Chattian

The Chattian ( shortened in the German language, mostly to Chatt ) is in the Earth's upper stratigraphic stage of the Oligocene ( Paleogene ). It is also equated with the Oberoligozän. The stage moves in absolute terms ( geochronological ) the period from about 28.1 to about 23.03 million years a. The stage following the Rupelium and is detached from the Aquitanian, the lowest level of the Miocene ( Neogene ).

Naming and history

The stage is named after the Germanic tribe of the Chatti. The original type locality is near Kassel. And stage name was suggested by the German geologist and paleontologist Theodor Fuchs 1894.

Definition and GSSP

The basic level is the extinction of the foraminiferal genus Chiloguembelina ( corresponding to the base of foraminiferal Zone P21b ) marks. The end of the stage is characterized by several events: the basis of magnetic polarity chronozone C6Cn.2n, first appearance of foraminiferal species Paragloborotalia kugleri and through the extinction of calcareous nannoplankton - type Reticulofenestra bisecta (base of nannoplankton zone NN1 ). A reference profile ( GSSP = Global Stratotype Section and Point) for the Chattian has not yet been determined.