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The Danian is the oldest age or lowest stage of the
The Danian was introduced in scientific literature by
GeoWhen Database – Danian
Paleogene timescale (2008)
at the website of the subcommission for stratigraphic information of the ICS
Stratigraphic chart of the Paleogene (2006)
at the website of Norges Network of offshore records of geology and stratigraphy {{Authority control Paleocene geochronology Geological ages
Paleocene
The Paleocene, ( ) or Palaeocene, is a geological epoch that lasted from about 66 to 56 million years ago (mya). It is the first epoch of the Paleogene Period in the modern Cenozoic Era. The name is a combination of the Ancient Greek ''pal ...
Epoch
In chronology and periodization, an epoch or reference epoch is an instant in time chosen as the origin of a particular calendar era. The "epoch" serves as a reference point from which time is measured.
The moment of epoch is usually decided by ...
or Series, of the Paleogene
The Paleogene ( ; also spelled Palaeogene or Palæogene; informally Lower Tertiary or Early Tertiary) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period million years ago (Mya) to the beginning of ...
Period or System, and of the Cenozoic
The Cenozoic ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterised by the dominance of mammals, birds and flowering plants, a cooling and drying climate, and the current configu ...
Era or Erathem. The beginning of the Danian (and the end of the preceding Maastrichtian
The Maastrichtian () is, in the ICS geologic timescale, the latest age (uppermost stage) of the Late Cretaceous Epoch or Upper Cretaceous Series, the Cretaceous Period or System, and of the Mesozoic Era or Erathem. It spanned the interv ...
) is at the Cretaceous–Paleogene extinction event
The Cretaceous–Paleogene (K–Pg) extinction event (also known as the Cretaceous–Tertiary extinction) was a sudden extinction event, mass extinction of three-quarters of the plant and animal species on Earth, approximately 66 million y ...
. The age ended , being followed by the Selandian.
Stratigraphic definitions
The Danian was introduced in scientific literature by German
German(s) may refer to:
* Germany (of or related to)
**Germania (historical use)
* Germans, citizens of Germany, people of German ancestry, or native speakers of the German language
** For citizens of Germany, see also German nationality law
**Ger ...
-Swiss
Swiss may refer to:
* the adjectival form of Switzerland
* Swiss people
Places
* Swiss, Missouri
*Swiss, North Carolina
* Swiss, West Virginia
* Swiss, Wisconsin
Other uses
* Swiss-system tournament, in various games and sports
*Swiss Internati ...
geologist Pierre Jean Édouard Desor in 1847 following a study of fossils found in France and Denmark.DanienDen Store Danske Encyklopædi
''Den Store Danske Encyklopædi'' (''The Great Danish Encyclopedia'') is the most comprehensive contemporary Danish language encyclopedia. The 20 volumes of the encyclopedia were published successively between 1994 and 2001; a one-volume suppleme ...
He identified this stage in deposits from Faxe
Faxe or Fakse is a town on the island of Zealand in eastern Denmark. It is located in Faxe Municipality in Region Zealand. The town is most known for the Faxe Brewery, Royal Unibrew, a relatively large brewery producing a range of beer and soft ...
and Møns Klint
Møns Klint is a 6 km stretch of limestone and chalk cliffs along the eastern coast of the Danish island of Møn in the Baltic Sea. Some of the cliffs fall a sheer 120 m to the sea below. The highest cliff is , which is 128 m above sea lev ...
and named it after the Latin
Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power ...
name for Denmark
)
, song = ( en, "King Christian stood by the lofty mast")
, song_type = National and royal anthem
, image_map = EU-Denmark.svg
, map_caption =
, subdivision_type = Sovereign state
, subdivision_name = Kingdom of Denmark
, establishe ...
. The Montian Stage from Belgian stratigraphy (named after the city of Mons
Mons (; German and nl, Bergen, ; Walloon and pcd, Mont) is a city and municipality of Wallonia, and the capital of the province of Hainaut, Belgium.
Mons was made into a fortified city by Count Baldwin IV of Hainaut in the 12th century. ...
) is now known to be roughly equivalent to the Upper Danian and is considered a junior synonym and is no longer in use.
The base of the Danian is defined at the iridium anomaly
The term iridium anomaly commonly refers to an unusual abundance of the chemical element iridium in a layer of rock strata at the Cretaceous–Paleogene (K–Pg) boundary. The unusually high concentration of a rare metal like iridium is often take ...
which characterized the Cretaceous–Paleogene boundary
The Cretaceous–Paleogene (K–Pg) boundary, formerly known as the Cretaceous–Tertiary (K–T) boundary, is a geological signature, usually a thin band of rock containing much more iridium than other bands. The K–Pg boundary marks the end ...
(K–T boundary) in stratigraphic sections worldwide. A section in El Kef
El Kef ( ar, الكاف '), also known as ''Le Kef'', is a city in northwestern Tunisia. It serves as the capital of the Kef Governorate.
El Kef is situated to the west of Tunis and some east of the border between Algeria and Tunisia. It has ...
, Tunisia
)
, image_map = Tunisia location (orthographic projection).svg
, map_caption = Location of Tunisia in northern Africa
, image_map2 =
, capital = Tunis
, largest_city = capital
, ...
was appointed as a reference profile (GSSP
A Global Boundary Stratotype Section and Point (GSSP) is an internationally agreed upon reference point on a stratigraphic section which defines the lower boundary of a stage on the geologic time scale. The effort to define GSSPs is conducted ...
) for this important boundary. The Danian is the oldest age of the Paleocene, defined at its base by the K-Pg boundary. It is very important because the readily recognized iridium anomaly and primitive Danian planktonic foraminifers define the base of the Danian. Danian foraminiferans repopulated the Paleocene seas after the Cretaceous mass extinction (Olsson et al., 1996). The first replacement foraminiferan of the Paleogene is the ''Globigerina eugubina,'' which is used to define the base of the Danian Age (Stainforth et al., 1975). This foraminiferan replaced the Cretaceous genus ''Globotruncana''.
The top of the Danian Stage (the base of the Selandian) is close to the boundary between biozone
In biostratigraphy, biostratigraphic units or biozones are intervals of geological strata that are defined on the basis of their characteristic fossil taxa, as opposed to a lithostratigraphic unit which is defined by the lithological properties ...
s NP4 and NP5 from marine biostratigraphy
Biostratigraphy is the branch of stratigraphy which focuses on correlating and assigning relative ages of rock strata by using the fossil assemblages contained within them.Hine, Robert. “Biostratigraphy.” ''Oxford Reference: Dictionary of Bio ...
. It is slightly after the first appearances of many new species of the calcareous nanoplankton genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...
''Fasciculithus'' (''F. ulii'', ''F. billii'', ''F. janii'', ''F. involutus'', ''F. tympaniformis'' and ''F. pileatus'') and close to the first appearance of calcareous nanoplankton species ''Neochiastozygus perfectus''.
The Danian Stage overlaps the Puercan and Torrejonian
The Torrejonian North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages
The North American land mammal ages (NALMA) establishes a geologic timescale for North American fa ...
North American land mammal ages
The North American land mammal ages (NALMA) establishes a geologic timescale for North American fauna beginning during the Late Cretaceous and continuing through to the present. These periods are referred to as ages or intervals (or stages when re ...
and the Shanghuan and lowest part of the Nongshanian Asian land mammal ages. It includes the oldest Mammal Paleogene zones, all included in the 1 - 5 group.
Paleontology
Though the non-aviandinosaur
Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...
s were gone, the mammals and other land animals remained small, most not even bigger than a sheep; however; a few (like ''Ankalagon saurognathus
''Ankalagon saurognathus'' is an extinct carnivorous mammal of the family Mesonychidae, endemic to North America during the Paleocene epoch (63.3—60.2 mya), existing for approximately .
Known from the Paleocene Nacimiento Formation of New Mex ...
)'' reached the size of a medium-sized bear. Numerous lineages of modern birds also survived, particularly in the area around Australia but also elsewhere, e.g. '' Scaniornis'' of the North Sea
The North Sea lies between Great Britain, Norway, Denmark, Germany, the Netherlands and Belgium. An epeiric sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian S ...
region. The oceans remained much the same as the Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', ...
seas, only that there was less life, few remaining marine reptiles (mostly turtle
Turtles are an order of reptiles known as Testudines, characterized by a special shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Cryptodira (hidden necked ...
s, choristodera
Choristodera (from the Greek χωριστός ''chōristos'' + δέρη ''dérē'', 'separated neck') is an extinct order of semiaquatic diapsid reptiles that ranged from the Middle Jurassic, or possibly Triassic, to the late Miocene (168 to 1 ...
and crocodile
Crocodiles (family Crocodylidae) or true crocodiles are large semiaquatic reptiles that live throughout the tropics in Africa, Asia, the Americas and Australia. The term crocodile is sometimes used even more loosely to include all extant ...
s), and other lesser-known animals.
There are controversial reports of ammonites
Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttle ...
(mainly of the Scaphitidae class in Turkmenistan
Turkmenistan ( or ; tk, Türkmenistan / Түркменистан, ) is a country located in Central Asia, bordered by Kazakhstan to the northwest, Uzbekistan to the north, east and northeast, Afghanistan to the southeast, Iran to the s ...
) still being around at this time, although they did not survive the Danian age.
Latest Danian Event
Close to the end of the Danian, around 62.2 Ma, occurred a hyperthermal, similar to but smaller in magnitude compared to the more famous Palaeocene-Eocene Thermal Maximum (PETM), known as the Latest Danian Event (LDE). The event, which took place over a 170-230 kyr time interval, is evidenced in the geologic record by two negative carbon isotope excursions and is believed to have led to a 2–3 °C warming of both deep and surface seawater. This hyperthermal also led to a shallowing of the oceanic lysocline, as evidenced by the significant decrease in calcium carbonate preservation.References
Literature
*; 1847: ''Sur le terrain Danien, nouvel étage de la craie'', Bulletin de la Société Géologique de France, série 2, 3, pp. 179–181, . *; 2004: ''A Geologic Time Scale 2004'',Cambridge University Press
Cambridge University Press is the university press of the University of Cambridge. Granted letters patent by Henry VIII of England, King Henry VIII in 1534, it is the oldest university press in the world. It is also the King's Printer.
Cambr ...
.
*; 2006: ''The Global Boundary Stratotype Section and Point for the base of the Danian Stage (Paleocene, Paleogene, "Tertiary", Cenozoic) at El Kef, Tunisia: original definition and revision'', Episodes 29(4), pp. 263–273, .
*; 1996:''The Cretaceous-Tertiary catastrophe event at Millers Ferry, Alabama'' in Ryder, G., Fastovsky, D., and Gartner, S., eds., The Cretaceous-Tertiary Event and other catastrophes in Earth history: Geological Society of America Special Paper 307, pp. 263–277.
*; 1975: ''Cenozoic planktonic foraminifera zonation and characteristics of index forms'': The University of Kansas Paleontological Institute, Article 62, 425 p.
External links
GeoWhen Database – Danian
Paleogene timescale (2008)
at the website of the subcommission for stratigraphic information of the ICS
Stratigraphic chart of the Paleogene (2006)
at the website of Norges Network of offshore records of geology and stratigraphy {{Authority control Paleocene geochronology Geological ages