The Aquitanian ( in German language, usually shortened to Aquitanian or called Aquitanian stage) is in Earth's history, the lowest stratigraphic stage of the Miocene ( Neogene ). The stage includes in absolute terms ( geochronological ) the period from about 23.03 to about 20.44 million years. The step comes after the Chattian and is followed by the Burdigalian.
Naming and history
The name of the stage is derived from the Latin name of Aquitaine ( France). And stage name was introduced by the Swiss geologist and palaeontologist Karl Mayer- Eymar 1853 in the scientific literature.
Definition and GSSP
The lower boundary of the stage is characterized by several events: the basis of magnetic polarity chronozone C6Cn.2n, first appearance of foraminiferal species Paragloborotalia kugleri and by the extinction of calcareous nannoplankton - type Reticulofenestra bisecta (base of nannoplankton zone NN1 ). The end is defined by the first appearance of foraminiferal species Globigerinoides altiaperturus or the upper limit of the magnetic polarity chronozone C6An. Laid down by the International Commission on Stratigraphy reference profile ( GSSP = Global Stratotype Section and Point) is the Lemme Carrosio profile near Carrosio, north of Genoa in Italy.