The Permian-Triassic boundary and the early Triassic sedimentation in the western peritethys basins: An overview

Autor: Sylvie BOURQUIN, Durand, M., Diez, J. B., Broutin, J., Frédéric Fluteau
Přispěvatelé: Géosciences Rennes (GR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre Armoricain de Recherches en Environnement-Centre National de la Recherche Scientifique (CNRS), Paléobiodiversité et paléoenvironnements, Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre Armoricain de Recherches en Environnement-Centre National de la Recherche Scientifique (CNRS), Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)
Jazyk: angličtina
Rok vydání: 2007
Předmět:
Zdroj: Journal of Iberian Geology
Journal of Iberian Geology, 2007, 33 (2), pp.221-236
Journal of Iberian Geology, Springer Verlag, 2007, 33 (2), pp.221-236
HAL
ISSN: 1698-6180
1886-7995
Popis: International audience; At the scale of the peri-Tethyan basins of western Europe, the "Buntsandstein" continental lithostratigraphic units are frequently attributed to the "Permian-Triassic" because, in most cases, the lack of any "Scythian" (i.e. Early Triassic) biochronological evidence makes it very difficult to attribute the basal beds of the cycle to the Permian or to the Triassic. A careful recognition of unconformities and sedimentary indications of clearly arid climate provide powerful tools for correlation within non-marine successions that are devoid of any biostratigraphic markers, at least on the scale of the West European Plate. From a review of the "Buntsandstein" series of several basins we can characterize the Permian-Triassic boundary and the beginning of Triassic sedimentation at the scale of Western Europe. We clearly show that, except for the Central Germanic Basin, an unconformity can be observed between the Permian and the Triassic. Apart from the Germanic Basin, there is a total lack of typically "Scythian" fossils in the rest of West European basins, and the oldest biochronological markers yielded by these units are palynomorphs allowing to assign an Anisian age generally to the upper part of the "Buntsandstein", but also its lowermost in a few cases. In the peri-Tethyan basins of western Europe, the Permian-Triassic boundary corresponds to an unconformity overlain by conglomerates containing ventifacts (followed by fluvial sandstones, sometimes rich in paleosols and sometimes totally devoid), which are attributed mainly to the lower Olenekian, i.e. Smithian. Alternatively, the succession passes up directly into fluvial sandstones containing the first paleosols, and then plant debris and palynomorphs attributed to the Anisian. In this way, the lack of typically Early Triassic fossils in most of the peri-Tethyan basins, at the scale of the west European Plate, can be explained by a true stratigraphic hiatus in the earliest Triassic (i.e. Induan) and by arid conditions unfavourable for the development of flora and fauna and their preservation during the Olenekian.
Databáze: OpenAIRE
Externí odkaz: