Ypresian
{{short description|First age of the Eocene Epoch}}
{{Infobox geologic timespan
| name = Ypresian
| color = Ypresian
| top_bar =
| time_start = 56.0
| time_end = 47.8
| image_map = Ypresian Earth 50 mya.jpg
| caption_map = Earth ~50 mya
| image_outcrop = Klondike Mountain Formation outcrop - Site A0307.JPG
| caption_outcrop = Klondike Mountain Formation, Republic, Washington
| image_art =
| caption_art =
| timeline = Paleogene
| formerly_part_of = Tertiary Period/System
| name_formality = Formal
| name_accept_date =
| alternate_spellings =
| synonym1 =
| synonym1_coined =
| synonym2 =
| synonym2_coined =
| synonym3 =
| synonym3_coined =
| nicknames =
| former_names =
| proposed_names =
| celestial_body = earth
| usage = Global (ICS)
| timescales_used = ICS Time Scale
| formerly_used_by =
| not_used_by =
| chrono_unit = Age
| strat_unit = stage
| proposed_by = Dumont
| type_section =
| timespan_formality = Formal
| lower_boundary_def = Strong negative anomaly in δ13C values at the PETM{{cite journal|last1=Aubry|first1=Marie-Pierre |last2=Ouda |first2=Khaled |last3=Dupuis |first3=Christian |author4=William A. Berggren |author5=John A. Van Couvering |author6=Working Group on the Paleocene/Eocene Boundary |title=The Global Standard Stratotype-section and Point (GSSP) for the base of the Eocene Series in the Dababiya section (Egypt)|journal=Episodes|year=2007|volume=30|issue=4|pages=271–286|url=http://www.stratigraphy.org/GSSP/file11.pdf|doi=10.18814/epiiugs/2007/v30i4/003 |doi-access=free}}
| lower_gssp_location = Dababiya section, Luxor, Egypt
| lower_gssp_coords = {{Coord|25.5000|N|32.5311|E|display=inline}}
| lower_gssp_accept_date = 2003
| upper_boundary_def = FAD of the calcareous nannofossil Blackites inflatus
| upper_gssp_location = Gorrondatxe section, Western Pyrenees, Basque Country, Spain
| upper_gssp_coords = {{Coord|43.3796|N|3.0143|W|display=inline}}
| o2 =
| co2 =
| temp =
| sea_level =
}}
In the geologic timescale the Ypresian is the oldest age or lowest stratigraphic stage of the Eocene. It spans the time between {{ma|Ypresian|and}} {{Ma|Lutetian|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 (Early Eocene).
Events
{{See also|Cambay Shale Formation|pCO2|l2=p{{chem2|CO2}}|δ18O|l3={{delta|18|O}}}}
The Ypresian Age begins during the throes of the Paleocene–Eocene Thermal Maximum (PETM). The Fur Formation in Denmark, 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.{{cite journal |last1=Greenwood |first1=D.R. |last2=Archibald |first2=S.B. |last3=Mathewes |first3=R.W |last4=Moss |first4=P.T. |year=2005 |title=Fossil biotas from the Okanagan Highlands, southern British Columbia and northeastern Washington State: climates and ecosystems across an Eocene landscape |journal=Canadian Journal of Earth Sciences |volume=42 |issue=2 |pages=167–185|bibcode=2005CaJES..42..167G |doi=10.1139/e04-100}}{{cite journal |last1=Archibald |first1=S. |last2=Greenwood |first2=D. |last3=Smith |first3=R. |last4=Mathewes |first4=R. |last5=Basinger |first5=J. |year=2011 |title=Great Canadian Lagerstätten 1. Early Eocene Lagerstätten of the Okanagan Highlands (British Columbia and Washington State) |journal=Geoscience Canada |volume=38 |issue=4 |pages=155–164}}{{cite journal |last1=Lowe |first1=A. J. |last2=Greenwood |first2=D. R. |last3=West |first3=C. K. |last4=Galloway |first4=J. M. |last5=Sudermann |first5=M. |last6=Reichgelt |first6=T. |year=2018 |title=Plant community ecology and climate on an upland volcanic landscape during the Early Eocene Climatic Optimum: McAbee Fossil Beds, British Columbia, Canada |journal=Palaeogeography, Palaeoclimatology, Palaeoecology |volume=511 |pages=433–448|doi=10.1016/j.palaeo.2018.09.010 |bibcode=2018PPP...511..433L |s2cid=134962126 }}
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,{{Cite journal |last1=Bijl |first1=Peter K. |last2=Schouten |first2=Stefan |last3=Sluijs |first3=Appy |last4=Reichart |first4=Gert-Jan |last5=Zachos |first5=James C. |last6=Brinkhuis |first6=Henk |date=October 2009 |title=Early Palaeogene temperature evolution of the southwest Pacific Ocean |url=https://www.nature.com/articles/nature08399 |journal=Nature |language=en |volume=461 |issue=7265 |pages=776–779 |doi=10.1038/nature08399 |pmid=19812670 |bibcode=2009Natur.461..776B |hdl=1874/385779 |s2cid=4358350 |issn=1476-4687|hdl-access=free }}{{Cite journal |last1=Hollis |first1=Christopher J. |last2=Handley |first2=Luke |last3=Crouch |first3=Erica M. |last4=Morgans |first4=Hugh E.G. |last5=Baker |first5=Joel A. |last6=Creech |first6=John |last7=Collins |first7=Katie S. |last8=Gibbs |first8=Samantha J. |last9=Huber |first9=Matthew |last10=Schouten |first10=Stefan |last11=Zachos |first11=James C. |last12=Pancost |first12=Richard D. |date=2009-02-01 |title=Tropical sea temperatures in the high-latitude South Pacific during the Eocene |url=https://doi.org/10.1130/G25200A.1 |journal=Geology |volume=37 |issue=2 |pages=99–102 |doi=10.1130/g25200a.1 |bibcode=2009Geo....37...99H |issn=1943-2682}}{{Cite journal |last1=Zachos |first1=James |last2=Pagani |first2=Mark |last3=Sloan |first3=Lisa |last4=Thomas |first4=Ellen |last5=Billups |first5=Katharina |date=2001-04-27 |title=Trends, Rhythms, and Aberrations in Global Climate 65 Ma to Present |url=https://www.science.org/doi/10.1126/science.1059412 |journal=Science |language=en |volume=292 |issue=5517 |pages=686–693 |doi=10.1126/science.1059412 |pmid=11326091 |bibcode=2001Sci...292..686Z |issn=0036-8075}} high levels of atmospheric pCO2,{{Cite journal |last1=Beerling |first1=David J. |last2=Royer |first2=Dana L. |date=July 2011 |title=Convergent Cenozoic CO2 history |url=https://www.nature.com/articles/ngeo1186 |journal=Nature Geoscience |language=en |volume=4 |issue=7 |pages=418–420 |doi=10.1038/ngeo1186 |bibcode=2011NatGe...4..418B |issn=1752-0908}}{{Cite journal |last1=Zachos |first1=James C. |last2=Dickens |first2=Gerald R. |last3=Zeebe |first3=Richard E. |date=January 2008 |title=An early Cenozoic perspective on greenhouse warming and carbon-cycle dynamics |journal=Nature |language=en |volume=451 |issue=7176 |pages=279–283 |doi=10.1038/nature06588 |pmid=18202643 |bibcode=2008Natur.451..279Z |s2cid=4360841 |issn=1476-4687|doi-access=free }} and low meridional thermal gradients.{{Cite journal |last1=Cramwinckel |first1=Margot J. |last2=Huber |first2=Matthew |last3=Kocken |first3=Ilja J. |last4=Agnini |first4=Claudia |last5=Bijl |first5=Peter K. |last6=Bohaty |first6=Steven M. |last7=Frieling |first7=Joost |last8=Goldner |first8=Aaron |last9=Hilgen |first9=Frederik J. |last10=Kip |first10=Elizabeth L. |last11=Peterse |first11=Francien |last12=van der Ploeg |first12=Robin |last13=Röhl |first13=Ursula |last14=Schouten |first14=Stefan |last15=Sluijs |first15=Appy |date=July 2018 |title=Synchronous tropical and polar temperature evolution in the Eocene |url=https://www.nature.com/articles/s41586-018-0272-2 |journal=Nature |language=en |volume=559 |issue=7714 |pages=382–386 |doi=10.1038/s41586-018-0272-2 |pmid=29967546 |bibcode=2018Natur.559..382C |hdl=1874/366626 |s2cid=256767465 |issn=1476-4687|hdl-access=free }} 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 calcareous nannofossils among others etc.{{Cite journal |last1=Cappelli |first1=C. |last2=Bown |first2=P. R. |last3=Westerhold |first3=T. |last4=Bohaty |first4=S. M. |last5=Riu |first5=M. |last6=Lobba |first6=V. |last7=Yamamoto |first7=Y. |last8=Agnini |first8=C. |date=December 2019 |title=The Early to Middle Eocene Transition: An Integrated Calcareous Nannofossil and Stable Isotope Record From the Northwest Atlantic Ocean (Integrated Ocean Drilling Program Site U1410) |journal=Paleoceanography and Paleoclimatology |language=en |volume=34 |issue=12 |pages=1913–1930 |doi=10.1029/2019PA003686 |bibcode=2019PaPa...34.1913C |s2cid=210245165 |issn=2572-4517|doi-access=free |hdl=11577/3322441 |hdl-access=free }}{{Cite journal |last1=Schneider |first1=Leah J. |last2=Bralower |first2=Timothy J. |last3=Kump |first3=Lee R. |date=October 2011 |title=Response of nannoplankton to early Eocene ocean destratification |url=https://linkinghub.elsevier.com/retrieve/pii/S0031018211003373 |journal=Palaeogeography, Palaeoclimatology, Palaeoecology |language=en |volume=310 |issue=3–4 |pages=152–162 |doi=10.1016/j.palaeo.2011.06.018|bibcode=2011PPP...310..152S }}
Stratigraphic definition
{{See also|List of geochronologic names}}
The Ypresian Stage was introduced in scientific literature by Belgian geologist 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.Steurbaut (2006) 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 δ13C values at the PETM. The official reference profile (GSSP) for the base of the Ypresian is the Dababiya profile near the Egyptian city of Luxor.The GSSP was established by Dupuis et al. (2003) Its original 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 European Land Mammal Mega Zones (it spans the Mammal Paleogene zones 7 through 10.{{cite web |last = Alroy |first = John | page = The Paleobiology Database | title = Mammal Paleogene zones |url = https://paleodb.org/cgi-bin/bridge.pl?action=processViewScale&scale_no=125 | access-date = 15 July 2009}}), the Wasatchian and lower and middle Bridgerian North American Land Mammal Ages, the Casamayoran South American Land Mammal Age and the Bumbanian and most of the Arshantan 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
{{Reflist}}
=Literature=
{{Wikisource portal|Cenozoic#Paleogene}}
- Dumont, A. H.; 1850: Rapport sur la carte géologique du Royaume, Bulletins de l’Académie Royale des Sciences, des Lettres et des Beaux-Arts de Belgique 16 (2), pp. 351–373. {{in lang|fr}}
- Dupuis, C.; Aubry, M.; Steurbaut, É; Berggren, W. A.; Ouda, K.; Magioncalda, R.; Cramer, B. S.; Kent, D. V.; Speijer, R. P. & Heilmann-Clausen, C.; 2003: The Dababiya Quarry Section: Lithostratigraphy, clay mineralogy, geochemistry and paleontology, Micropaleontology 49 (1), pp. 41–59, {{ISSN|0026-2803}}.
- Gradstein, F. M.; Ogg, J. G. & Smith, A. G.; 2004: A Geologic Time Scale 2004, Cambridge University Press.
- Steurbaut, É.; 2006: [http://popups.ulg.ac.be/Geol/docannexe.php?id=1107 Ypresian] {{Webarchive|url=https://web.archive.org/web/20120218045549/http://popups.ulg.ac.be/Geol/docannexe.php?id=1107 |date=2012-02-18 }}, Geologica Belgica 9 (1–2), pp. 73–93.
External links
- [https://web.archive.org/web/20100822030507/http://www.stratigraphy.org/bak/geowhen/stages/Ypresian.html GeoWhen Database – Ypresian]
- [http://stratigraphy.science.purdue.edu/charts/Timeslices/2_Paleogene.pdf Paleogene timescale], at the website of the subcommission for stratigraphic information of the ICS
- [https://web.archive.org/web/20060518101848/http://norges.uio.no/timescale/Fig19.1_Pal_bio_colB.pdf Stratigraphic chart of the Paleogene], at the website of Norges Network of offshore records of geology and stratigraphy
{{Paleogene Footer}}
{{Geological history|p|c}}