New integrated high-resolution dinoflagellate cyst stratigraphy and litho- and chemostratigraphy from the Paris and Dieppe–Hampshire Basins for the 'Sparnacian'

The Paris Basin represents an historical cradle of Palaeogene stratigraphy, where during the nineteenth century the Palaeocene Series and the "Sparnacian Stage'' were established. As highlighted by Aubry et al. (2005), whereas the chronostratigraphic connotation of the "Sparnacian Stage'' has been controversial since its definition, modern studies of the late Palaeocene-early Eocene interval have revealed that the so-called "Sparnacian'' deposits encompass a remarkable and short (similar to 170 kyr) episode of the Cenozoic, the Palaeocene-Eocene Thermal Maximum (PETM, similar to 55.8-55.6 Ma). Dinoflagellate assemblages from the "Sparnacian'' of the Dieppe-Hampshire and Paris basins do not contain the key species Apectodinium augustum, whereas it is present in the northern Belgian Basin Tienen Formation and is coeval there with the CIE and the Apectodinium acme interval. However, our calibration of the Apectodinium acme to the CIE in the Dieppe-Hampshire and Paris basins suggests its attribution to the A. augustum zone. The absence of species A. augustum in the Anglo-Paris Basin may be explained by its restriction to more offshore conditions