HR: 08:30h
AN: B31E-03    [Abstracts]
TI: Impact vs. Volcanic Causes of the End-Permian Mass Extinction
AU: Valiulis, E
EM: valiulise@si.edu
AF: Smithsonian Institution, Dept of Paleobiology MRC-121, Washington, DC 2050 United States
AU: * Erwin, D
EM: erwind@si.edu
AF: Smithsonian Institution, Dept of Paleobiology MRC-121, Washington, DC 2050 United States
AB: Although much paleontological, and geochemical evidence is consistent with an extra-terrestrially induced impact at the Permo-Triassic boundary, and suggestive evidence of such an impact has been published, significant dispute exists within the paleontologic community about the viability of this cause. The leading alternative cause involves the effects of massive volcanic eruptions associated with the generation of the Siberian flood basalts over about 1million years. Much of the Siberian flood basalts erupted through a massive coal basin, adding additional atmospheric carbon dioxide to that released by the eruptions, but as Svenson et al recently observed for the Late Eocene, causing thermal generation of methane via oxidation of the coal. . The combination of acid rain from volcanically induced sulfur dioxide, the volcanically released carbon dioxide and the generation of carbon dioxide and methane from the coal beds would cause rapid greenhouse warming and ocean acidification. Such a model is consistent with the evidence for shallow-water anoxia, the rapidity (but not catastrophic nature) of th e extinction and with the geochemical record.
DE: 0370 Volcanic effects (8409)
DE: 0400 Biogeosciences
SC: Biogeosciences [B]
MN: 2004 AGU Fall Meeting