Permian


Permian
Chronology
Etymology
Name formalityFormal
Usage information
Regional usageGlobal (ICS)
Time scale(s) usedICS Time Scale
Definition
Chronological unitPeriod
Stratigraphic unitSystem
Time span formalityFormal
Lower boundary definitionFAD of the Conodont Streptognathodus isolatus within the morphotype Streptognathodus wabaunsensis chronocline.
Lower boundary GSSPAidaralash, Ural Mountains, Kazakhstan
50°14′45″N 57°53′29″E / 50.2458°N 57.8914°E / 50.2458; 57.8914
Lower GSSP ratified1996[2]
Upper boundary definitionFAD of the Conodont Hindeodus parvus.
Upper boundary GSSPMeishan, Zhejiang, China
31°04′47″N 119°42′21″E / 31.0798°N 119.7058°E / 31.0798; 119.7058
Upper GSSP ratified2001[3]

The Permian (/ˈpɜːrmi.ən/ PUR-mee-ən)[4] is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period 298.9 million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleozoic Era; the following Triassic Period belongs to the Mesozoic Era. The concept of the Permian was introduced in 1841 by geologist Sir Roderick Murchison, who named it after the region of Perm in Russia.[5][6][7][8][9]

The Permian witnessed the diversification of the two groups of amniotes, the synapsids and the sauropsids (reptiles). The world at the time was dominated by the supercontinent Pangaea, which had formed due to the collision of Euramerica and Gondwana during the Carboniferous. Pangaea was surrounded by the superocean Panthalassa. The Carboniferous rainforest collapse left behind vast regions of desert within the continental interior.[10] Amniotes, which could better cope with these drier conditions, rose to dominance in place of their amphibian ancestors.

Various authors recognise at least three,[11] and possibly four[12] extinction events in the Permian. The end of the Early Permian (Cisuralian) saw a major faunal turnover, with most lineages of primitive "pelycosaur" synapsids becoming extinct, being replaced by more advanced therapsids. The end of the Capitanian Stage of the Permian was marked by the major Capitanian mass extinction event,[13] associated with the eruption of the Emeishan Traps. The Permian (along with the Paleozoic) ended with the Permian–Triassic extinction event, the largest mass extinction in Earth's history (which is the last of the three or four crises that occurred in the Permian), in which nearly 81% of marine species and 70% of terrestrial species died out, associated with the eruption of the Siberian Traps. It took well into the Triassic for life to recover from this catastrophe;[14] on land, ecosystems took 30 million years to recover.[15]

  1. ^ "Chart/Time Scale". www.stratigraphy.org. International Commission on Stratigraphy.
  2. ^ Davydov, Vladimir; Glenister, Brian; Spinosa, Claude; Ritter, Scott; Chernykh, V.; Wardlaw, B.; Snyder, W. (March 1998). "Proposal of Aidaralash as Global Stratotype Section and Point (GSSP) for base of the Permian System" (PDF). Episodes. 21: 11–18. doi:10.18814/epiiugs/1998/v21i1/003. Retrieved 7 December 2020.
  3. ^ Hongfu, Yin; Kexin, Zhang; Jinnan, Tong; Zunyi, Yang; Shunbao, Wu (June 2001). "The Global Stratotype Section and Point (GSSP) of the Permian-Triassic Boundary" (PDF). Episodes. 24 (2): 102–114. doi:10.18814/epiiugs/2001/v24i2/004. Retrieved 8 December 2020.
  4. ^ "Permian". Dictionary.com Unabridged (Online). n.d.
  5. ^ Olroyd, D.R. (2005). "Famous Geologists: Murchison". In Selley, R.C.; Cocks, L.R.M.; Plimer, I.R. (eds.). Encyclopedia of Geology, volume 2. Amsterdam: Elsevier. p. 213. ISBN 0-12-636380-3.
  6. ^ Ogg, J.G.; Ogg, G.; Gradstein, F.M. (2016). A Concise Geologic Time Scale: 2016. Amsterdam: Elsevier. p. 115. ISBN 978-0-444-63771-0.
  7. ^ Murchison, R.I.; de Verneuil, E.; von Keyserling, A. (1842). On the Geological Structure of the Central and Southern Regions of Russia in Europe, and of the Ural Mountains. London: Richard and John E. Taylor. p. 14. Permian System. (Zechstein of Germany — Magnesian limestone of England)—Some introductory remarks explain why the authors have ventured to use a new name in reference to a group of rocks which, as a whole, they consider to be on the parallel of the Zechstein of Germany and the magnesian limestone of England. They do so, not merely because a portion of deposits has long been known by the name "grits of Perm", but because, being enormously developed in the governments of Perm and Orenburg, they there assume a great variety of lithological features ...
  8. ^ Murchison, R.I.; de Verneuil, E.; von Keyserling, A. (1845). Geology of Russia in Europe and the Ural Mountains. Vol. 1: Geology. London: John Murray. pp. 138–139. ...Convincing ourselves in the field, that these strata were so distinguished as to constitute a system, connected with the carboniferous rocks on the one hand, and independent of the Trias on the other, we ventured to designate them by a geographical term, derived from the ancient kingdom of Permia, within and around whose precincts the necessary evidences had been obtained. ... For these reasons, then, we were led to abandon both the German and British nomenclature, and to prefer a geographical name, taken from the region in which the beds are loaded with fossils of an independent and intermediary character; and where the order of superposition is clear, the lower strata of the group being seen to rest upon the Carboniferous rocks.
  9. ^ Verneuil, E. (1842). "Correspondance et communications". Bulletin de la Société Géologique de France. 13: 11–14. pp. 12–13: Le nom de Système Permien, nom dérivé de l'ancien royaume de Permie, aujourd'hui gouvernement de Perm, donc ce dépôt occupe une large part, semblerait assez lui convener ... [The name of the Permian System, a name derived from the ancient kingdom of Permia, today the Government of Perm, of which this deposit occupies a large part, would seem to suit it well enough ...]
  10. ^ Sahney, S., Benton, M.J. & Falcon-Lang, H.J. (2010). "Rainforest collapse triggered Pennsylvanian tetrapod diversification in Euramerica". Geology. 38 (12): 1079–1082. Bibcode:2010Geo....38.1079S. doi:10.1130/G31182.1. S2CID 128642769.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  11. ^ Didier, Gilles; Laurin, Michel (9 December 2021). "Distributions of extinction times from fossil ages and tree topologies: the example of mid-Permian synapsid extinctions". PeerJ. 9: e12577. doi:10.7717/peerj.12577. PMC 8667717. PMID 34966586.
  12. ^ Lucas, S.G. (July 2017). "Permian tetrapod extinction events". Earth-Science Reviews. 170: 31–60. Bibcode:2017ESRv..170...31L. doi:10.1016/j.earscirev.2017.04.008.
  13. ^ Day, Michael O.; Ramezani, Jahandar; Bowring, Samuel A.; Sadler, Peter M.; Erwin, Douglas H.; Abdala, Fernando; Rubidge, Bruce S. (22 July 2015). "When and how did the terrestrial mid-Permian mass extinction occur? Evidence from the tetrapod record of the Karoo Basin, South Africa". Proceedings of the Royal Society B: Biological Sciences. 282 (1811): 20150834. doi:10.1098/rspb.2015.0834. PMC 4528552. PMID 26156768.
  14. ^ "GeoKansas--Geotopics--Mass Extinctions". ku.edu. Archived from the original on 2012-09-20. Retrieved 2009-11-05.
  15. ^ Sahney, S.; Benton, M. J. (2008). "Recovery from the most profound mass extinction of all time". Proceedings of the Royal Society B: Biological Sciences. 275 (1636): 759–65. doi:10.1098/rspb.2007.1370. PMC 2596898. PMID 18198148.

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