Chattian

The Chattian is, in the geologic timescale, the youngest of two ages or upper of two stages of the Oligocene epoch/series. It spans the time between 28.1 and 23.03 Ma. The Chattian is preceded by the Rupelian and is followed by the Aquitanian (the lowest stage of the Miocene).^[1]

Stratigraphic definition

The Chattian was introduced by Austrian palaeontologist Theodor Fuchs in 1894. Fuchs named the stage after the Chatti, a Germanic tribe.^{[<span title="on pattern of Ypresian and the general habits of geologers, it is more likely that it refers to "Chattia", the land of the Chatti, which is today named Hesse or Hessia (November 2012)">citation needed]} The original type locality was near the German city of Kassel.

The base of the Chattian is at the extinction of the foram genus Chiloguembelina (which is also the base of foram biozone P21b). An official GSSP for the Chattian stage had not been established yet in 2009.

The top of the Chattian stage (which is the base of the Aquitanian stage, Miocene series and Neogene system) is at the first appearance of foram species Paragloborotalia kugleri, the extinction of calcareous nannoplankton species Reticulofenestra bisecta (which forms the base of nannoplankton biozone NN1), and the base of magnetic chronozone C6Cn.2n.

The Chattian is coeval with regionally used stages or zones like the upper Avernian European mammal zone (it spans the Mammal Paleogene zones 30 through 26 and part of 25.^[2]), the upper Geringian and lower Arikareean mammal zones of North America, most of the Deseadan mammal zone of South America, the upper Hsandgolian and whole Tabenbulakian mammal zone of Asia, the upper Kiscellian and lower Egerian Paratethys stages of Central and eastern Europe, the upper Janjukian and lower Longfordian Australian regional stages, part of the Zemorrian Californian stage and Chickasawhayan regional stage of the eastern US.

Volcanic event

During the Chattian the largest known single-event volcanic eruption occurred: the Fish Canyon eruption of La Garita with a magnitude of 9.2.^[3] It has been dated to 27.51 Ma ago.^[4]

References

Footnotes

Literature

• Fuchs, T.; 1894: Tertiaerfossilien aus den kohlenführenden Miocaenablagerungen der Umgebung von Krapina und Radaboj und über die Stellung der sogenannten "Aquitanischen Stufe", Königlich- Ungarische Geologische Anstalt, Mittheilungen und Jahrbuch 10, p. 163-175. (German)
• Gradstein, F.M.; Ogg, J.G. & Smith, A.G.; 2004: A Geologic Time Scale 2004, Cambridge University Press.
• Lanphere, M.A. & Baadsgaard, H.; 2001: Precise K–Ar, ⁴⁰Ar/³⁹Ar, Rb–Sr and U/Pb mineral ages from the 27.5 Ma Fish Canyon Tuff reference standard, Chemical Geology 175(3–4), pp 653–671.
• Mason, B.G.; Pyle, D.M. & Oppenheimer, C.; 2004: The size and frequency of the largest explosive eruptions on Earth, Bulletin of Volcanology 66(8), pp 735–748.

External links

• GeoWhen Database - Chattian
• Neogene timescale (including the upper Paleogene), 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]