Influence of Intensified Volcanism in the Latest Permian on the Ecosystem: Ev-Idence from the Deep-Water Dongpan Section, South China

The end-Permian mass extinction (EPME) represents one of the most severe biocrises in Earth’s history. Although large-scale volcanism is widely regarded as the primary driver of this event, the mechanisms linking volcanic activity to ecosystem collapse remain debated. Here we integrate records of volcanic frequency and intensity, geochemical evolution, and diversity changes of various taxa at Dongpan (South China), to elucidate the linkages between volcanism, paleoceanography (particularly ocean anoxia) and the EPME. Four eruptive stages are identified, revealing a progressive intensification of volcanic activity. Redox proxy data record a transition from intermittent anoxic episodes to more sustained (prolonged) anoxic intervals. The latter align with the phase of successive losses in marine biodiversity. Initially, episodic volcanic eruptions caused transient oxygen depletion with limited ecological consequences. As volcanism intensified and became more frequent, however, it enhanced nutrient inputs, triggering eutrophication and prolonging oxygen depletion. This process drove the stepwise collapse of planktonic and benthic communities. Ultimately, increased eruption frequency, together with ocean stratification induced by global warming and increased terrestrial influx, amplified oxygen depletion, leading to the vertical expansion of the oxygen minimum zone (OMZ), persistent anoxia, and the final collapse of marine ecosystems. These findings demonstrate how cumulative volcanic forcing drove the prolonged ocean anoxia and the stepwise ecosystem breakdown, offering new insights into environmental deterioration preceding the EPME.