The Global Boundary Stratotype Section and Point (GSSP) of the Barremian Stage at Río Argos (Caravaca, SE Spain).
Résumé
Following votes by the Barremian Working Group, the International Subcommission on Cretaceous Stratigraphy and the International Commission on Stratigraphy, the Executive Committee of the International Union of Geological Sciences unanimously approved in March 2023 the Global Stratotype Section and Point (GSSP) for the Barremian Stage (Lower Cretaceous). The base of the Barremian Stage is defined at the base of bed 171 of the Río Argos section, near Caravaca (SE Spain) and correlated by the first appearance of the ammonite species Taveraidiscus hugii. This event falls within the NC5C calcareous nannofossil Subzone, the Lilliputianella semielongata planktonic foraminiferal Zone, and the Dorothia ouachensis benthic foraminiferal Zone. It roughly coincides with the beginning of a slightly negative trend interval in the δ13C curve. Indirect calibration to the magnetostratigraphic scale suggests that the boundary falls in the lowermost part of polarity chron M3r. According to the astrochronological analysis, a time interval of 0.74 myr separates the beginning of the late Hauterivian Faraoni Episode from the base of the Barremian, which is dated at 125.77 MA.
Domaines
Stratigraphie| Origine | Fichiers éditeurs autorisés sur une archive ouverte |
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