Tortonian

Tortonian
Tortonian
11.63 – 7.246 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
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.;
Formerly part of	Tertiary Period/System
Etymology
Name formality	Formal
Usage information
Celestial body	Earth
Regional usage	Global (ICS)
Time scale(s) used	ICS Time Scale
Definition
Chronological unit	Age
Stratigraphic unit	Stage
Time span formality	Formal
Lower boundary definition	LAD of the Haptophyte Discoaster kugleri
Lower boundary GSSP	Monte dei Corvi Beach section, Ancona, Italy; 43°35′12″N 13°34′10″E / 43.5867°N 13.5694°E
Lower GSSP ratified	2003
Upper boundary definition	First regular occurrence of the Planktonic Foraminifer Globorotalia miotumida; FAD of the Haptophyte Amaurolithus delicatus;
Upper boundary GSSP	Oued Akrech section, Rabat, Morocco; 33°56′13″N 6°48′45″W / 33.9369°N 6.8125°W
Upper GSSP ratified	January 2000

The Tortonian is in the geologic time scale an age or stage of the late Miocene that spans the time between 11.608 ± 0.005 Ma and 7.246 ± 0.005 Ma (million years ago)^{[citation needed]}. It follows the Serravallian and is followed by the Messinian.

The Tortonian roughly overlaps with the regional Pannonian Stage of the Paratethys timescale of Central Europe. It also overlaps the upper Astaracian, Vallesian and lower Turolian European land mammal ages, the upper Clarendonian and lower Hemphillian North American land mammal ages and the upper Chasicoan and lower Huayquerian South American land mammal ages.

Definition

The Tortonian was introduced by Swiss stratigrapher Karl Mayer-Eymar in 1858. It was named after the Italian city of Tortona in the Piedmont region.

The base of the Tortonian Stage is at the last common appearance of calcareous nanoplankton Discoaster kugleri and planktonic foram Globigerinoides subquadratus. It is also associated with the short normal polarized magnetic chronozone C5r.2n. A GSSP for the Tortonian has been established in the Monte dei Corvi section near Ancona (Italy).^[6]

The top of the Tortonian (the base of the Messinian) is at the first appearance of the planktonic foram species Globorotalia conomiozea and is stratigraphically in the middle of magnetic chronozone C3Br.1r.

Geologic history

In 2020, geologists reported two newly-identified supervolcano eruptions associated with the Yellowstone hotspot track, including the region's largest and most cataclysmic event – the Grey's Landing super-eruption – which had a volume of at least 2,800 cubic kilometres (670 cubic miles) and occurred around 8.72 Ma.^[7]^[8]

References

Notes

^ 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 2008-02-11.
^ "ICS Timescale Chart" (PDF). www.stratigraphy.org.
^ Hilgen, F. J.; Hayfaa Abdul Aziz; Bice, David; Iaccarino, Silvia; Krijgsman, Wout; Kuiper, Klaudia; Montanari, Alessandro; Raffi, Isabella; Turco, Elena; Willem-Jan Zachariasse (2005). "The Global boundary Stratotype Section and Point (GSSP) of the Tortonian Stage (Upper Miocene) at Monte Dei Corvi" (PDF). Episodes. 28 (1): 6–17. doi:10.18814/epiiugs/2005/v28i1/001. Retrieved 26 December 2020.
^ Hilgen, F. J.; S. Iaccarino; W. Krijgsman; G. Villa; C. G. Langereis; W. J. Zachariasse (2000). "The Global Boundary Stratotype Section and Point (GSSP) of the Messinian Stage (uppermost Miocene)" (PDF). Episodes. 23 (3): 172–178. doi:10.18814/epiiugs/2000/v23i3/004.
^ By Hilgen et al. (2005)
^ Knott, T.R.; Branney, M.J.; Reichow, M.K.; Finn, D.R.; Tapster, S.; Coe, R.S. (2020). "Discovery of two new super-eruptions from the Yellowstone hotspot track (USA): Is the Yellowstone hotspot waning?". Geology. 48 (9): 934–938. Bibcode:2020Geo....48..934K. doi:10.1130/G47384.1.
^ "Discovery of Ancient Super-Eruptions Indicates the Yellowstone Hotspot May Be Waning". The Geological Society of America. 3 June 2020. Retrieved 17 June 2020.

Literature

Gradstein, F.M.; Ogg, J.G. & Smith, A.G.; 2004: A Geologic Time Scale 2004, Cambridge University Press.
Hilgen, F.; Abdul Aziz, H.; Bice, D.; Iaccarino, S.; Krijgsman, W.; Kuiper, K.; Montanari, A.; Raffi, I.; Turco, E. & Zachariasse, W.-J.; 2005: The Global boundary Stratotype Section and Point (GSSP) of the Tortonian Stage (Upper Miocene) at Monte Dei Corvi, Episodes 28, p. 6-17.
Mayer-Eymar, K.; 1858: Versuch einer neuen Klassifikation der Tertiär-Gebilde Europa’s, Verhandlungen der Schweizerischen Naturforschenden Gesellschaft, Jahresversammlung 1857, p. 70–71 & 165–199. (in German)

External links

GeoWhen Database - Tortonian
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

[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 2008-02-11.

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

[4] Hilgen, F. J.; Hayfaa Abdul Aziz; Bice, David; Iaccarino, Silvia; Krijgsman, Wout; Kuiper, Klaudia; Montanari, Alessandro; Raffi, Isabella; Turco, Elena; Willem-Jan Zachariasse (2005). "The Global boundary Stratotype Section and Point (GSSP) of the Tortonian Stage (Upper Miocene) at Monte Dei Corvi" (PDF). Episodes. 28 (1): 6–17. doi:10.18814/epiiugs/2005/v28i1/001. Retrieved 26 December 2020.

[5] Hilgen, F. J.; S. Iaccarino; W. Krijgsman; G. Villa; C. G. Langereis; W. J. Zachariasse (2000). "The Global Boundary Stratotype Section and Point (GSSP) of the Messinian Stage (uppermost Miocene)" (PDF). Episodes. 23 (3): 172–178. doi:10.18814/epiiugs/2000/v23i3/004.

[6] By Hilgen et al. (2005)

[7] Knott, T.R.; Branney, M.J.; Reichow, M.K.; Finn, D.R.; Tapster, S.; Coe, R.S. (2020). "Discovery of two new super-eruptions from the Yellowstone hotspot track (USA): Is the Yellowstone hotspot waning?". Geology. 48 (9): 934–938. Bibcode:2020Geo....48..934K. doi:10.1130/G47384.1.

[8] "Discovery of Ancient Super-Eruptions Indicates the Yellowstone Hotspot May Be Waning". The Geological Society of America. 3 June 2020. Retrieved 17 June 2020.

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