Structural basin

Ecosystem

Physics

Geology

Terrestrial plant

Sociology

Population

Charcoal

Terrestrial ecosystem

Biology

Permian–Triassic extinction event

Oceanography

Demography

Total organic carbon

Paleontology

δ13C

Isotopes of carbon

Ecology

Metallurgy

Materials science

Earth science

Stable isotope ratio

Rainforest

Extinction event

Quantum mechanics

Environmental science

Biological dispersal

Peat

Permian

The Permian-Triassic mass extinction is widely attributed to the global environmental changes caused by the eruption of the Siberian Traps. However, the precise temporal link between marine and terrestrial crises and volcanism is unclear. Here, we report anomalously high mercury (Hg) concentrations in terrestrial strata from southwestern China, synchronous with Hg anomalies in the marine Permian-Triassic type section. The terrestrial sediments also record increased abundance of fossil charcoal coincident with the onset of a negative carbon isotope excursion and the loss of tropical rainforest vegetation, both of which occurred immediately before the peak of Hg concentrations. The organic carbon isotope data show an ∼5‰–6‰ negative excursion in terrestrial organic matter (bulk organic, cuticles, and charcoal), reflecting change in atmospheric CO2 carbon-isotope composition coincident with enhanced wildfire indicated by increased charcoal. Hg spikes provide a correlative tool between terrestrial and marine records along with carbon isotope trends. These data demonstrate that ecological deterioration occurred in tropical peatlands prior to the main marine mass extinction.

Ecological disturbance in tropical peatlands prior to marine Permian-Triassic mass extinction