Improved chronostratigraphy for the Messel Formation (Hesse, Germany) provides insight into early to middle Eocene climate variability

A refined chronostratigraphy for the Messel Formation reveals that its sediments, spanning from 48.06 to 47.22 million years ago, were deposited over approximately 840 thousand years during the early to middle Eocene epoch. This precise dating, achieved through astronomical tuning of geochemical proxy data (gamma ray, total organic carbon, and carbon isotopes), corrects previous estimates by showing that the Lower Messel Formation (LMF) lasted around 130 thousand years while the Middle Messel Formation (MMF) took roughly 430 thousand years to accumulate. The study also indicates a slightly higher average sedimentation rate (~20 cm/kyr) for the oil-shale intervals, contradicting earlier assumptions. Additionally, the findings suggest that climate variability during this period was strongly influenced by orbital precession and eccentricity, with humidity changes paced by these factors. The synchronicity of carbon-isotope anomalies in Messel's sediments with global records further validates the age model, offering unprecedented temporal resolution to study ecosystem responses to abrupt climate disturbances like hyperthermals.

Kaboth-Bahr, S., Schmitt, C., Bauersachs, T., Zeeden, C., Wonik, T., Schandl, J., Lenz, O., Wedmann, S., Vasiliev, I., Mulch, A., Lourens, L., Pross, J., & Bahr, A. (2024). Improved chronostratigraphy for the Messel Formation (Hesse, Germany) provides insight into early to middle Eocene climate variability. Newsletters on Stratigraphy, 57(2), 153–170. https://doi.org/10.1127/nos/2024/0799