The Aquitanian is, in the

International Commission on Stratigraphy The International Commission on Stratigraphy (ICS), sometimes unofficially referred to as the International Stratigraphic Commission, is a daughter or major subcommittee grade scientific organization that concerns itself with stratigraphy, strati ...

's (ICS)

geologic timescale The geologic time scale or geological time scale (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geochron ...

, the oldest age or lowest stage in the

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

. It spans the time between 23.03 Ma and 20.44 Ma (million years ago) during the

Early Miocene The Early Miocene (also known as Lower Miocene) is a sub-epoch of the Miocene epoch (geology), Epoch made up of two faunal stage, stages: the Aquitanian age, Aquitanian and Burdigalian stages. The sub-epoch lasted from 23.03 ± 0.05 annum, Ma to ...

. It was a dry, cooling period. The Aquitanian succeeds the Chattian (the youngest age of the

Oligocene The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...

) and precedes the

Burdigalian The Burdigalian is, in the geologic timescale, an age (geology), age or stage (stratigraphy), stage in the early Miocene. It spans the time between 20.43 ± 0.05 annum, Ma and 15.97 ± 0.05 Ma (million years ago). Preceded by the Aquitanian (sta ...

. The Aquitanian Age overlaps with the Harrisonian, Agenian, Pareora, Landon, Otaian, and Waitakian Ages from various regional timescales.

Stratigraphic definition

The Aquitanian Stage was named after the

Aquitaine Aquitaine (, ; ; ; ; Poitevin-Saintongeais: ''Aguiéne''), archaic Guyenne or Guienne (), is a historical region of southwestern France and a former Regions of France, administrative region. Since 1 January 2016 it has been part of the administ ...

region in

France France, officially the French Republic, is a country located primarily in Western Europe. Overseas France, Its overseas regions and territories include French Guiana in South America, Saint Pierre and Miquelon in the Atlantic Ocean#North Atlan ...

and was introduced in scientific literature by

Swiss Swiss most commonly refers to: * the adjectival form of Switzerland * Swiss people Swiss may also refer to: Places * Swiss, Missouri * Swiss, North Carolina * Swiss, West Virginia * Swiss, Wisconsin Other uses * Swiss Café, an old café located ...

stratigrapher Karl Mayer-Eymar in 1858. The base of the Aquitanian (also the base of the Miocene Series and the

Neogene The Neogene ( ,) is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago ( Mya) to the beginning of the present Quaternary Period million years ago. It is the second period of th ...

System A system is a group of interacting or interrelated elements that act according to a set of rules to form a unified whole. A system, surrounded and influenced by its open system (systems theory), environment, is described by its boundaries, str ...

) is defined as the place in the stratigraphic column at the first appearance of foram species '' Paragloborotalia kugleri'', the

extinction Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

of calcareous nanoplankton species '' Reticulofenestra bisecta'' (which forms the base of nanoplankton biozone NN1), and the base of magnetic chronozone C6Cn.2n. The official

GSSP A Global Boundary Stratotype Section and Point (GSSP), sometimes referred to as a golden spike, is an internationally agreed upon reference point on a stratigraphic section which defines the lower boundary of a stage on the geologic time scale. ...

for the Aquitanian Stage lies in the Lemme-Carrosio section near the small village of Carrosio (north of

Genoa Genoa ( ; ; ) is a city in and the capital of the Italian region of Liguria, and the sixth-largest city in Italy. As of 2025, 563,947 people live within the city's administrative limits. While its metropolitan city has 818,651 inhabitan ...

) in northern

Italy Italy, officially the Italian Republic, is a country in Southern Europe, Southern and Western Europe, Western Europe. It consists of Italian Peninsula, a peninsula that extends into the Mediterranean Sea, with the Alps on its northern land b ...

.The Aquitanian GSSP was established by Steininger ''et al.'' (1997) The top of the Aquitanian Stage (the base of the Burdigalian) is at the first appearance of foram species '' Globigerinoides altiaperturus'' and the top of magnetic chronozone C6An.

References

Footnotes

Literature

*; 2004: ''A Geologic Time Scale 2004'',

Cambridge University Press Cambridge University Press was the university press of the University of Cambridge. Granted a letters patent by King Henry VIII in 1534, it was the oldest university press in the world. Cambridge University Press merged with Cambridge Assessme ...

. *; 1858: ''Versuch einer neuen Klassifikation der Tertiär-Gebilde Europa’s'', Verhandlungen der Schweizerischen Naturforschenden Gesellschaft 17–19 (August 1857), p. 70–71 & 165–199. *; 1997: ''The Global Stratotype Section and Point (GSSP) for the base of the Neogene'', Episodes 20(1), p. 23-28.

External links

GeoWhen Database - AquitanianNeogene timescale
at the website of the subcommission for stratigraphic information of the ICS
Neogene timescale
at the website of the Norwegian network of offshore records of geology and stratigraphy {{coord, 44.6589, N, 8.8364, E, source:wikidata, display=title *01 Miocene geochronology Geological ages