Quantitative Correlation of Large Igneous Provinces and Phanerozoic Extinctions

Abstract:

Large Igneous Provinces (LIPs), comprising >10⁵ km³ of typically mafic magma often erupted in < ~1 Myr, have long been associated with Phanerozoic mass extinctions. Here we quantitatively evaluate this correlation, incorporating recent advances in the geochronologic record of both Phanerozoic LIPs and faunal turnover associated with geologic timescale boundaries. We find that the degree of temporal correlation between continental LIPs and faunal turnover is unlikely to occur by chance in the absence of a causal relationship. This correlation is found to be stronger for LIPs with higher eruptive rates and boundaries with higher extinction percentages. In contrast to continental LIPs, oceanic LIPs are less well correlated with mass extinction, with lower extinction percentages than would be expected to result from a continental LIP of similar eruption rate. We propose that this discrepancy may result in part due to diminished degassing of volatiles including CO₂, SO₂, Cl, and F in submarine LIPs. Though other kill mechanisms have been suggested for mass extinctions, our results suggest continental LIPs and their volatile emissions as a major, direct driver of Phanerozoic extinctions.