| Zdroj: |
Heilmann-Clausen, C 2020, ' Observations of the dinoflagellate Wetzeliella in Sparnacian facies (Eocene) near Epernay, France, and a note on tricky acmes of Apectodinium ', Proceedings of the Geologists' Association, vol. 131, no. 5, pp. 450-457 . https://doi.org/10.1016/j.pgeola.2018.06.001 |
| Popis: |
The wetzelielloid dinocyst genera Wetzeliella and Apectodinium are crucial for dating and correlation of Lower Eocene Sparnacian facies in NW Europe. Previous ill-documented reports of Wetzeliella in one of these facies, the Epernay Formation, Paris Basin, are corroborated by a study of new samples. The findings support current age-interpretations of the Epernay Formation as early-mid Ypresian. Apectodinium was a thermophilic genus, but it may have been more sensitive to other ecologic conditions than warmth. Three examples show that even extreme acmes of Apectodinium developed locally in lagoonal/coastal environments at times when no warming took place and when Apectodinium was absent or rare in adjacent, offshore areas. The best known Apectodinium acme, the quasi-global acme developed within the Paleocene-Eocene Thermal Maximum (PETM), may not be directly attributable to the increased warmth, but caused by a secondary climatic effect, elevated nutrients in the neritic waters. |
