The Piacenzian is in the international geologic timescale the upper stage or latest age of the Pliocene

Pliocene

The Pliocene Epoch is the period in the geologic timescale that extends from 5.332 million to 2.588 million years before present. It is the second and youngest epoch of the Neogene Period in the Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch...

. It spans the time between 3.6 ± 0.005 Ma and 2.588 ± 0.005 Ma (million years ago). The Piacenzian is on top of the Zanclean

Zanclean

The Zanclean is the lowest stage or earliest age on the geologic time scale of the Pliocene. It spans the time between 5.332 and 3.6 Ma ± 0.005 Ma . It is preceded by the Messinian age of the Miocene epoch, and followed by the Piacenzian age....

 and is followed by the Gelasian

Gelasian

The Gelasian is an age in the international geologic timescale or a stage in chronostratigraphy, being the earliest or lowest subdivision of the Quaternary period/system and Pleistocene epoch/series. It spans the time between 2.588 ± 0.005 Ma and 1.806 ± 0.005 Ma...

 (part of the Pleistocene

Pleistocene

The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....

).

The Piacenzian is roughly coeval with the European Land Mammal Mega Zone MN 16, overlaps the late Chapadmalalan

Chapadmalalan

The Chapadmalalan age is a period of geologic time within the Pliocene epoch of the Neogene used more specifically with South American Land Mammal Ages. It follows the Montehermosan and precedes the Uquian age....

 and early Uquian

Uquian

The Uquian age is a period of geologic time within the Pliocene epoch of the Neogene used more specifically with South American Land Mammal Ages. It follows the Montehermosan and precedes the Ensenadan age....

 South American Land Mammal Ages, and falls inside the more extensive Blancan

Blancan

The Blancan 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 4,750,000 to 1,808,000 years BP, a period of .. It is usually considered to start in the early-mid Pliocene epoch and end...

 North American Land Mammal Age. It also correlates with regional stages like the Astian, Redonian, Waltonian (England), Reuverian

Reuverian

The Reuverian is a geological era in northwestern Europe. It is dated approximately 2.6 million years ago, and is part of the late Pliocene.Clay deposits from the Reuverian stage can be found in the Netherlands and neighbouring parts of Germany. The stage is named after the town of Reuver, in the...

 (Netherlands

Netherlands

The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...

) or Romania

Romania

Romania is a country located at the crossroads of Central and Southeastern Europe, on the Lower Danube, within and outside the Carpathian arch, bordering on the Black Sea...

n (Central Europe).

Definition

The Piacenzian was introduced in scientific literature by Swiss

Switzerland

Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....

 stratigrapher Karl Mayer-Eymar in 1858. It is named after 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...

 city of Piacenza

Piacenza

Piacenza is a city and comune in the Emilia-Romagna region of northern Italy. It is the capital of the province of Piacenza...

.

The base of the Piacenzian is at the base of magnetic chronozone C2An (the base of the Gauss chronozone and at the extinction

Extinction

In biology and ecology, extinction is the end of an organism or of a group of organisms , normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point...

 of the plankton

Plankton

Plankton are any drifting organisms that inhabit the pelagic zone of oceans, seas, or bodies of fresh water. That is, plankton are defined by their ecological niche rather than phylogenetic or taxonomic classification...

ic forams Globorotalia margaritae and Pulleniatina primalis. The GSSP for the Piacenzian stage is at Punta Piccola on Sicily

Sicily

Sicily is a region of Italy, and is the largest island in the Mediterranean Sea. Along with the surrounding minor islands, it constitutes an autonomous region of Italy, the Regione Autonoma Siciliana Sicily has a rich and unique culture, especially with regard to the arts, music, literature,...

, Italy.

The top of the Piacenzian (the base of the Quaternary system and the Pleistocene series) is defined magnetostratigraphically

Magnetostratigraphy

Magnetostratigraphy is a geophysical correlation technique used to date sedimentary and volcanic sequences. The method works by collecting oriented samples at measured intervals throughout the section. The samples are analyzed to determine their characteristic remanent magnetization , that is, the...

 as the base of the Matuyama (C2r) chronozone

Chronozone

A chronozone or chron is a slice of time that begins at a given identifiable event and ends at another. In the fossil record such tracer events are usually keyed to disappearance of a widely distributed and rapidly changing species or the appearance of such a species in the geological record...

 (at the Gauss-Matuyama reversal

Gauss-Matuyama reversal

The Gauss-Matuyama Reversal was a geologic event approximately 2.588 million years ago when the Earth's magnetic field underwent reversal.This event, which separates the Piacenzian from the Gelasian and marks the start of the Quaternary, is useful in dating sediments.-Biological effects:The event...

), and isotopic stage 103. Above this point there are notable extinctions of the calcareous nannofossils: Discoaster pentaradiatus

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 Discoaster surculus.

Climate

Climate of the Piacenzian would have started as a somewhat wet and warm period in North America occurring just after a brief cooling period of the Zanclean. Deposition of sediments and mollusks of the Piacenzian correspond with the rise in sea level creating the Tamiami Subsea and Jackson Subsea of Florida, Duplin Subsea generally of South Carolina

South Carolina

South Carolina is a state in the Deep South of the United States that borders Georgia to the south, North Carolina to the north, and the Atlantic Ocean to the east. Originally part of the Province of Carolina, the Province of South Carolina was one of the 13 colonies that declared independence...

, and Yorktown Subsea of the Outer Banks

Outer Banks

The Outer Banks is a 200-mile long string of narrow barrier islands off the coast of North Carolina, beginning in the southeastern corner of Virginia Beach on the east coast of the United States....

 and inland North Carolina

North Carolina

North Carolina is a state located in the southeastern United States. The state borders South Carolina and Georgia to the south, Tennessee to the west and Virginia to the north. North Carolina contains 100 counties. Its capital is Raleigh, and its largest city is Charlotte...

. Dates have been established on the basis of the genera and species of mollusks found.

Literature

; (1998) "The Global Standard Stratotype section and Point (GSSP) of the Piacenzian Stage (Middle Pliocene)" Episodes 21(2): pp 88-93. (eds.) (2005) A Geologic Time Scale 2004 Cambridge University Press, Cambridge, UK, ISBN 0-521-78142-6. (1998) "The Gelasian Stage (Upper Pliocene): A new unit of the global standard chronostratigraphic scale" Episodes 21(2): 82-87. (1996) "Middle Pliocene vegetation: reconstructions, paleoclimatic inferences, and boundary conditions for climate modeling" Marine Micropaleontology 27(1): pp. 27-49

External links

• GeoWhen Database - Piacenzian
• 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