Induan
Induan | |
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The Induan is the first
The Induan is roughly coeval with the regional Feixianguanian Stage of China.
Geology
Stratigraphy
The
Stages can be defined globally or regionally. For global stratigraphic correlation, the
The Induan is succeeded by the
History
There have been several propositions for the organization of the Triassic timescale. Most of the Triassic stages and sub-stages, which are still used today, were coined in an 1895 publication by Austro-Hungarian geologist
In 1956, Soviet paleontologists Lubov D. Kiparisova and Yurij N. Popov decided to divide the Lower Triassic series into, what they coined, the Induan and Olenekian stages.[16] The Induan honors the Indus River, as they also bounded it using the same criteria and sites as Mojsisovics' Brahmanian in the Indus region, though they resided in Siberia at the time. That is, the Induan is synonymous with the Brahmanian.[15]
In the 1960s, English paleontologist Edward T. Tozer (sometimes collaborating with American geologist Norman J. Silberling) crafted Triassic timescales based on North American ammonoid zones (further refining it in the following decades), based on the works of Frank McLearn in British Columbia and Siemon Muller in Nevada who pieced together the ammonoid fossil record of the North American Cordillera. Tozer's nomenclature was largely derived from Mojsisovics's work, but he redefined them using North American sites. He recommended the Lower Triassic series be divided into the: Griesbachian, Dienerian, Smithian, and Spathian. The former two roughly correspond with the Induan. Tozer's timescale became popular in the Americas.[15] He named the Griesbachian after Griesbach Creek on Axel Heiberg Island, Canada, and further split it into the Gangetian and Ellesmarian substages; the former he defined by the ammonite zones of O. concavum and O. boreale, and the latter by Ophiceras commune and Proptychites striatus. He named the Dienerian after Diener Creek on Ellesmere Island, Canada, and defined it by the ammonite zones P. candus and Vavilovites sverdrupi.[9]
In the 1970s, the ICS was founded to globally standardize stratigraphy. They erected the Subcommission on Triassic Stratigraphy (STS), which published its first timescale to Triassic stratigraphy in 1985. They divided it into the Lower, Middle, and Upper series; the Lower Triassic divided into the Induan and Olenekian stages; and the Induan further divided into the Griesbachian and Dienerian substages. In a revised 1991
In the 1990s, detailed studies of Otoceras sites in Tibet, Kashmir, Himalayas, Greenland, Svalbard and the Arctic territories of North America have revealed the problematic interval of existence of this genus.[17] By the same decade, most geologists had moved away from ammonite zones, preferring conodonts. Consequently, in 1996, the STS moved the Induan's GSSP to Meishan, China, with the appearance of H. parvus. It was the first GSSP approved by the STS.[15]
Coal gap
Paleogeography
During the Induan, all major landmasses had already amalgamated into the
A major
Induan life
![](http://upload.wikimedia.org/wikipedia/commons/thumb/e/e3/Claraia_Clarai_Museum_Gr%C3%B6den.jpg/220px-Claraia_Clarai_Museum_Gr%C3%B6den.jpg)
The Induan followed the
Much of the
The
Regarding
Induan
a mainly Palaeozoic group. Cartilaginous fishes were seemingly rare during the Induan.Crocodile-shaped, marine
The
Notable formations
- Arcadia Formation* (Queensland, Australia)
- Candelaria Formation (Nevada, USA)
- Daye Formation (Guizhou, China)
- Dinwoody Formation (western USA)
- lower Fremouw Formation* (Antarctica)
- upper Guodikeng Formation (Xinjiang, China)
- lower Jiucaiyuan Formation (Xinjiang, China)
- Knocklofty Formation* (Tasmania, Australia)
- Lystrosaurus Assemblage Zone* (South Africa)
- Panchet Formation* (India)
- middle Sakamena Formation (Madagascar)
- Vardebukta Formation (Svalbard, Norway)
- Vokhmian Gorizont / Kopanskaya Svita* (Russia)
- Werfen Formation (Austria, Bosnia and Herzegovina, Italy)
- Wordie Creek Formation (Greenland)
* Tentatively assigned to the Induan; age estimated primarily via terrestrial tetrapod biostratigraphy (see Triassic land vertebrate faunachrons)
See also
- Geologic time scale – System that relates geologic strata to time
References
- .
- PMID 17919771.
- ^ Retallack, G. J.; . Retrieved 2007-09-29.
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- . Retrieved 8 December 2020.
- ^ "Global Boundary Stratotype Section and Point". International Commission of Stratigraphy. Retrieved 23 December 2020.
- ^ "ICS - Chart/Time Scale". Archived from the original on 2014-05-30. Retrieved 2017-09-28.
- ^ doi:10.4095/100985.
- ^ "International Chronostratigraphic Chart" (PDF). www.stratigraphy.org. International Commission on Stratigraphy. Retrieved 25 August 2022.
- ^ "GSSP for Induan Stage". www.stratigraphy.org. International Commission on Stratigraphy. Retrieved 16 June 2022.
- ISBN 978-0-385-18101-3.
- ^ "Global Boundary Stratotype Section and Points". www.stratigraphy.org. International Commission on Stratigraphy. Retrieved 16 June 2022.
- ^ Mojsisovics, E.; Waagen, W. H.; Diener, C. "Entwurf einer Gliederung der pelagischen Sediments des Trias-Systems" [Outline of a classification of the pelagic sediments of the Triassic system]. Vienna Academy of Sciences, Mathematical and Scientific Class Meeting Reports (in German). 104: 1279–1302.
- ^ S2CID 129648527.
- ^ Kiparisova, L. D.; Popov, Y. N. (1956). "Raschlenenie nizhnego otdela triasovoy sistemy na yarusy" [Subdivision of the Lower series of the Triassic System into stages]. Proceedings of the USSR Academy of Sciences (in Russian). 109: 842–845.
- doi:10.26907/2542-064X.2019.4.550-570. Archived (PDF) from the original on March 31, 2022.)
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- ^ .
- ^ a b Ware et al. (2015): High-resolution biochronology and diversity dynamics of the Early Triassic ammonoid recovery: the Dienerian faunas of the Northern Indian Margin. Palaeogeography, Palaeoclimatology, Palaeoecology 440:363-373 https://doi.org/10.1016/j.palaeo.2015.09.013
- ^ S2CID 256697946.
- ^ PMID 18198148.
- ^ Schneebeli-Hermann et al. (2015): Vegetation history across the Permian–Triassic boundary in Pakistan (Amb section, Salt Range). Gondwana Research 27:911-924 http://dx.doi.org/10.1016/j.gr.2013.11.007
- ^ Hochuli et al. (2016): Severest crisis overlooked—Worst disruption of terrestrial environments postdates the Permian–Triassic mass extinction. Scientific Reports 6:28372 https://doi.org/10.1038/srep28372
- ^ Foster et al. (2020): Suppressed competitive exclusion enabled the proliferation of Permian/Triassic boundary microbialites. The Depositional record 6. 1–13. https://doi.org/10.1002/dep2.97
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- ^ Smithwick F.M., and Stubbs T.L. (2018): Phanerozoic survivors: Actinopterygian evolution through the Permo‐Triassic and Triassic‐Jurassic mass extinction events. Evolution 72:348-362. https://doi.org/10.1111/evo.13421
- OCLC 938169014.
- ^ Nielsen, Eigil (1936). "Some few preliminary remarks on Triassic fishes from East Greenland". Meddelelser om Grønland. 112 (3): 1–55.
- ^ Beltan, Laurence (1996). "Overview of systematics, paleobiology, and paleoecology of Triassic fishes of northwestern Madagascar". In G. Arratia; G. Viohl (eds.). Mesozoic Fishes—Systematics and Paleoecology. München: Dr. Friedrich Pfeil. pp. 479–500.
- S2CID 155564297.
- .
- ^ Stensiö, E. (1921). Triassic fishes from Spitzbergen 1. Wien: Adolf Holzhausen. pp. xxviii+307.
- ^ Stensiö, E. (1925). "Triassic fishes from Spitzbergen 2". Kungliga Svenska Vetenskapsakademiens Handlingar. 3: 1–261.
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- doi:10.3140/bull.geosci.1337.)
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- ^ Scheyer et al. (2014): Early Triassic Marine Biotic Recovery: The Predators' Perspective. PLoS ONE https://doi.org/10.1371/journal.pone.0088987
- ^ Hautmann et al. (2017): Geologically oldest oysters were epizoans on Early Triassic ammonoids. Journal of Molluscan Studies 83:253-260 https://doi.org/10.1093/mollus/eyx018
Sources
- Brack, P.; Rieber, H.; Nicora, A. & Mundil, R.; 2005: The Global boundary Stratotype Section and Point (GSSP) of the Ladinian Stage (Middle Triassic) at Bagolino (Southern Alps, Northern Italy) and its implications for the Triassic time scale, Episodes 28(4), pp. 233–244.
- Gradstein, F. M.; Ogg, J. G. & Smith, A. G.; 2004: A Geologic Time Scale 2004, Cambridge University Press.
- Kiparisova, Lubov Dmitrievna & Popov, Yurij Nikolaivitch; 1956: Расчленение нижнего отдела триасовой системы на ярусы (Subdivision of the lower series of the Triassic System into stages), Doklady Akademii Nauk SSSR109(4), pp 842–845 (in Russian).
External links
- GeoWhen Database - Induan
- Lower Triassic timescale at the website of the subcommission for stratigraphic information of the ICS
- Lower Triassic timescale at the website of Norges Network of offshore records of geology and stratigraphy.