Collaborative Research: Coring Seymour Island (CSI) Antarctica: Evaluating Causes and Effects of the End Cretaceous Mass Extinction

Technical description: The proposed research is applying multiple techniques to address an overarching research question for which recent studies are in disagreement: Is the fossil evidence from a unique outcropping on Seymour Island, Antarctica consistent with a single or double phased extinction? In a two-phased model, the first extinction would affect primarily benthic organisms and would have occurred ~150 kiloyears prior to a separate extinction at the K-Pg boundary.

However, this early extinction could plausibly be explained by an unrecognized facies control that is obscured by surficial weathering. This team is using microfossil evidence with detailed sedimentary petrology and geochemistry data to evaluate if the fossil evidence from Seymour Island is consistent with a single or double phased extinction process. The team is using detailed sedimentary petrology and geochemistry methods to test for facies changes across the K-PG interval that would explain the apparent early extinction.

Samples of core sedimentary foraminifera, siliceous microfossils, and calcareous nannofossils are being evaluated to provide a high-resolution stratigraphic resolution and to evaluate whether evidence for an early extinction is present. Additionally, the team is using multiple geochemical methods to evaluate whether there is evidence for intermittent anoxia or euxinia and/or physical restriction of the Seymore region basin.

Data from this analysis will indicate if this region was a restricted, suboxic marine environment or an open well-mixed shelf.