Ypresian

Ypresian

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In the geologic timescale the Ypresian is the oldest age or lowest stratigraphic stage of the Eocene
Eocene
The Eocene Epoch, lasting from about 56 to 34 million years ago , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Palaeocene Epoch to the beginning of the Oligocene Epoch. The start of the...

. It spans the time between and , is preceded by the Thanetian
Thanetian
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 and . The Thanetian is preceded by the Selandian age and followed by the Ypresian age...

 age (part of the Paleocene
Paleocene
The Paleocene or Palaeocene, the "early recent", is a geologic epoch that lasted from about . It is the first epoch of the Palaeogene Period in the modern Cenozoic Era...

) and is followed by the Eocene Lutetian
Lutetian
The Lutetian is, in the geologic timescale, a stage or age in the Eocene. It spans the time between and . The Lutetian is preceded by the Ypresian and is followed by the Bartonian. Together with the Bartonian it is sometimes referred to as the Middle Eocene subepoch...

 age.

The Ypresian is sometimes included with the Lutetian
Lutetian
The Lutetian is, in the geologic timescale, a stage or age in the Eocene. It spans the time between and . The Lutetian is preceded by the Ypresian and is followed by the Bartonian. Together with the Bartonian it is sometimes referred to as the Middle Eocene subepoch...

 in an Early Eocene subepoch.

Events


The Ypresian age begins during the throes of the Paleocene-Eocene Thermal Maximum
Paleocene-Eocene Thermal Maximum
The most extreme change in Earth surface conditions during the Cenozoic Era began at the temporal boundary between the Paleocene and Eocene epochs . This event, the Paleocene–Eocene Thermal Maximum , was associated with rapid global...

 (PETM). The Messel shales in Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

 are from this age.

Stratigraphic definition


The Ypresian stage was introduced in scientific literature by Belgian
Belgium
Belgium , officially the Kingdom of Belgium, is a federal state in Western Europe. It is a founding member of the European Union and hosts the EU's headquarters, and those of several other major international organisations such as NATO.Belgium is also a member of, or affiliated to, many...

 geologist André Hubert Dumont in 1850. The Ypresian is named after Ypres, the French
French language
French is a Romance language spoken as a first language in France, the Romandy region in Switzerland, Wallonia and Brussels in Belgium, Monaco, the regions of Quebec and Acadia in Canada, and by various communities elsewhere. Second-language speakers of French are distributed throughout many parts...

 name of the Belgian (Flemish
Flanders
Flanders is the community of the Flemings but also one of the institutions in Belgium, and a geographical region located in parts of present-day Belgium, France and the Netherlands. "Flanders" can also refer to the northern part of Belgium that contains Brussels, Bruges, Ghent and Antwerp...

) city of Ieper. The definitions of the original stage were totally different from the modern ones. The Ypresian shares its name with the Belgian Ieper Group
Ieper Group
The Ieper Group is a group of rock strata in the subsurface of northwest Belgium. The group is subdivided into three marine formations, all formed during the Ypresian, a single age of the geologic timescale...

 (French: Group 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 Egypt
Egypt
Egypt , officially the Arab Republic of Egypt, Arabic: , is a country mainly in North Africa, with the Sinai Peninsula forming a land bridge in Southwest Asia. Egypt is thus a transcontinental country, and a major power in Africa, the Mediterranean Basin, the Middle East and the Muslim world...

ian city of Luxor
Luxor
Luxor is a city in Upper Egypt and the capital of Luxor Governorate. The population numbers 487,896 , with an area of approximately . As the site of the Ancient Egyptian city of Thebes, Luxor has frequently been characterized as the "world's greatest open air museum", as the ruins of the temple...

. 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 foram genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 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
Wasatchian
The Wasatchian North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology , typically set from 55,400,000 to 50,300,000 years BP lasting . It is usually considered to be within the Eocene, more specifically the...

 and lower and middle Bridgerian North American Land Mammal Ages
North American Land Mammal Ages
The North American Mammal Ages establishes a geologic timescale for prehistoric North American fauna beginning 66.5 Ma during the Paleocene and continuing through to the Late Pleistocene...

, the Casamajoran South American Land Mammal Age
South American Land Mammal Age
The South American Mammal Ages establish a geologic timescale for prehistoric South American fauna beginning 64.5 Ma during the Paleogene and continuing through to the Middle Pleistocene...

 and the Bumbanian
Bumbanian
The Bumbanian is an Asian Land Mammal Age , a large biozone which corresponds to ages between 55.8—46.8 Ma for finds of fossil mammals in Asia. This zone lies within the Ypresian stage of the Eocene series. It follows the Gashatan ALMA and precedes the Arshantan ALMA....

 and most of the Arshantan
Arshantan
The Arshantan age is a period of geologic time within the Early Eocene epoch of the Paleogene used more specifically with Asian Land Mammal Ages. It follows the Bumbanian age and precedes the Irdinmanhan age....

 Asian Land Mammal Ages
Asian land mammal ages
The Asian Land Mammal Ages establishes a geologic timescale for prehistoric Asian fauna beginning 58.7 Mya during the Paleogene and continuing through to the Middle Pleistocene...

. It is also coeval with the upper Wangerripian and lowest Johannian regional stages of Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

 and the Bulitian, Penutian and Ulatisian regional stages of California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

.

Literature

; 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), p. 351-373. ; 2003: The Dababiya Quarry Section: Lithostratigraphy, clay mineralogy, geochemistry and paleontology, Micropaleontology 49(1), p. 41-59, ISSN 0026-2803.; 2004: A Geologic Time Scale 2004, Cambridge University Press
Cambridge University Press
Cambridge University Press is the publishing business of the University of Cambridge. Granted letters patent by Henry VIII in 1534, it is the world's oldest publishing house, and the second largest university press in the world...

.; 2006: Ypresian, Geologica Belgica 9(1-2), p. 73-93.

External links