Serravallian

The Serravallian is in the geologic timescale an age or a stage in the middle Miocene epoch/series, that spans the time between 13.65 ± 0.05 Ma and 11.608 ± 0.005 Ma (million years ago). The Serravallian follows the Langhian and is followed by the Tortonian.^[1]

It overlaps with the middle of the Astaracian European Land Mammal Mega Zone, the upper Barstovian and lower Clarendonian North American Land Mammal Ages and the Laventan and lower Mayoan South American Land Mammal Ages. It is also coeval with the Sarmatian and upper Badenian stages of the Paratethys time scale of Central and eastern Europe.

Definition

The Serravallian stage was introduced in stratigraphy by the Italian geologist Lorenzo Pareto in 1865.^[2] It was named after the town of Serravalle Scrivia in northern Italy.

The base of the Serravallian is at the first occurrence of fossils of the nannoplankton species Sphenolithus heteromorphus and is located in the magnetic chronozone C5ABr. The official Global Boundary Stratotype Section and Point for the Serravallian is in the Ras el Pellegrin section, close to the castle at Fomm ir-Riħ, southern Malta.

The top of the Serravallian (the base of the Tortonian stage) is at the last common appearance of calcareous nannoplanktons Discoaster kugleri and planktonic foram Globigerinoides subquadratus. It is also associated with the short normal-polarized magnetic chronozone C5r.2n.

References

Notes

1. ↑ Gradstein et al. (2004)
2. ↑ Lorenzo Pareto, Note sur les subdivisions que l'on pourrait établir dans les terrains tertaires de l'Apennin septentrional In Bulletin de la Société Géologique de France, volume 22, série 2, pp. 210-277

Literature

Wikisource has original works on the topic: Cenozoic#Neogene

• Gradstein, F.M.; Ogg, J.G. & Smith, A.G.; 2004: A Geologic Time Scale 2004, Cambridge University Press.
• Pareto, L.; 1865: Note sur la subdivision que l'on pourrait etablir dans les terrains de l'Apennin septentrional, Bulletin de la Societé Géologique de France 2(22), p. 210-277. (French)

External links

• GeoWhen Database - Serravallian
• Neogene 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