A nutrient control on expanded anoxia and global cooling during the Late Ordovician mass extinction

Abstract Expanded ocean anoxia and global cooling have been invoked as major causal mechanisms for the Late Ordovician mass extinction, but factors underpinning extinction remain unresolved. Here, we document two intervals of particularly intense phosphorus recycling in marine rocks deposited across a bathymetric transect Yangtze Shelf Sea. The first occurred during initial phase and, coincident with cooling, drove development euxinia on shelf. second re-established shelf after peak glaciation, leading to extinction. Integration these data into biogeochemical model indicates that would doubled long-term burial rate organic carbon, driving ~4°C cooling. Thus, through its impact both spread extensive redox-promoted was critical factor Earth’s catastrophic loss animal life.