Christian Dupuis

First Clarkforkian equivalent Land Mammal Age in the latest Paleocene basal Sparnacian facies of Europe: fauna, flora, paleoenvironment and (bio)stratigraphy.

The Paleocene-Eocene Thermal Maximum (PETM) is correlated with the first occurrences of earliest modern mammals in the Northern Hemisphere. The latest Paleocene Clarkforkian North American Land Mammal Age, that has yielded rodents and carnivorans, is the only exception to this rule. However, until now no pre-PETM localities have yielded modern mammals in Europe or Asia. We report the first Clarkforkian equivalent Land Mammal Age in the latest Paleocene deposits of the basal Sparnacian facies at Rivecourt, in the north-central part of the Paris Basin. The new terrestrial vertebrate and macroflora assemblages are analyzed through a multidisciplinary study including sedimentologic, stratigraphic, isotopic, and palynological aspects in order to reconstruct the paleoenvironment and to evaluate biochronologic and paleogeographic implications. The mammals are moderately diverse and not abundant, contrary to turtles and champsosaurs. The macroflora is exceptional in preservation and diversity with numerous angiosperms represented by flowers, fruits, seeds and wood preserved as lignite material, revealing an abundance of Arecaceae, Betulaceae, Icacinaceae, Menispermaceae, Vitaceae and probably Cornaceae. Results indicate a Late Paleocene age based on carbon isotope data, palynology and vertebrate occurrences such as the choristoderan Champsosaurus, the arctocyonid Arctocyon, and the plesiadapid Plesiadapis tricuspidens. However, several mammal species compare better with the earliest Eocene. Among these, the particular louisinid Teilhardimys musculus, also recorded from the latest Paleocene of the Spanish Pyrenees, suggests a younger age than the typical MP6 reference level. Nevertheless, the most important aspect of the Rivecourt fauna is the presence of dental remains of a rodent and a “miacid” carnivoran, attesting to the presence of two modern mammalian orders in the latest Paleocene of Europe. Interestingly, these two groups are also the only modern groups recorded from the latest Paleocene of North America, making Rivecourt the first direct equivalent to the Clarkforkian Land Mammal Age outside of North America.

Dinoflagellate cyst events and depositional history of the Paleocene/Eocene boundary interval in the southern North Sea Basin

High-resolution stratigraphic and micropalaeontological investigations of 30 outcrop and borehole sections throughout Belgium and northern France (Fig. 1) have documented a complex mid-Paleocene to early Eocene depositional history, marked by many discontinuities and major biotic and lithofacies changes (Steurbaut et al. 1998, and in prep.). In the present paper the aquatic palynological stratigraphic record across the Paleocene/ Eocene boundary in northwestern Europe is summarised (pollen and spores are not discussed) and correlated to a revised lithostratigraphic and sequence stratigraphic framework (lithostratigraphy based on Steurbaut 1998).

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 (~170 kyr) episode of the Cenozoic, the Palaeocene–Eocene Thermal Maximum (PETM, ~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.

Erosion surfaces in the Ardenne-Oesling and their associated kaolinic weathering mantle

This chapter deals with the long-term geomorphology of the Paleozoic Ardenne–Oesling massif of S Belgium and the landforms that currently attest the very long persistence and high resistance to erosion of landscape elements created as far back in time as the Lower Cretaceous in a region of predominantly continental regime and constant low to moderate elevation since the Permian. We first present recent results regarding the antiquity of kaolinic weathering mantles preserved in four sites on or close to the plateau surfaces characteristic of the Ardennian landscape, showing that they record at least three main weathering phases, namely in the Early Cretaceous (extending in the early Late Cretaceous), the Late Paleocene, and the Early Miocene. Then, having provided a working definition of the erosion surface and listed criteria helping recognize them in the landscape, we focus on the Hautes Fagnes massif, the highest NE part of the Ardenne–Oesling. We describe the geometric and sedimentary evidence that allow one to recognize a succession of four erosion surfaces formed during the Cretaceous and the Cenozoic and reconstruct the morphogenetic evolution of the area that responded to the variable interplay of the marine transgression-regression, climatic, and tectonic controls. Finally, we present the few estimates of long-term denudation rates available for the Ardenne massif, fission track and cosmogenic nuclide studies both suggesting Cenozoic denudation rates in the order of a few 10 m/Myr, and comment on their compatibility with field observations.