CLIMATIC IMPACTS OF DECCAN TRAPS VOLCANISM RECORDED IN MOLLUSK SHELLS FROM SEYMOUR ISLAND, ANTARCTICA

The Deccan Traps volcanic event lasted approximately three-quarters of a million years during the late Maastrichtian and early Paleogene, during which time significant amounts of CO₂ were emitted into the atmosphere. We study climate before and across the K-Pg boundary using stable and clumped isotope measurements of well-preserved bivalve shells from Seymour Island, Antarctica, a site with expanded, continuous sedimentation across the K-Pg boundary. Clumped isotope temperatures record a large (~8°C) warming spike at the onset of Deccan volcanism, potentially amplified over average global warming due to the coincident removal of local ice cover. Comparison of early- and late-life shell material within individual shells shows differences in temperature between positions prior to volcanism that disappear at the same time as the warming spike. This potentially indicates a reduction in temperature seasonality or a reduction in allowable growth season due to environmental stress. We examine the cause of the position-specific differences and look to high-resolution stable isotope measurements that may record seasonality.