SoSe 2025
May 14, 2025 – Dr. Maximilian Dröllner
University of Göttingen, Dept. of Sedimentology and Environmental Geology
To see the world in a grain of sand
Sediments are an archive of Earth's evolution: from an anoxic Hadean world to a habitable planet with an oxygenated atmosphere. Yet, reading this archive is anything but straightforward. Single-grain sedimentary provenance analysis, through the lens of accessory detrital minerals, offers a way to address the intrinsically fragmentary nature of the sedimentary record. The first part of the talk showcases examples of integrated in situ analytical techniques (e.g., U–Pb–He, Lu–Hf, trace elements) used to reconstruct complex grain histories and unravel sedimentary recycling. The second part presents ongoing work that extends conventional provenance approaches by incorporating a novel tool: cosmogenic krypton in detrital zircon. This method combines the best of both worlds, providing a previously unavailable window into the surface history of accessory mineral grains. Preliminary results reveal an apparent relationship between zircon surface exposure history and sediment composition, emphasizing the potential of this approach for developing a more complete understanding of ancient sedimentary systems.
May 21, 2025
No speaker scheduled.May 28, 2025
No speaker scheduled.June 4, 2025
No speaker scheduled.June 11, 2025 – Prof. Dr. Eberhard Gischler
Goethe University Frankfurt
A 5700-year storm and climate archive at annual resolution: the sunken cave of the Blue Hole in Belize
Predicting the frequency of tropical cyclones is hampered by insufficient knowledge of their natural variability in the past. A 30-meter-long sediment core from the Great Blue Hole, a flooded karst cave off the coast of Belize, provides the longest available continuous and annually resolved archive of storm frequency. This dataset extends our understanding from the instrumental record (73 years), historical documentation (173 years) and paleotempestological record (2000 years) to the last 5700 years. A total of 694 event layers were identified. They show a clear regional trend of increasing storm activity in the southwestern Caribbean following an orbitally induced shift of the Intertropical Convergence Zone. The superimposed short-term variations match Holocene climate intervals and are caused by solar radiation-driven sea surface temperature anomalies. An extrapolation for the 21st century indicates an unprecedented increase in storm frequency due to Industrial-Age warming.
June 18, 2025 – Dr. Tim Vietor
Nationale Genossenschaft für die Lagerung radioaktiver Abfälle [NAGRA], CH
1 Mio years of safety for radioactive waste - is geological disposal a reliable option?
June 25, 2025 – Dr. Jacek Raddatz
GEOMAR Helmholtz Centre for Ocean Research Kiel
Title to be announcedJuly 2, 2025 – Prof. Dr. Jakob Santner
University of Giessen
Siliziumdüngung zur Steigerung der Nutzungseffizienz von gedüngtem Phosphor?
July 9, 2025 – Dr. Christine Liang
Helmholtz Centre for Environmental Research, Leipzig
Title to be announced