Paper No. 9
Presentation Time: 3:00 PM


GRASBY, Stephen E., Geological Survey of Canada, Natural Resources Canada, 3303 33rd Street NW, Calgary, AB T2L 2A7, Canada and BEAUCHAMP, Benoit, Geoscience, University of Calgary, 2500 University Dr. NW, Calgary, AB T2N1N4, Canada,

NW Pangea records a complex history of recurrent development of anoxia through the Permo-Triassic Biotic Crises. The Early Triassic record from the Smithian strato-type in the Sverdrup Basin, as well as for the more open ocean setting of Svalbard, have organic carbon isotope records that closely correspond to major fluctuations in the inorganic carbon records from the Tethys, demonstrating truly global perturbations of the carbon cycle occurred during this time. Geochemical proxies for anoxia are strongly correlated with carbon isotopes, whereby negative shifts in δ13Corg are associated with shifts to more anoxic to euxinic conditions, and positive shifts are related to return to more oxic conditions. Rather than a delayed or prolonged recovery, the Early Triassic is characterized better by a series of aborted biotic recoveries related to shifts back to ocean anoxia, potentially driven by recurrent volcanism.