A REMARKABLY RESILIENT LATEST CRETACEOUS MARINE CARBON CYCLE (Invited Presentation)

It is generally agreed that flood basalt volcanism drove two of largest mass extinction events in earth history: the Permian-Triassic mass extinction and the Triassic-Jurassic mass extinction. In contrast, the eruption of massive flood basalts in India that coincided with the late Maastrichtian warming event had minor effects on marine ecosystems due to long-term changes in the earth system. What’s more, species and ecosystems appear surprisingly resilient to the severe impact winter following the Chicxulub impact. As Vermeij long ago noted, the most effective way to drive a global mass extinction is to take out the primary producers. Yet global darkness on the order of years, accompanied by global cooling of an astonishing >25ºC for decades to centuries, only appears to have driven the extinction of an (roughly) estimated 75% of taxa alive at the time and a ~50% reduction in global ocean primary productivity. This talk will provide a synthetic overview of the events and dynamics of marine ecosystems in the latest Cretaceous through Paleocene. In this context, we will consider the dynamics of the marine carbon cycle in response to Deccan volcanism, the Chicxulub impact, the mass extinction at the K-Pg boundary, and long-term changes in the Paleocene.