SEE PROFILE

The approximate temporal coincidence between the five major extinc-tion events over the past 542 million years and the eruption of large ig-neous provinces (LIPs) has led to speculation that environmental perturbations generated by the emplacement of large volumes of magma and associated outgassing over short periods of time triggered each global biologic crisis (1). Establishing an exact link between extinctions and LIP eruptions has proved difficult because of the geographic separa-tion between LIP volcanic deposits and stratigraphic sequences preserv-ing evidence of the extinction. In most cases, uncertainties on radioisotopic dates used to correlate between geographically separated study areas exceed the duration of both the extinction interval and LIP volcanism by an order of magnitude. This hinders evaluation of any relationship between magmatism and extinction and precludes accurate estimates of volcanic effusion rates, associated volatile release, and ex-tinction mechanisms