In the geologic timescale the Ypresian is the oldest age or lowest stratigraphic stage of the Eocene. It spans the time between , 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). The beginning of the age is defined by a strong negative anomaly in δ13C values at the PETM.
Palaeoclimatology
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.
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, high levels of atmospheric p, and low meridional thermal gradients. 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.
Southern China was incredibly arid during the Ypresian, owing to a strong subtropical anticyclone engendered by extremely warm temperatures and a rain–shadow effect resulting from coastal mountains.
Stratigraphic definition
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 are 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.), 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.
Notable geological formations Being a period of high sea levels, numerous geological formations worldwide were deposited during the Ypresian stage in both inland and marine habitats. The following fossiliferous geological formations are among those known from this time:Fossilworks .org
North America
Manasquan Formation, New Jersey Nanjemoy Formation, Virginia and Maryland Bashi Formation, Alabama Hatchetigbee Bluff and Sabinetown Bluff Formations, Southeastern United States Klondike Mountain Formation, Republic & Curlew Basin, Washington State Crescent Formation, Washington Allenby and Coldwater Beds Formations and Ootsa Lake and Kamloops Group, British Columbia Lookingglass and Umpqua Formations, Oregon Wasatch Formation, and Tatman, Willwood, Wind River, Pass Peak and Indian Meadows Formations, Wyoming Challis Volcanics Formation, Idaho Golden Valley Formation, North Dakota Claron Formation, Utah Green River Formation, western United States Coalmont, Cuchara and DeBeque Formations, Colorado Sheep Pass Formation, Nevada San Jose and Galisteo Formations, New Mexico Capay, Juncal, Llajas, Maniobra, Matilija, Meganos & Santa Susana Formations, California Margaret Formation, Northwest Territories and Nunavut, Canada Mokka Fiord Formation, Remus Basin, Northern Territories Bateque and Las Tetas de Cabra Formations, Baja California Hannold Hill and Pendleton Ferry Formations, Gulf of Mexico Adjuntas and Indio Formations and Lechería Limestone, Mexico Descartes Formation, Costa Rica Stettin Formation, Jamaica Scotland Formation, Barbados Lizard Springs Formation, Trinidad and Tobago
South America
Bogotá Formation, Altiplano Cundiboyacense, Colombia Cerrejón Formation, Cesar-Ranchería Basin, Colombia Los Cuervos Formation, Catatumbo, Cesar-Ranchería and Llanos Basins, Colombia Caballas Formation, Pisco Basin, Peru Chacras and Negritos Formations, Peru Fonseca Formation, Brazil Itaboraí Formation, Itaboraí Basin, Brazil Lumbrera Formation, Salta Basin, Argentina Laguna del Hunco Formation, Cañadón Asfalto Basin, Argentina Huitrera Formation, Neuquén Basin, Argentina Sarmiento and Ventana Formations, Golfo San Jorge Basin, Argentina Las Flores Formation, Austral Basin, Argentina
Antarctica
lower La Meseta Formation
Europe
Kortrijk Clay, Bruxellian Formation and Dormaal Member of Tienen Formation, Belgium Sables de Pierrefonds, Calcares marins à alvéolines, Lignites de Soissonais, Marnes de Foncouverte, Argiles d'lignite du Soissonnais, Marnes de Gan and Carcassonne Group, France Fur Formation, Ølst Formation and southeastern North Sea Graben, Denmark Balder Formation, Faroe-Shetland Basin, North Sea London Clay, Bagshot Formation, London Basin, England Oldhaven Formation, England Roterzschicht Formation, Austria Lefkara Formation, Cyprus Silveirinha Formation, Portugal Armàncies, Corca and Roda Formations, Spain Pesciara Formation, Italy , Monte Bolca, Italy
Asia
Çeltek, Kirkkavak and Yoncali Formations, Turkey Umm al-Rua'us Formation, Saudi Arabia Alai Beds, Kyrgyzstan Ghazij, Mami Khel, Shekhan Formation and Kuldana Formations, Pakistan Cambay Shale, Naredi and Subathu Formations, Sylhet Limestone and Upper Ranikot Group, India Dabu, Qimugen Formation and Ulunguhe Formations, Xinjiang, China Arshanto Formation, Inner Mongolia, China Yangxi Formation, Hubei, China Lingcha Formation, Hunan, China Wutu Formation, Shandong, China Tadushi Formation, Primorsky Krai, Russia Takaradayskaya Formation, Sakhalin, Russia Ommai Formation, Kamchatka, Russia Akasaki Formation, Japan
Africa
Esna, El Rufuf Formation and Thebes Formations, Egypt Al Jir and Jdeir Formations, Libya Gafsa Phosphates Formation, Tunisia Ait Ouarhitane Formation, Morocco Tamaguélelt Formation, Mali Thies Formation, Senegal Auradu Formation, Somalia Landana Formation, Cabinda, Angola
Oceania
Red Bluff Tuff Formation, Tutuiri Greensand and Tumaio and Te Whanga Limestones, New Zealand Macquarie Harbor Formation, Tasmania, Australia Dilwyn Formation, Victoria Redbank Plains Formation, Queensland Jubilee Member of Cardabia Formation, Western Australia
References
Literature
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. 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, . Gradstein, F. M.; Ogg, J. G. & Smith, A. G.; 2004: A Geologic Time Scale 2004, Cambridge University Press. Steurbaut, É.; 2006: Ypresian , Geologica Belgica 9 (1–2), pp. 73–93.
External links GeoWhen Database – Ypresian Paleogene timescale, at the website of the subcommission for stratigraphic information of the ICS Stratigraphic chart of the Paleogene, at the website of Norges Network of offshore records of geology and stratigraphy