Earth:Santonian

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Short description: Fourth age of the Late Cretaceous epoch
Santonian
86.3 ± 0.5 – 83.6 ± 0.2 Ma
Chronology
Cretaceous graphical timeline
Subdivision of the Cretaceous according to the ICS, as of 2021.[1]
Vertical axis scale: millions of years ago.
Etymology
Name formalityFormal
Usage information
Celestial bodyEarth
Regional usageGlobal (ICS)
Time scale(s) usedICS Time Scale
Definition
Chronological unitAge
Stratigraphic unitStage
Time span formalityFormal
Lower boundary definitionFAD of the Inoceramid Bivalve Cladoceramus undulatoplicatus
Lower boundary GSSPOlazagutia, Spain
[ ⚑ ] 42°52′00″N 2°11′48″W / 42.8668°N 2.1968°W / 42.8668; -2.1968
GSSP ratifiedJanuary 2013[2]
Upper boundary definitionBase of Chron C33r[3]
Upper boundary GSSPBottaccione, Gubbio, Italy[3]
[ ⚑ ] 43°21′46″N 12°34′58″E / 43.3627°N 12.5828°E / 43.3627; 12.5828[4]
GSSP ratifiedOctober 2022[5]

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]

Stratigraphic definition

The Santonian Stage was established by France 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. Super User. "ICS - Chart/Time Scale". http://www.stratigraphy.org/index.php/ics-chart-timescale. 
  2. Lamolda, M.; Paul, C.; Peryt, D.; Pons, J. (March 2014). "The Global Boundary Stratotype and Section Point (GSSP) for the base of the Santonian Stage, "Cantera de Margas", Olazagutia, northern Spain". Episodes 37 (1): 2–13. doi:10.18814/epiiugs/2014/v37i1/001. https://www.researchgate.net/publication/263378103. Retrieved 24 December 2020. 
  3. 3.0 3.1 3.2 Jarvis, Ian (2023). "Carbon isotopes, palynology and stratigraphy of the Santonian–Campanian boundary: The GSSP auxiliary sections, Seaford Head (England) and Bocieniec (Poland), and correlation between the Boreal and Tethyan realms". Cretaceous Research 143: 105415. doi:10.1016/j.cretres.2022.105415. Bibcode2023CrRes.14305415J. https://www.sciencedirect.com/science/article/pii/S0195667122002798. Retrieved 14 January 2023. 
  4. Gale, Andy; Batenburg, Sietske; Coccioni, Rodolfo; Dubicka, Zofia; Erba, Elisabetta; Falzoni, Francesca; Haggart, Jim; Hasegawa, Takishi et al. (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. https://www.episodes.org/journal/view.html?uid=2319&vmd=Full. Retrieved 27 March 2023. 
  5. "Campanian GSSP Ratified by IUGS". International Commission on Stratigraphy. https://cretaceous.stratigraphy.org/news/campanian_gssp. 
  6. Gradstein et al. (2004)
  7. 7.0 7.1 Gradstein, F.M.; Ogg, J.G.; Schmitz, M.D. et al., eds (2020). Geologic Time Scale 2020. Elsevier. p. 1038. ISBN 978-0-12-824360-2. 
  8. Gradstein, F.M.; Ogg, J.G.; Schmitz, M.D. et al., 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 .

External links