Santonian

Santonian

Santonian

Fourth age of the Late Cretaceous epoch


The Santonian is an age in the geologic timescale or a chronostratigraphic stage. It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series. It spans the time between 86.3 ± 0.7 mya (million years ago) and 83.6 ± 0.7 mya. The Santonian is preceded by the Coniacian and is followed by the Campanian.[6]

Quick Facts Chronology, Etymology ...

Stratigraphic definition

The Santonian Stage was established by French geologist Henri Coquand in 1857. It is named after the city of Saintes in the region of Saintonge, where the original type locality is located.[7]

The base of the Santonian Stage is defined by the appearance of the inoceramid bivalve Cladoceramus undulatoplicatus. The GSSP (official reference profile) for the base of the Santonian Stage is located near Olazagutia, Spain; it was ratified by the Subcommission on Cretaceous Stratigraphy in 2012.[7] The Santonian's top (the base of the Campanian Stage) is informally marked by the extinction of the crinoid Marsupites testudinarius.[8] A GSSP for the top of the Santonian was ratified in October 2022 in Bottaccione, Gubbio, Italy.[3]

Subdivision

The Santonian is sometimes subdivided into Lower, Middle and Upper Substages. In the Tethys domain the Santonian is coeval with a single ammonite biozone: that of Placenticeras polyopsis. Biostratigraphy based on inoceramids, nanoplankton or forams is more detailed.


References

Notes

  1. International Commission on Stratigraphy. "ICS - Chart/Time Scale". www.stratigraphy.org.
  2. Gale, Andy; Batenburg, Sietske; Coccioni, Rodolfo; Dubicka, Zofia; Erba, Elisabetta; Falzoni, Francesca; Haggart, Jim; Hasegawa, Takishi; Ifrim, Christina; Jarvis, Ian; Jenkyns, Hugh; Jurowska, Agata; Kennedy, Jim; Maron, Matteo; Muttoni, Giovanni; Pearce, Martin; Petrizzo, Maria Rose; Premoli-Silva, Isabella; Thibault, Nicolas; Voigt, Silke; Wagreich, Michael; Walaszczyk, Irek (1 February 2023). "The Global Boundary Stratotype Section and Point (GSSP) of the Campanian Stage at Bottaccione (Gubbio, Italy) and its Auxiliary Sections: Seaford Head (UK), Bocieniec (Poland), Postalm (Austria), Smoky Hill, Kansas (U.S.A), Tepayac (Mexico)". Episodes: 6. doi:10.18814/epiiugs/2022/022048. hdl:2434/968946. S2CID 256539746. Retrieved 27 March 2023.
  3. "Campanian GSSP Ratified by IUGS". Subcommission on Cretaceous Stratigraphy. International Commission on Stratigraphy. Retrieved 14 January 2023.
  4. Gradstein et al. (2004)
  5. Gradstein, F.M.; Ogg, J.G.; Schmitz, M.D.; Ogg, G.M., eds. (2020). Geologic Time Scale 2020. Elsevier. p. 1038. ISBN 978-0-12-824360-2.
  6. Gradstein, F.M.; Ogg, J.G.; Schmitz, M.D.; Ogg, G.M., eds. (2020). Geologic Time Scale 2020. Elsevier. p. 1040. ISBN 978-0-12-824360-2.

Literature

  • Gradstein, F.M.; Ogg, J.G. & Smith, A.G.; 2004: A Geologic Time Scale 2004, Cambridge University Press.

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