Common volcanic activity maintains the atmosphere and the oceans by gradually liberating volatile gases from the Earth's mantle. In contrast, outbursts of gaseous SO2, CO2, and halogens during rare super eruptions have caused environmental crises. Flood basalts represent the rarest and greatest mode of volcanism and may have caused mass extinctions. Their origin and environmental impacts remain disputed, however, because processes in magma chambers and during eruptions have disturbed the isotopic and volatile compositions of all but very few flood basalts.
We have discovered exceptionally well-preserved, primitive types of flood basalts in Antarctica and Africa. Their pristine, early-formed minerals with tiny pockets of trapped initial magma give us the rare opportunity for combined analysis of trace element, isotope and volatile compositions of initial flood basalts. Our results are expected to provide unique insights into the origins and impacts of the largest volcanic eruptions.