Extreme Warming and Pulsed Volcanism During the Paleocene-Eocene Thermal Maximum

· Hg spike during PETM onset indicates pulsed NAIP volcanism.· Evidence for pre-PETM warming of ~3°C with negative δ¹³C excursion (~1‰).· Extreme warming of ~8°C anomaly (exceeding 40°C) during the PETM peak.· Extreme temperature rise lagged the Hg spike implies feedback amplification.