Dr. Preston Cosslett Kemeny will receive $180,000 through a two-year Project Grant from the National Science Foundation's Geosciences program (CFDA 47.050) to conduct research disentangling diagenesis, seawater chemistry, and ecological change across Cambrian trilobite extinctions. Dr. Kemeny will measure calcium and magnesium isotope ratios in drill core samples from the Missouri Basin to determine the relationship between the Steppean positive carbon isotope excursion and shifts in the marine carbon cycle or diagenetic alteration. He will also evaluate trilobite fossils as a novel proxy for diagenetic modification and seawater chemistry. Findings will be incorporated into a numerical model to constrain the temporal and spatial scales over which diagenesis can produce carbon isotope excursions. This research aims to further understanding of the co-evolution of life and climate by quantifying connections between the global carbon cycle and trilobite extinction during the Cambrian Period.