The Serravallian is in the geologic timescale an age or a stage in the middle Miocene

Miocene

The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...

 epoch

Epoch (geology)

An epoch is a subdivision of the geologic timescale based on rock layering. In order, the higher subdivisions are periods, eras and eons. We are currently living in the Holocene epoch...

/series

Series (stratigraphy)

Series are subdivisions of rock layers made based on the age of the rock and corresponding to the dating system unit called an epoch, both being formally defined international conventions of the geological timescale. A series is therefore a sequence of rock depositions defining a...

, that spans the time between 13.65 ± 0.05 Ma and 11.608 ± 0.005 Ma (million years ago). The Serravallian follows the Langhian

Langhian

The Langhian is, in the ICS geologic timescale, an age or stage in the middle Miocene epoch/series. It spans the time between 15.97 ± 0.05 Ma and 13.65 ± 0.05 Ma . The Langhian was a continuing warming period defined by Lorenzo Pareto in 1864, it was originally established in the Langhe area north...

 and is followed by the Tortonian

Tortonian

The Tortonian is in the geologic timescale an age or stage of the late Miocene that spans the time between 11.608 ± 0.005 Ma and 7.246 ± 0.005 Ma . It follows the Serravallian and is followed by the Messinian....

.

It overlaps with the middle of the Astaracian

Astaracian

The Astaracian age age is a period of geologic time , equivalent with the Middle Miocene and used more specifically with European Land Mammal Ages. It precedes the Vallesian age and follows the Orleanian age. The Astaracian overlaps the Langhian and Serravallian ages....

 European Land Mammal Mega Zone, the upper Barstovian

Barstovian

The Barstovian North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology , typically set from 16,300,000 to 13,600,000 years BP, a period of . It is usually considered to overlap the Langhian and Serravallian...

 and lower Clarendonian

Clarendonian

The Clarendonian North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology , typically set from 13,600,000 to 10,300,000 years BP, a period of . It is usually considered to overlap the Serravallian of the Middle...

 North American Land Mammal Ages

North American Land Mammal Ages

The North American Mammal Ages establishes a geologic timescale for prehistoric North American fauna beginning 66.5 Ma during the Paleocene and continuing through to the Late Pleistocene...

 and the Laventan

Laventan

The Laventan age is a period of geologic time within the Miocene epoch of the Neogene used more specifically with South American Land Mammal Ages. It follows the Colloncuran and precedes the Mayoan age....

 and lower Mayoan

Mayoan

The Mayoan age is a period of geologic time within the Miocene epoch of the Neogene used more specifically with South American Land Mammal Ages. It follows the Laventan and precedes the Chasicoan age....

 South American Land Mammal Ages. It is also coeval with the Sarmatian and upper Badenian stages of the Paratethys

Paratethys

The Paratethys ocean, Paratethys sea or just Paratethys was a large shallow sea that stretched from the region north of the Alps over Central Europe to the Aral Sea in western Asia. The sea was formed during the Oxfordian epoch as an extension of the rift that formed the Central Atlantic Ocean and...

 time scale of Central and eastern Europe.

Definition

The Serravallian stage was introduced in stratigraphy by the Italian

Italy

Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...

 geologist Lorenzo Pareto in 1864. It was named after the town of Serravalle Scrivia

Serravalle Scrivia

Serravalle Scrivia is a comune in the Province of Alessandria in the Italian region of Piedmont, located about 100 km southeast of Turin and about 25 km southeast of Alessandria....

 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 GSSP for the Serravallian is in the Ras el Pellegrin section, close to the castle at Fomm ir-Riħ, southern Malta

Malta

Malta , officially known as the Republic of Malta , is a Southern European country consisting of an archipelago situated in the centre of the Mediterranean, south of Sicily, east of Tunisia and north of Libya, with Gibraltar to the west and Alexandria to the east.Malta covers just over in...

.

The top of the Serravallian (the base of the Tortonian stage) is at the last common appearance of calcareous nannoplanktons Discoaster kugleri

Discoaster

Discoaster is a genus of fossil haptophytes.- Species :Some species in this genus include:*D. asymmetricus Gartner*D. bellus Bukry and Percival*D. berggrenii Bukry*D. bollii Martini and Bramlette...

and planktonic foram Globigerinoides subquadratus. It is also associated with the short normal polarized magnetic chronozone C5r.2n.

Literature

; 2004: A Geologic Time Scale 2004, Cambridge University Press.; 1864: 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.

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