| Artinskian | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 290.1 ± 0.26 – 283.5 ± 0.6Ma | |||||||||||||
| Chronology | |||||||||||||
| |||||||||||||
| 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 | FAD of theConodontSweetognathus whitei | ||||||||||||
| Lower boundary GSSP | Dalny Tulkas section,Southern Ural Mountains,Russia 53°55′29″N56°30′58″E / 53.9247°N 56.51615°E /53.9247; 56.51615 | ||||||||||||
| Lower GSSP ratified | February 2022[2] | ||||||||||||
| Upper boundary definition | Not formally defined | ||||||||||||
| Upper boundary definition candidates | Near FAD of the ConodontNeostreptognathodus pnevi | ||||||||||||
| Upper boundary GSSP candidate section(s) | Mechetlino,Southern Ural Mountains,Russia | ||||||||||||
In thegeologic timescale, theArtinskian is anage orstage of thePermian. It is a subdivision of theCisuralianEpoch orSeries. The Artinskian likely lasted between 290.1 and 283.3million years ago (Ma) according to the most recent revision of theInternational Commission on Stratigraphy (ICS) in 2022.[1] It was preceded by theSakmarian and followed by theKungurian.
The Artinskian is named after the goniatite grits of Artinsk which was introduced byRoderick Murchison,Édouard de Verneuil and countAlexander von Keyserling in theirThe Geology of Russia in Europe and the Ural Mountains (1845).[3] The grits of Artinsk, in turn, get its name from theArtinsky District with center in theRussian smalltown ofArti (formerlyArtinsk zavod), situated in the middleUrals, about 170 km southwest ofYekaterinburg. The stage was introduced into scientific literature byAlexander Karpinsky in 1874.[4]
The base of the Artinskian Stage is defined as thefirst appearance datum (FAD) of theconodont speciesSweetognathus whitei andMesogondolella bisselli. In order to constrain this age, the ICS subcommission on Permianstratigraphy informally proposed a candidateGSSP in 2002, later followed by a formal proposal in 2013. The proposed GSSP location — the Dal'ny Tulkas roadcut in theSouthern Urals, near the town ofKrasnousolsky[5] — was eventually ratified in February 2022.[2]
U-Pb radiometric dating found that the base of the Artinskian was approximately 290.1 million years old (Ma), based on the position of the rock layer at the Dal'ny Tulkas roadcut containing the FAD of S. whitei relative to three precisely dated ash beds surrounding it.[6] Earlier radiometric reported a much younger age of 280.3 Ma for theSakmarian-Artinskian boundary.
The top of the Artinskian (and the base of theKungurian) is defined as the place in the stratigraphic record where fossils of conodontsNeostreptognathodus pnevi andNeostreptognathodus exculptus first appear.[4] The proposed GSSP candidate — theMechetlino section (Southern Urals).[7]
Around 287 million years ago occurred an interval of pronounced warming known as the Artinskian Warming Event (AWE). This period ofglobal warming accelerated thedeglaciation that had been occurring since the Sakmarian following the end of the most intenseglacial phase of theLate Palaeozoic Ice Age.[8] In addition, it is also associated with significantglobal drying, which had gradually been occurring since the Carboniferous-Permian boundary.[9][10] Major aridification during the AWE is evidenced by a positiveδ18O excursion observed inbrachiopodfossils,[11] with arid and semi-arid conditions expanding across much of Pangaea asglaciers receded torefugia in the polar regions ofGondwana.[8]
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