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Thanetian

Thanetian
59.2 – 56.0 Ma
Chronology
Formerly part ofTertiary Period/System
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 definitionBase of magnetic polarity chronozone C26n
Lower boundary GSSPZumaia Section, Basque Country, Spain
43°17′59″N 2°15′39″W / 43.2996°N 2.2609°W / 43.2996; -2.2609
Lower GSSP ratified2008[3]
Upper boundary definitionStrong negative anomaly in δ13C values at the PETM[4]
Upper boundary GSSPDababiya section, Luxor, Egypt[4]
25°30′00″N 32°31′52″E / 25.5000°N 32.5311°E / 25.5000; 32.5311
Upper GSSP ratified2003[4]

The Thanetian is, in the ICS Geologic timescale, the latest age or uppermost stratigraphic stage of the Paleocene Epoch or Series. It spans the time between 59.2 and 56 Ma. The Thanetian is preceded by the Selandian Age and followed by the Ypresian Age (part of the Eocene).[5] The Thanetian is sometimes referred to as the Late Paleocene.

Stratigraphic definition

The Thanetian was established by Swiss geologist Eugène Renevier in 1873. The Thanetian is named after the Thanet Formation, the oldest Cenozoic deposit of the London Basin, which was first identified in the area of Kent (southern England) known as the Isle of Thanet.

The base of the Thanetian Stage is laid at the base of magnetic chronozone C26n. The references profile (Global Boundary Stratotype Section and Point) is in the Zumaia section (43° 18'N, 2° 16'W) at the beach of Itzurun, Pais Vasco, northern Spain.[6] Fossils of the unicellular planktonic marine coccolithophore Areoligeria gippingensis make their first appearance at the base of the Thanetian, and help define its lowest stratigraphic boundary.

The top of the Thanetian Stage (the base of the Ypresian) is defined at a strong negative anomaly in δ13C values at the global thermal maximum at the Paleocene-Eocene boundary.

The Thanetian Stage is coeval the lower Neustrian European land mammal age (it spans the Mammal Paleogene zone 6 and part of zones 1 through 5.[7]), the upper Tiffanian and Clarkforkian North American land mammal ages, the Riochican and part of the Itaboraian South American land mammal ages and the upper Nongshanian and Gashatan Asian land mammal ages. The Thanetian is contemporary with the middle Wangerripian regional stage of Australia and the upper Ynezian regional stage of California. It overlaps the obsolete regional stages Landenian and Heersian of Belgium.

Palaeontology

The Sézanne flora is a fossil assemblage preserved in freshwater limestone deposits at Sézanne, laid down during the Thanetian Age, when Europe enjoyed a tropical climate. In the lagerstätte, leaves, entire flowers and seeds are minutely preserved. Also, the first representatives of Proboscidea appeared, Eritherium.[8]

Climate

This period was characterized by temperatures warmer than those of today.[9]

See also

References

  1. ^ Zachos, J. C.; Kump, L. R. (2005). "Carbon cycle feedbacks and the initiation of Antarctic glaciation in the earliest Oligocene". Global and Planetary Change. 47 (1): 51–66. Bibcode:2005GPC....47...51Z. doi:10.1016/j.gloplacha.2005.01.001.
  2. ^ "International Chronostratigraphic Chart" (PDF). International Commission on Stratigraphy.
  3. ^ Schmitz, B.; Pujalte, V.; Molina, E.; Monechi, S.; Orue-Etxebarria, X.; Speijer, R. P.; Alegret, L.; Apellaniz, E.; Arenillas, I.; Aubry, M.-P.; Baceta, J.-I.; Berggren, W. A.; Bernaola, G.; Caballero, F.; Clemmensen, A.; Dinarès-Turell, J.; Dupuis, C.; Heilmann-Clausen, C.; Orús, A. H.; Knox, R.; Martín-Rubio, M.; Ortiz, S.; Payros, A.; Petrizzo, M. R.; von Salis, K.; Sprong, J.; Steurbaut, E.; Thomsen, E. (2011). "The global Stratotype Sections and Points for the bases of the Selandian (Middle Paleocene) and Thanetian (Upper Paleocene Paleocene) stages at Zumaia, Spain". Episodes. 34 (4): 220–243. doi:10.18814/epiiugs/2011/v34i4/002.
  4. ^ a b c Aubry, Marie-Pierre; Ouda, Khaled; Dupuis, Christian; William A. Berggren; John A. Van Couvering; Working Group on the Paleocene/Eocene Boundary (2007). "The Global Standard Stratotype-section and Point (GSSP) for the base of the Eocene Series in the Dababiya section (Egypt)" (PDF). Episodes. 30 (4): 271–286. doi:10.18814/epiiugs/2007/v30i4/003.
  5. ^ International Commission on Stratigraphy 2017
  6. ^ Proposed by Dinarès-Turell et al. (2007), ratified by the IUGS in 2008
  7. ^ Alroy, John. "Mammal Paleogene zones". p. The Paleobiology Database. Archived from the original on 12 October 2012. Retrieved 15 July 2009.
  8. ^ Emmanuel Gheerbrant (2009). "Paleocene emergence of elephant relatives and the rapid radiation of African ungulates". Proceedings of the National Academy of Sciences of the United States of America. 106 (26): 10717–10721. Bibcode:2009PNAS..10610717G. doi:10.1073/pnas.0900251106. PMC 2705600. PMID 19549873.
  9. ^ "AR6 Climate Change 2021: The Physical Science Basis — IPCC". Retrieved 24 August 2021.

Literature

  • Dinarès-Turell, J.; Baceta, J. I.; Bernaola, G.; Orue-Etxebarria, X. & Pujalte, V.; 2007: Closing the Mid-Palaeocene gap: Toward a complete astronomically tuned Palaeocene Epoch and Selandian and Thanetian GSSPs at Zumaia (Basque Basin, W. Pyrenees), Earth and Planetary Science Letters 262: pp 450–467.
  • Gradstein, F.M.; Ogg, J.G. & Smith, A.G.; 2004: A Geologic Time Scale 2004, Cambridge University Press.
  • Renevier, E.; 1873: Tableau des terrains sédimentaires formés pendant les époques de la phase organique du globe terrestre, Bulletin de la Société Vaudoise des Sciences Naturelles (Lausanne) 12: pp 218–252.
Quelle: https://en.wikipedia.org/wiki/Thanetian