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A scientific challenge is to assess the role of Deccan volcanism in the Cretaceous-Tertiary boundary (KTB) mass extinction. Here we report on the stratigraphy and biologic effects of Deccan volcanism in eleven deep wells from the Krishna-Godavari (K-G) Basin, Andhra Pradesh, India. In these wells, two phases of Deccan volcanism record the world's largest and longest lava mega-flows interbedded in marine sediments in the K-G Basin about 1500 km from the main Deccan volcanic province. The main phase-2 eruptions (~80% of total Deccan Traps) began in C29r and ended at or near the KTB, an interval that spans planktic foraminiferal zones CF1-CF2 and most of the nannofossil Micula prinsii zone, and is correlative with the rapid global warming and subsequent cooling near the end of the Maastrichtian. The mass extinction began in phase-2 preceding the first of four mega-flows. Planktic foraminifera suffered a 50% drop in species richness. Survivors suffered another 50% drop after the first mega-flow, leaving just 7 to 8 survivor species. No recovery occurred between the next three mega-flows and the mass extinction was complete with the last phase-2 megaflow at the KTB. The mass extinction was likely the consequence of rapid and massive volcanic CO 2 and SO 2 gas emissions, leading to high continental weathering rates, global warming, cooling, acid rains, ocean acidification and a carbon crisis in the marine environment.Deccan volcanism phase-3 began in the early Danian near the C29R/C29n boundary correlative with the planktic foraminiferal zone P1a/P1b boundary and accounts for ~14% of the total volume of Deccan eruptions, including four of Earth's longest and largest mega-flows. No major faunal changes are observed in the intertrappeans of zone P1b, which suggests that environmental conditions remained tolerable, volcanic eruptions were less intense and/or separated by longer time intervals thus preventing runaway effects. Alternatively, early Danian assemblages evolved in adaptation to high-stress conditions in the aftermath of the mass extinction and therefore survived phase-3 volcanism. Full marine biotic recovery did not occur until after Deccan phase-3. These data suggest that the catastrophic effects of phase-2 Deccan volcanism upon the Cretaceous planktic foraminifera were a function of both the rapid and massive volcanic eruptions and the highly specialized faunal assemblages prone to extinction in a changing environment. Data from the K-G Basin indicates that Deccan phase-2 alone could have caused the KTB mass extinction and that impacts may have had secondary effects.

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Subaerial sediments and silicic and mafic lavas of the Cape St. John Group in northern Newfoundland, were originally interpreted as younger than the Betts Cove ophiolite suite and the Lower Ordovician (Arenig) Snooks Arm pillow lavas and oceanic sediments, but recently have been considered as part of the pre-Ordovician Fleur de Lys Supergroup and hence older than the Snooks Arm Group. The volcanic rocks that underlie the Cape St. John were reinterpreted as a pre-Snooks Arm oceanic foundation to the Fleur de Lys rocks.Our work reaffirms the original interpretation of the Cape St. John rocks as unconformably above the Lower Ordovician pillow lavas and ophiolites and we tentatively correlate them with the Springdale and Mic Mac Groups and other nearby Silurian (?) clastic/volcanic sequences of Old Red Sandstone equivalence. The Cape St. John Group grades northward and westward into polydeformed rocks, hence its re-establishment as a post-ophiolite assemblage bears on the history of deformation of adjacent groups.

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