In the

geologic timescale The geologic time scale, or geological time scale, (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geochronol ...

, the Artinskian is an age or stage of the Permian. It is a subdivision of the

Cisuralian The Cisuralian is the first Series (stratigraphy), series/Epoch (geology), epoch of the Permian. The Cisuralian was preceded by the Pennsylvanian (geology), Pennsylvanian and followed by the Guadalupian. The Cisuralian Epoch is named after the w ...

Epoch or Series. The Artinskian likely lasted between and million years ago (Ma) according to the most recent revision of the International Commission on Stratigraphy (ICS) in 2022. It was preceded by the Sakmarian and followed by the Kungurian.

Stratigraphy

Jimbacrinus bostocki MHNT Gascoyne Junction, Western Australia

The Artinskian is named after the small Russian city of Arti (formerly ''Artinsk''), situated in the southern Ural mountains, about 200 km southwest of Yekaterinburg. The stage was introduced into scientific literature by

Alexander Karpinsky Alexander Petrovich Karpinsky (russian: Александр Петрович Карпинский, trl. Aljeksandr Pjetrovič Karpinskij; 7 January 1847 ( NS) – 15 July 1936) was a prominent Russian and Soviet geologist and mineralogist, and ...

in 1874.

Base of the Artinskian

The base of the Artinskian Stage is defined as the first appearance datum (FAD) of the

conodont Conodonts (Greek ''kōnos'', "cone", + ''odont'', "tooth") are an extinct group of agnathan (jawless) vertebrates resembling eels, classified in the class Conodonta. For many years, they were known only from their tooth-like oral elements, which ...

species ''

Sweetognathus whitei ''Sweetognathus'' is an extinct genus of conodonts in the family Sweetognathidae that evolved at the beginning of the Permian period (298.9 Ma), in near-equatorial, shallow-water seas. The genus is characterized by pustulose ornamentation on a ...

'' and '' Mesogondolella bisselli''. In order to constrain this age, the ICS subcommission on Permian

stratigraphy Stratigraphy is a branch of geology concerned with the study of rock (geology), rock layers (Stratum, strata) and layering (stratification). It is primarily used in the study of sedimentary rock, sedimentary and layered volcanic rocks. Stratigrap ...

informally proposed a candidate GSSP in 2002, later followed by a formal proposal in 2013. The proposed GSSP location - the Dal'ny Tulkas roadcut in the Southern Urals, near the town of Krasnousolsky - was eventually ratified in February 2022. 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. Earlier radiometric reported a much younger age of 280.3 Ma for the Sakmarian-Artinskian boundary.

Top of the Artinskian

The top of the Artinskian (and the base of the Kungurian) is defined as the place in the stratigraphic record where fossils of conodonts '' Neostreptognathodus pnevi'' and ''Neostreptognathodus exculptus'' first appear.

Artinskian Warming Event

Around 287 million years ago occurred an interval of pronounced warming known as the Artinskian Warming Event (AWE). This period of global warming accelerated the

deglaciation Deglaciation is the transition from full glacial conditions during ice ages, to warm interglacials, characterized by global warming and sea level rise due to change in continental ice volume. Thus, it refers to the retreat of a glacier, an ice shee ...

that had been occurring since the Sakmarian following the end of the most intense glacial phase of the Late Palaeozoic Ice Age. In addition, it is also associated with significant

global drying Land surface effects on climate are wide-ranging and vary by region. Deforestation and exploitation of natural landscapes play a significant role. Some of these environmental changes are similar to those caused by the effects of global warming. De ...

, which had gradually been occurring since the Carboniferous-Permian boundary. Major aridification during the AWE is evidenced by a positive δ¹⁸O excursion observed in brachiopod

fossils A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in ...

, with arid and semi-arid conditions expanding across much of Pangaea as

glaciers A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires distinguishing features, such as ...

receded to refugia in the polar regions of

Gondwana Gondwana () was a large landmass, often referred to as a supercontinent, that formed during the late Neoproterozoic (about 550 million years ago) and began to break up during the Jurassic period (about 180 million years ago). The final stages ...

References

External links

GeoWhen Database - Artinskian

Upper Paleozoic stratigraphic chart
at the website of the subcommission for stratigraphic information of the ICS {{Geological history, p, p Permian geochronology .