A proposal for drilling “Geiseltal” – a near complete terrestrial section of the Eocene in Central Europe

As the world warms due to rising greenhouse gas concentrations, the Earth system moves toward climate states without historic precedent, challenging societal adaptation. One way to investigate these unprecedented conditions is to study past climates and ecosystems that shar similarities to our current and future ones. One such period is the Eocene (~56 – 33 Ma), during which the climate changed from a hot-house to a greenhouse state, comprising a wide range of atmospheric CO2 concentrations. However, our knowledge of the Eocene climate evolution is incomplete because of a lack of terrestrial records covering the entire period. To address this gap in our understanding, we propose to obtain drill cores at Geiseltal in Eastern Germany as part of the International Continental Scientific Drilling Program (ICDP).

This former lignite quarry is famous for its exceptionally well-preserved Eocene mammal fossils, but its potential as a climate archive has not yet been explored due to the lack of existing drill cores. By drilling a maximum of three cores, we aim to create a spliced 100-120 m long record comprising the entire Eocene archived in Geiseltal as an alteration of lignite seems intercalated with fluvial strata. High-resolution, multi-proxy analyses of the obtained sediments will allow to generate a unique record of (sub)orbital climate variability under various atmospheric greenhouse gas concentrations. The integration of newly developed paleoclimate records with the existing paleoecological data will further help to inform how the terrestrial ecosystems reacted to long-term as well short-term changes, e.g., during hyperthermals. To advance this project, we welcome scientific input from a wide range of disciplines (e.g., stratigraphy, sedimentology, paleolimnology, paleobotany, paleontology, and organic/inorganic geochemistry) as well as are actively seeking interested groups and individuals to collaborate with us on this project.