Sprecher
Beschreibung
The Paleocene Eocene Thermal Maximum (PETM, ca. 56 Ma) was a short (200 ky) and major global warming event characterized by a temperature increase of 5 to 8°C and a profound impact on diversity, biogeographic distribution and extinction patterns. The two fossiliferous sites of Rivecourt (56 Ma) and Le Quesnoy (ca. 55 Ma) located in the Paris Basin (Oise, France) provide a valuable opportunity to compare terrestrial paleoenvironments before and after the PETM in western Europe.
Both sites have yielded abundant fossil assemblages including vertebrates as well as a large amount of plant fossils such as wood, flowers, inflorescences, fruits, seeds and amber (only in Le Quesnoy). Previous studies documented a predominantly tropical to subtropical forested environment, comparable to modern South-East Asian ecosystems. However, several questions remain unresolved, particularly concerning the diagenetic history of fossil woods, the origin of their contrasting coloration and preservation and the taxonomic affinities of an inflorescence.
This study aims to address these issues through a multiproxy geochemical approach. Raman and infrared spectroscopy, combined with Rock-Eval pyrolysis and elemental analysis, are used to characterize the immature diagenesis of the samples and investigate potential evidence for local paleo-wildfires. Stable carbon isotopic analysis (δ13C) provides insight into palaeoecological and hydrological conditions. Finally, biomarker analysis (GDGTs, lipids etc…) are used to reconstruct paleoenvironmental conditions and explore the chemotaxonomic affinities of the fossil inflorescence.