Centennial scale sequences of environmental deterioration preceded the end-Permian mass extinction

The exact drivers for the end-Permian mass extinction (EPME) remain controversial. Here we focus on a ~10,000 yr record from the marine type section at Meishan, China, preceding and covering the onset of the EPME. Analyses of polyaromatic hydrocarbons at sampling intervals representing 1.5–6.3 yr reveal recurrent pulses of wildfires in the terrestrial realm. Massive input pulses of soil-derived organic matter and clastic materials into the oceans are indicated by patterns of C2-dibenzofuran, C30 hopane and aluminum. Importantly, in the ~2,000 years preceding the main phase of the EPME, we observe a clearly defined sequence of wildfires, soil weathering, and euxinia provoked by the fertilization of the marine environment with soil-derived nutrients. Euxinia is indicated by sulfur and iron concentrations. Our study suggests that, in South China, centennial scale processes led to a collapse of the terrestrial ecosystem ~300 yr (120–480 yr; ± 2 s.d.) before the onset of the EPME and that this collapse induced euxinic conditions in the ocean, ultimately resulting in the demise of marine ecosystems.

Ryosuke Saito, Lars Wörmer, Heidi Taubner, Kunio Kaiho, Satoshi Takahashi, Li Tian, Masayuki Ikeda, Roger E. Summons, Kai-Uwe Hinrichs