Danium

from Wikipedia, the free encyclopedia
system series step ≈ age ( mya )
higher higher higher younger
Paleogene Oligocene Chattium 23.03
⬍
28.1
Rupelium 28.1
⬍
33.9
Eocene Priobonium 33.9
⬍
38
Bartonium 38
⬍
41.3
lutetium 41.3
⬍
47.8
Ypresium 47.8
⬍
56
Paleocene Thanetium 56
⬍
59.2
Seelandium 59.2
⬍
61.6
Danium 61.6
⬍
66
deeper deeper deeper older

The Danium (also abbreviated Dan or rarely Danish level) is the lowest chronostratigraphic level of the Paleocene in the history of the earth and thus also the basal level of the Paleogene . It is also equated with the Lower Paleocene . Expressed in absolute numbers ( geochronologically ), the stage represents the period from about 66 million years to about 61.6 million years. Until a few years ago the Cretaceous / Paleogene boundary was given as 65 million years; this is obsolete according to the latest correlation between chronostratigraphy and geochronology. The Danium follows the Maastrichtium , the highest level of the Chalk , and is replaced by the Seelandium . The danium used to be counted as a chalk .

Naming and history

The Danium is named after the Latin name of Denmark . It was proposed by the Swiss geologist Pierre Jean Édouard Desor in 1847.

Definition and GSSP

The base of the Danium is very well defined with the Iridium anomaly of the Cretaceous-Tertiary boundary . The end of the stage has not yet been finally determined. The boundary of the Danium to the Seelandium lies within the very short magnetic polarity chronozone C27r. However, the reference profile (GSSP = Global Stratotype Section and Point) for the basis of the Danium was determined for the locality El Kef in Tunisia .

Chalk or tertiary

In the Dan, the deposition of chalk-like rocks continued in the Central and Western European Chalk Basin, so that lithologically there are hardly any differences to the deposits of the Maastrichtian. This was the reason for the initial assignment of the danium to the chalk. Clear differences in the species compositions and in particular the discovery of the Cretaceous-Tertiary border as a distinctive border horizon finally led to the regrouping as the oldest stage of the Tertiary (today Paleogene).

literature

  • Pierre Jean Édouard Desor: Sur le terrain Danien, nouvel étage de la craie . In: Bulletin de la Societé Géologique de France . Série 2, 3, 1847, ISSN  0037-9409 , pp. 179-181.
  • Felix M. Gradstein, Jim Ogg, Jim Smith, Alan Smith (Eds.): A Geologic timescale 2004 . 3rd edition. Cambridge University Press, Cambridge et al. 2004, ISBN 0-521-78673-8 .
  • Eustoquio Molina, Laia Alegret, Ignacio Arenillas, José A. Arz, Njoud Gallala, Jan Hardenbol, Katharina von Salis, Etienne Steurbaut, Noël Vandenberghe, Dalila Zaghbib-Turki: 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 . In: Episodes . 29, 4, 2006, ISSN  0705-3797 , pp. 263-273.
  • Hans Murawski, Wilhelm Meyer: Geological dictionary . 10th revised and expanded edition. Enke Verlag, Stuttgart 1998, ISBN 3-432-84100-0 ( Enke paperback ).

Web links

  • German Stratigraphic Commission, Manfred Menning (Hrsg.): Stratigraphische Tisch von Deutschland 2002 . Potsdam 2002, ISBN 3-00-010197-7 (1 sheet, Stratigraphie.de [PDF; 6.6 MB ]).
  • Commission for the paleontological and stratigraphic research of Austria of the Austrian Academy of Sciences (Ed.): The Stratigraphic Table of Austria (sedimentary layer sequences). Vienna 2004 PDF (large)
  • International Chronostratigraphic Chart 2015/01 (PDF)