Life’s Great Reset: Volcanic Triggers of the Ediacaran–Cambrian Extinctions

The Ediacaran–Cambrian transition marks a pivotal restructuring of Earth’s biosphere, characterized by the decline of soft-bodied Ediacaran assemblages and the sudden rise of complex, skeletonized metazoans. While biotic factors such as predation, bioturbation, and ecological innovation have been emphasized in explaining this transition, accumulating evidence suggests a parallel role for geodynamic forcing, particularly via large igneous province (LIP) volcanism. This seminar examines the hypothesis that episodic LIP emplacement, associated with plume activity, played a significant role in destabilizing early life environments. Multiple Ediacaran and Cambrian LIPs show spatial and temporal correspondence with long-lived mantle plume-generation zones. These regions are inferred to have remained quasi-stationary through geologic time and are thought to have also sourced later LIPs. The environmental consequences of LIP emplacement—rapid CO₂ and CH₄ emissions, short-lived aerosol-induced cooling, and longer-term greenhouse warming—are strong candidates as major contributors to the extinctions. The talk emphasizes the relevance of planetary-scale volcanic processes in shaping the earliest stages of animal evolution.