Eruptive tempo of Emeishan large igneous province, southwestern China and northern Vietnam: Relations to biotic crises and paleoclimate changes around the Guadalupian-Lopingian boundary

The Emeishan large igneous province (LIP), southwestern China and northern Vietnam, is thought to have been a potential driver for the biotic crises and paleoclimate changes around the Guadalupian-Lopingian boundary (GLB; Permian), but the lack of high-precision radiometric dates to constrain the duration and eruption rates of the volcanism has limited the assessment of their relationship. We present new chemical abrasion-isotope dilution-isotope ratio mass spectrometry U-Pb zircon geochronology of three samples from the lowermost and uppermost parts of the volcanic succession in the central portion of the Emeishan LIP. The results demonstrate that Emeishan volcanism began by 260.55 +/- 0.07 Ma and persisted until at least 257.22 +/- 0.37 Ma. Combined with a previously published age of 259.1 +/- 0.5 Ma for silicic ignimbrites, we estimate that similar to 85% of Emeishan LIP volume erupted within 1.45 +/- 0.50 m.y. Our new results confirm that the Emeishan volcanism began slightly prior to the initiation of the associated mass extinction event and was contemporaneous with the associated warming interval. The new data support the hypothesis that the Emeishan LIP likely triggered the biotic crises and paleoclimate changes around the GLB.