System | Series | Stage | Age (Ma) | |
---|---|---|---|---|
Neogene | Miocene | Aquitanian | younger | |
Paleogene | Oligocene | Chattian | 23.03–28.4 | |
Rupelian | 28.4–33.9 | |||
Eocene | Priabonian | 33.9–37.2 | ||
Bartonian | 37.2–40.4 | |||
Lutetian | 40.4–48.6 | |||
Ypresian | 48.6–55.8 | |||
Paleocene | Thanetian | 55.8–58.7 | ||
Selandian | 58.7–61.7 | |||
Danian | 61.7–65.5 | |||
Cretaceous | Upper | Maastrichtian | older | |
Subdivision of the Paleogene Period according to the IUGS, as of July 2009. |
The Danian is the oldest age or lowermost stage of the Paleocene epoch or series, the Paleogene period or system and the Cenozoic era or erathem. The beginning of the Danian age (and the end of the precessing Maastrichtian age) is at the Cretaceous-Tertiary extinction event 65.5 ± 0.3 Ma (million years ago). The age ended 61.7 ± 0.2 Ma, being followed by the Selandian age.[1]
Contents |
Stratigraphic definitions
The Danian was introduced in scientific literature by German-Swiss geologist Pierre Jean Édouard Desor in 1847. It is named after the Latin name for Denmark. The Montian stage from Belgian stratigraphy (named after the city of Mons) is now considered a junior synonym and is no longer in use.
The base of the Danian is defined at the iridium anomaly which characterized the Cretaceous-Paleogene boundary in stratigraphic sections worldwide. A section in El Kef, Tunisia was appointed as a reference profile (GSSP) for this important boundary.[2]
The top of the Danian stage (the base of the Selandian) is close to the boundary between biozones NP4 and NP5 from marine biostratigraphy. It is slighltly after the first appearances of many new species of the calcareous nannoplankton genus Fasciculithus (F. ulii, F. billii, F. janii, F. involutus, F. tympaniformis and F. pileatus) and close to the first appearance of calcareous nannoplankton species Neochiastozygus perfectus.
The Danian stage overlaps the Puercan and Torrejonian North American Land Mammal Ages 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. [3]
Palaeontology
Though the dinosaurs were gone, the mammals, and other land animals remained small, none bigger than a large domestic cat. But most of the mammals' orders already had appeared. Numerous lineages of modern birds also survived, particularly in the area around Australia but also elsewhere, e.g. Scaniornis of the North Sea region. The oceans remained much the same as the Late Cretaceous seas, only that there was less life, no marine reptiles, and other lesser known animals.
References
Notes
- ^ See Gradstein et al. (2004) for the official geologic timescale
- ^ The GSSP for the Danian stage was established by Molina et al. (2006)
- ^ Alroy, John. "Mammal Paleogene zones". p. The Paleobiology Database. http://paleodb.org/cgi-bin/bridge.pl?action=processViewScale&scale_no=125. Retrieved 15 July 2009.
Literature
- Desor, P.J.É.; 1847: Sur le terrain Danien, nouvel étage de la craie, Bulletin de la Societé Géologique de France, série 2, 3, p. 179-181, ISSN 0037-9409.(French)
- Gradstein, F.M.; Ogg, J.G. & Smith, A.G.; 2004: A Geologic Time Scale 2004, Cambridge University Press.
- Molina, E.; Alegret, L.; Arenillas, I.; Arz, J.A.; Gallala, N.; Hardenbol, J.; Salis, K. von; Steurbaut, E.; Vandenberghe, N. & Zaghbib-Turki, D.; 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), p. 263-273, ISSN 0705-3797.
External links
- GeoWhen Database - Danian
- 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
Paleogene Period | ||
---|---|---|
Paleocene Epoch | Eocene Epoch | Oligocene Epoch |
Danian | Selandian Thanetian |
Ypresian | Lutetian Bartonian | Priabonian |
Rupelian | Chattian |