Evolution of the paleoclimate during late Eocene in Western Europe: a study in the Alès Basin (Gard, France) - Archive ouverte HAL Accéder directement au contenu
Communication Dans Un Congrès Année : 2015

Evolution of the paleoclimate during late Eocene in Western Europe: a study in the Alès Basin (Gard, France)

Résumé

The Priabonian (38-33.9 Ma), is a critical period for the evolution of terrestrial environments. A progressive deterioration of the climate leads to an increase of the seasonality in mid latitudes and a quick drop of the global temperature marks the end of the stage, which is renowned as the Terminal Eocene Event. Deep changes in the floras composition are associated to the climate changes in North America, northern China, Central and Northern Europe, but data remain limited for other parts of the globe. Here, we present preliminary reappraisal of the Priabonian fossil plants found in the Alès Basin (southern France). The aims of this study are: (1) to characterize the fossil vegetation types in several localities of different ages and sedimentary facies; (2) to derive paleoclimatic interpretation from the fossil leave associations and finally (3) to outline and reconstruct the paleoflora and climate evolution of the Alès Basin during late Eocene. The Alès Basin has yielded numerous plant remains but only the paleoflora from Célas locality was published and studied in detail (Laurent, 1899). We investigated the historical collections housed in the Museum of Natural History of Marseille, as well as newly collected material form the varied sections (Saint Jean de Ceyrargues, Saint-Jean de Maruéjols, Saint-Hippolyte-de-Caton, and Vieilles Fumades). The floristic composition of the Alès Basin flora looks close to that of other Late Eocene European localities, especially the ones in the Transeuropean Paratethys and Mediterranean Tethys bioprovinces (Kvacek, 2010). The vegetation is characterized by a mixture of broad-leaved and sclerophyllous elements. Main components of the Célas locality are members of the Moraceae (Ficus), Lauraceae (Cinnamomum) families or genus Doliostrobus, Zizyphus, along with some sclerophyllous Myricaceae, Proteaceae and Fabaceae. Fossil plants remains are commonly used by paleobotanists to reconstruct paleoclimate. In particular, Physiognomic analyses, especially Climate Leaf Analysis Multivariate Program (CLAMP), have proved being worthwhile reconstructing Paleogene paleo-temperatures and paleo-precipitations. First applications to the two early Priabonian localities of Célas and Saint-Hippolyte-de-Caton) are similar with previous studies conducted in Central and Northern Europe. They clearly indicate a subtropical environment, probably comparable to those of subtropical Queensland (Eastern Australia). The localities from middle and late Priabonian will be investigated later on. Available sedimentological, geochemical and paleontological data clearly show a climate cooling that should be recorded in the progressive renewal of floras.
Fichier non déposé

Dates et versions

hal-03618521 , version 1 (24-03-2022)

Identifiants

  • HAL Id : hal-03618521 , version 1

Citer

Mélanie Tanrattana, Anais A Boura, François Fournier, Loïc Villier. Evolution of the paleoclimate during late Eocene in Western Europe: a study in the Alès Basin (Gard, France). Congrès Agora paleobotanica, Jul 2015, Autun, France. ⟨hal-03618521⟩
28 Consultations
0 Téléchargements

Partager

Gmail Facebook X LinkedIn More