Shock-Induced Desulfurization of Natural Pyrite and Its Implications for the Early Earth’s Environment

Meteorite impact events are considered as important influences on the composition of Earth’s early atmosphere, with substantial implications for biological evolution. The physicochemical behavior of sulfur-bearing minerals during such natural impact events is crucial for understanding the role of sulfur in the evolution of Earth’s ocean-atmosphere system. Here, we conducted shock recovery experiments on natural pyrite (FeS₂) under shock pressures of approximately 20 and 55 GPa to investigate its decomposition characteristics under high-velocity impact. The experimental results indicate that pyrite undergoes partially decomposition into pyrrhotite and sulfur at the shock pressure of about 55 GPa, revealing its thermodynamic instability and the release of sulfur vapor. Our results suggest that the desulfurization of pyrite during meteorite impacts may contribute to the release of sulfur gases into oceanic and atmospheric systems. Such environmental changes may be linked to the Permian-Triassic mass extinction event approximately 250 million years ago, providing important insights into the biological crises of that era.