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Wikipedia / Ypresian

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).

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 pCO2, 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. 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. 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:

  1. North America

  2. Manasquan Formation, New Jersey

  3. Nanjemoy Formation, Virginia and Maryland

  4. Bashi Formation, Alabama

  5. Hatchetigbee Bluff and Sabinetown Bluff Formations, Southeastern United States

  6. Klondike Mountain Formation, Republic & Curlew Basin, Washington State

  7. Crescent Formation, Washington

  8. Allenby and Coldwater Beds Formations and Ootsa Lake and Kamloops Group, British Columbia

  9. Lookingglass and Umpqua Formations, Oregon

  10. Wasatch Formation, and Tatman, Willwood, Wind River, Pass Peak and Indian Meadows Formations, Wyoming

  11. Challis Volcanics Formation, Idaho

  12. Golden Valley Formation, North Dakota

  13. Claron Formation, Utah

  14. Green River Formation, western United States

  15. Coalmont, Cuchara and DeBeque Formations, Colorado

  16. Sheep Pass Formation, Nevada

  17. San Jose and Galisteo Formations, New Mexico

  18. Capay, Juncal, Llajas, Maniobra, Matilija, Meganos & Santa Susana Formations, California

  19. Margaret Formation, Northwest Territories and Nunavut, Canada

  20. Mokka Fiord Formation, Remus Basin, Northern Territories

  21. Bateque and Las Tetas de Cabra Formations, Baja California

  22. Hannold Hill and Pendleton Ferry Formations, Gulf of Mexico

  23. Adjuntas and Indio Formations and Lechería Limestone, Mexico

  24. Descartes Formation, Costa Rica

  25. Stettin Formation, Jamaica

  26. Scotland Formation, Barbados

  27. Lizard Springs Formation, Trinidad and Tobago

  28. South America

  29. Bogotá Formation, Altiplano Cundiboyacense, Colombia

  30. Cerrejón Formation, Cesar-Ranchería Basin, Colombia

  31. Los Cuervos Formation, Catatumbo, Cesar-Ranchería and Llanos Basins, Colombia

  32. Caballas Formation, Pisco Basin, Peru

  33. Chacras and Negritos Formations, Peru

  34. Fonseca Formation, Brazil

  35. Itaboraí Formation, Itaboraí Basin, Brazil

  36. Lumbrera Formation, Salta Basin, Argentina

  37. Laguna del Hunco Formation, Cañadón Asfalto Basin, Argentina

  38. Huitrera Formation, Neuquén Basin, Argentina

  39. Sarmiento and Ventana Formations, Golfo San Jorge Basin, Argentina

  40. Las Flores Formation, Austral Basin, Argentina

  41. Antarctica

  42. lower La Meseta Formation

  43. Europe

  44. Kortrijk Clay, Bruxellian Formation and Dormaal Member of Tienen Formation, Belgium

  45. 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

  46. Fur Formation, Ølst Formation and southeastern North Sea Graben, Denmark

  47. Balder Formation, Faroe-Shetland Basin, North Sea

  48. London Clay, Bagshot Formation, London Basin, England

  49. Oldhaven Formation, England

  50. Roterzschicht Formation, Austria

  51. Lefkara Formation, Cyprus

  52. Silveirinha Formation, Portugal

  53. Armàncies, Corca and Roda Formations, Spain

  54. Pesciara Formation, Italy

  55. , Monte Bolca, Italy

  56. Asia

  57. Çeltek, Kirkkavak and Yoncali Formations, Turkey

  58. Umm al-Rua'us Formation, Saudi Arabia

  59. Alai Beds, Kyrgyzstan

  60. Ghazij, Mami Khel, Shekhan Formation and Kuldana Formations, Pakistan

  61. Cambay Shale, Naredi and Subathu Formations, Sylhet Limestone and Upper Ranikot Group, India

  62. Dabu, Qimugen Formation and Ulunguhe Formations, Xinjiang, China

  63. Arshanto Formation, Inner Mongolia, China

  64. Yangxi Formation, Hubei, China

  65. Lingcha Formation, Hunan, China

  66. Wutu Formation, Shandong, China

  67. Tadushi Formation, Primorsky Krai, Russia

  68. Takaradayskaya Formation, Sakhalin, Russia

  69. Ommai Formation, Kamchatka, Russia

  70. Akasaki Formation, Japan

  71. Africa

  72. Esna, El Rufuf Formation and Thebes Formations, Egypt

  73. Al Jir and Jdeir Formations, Libya

  74. Gafsa Phosphates Formation, Tunisia

  75. Ait Ouarhitane Formation, Morocco

  76. Tamaguélelt Formation, Mali

  77. Thies Formation, Senegal

  78. Auradu Formation, Somalia

  79. Landana Formation, Cabinda, Angola

  80. Oceania

  81. Red Bluff Tuff Formation, Tutuiri Greensand and Tumaio and Te Whanga Limestones, New Zealand

  82. Macquarie Harbor Formation, Tasmania, Australia

  83. Dilwyn Formation, Victoria

  84. Redbank Plains Formation, Queensland

  85. 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: , Geologica Belgica 9 (1–2), pp.73–93.