Siberian Traps large igneous province

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One of the largest continental flood basalt provinces known, erupted across northern Siberia at the Permian–Triassic boundary. Estimates of the total erupted and intruded volume run to several million cubic kilometres, and radiometric dating shows the bulk was emplaced in well under a million years, straddling the extinction interval. The causal argument does not rest on the lava itself, which is a local phenomenon, but on what the magma passed through. The Siberian magmas intruded a thick sedimentary basin containing coal, evaporites and carbonates, and heating those rocks would have released enormous quantities of carbon dioxide, methane and halogens far in excess of what the basalt alone could degas. The proposed consequences form a chain that the marine record independently supports: rapid greenhouse warming of the order of ten degrees in tropical sea-surface temperatures, widespread ocean anoxia, ocean acidification recorded in a collapse of carbonate-shelled groups, and possibly ozone damage. What remains genuinely unresolved is the relative weight of these effects and which of them was the proximate killer.