The Lower Triassic sedimentary and carbon isotope records from Tulong (South Tibet) and their significance for Tethyan palaeoceanography

Détails

ID Serval
serval:BIB_50B01C64BEBE
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
The Lower Triassic sedimentary and carbon isotope records from Tulong (South Tibet) and their significance for Tethyan palaeoceanography
Périodique
Sedimentary Geology
Auteur⸱e⸱s
Brühwiler Thomas, Goudemand Nicolas, Galfetti Thomas, Bucher Hugo, Baud Aymon, Ware David, Hermann Elke, Hochuli Peter, Martini Rossanna
Statut éditorial
Publié
Date de publication
2009
Langue
anglais
Résumé
The Lower Triassic sedimentary and carbonate/organic carbon isotope records from the Tulong area (South Tibet) are documented in their integrality for the first time. New age control is provided by ammonoid and conodont biostratigraphy. The basal Triassic series consists of Griesbachian dolomitic limestones, similar to the Kathwai Member in the Salt Range (Pakistan) and to the Otoceras Beds in Spiti (India). The overlying thin-bedded limestones of Dienerian age strongly resemble the Lower Ceratite Limestone of the Salt Range. They are followed by a thick series of dark green, silty shales of Dienerian–early Smithian age without fauna that strikingly resemble the Ceratite Marls of the Salt Range. This interval is overlain by thin-bedded, light grey fossil-rich limestones of middle to late Smithian age, resembling the Upper Ceratite Limestone of the Salt Range. These are followed by a shale interval of early Spathian age that has no direct counterpart in other Tethyan sections. Carbonate production resumes during the late early and middle Spathian with the deposition of red, bioclastic nodular limestone (“Ammonitico Rosso” type facies). Apart from its colour this facies is similar to the one of the Niti Limestone in Spiti and of the Spathian nodular limestone in Guangxi (South China). As in other Tethyan localities such as Spiti, the early–middle Anisian part of the Tulong section is strongly condensed and is characterized by grey, thin-bedded limestones with phosphatized ammonoids. As for many other Tethyan localities the carbon isotope record from Tulong is characterized by a late Griesbachian–Dienerian positive δ13Ccarb excursion (2‰), and a very prominent positive excursion (5‰) at the Smithian–Spathian boundary, thus confirming the well-documented perturbations of the global carbon cycle following the Permian–Triassic mass extinction event.
Mots-clé
Early Triassic South Tibet Microfacies Palaeoenvironments Carbon isotopes
Création de la notice
05/07/2021 14:58
Dernière modification de la notice
13/03/2022 6:32
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