Latest Permian mercury anomalies

A sedimentary record from the Buchanan Lake section, Canadian High Arctic, shows anomalous high levels of mercury (Hg) during the latest Permian extinction (LPE) on northwest Pangea. Significant influx of Hg progressively overwhelmed the marine system. Major disruption of the organic matter-mediated Hg drawdown process resulted in accumulation of dissolved Hg to maximum levels at the LPE boundary, affecting an already stressed global ecosystem. A switch to euxinic marine conditions at the LPE boundary led to chemical drawdown of Hg sulfides, as marked by progressive Hg mitigation. This allowed self-recovery from toxic Hg conditions, and ultimately led to reestablishment of the internal Hg-organic matter drawdown process. We hypothesize that anomalous Hg levels may be attributed to the significant natural atmospheric emissions caused by catastrophic Siberian Traps volcanic eruptions.