Nicole Mizrahi L&S Sciences
Sulfur Abundance and Isotopic Composition Across the Terrestrial Cretaceous-Paleogene Boundary
The Cretaceous-Paleogene (K-Pg) mass extinction (~66 million years ago) is hypothesized to have been caused by environmental effects of the Chicxulub asteroid impact and/or Deccan Traps flood volcanism in India. Both potentially caused major climatic change through increased sulfate aerosol production, which would have caused significant global cooling and/or acid rain. Sulfur released by each of these events has a distinguishable isotopic composition. To characterize changes to the sulfur cycle across the K-Pg boundary and investigate the role each catastrophic event played in the extinction, I will measure sulfur abundance and isotopic composition of sediment across the K-Pg boundary in the Hell Creek region (Montana), at high-resolution over a longer interval than previously studied. This will allow us to test whether a reported increase in sulfur abundance and isotopic composition at the boundary is statistically unique and can be correlated to the Chicxulub impact, as well as identify any other excursions outside the narrow interval previously sampled, which would reflect sulfur released from from local eruptions and/or the more distal Deccan eruptions.