Continental flood basalts drive Phanerozoic extinctions

Area of Science:

• Geoscience
• Paleontology
• Geochronology

Background:

• Radiometric dating reveals apparent correlations between large igneous provinces (LIPs) and Phanerozoic faunal turnover.
• Previous discussions of this correlation have been largely qualitative, lacking quantitative testing for chance occurrence.
• Alternative extinction mechanisms have been proposed for many mass extinctions.

Purpose of the Study:

• To quantitatively assess the likelihood of chance temporal correlations between continental LIPs and Phanerozoic faunal turnover.
• To investigate a potential causal relationship between continental flood basalts and extinction events.
• To explore LIP magma degassing as a primary kill mechanism.

Main Methods:

• Quantitative analysis of temporal correlations between continental LIPs and faunal turnover events.
• Statistical testing to determine if observed correlations exceed chance expectations.
• Examination of the relationship between LIP eruptive rates, extinction magnitudes, and correlation strength.

Main Results:

• The temporal correlation between continental LIPs and Phanerozoic faunal turnover is statistically significant and unlikely to occur by chance.
• The correlation is stronger for LIPs with higher estimated eruptive rates.
• The relationship is more pronounced for stage boundaries with higher extinction magnitudes.

Conclusions:

• Continental LIPs are a major, direct driver of Phanerozoic extinctions.
• LIP magma degassing, potentially involving the release of elements like S, Cl, and F, is suggested as a primary kill mechanism.
• The findings support a causal link between continental flood basalts and mass extinctions.