Ypresian

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Ypresian
56.0 – 47.8 Ma
δ13C values at the PETM[3]
Lower boundary GSSPDababiya section, Luxor, Egypt[3]
25°30′00″N 32°31′52″E / 25.5000°N 32.5311°E / 25.5000; 32.5311
Lower GSSP ratified2003[3]
Upper boundary definitionFAD of the calcareous nannofossil Blackites inflatus
Upper boundary GSSPGorrondatxe section, Western Pyrenees, Basque Country, Spain
43°22′47″N 3°00′51″W / 43.3796°N 3.0143°W / 43.3796; -3.0143
Upper GSSP ratifiedApril 2011[4]

In the

age or lowest stratigraphic stage of the Eocene. It spans the time between 56 and 47.8 Ma, is preceded by the Thanetian Age (part of the Paleocene) and is followed by the Eocene Lutetian
Age. The Ypresian is consistent with the lower Eocene.

Events

The Ypresian Age begins during the throes of the

Messel shales in Germany, the Oise amber of France and Cambay amber of India are of this age. The Eocene Okanagan Highlands are an uplands subtropical to temperate series of lakes from the Ypresian.[5][6][7]

The Ypresian is additionally marked by another warming event called the Early Eocene Climatic Optimum (EECO). The EECO is the longest sustained warming event in the Cenozoic record, lasting about 2–3 million years between 53 and 50 Ma. The interval is characterized by low oxygen 18 isotopes,[8][9][10] high levels of atmospheric pCO2,[11][12] and low meridional thermal gradients.[13] Biodiversity has been reported to have been significantly impacted by the conditions prevalent during the EECO. For instance, there were biotic turnovers among marine producers such as calcerous nannofossil among others etc.[14][15]

Stratigraphic definition

The Ypresian Stage was introduced in scientific literature by

André Hubert Dumont in 1850. The Ypresian is named after the Flemish city of Ypres in Belgium (spelled Ieper in Dutch). The definitions of the original stage were totally different from the modern ones.[16] The Ypresian shares its name with the Belgian Ieper Group
(French: Groupe d'Ypres), which has an Ypresian age.

The base of the Ypresian Stage is defined at a strong negative anomaly in

type section
was located in the vicinity of Ieper.

The top of the Ypresian (the base of the Lutetian) is identified by the first appearance of the foraminifera genus Hantkenina in the fossil record.

The Ypresian Stage overlaps the upper Neustrian and most of the Grauvian

Asian Land Mammal Ages. It is also coeval with the upper Wangerripian and lowest Johannian regional stages of Australia and the Bulitian, Penutian, and Ulatisian regional stages of California
.

References

  1. doi:10.1016/j.gloplacha.2005.01.001
    .
  2. ^ "International Chronostratigraphic Chart" (PDF). International Commission on Stratigraphy.
  3. ^
    doi:10.18814/epiiugs/2007/v30i4/003
    .
  4. doi:10.18814/epiiugs/2011/v34i2/006
    .
  5. doi:10.1139/e04-100
    .
  6. ^ Archibald, S.; Greenwood, D.; Smith, R.; Mathewes, R.; Basinger, J. (2011). "Great Canadian Lagerstätten 1. Early Eocene Lagerstätten of the Okanagan Highlands (British Columbia and Washington State)". Geoscience Canada. 38 (4): 155–164.
  7. S2CID 134962126
    .
  8. S2CID 4358350
    .
  9. ISSN 1943-2682
    .
  10. PMID 11326091
    .
  11. ISSN 1752-0908
    .
  12. S2CID 4360841
    .
  13. S2CID 256767465
    .
  14. S2CID 210245165
    .
  15. doi:10.1016/j.palaeo.2011.06.018
    .
  16. ^ Steurbaut (2006)
  17. ^ The GSSP was established by Dupuis et al. (2003)
  18. ^ Alroy, John. "Mammal Paleogene zones". p. The Paleobiology Database. Retrieved 15 July 2009.

Literature

Wikisource has original works on the topic: Cenozoic#Paleogene

External links

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