Late Oligocene

The Chattian is, in the geologic timescale, the younger 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).

The Chattian was introduced by Austrian palaeontologist Theodor Fuchs in 1894. Fuchs named the stage after the Chatti, a Germanic tribe. 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 C6Cn.2n.

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