Description: The lack of diatoms in the fossil record has skewed our understanding of the evolution of diatoms and their impact on the global biogeochemical cycle of silica. To date most studies have focused on diversification during the mid-Cenozoic, 30 Ma ago, where abundant diatom fossils are found with their expansion related to a significant enhancement of weathering and dissolved Si flux to the oceans. Our research suggests that the older evidence for diatoms has likely been destroyed by dissolution during diagenesis. We are also investigating the timing and magnitude of dissolved Si drawdown in the oceans following the origin of diatoms using the isotopic silicon composition of fossil sponge spicules, radiolarians and diatoms.

Target audience: The webinar is targeted towards those that are interested in the evolution of diatoms and their influence on oceanic biogeochemical cycles.