Breaking news from the latest Permian…
The end-Permian mass extinction, apart from being the largest extinction event in history, is one of the earth sciences’ greatest whodunits. Once thought to be a consequence of plate tectonic movement, it is now widely held that the main driver of the extinction was the magmatic event associated with the Siberian Traps large igneous province (but see this study from a couple years ago for an interesting wrinkle).
Now there’s this, from Science Advances; namely, “[in]direct evidence” of elevated UV radiation at the Permo-Triassic (P/Tr) boundary in Tibet. The evidence comes from pollen grains, which show a spike in the prevalence of ultraviolet absorbing compounds near the P/Tr boundary. This, in the words of the abstract, “suggest[s] a close temporal link between large-scale volcanic eruptions, global carbon and mercury cycle perturbations, and ozone layer depletion.” And this in turn supplies another potential cause of the environmental deterioration implicated in the land extinctions.
The article is open access, so you can read the whole thing by following the link, above.