Danian

The Danian (also shortened Dan or rarely Danish stage) is in Earth's history, the lowest stratigraphic stage of the Paleocene and thus the basal level of the Paleogene. It is also equated with the Lower Paleocene. In absolute terms, expressed ( geochronological ), represents the stage of the period about 66 million years ago to about 61.6 million years. The Danian following the Maastrichtian, the highest level of chalk, and is detached from the Seelandium. The Danian was formerly also expected to chalk.

Naming and history

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

Definition and GSSP

The base of the Danian is very well defined with the iridium anomaly in the Cretaceous-Tertiary boundary. The end of the stage is, however, not yet been finally determined. The boundary of the Danian to Seelandium lies within the relatively short magnetic polarity zone C27r Chrono. The reference profile ( GSSP = Global Stratotype Section and Point) for the base of the Danian, however, was set for the locality El Kef in Tunisia.

Cretaceous or Tertiary

In Dan sat down in the Central and Western European Cretaceous Basin deposition chalky rocks away so that lithological hardly show differences to the deposits of the Maastrichtian. This was the cause for the initial assignment of the Danian in the chalk. Significant differences in the Artzusammensetzungen and in particular the discovery of the Cretaceous-Tertiary boundary as a distinctive boundary horizon eventually led to the regrouping as the oldest stage of the Tertiary ( Paleogene today ).