Deccan Traps Volcanism Implicated in the Extinction of Non-Avian Dinosaurs in Southeastern China

The extinction of non-avian dinosaurs and its cause(s) have been a matter of debate for several decades. Here we measured Hg and its isotopic composition, heavy metals, and magnetic parameter in a terrestrial basin in southeastern China. Hg exhibited anomalies from 66.4 to 65.6 Ma, with near-zero to positive Delta Hg-199 values, which reflected the eruption of Deccan Traps (DT) magma. In addition, Hg anomalies coincided with the gradual extinction of non-avian dinosaurs, thereby consistent with the hypothesis that DT played a key role in the mass extinction. Analysis of paleoclimatic records showed that both the Late Maastrichtian warming event (LMWE) and Dan-C2 event occurred at the maxima of the 405-kyr long eccentricity cycle, and the onset of the dinosaur decline was earlier than the LMWE, suggesting that the LMWE played an ancillary role in the mass extinction. The mechanism of how DT caused the mass extinction requires further investigation.