Pliocene

Pliocene
Pliocene
Chronology
←	Messinian salinity crisis
←	North American prairie expands
	Subdivision of the Neogene according to the ICS, as of 2021.; Vertical axis: millions of years ago.;
Etymology
Name formality	Formal
Usage information
Celestial body	Earth
Regional usage	Global (ICS)
Time scale(s) used	ICS Time Scale
Definition
Chronological unit	Epoch
Stratigraphic unit	Series
Time span formality	Formal
Lower boundary definition	Base of the Thvera magnetic event (C3n.4n), which is only 96 ka (5 precession cycles) younger than the GSSP
Lower boundary GSSP	Heraclea Minoa section, Heraclea Minoa, Cattolica Eraclea, Sicily, Italy; 37°23′30″N 13°16′50″E / 37.3917°N 13.2806°E
Lower GSSP ratified	2000
Upper boundary definition	Base of magnetic polarity chronozone C2r (Matuyama); Extinction of the Haptophytes Discoaster pentaradiatus and Discoaster surculus;
Upper boundary GSSP	Monte San Nicola Section, Gela, Sicily, Italy; 37°08′49″N 14°12′13″E / 37.1469°N 14.2035°E
Upper GSSP ratified	2009 (as base of Quaternary and Pleistocene)

The Pliocene ( /ˈplaɪ.əsiːn, ˈplaɪ.oʊ-/ PLY-ə-seen, PLY-oh-;^[6]^[7] also Pleiocene)^[8] is the epoch in the geologic time scale that extends from 5.333 million to 2.58^[9] million years ago. It is the second and most recent epoch of the Neogene Period in the Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch. Prior to the 2009 revision of the geologic time scale, which placed the four most recent major glaciations entirely within the Pleistocene, the Pliocene also included the Gelasian Stage, which lasted from 2.588 to 1.806 million years ago, and is now included in the Pleistocene.^[10]

As with other older geologic periods, the geological strata that define the start and end are well-identified but the exact dates of the start and end of the epoch are slightly uncertain. The boundaries defining the Pliocene are not set at an easily identified worldwide event but rather at regional boundaries between the warmer Miocene and the relatively cooler Pleistocene. The upper boundary was set at the start of the Pleistocene glaciations.

^ Krijgsman, W.; Garcés, M.; Langereis, C. G.; Daams, R.; Van Dam, J.; Van Der Meulen, A. J.; Agustí, J.; Cabrera, L. (1996). "A new chronology for the middle to late Miocene continental record in Spain". Earth and Planetary Science Letters. 142 (3–4): 367–380. Bibcode:1996E&PSL.142..367K. doi:10.1016/0012-821X(96)00109-4.
^ Retallack, G. J. (1997). "Neogene Expansion of the North American Prairie". PALAIOS. 12 (4): 380–390. doi:10.2307/3515337. JSTOR 3515337. Retrieved 11 February 2008.
^ "ICS Timescale Chart" (PDF). www.stratigraphy.org.
^ Van Couvering, John; Castradori, Davide; Cita, Maria; Hilgen, Frederik; Rio, Domenico (September 2000). "The base of the Zanclean Stage and of the Pliocene Series" (PDF). Episodes. 23 (3): 179–187. doi:10.18814/epiiugs/2000/v23i3/005.
^ Gibbard, Philip; Head, Martin (September 2010). "The newly-ratified definition of the Quaternary System/Period and redefinition of the Pleistocene Series/Epoch, and comparison of proposals advanced prior to formal ratification" (PDF). Episodes. 33 (3): 152–158. doi:10.18814/epiiugs/2010/v33i3/002. Retrieved 8 December 2020.
^ "Pliocene". Merriam-Webster.com Dictionary.
^ "Pliocene". Dictionary.com Unabridged (Online). n.d.
^ "Pleiocene". Dictionary.com Unabridged (Online). n.d.
^ See the 2014 version of the ICS geologic time scale Archived 2014-05-30 at the Wayback Machine
^ Ogg, James George; Ogg, Gabi; Gradstein F. M. (2008). The Concise Geologic Time Scale. Cambridge University Press. pp. 150–1. ISBN 9780521898492.

[Krijgsman1996-1] Krijgsman, W.; Garcés, M.; Langereis, C. G.; Daams, R.; Van Dam, J.; Van Der Meulen, A. J.; Agustí, J.; Cabrera, L. (1996). "A new chronology for the middle to late Miocene continental record in Spain". Earth and Planetary Science Letters. 142 (3–4): 367–380. Bibcode:1996E&PSL.142..367K. doi:10.1016/0012-821X(96)00109-4.

[Retallack1997-2] Retallack, G. J. (1997). "Neogene Expansion of the North American Prairie". PALAIOS. 12 (4): 380–390. doi:10.2307/3515337. JSTOR 3515337. Retrieved 11 February 2008.

[3] "ICS Timescale Chart" (PDF). www.stratigraphy.org.

[vancouvering_etal_2000-4] Van Couvering, John; Castradori, Davide; Cita, Maria; Hilgen, Frederik; Rio, Domenico (September 2000). "The base of the Zanclean Stage and of the Pliocene Series" (PDF). Episodes. 23 (3): 179–187. doi:10.18814/epiiugs/2000/v23i3/005.

[5] Gibbard, Philip; Head, Martin (September 2010). "The newly-ratified definition of the Quaternary System/Period and redefinition of the Pleistocene Series/Epoch, and comparison of proposals advanced prior to formal ratification" (PDF). Episodes. 33 (3): 152–158. doi:10.18814/epiiugs/2010/v33i3/002. Retrieved 8 December 2020.

[6] "Pliocene". Merriam-Webster.com Dictionary.

[7] "Pliocene". Dictionary.com Unabridged (Online). n.d.

[8] "Pleiocene". Dictionary.com Unabridged (Online). n.d.

[ICS2014-9] See the 2014 version of the ICS geologic time scale Archived 2014-05-30 at the Wayback Machine

[10] Ogg, James George; Ogg, Gabi; Gradstein F. M. (2008). The Concise Geologic Time Scale. Cambridge University Press. pp. 150–1. ISBN 9780521898492.

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