Prof. Dr. Roger Everett Summons 

The end-Cretaceous mass extinction is well-known for the demise of the dinosaurs and for the fact that it was caused by a meteorite. In the latter respect, it differs from all other known biological extinctions. One of the outcomes of my 2008 HWK Fellowship was a study of this event based on samples collected from a sedimentary rock section on the Baltic Sea coast of Southern Denmark. In that work, and contrary to expectations, we were able to show that the photosynthetic ecosystem recovered on a timescale of just decades rather than millions of years. Developments in mass spectrometry instrumentation opened the way to take a closer look at this phenomenon with a very high sampling resolution. That is, with a laser-based approach, we could potentially query samples for molecular markers of photosynthesis at a micron scale as opposed to the centimeter scale of our earlier work. Accordingly, a new collaboration was established with scientists from the MARUM – Center of Marine Environmental Science at University of Bremen and the University of Copenhagen returning to this iconic site in July 2023. Our analyses are not yet complete, but we are hopeful that this new data will provide a fresh view of the time it takes for primary productivity to recover following a bolide impact.