e2120441119.