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 geochron ...

, the Artinskian is an

age Age or AGE may refer to: Time and its effects * Age, the amount of time someone has been alive or something has existed ** East Asian age reckoning, an Asian system of marking age starting at 1 * Ageing or aging, the process of becoming older ...

stage Stage, stages, or staging may refer to: Arts and media Acting * Stage (theatre), a space for the performance of theatrical productions * Theatre, a branch of the performing arts, often referred to as "the stage" * ''The Stage'', a weekly Brit ...

of the

Permian The Permian ( ) is a geologic period and System (stratigraphy), stratigraphic system which spans 47 million years, from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.902 Mya. It is the s ...

. It is a subdivision of the

Cisuralian The Cisuralian, also known as the Early Permian, is the first series/epoch of the Permian. The Cisuralian was preceded by the Pennsylvanian and followed by the Guadalupian. The Cisuralian Epoch is named after the western slopes of the Ural Mou ...

Epoch In chronology and periodization, an epoch or reference epoch is an instant in time chosen as the origin of a particular calendar era. The "epoch" serves as a reference point from which time is measured. The moment of epoch is usually decided b ...

Series Series may refer to: People with the name * Caroline Series (born 1951), English mathematician, daughter of George Series * George Series (1920–1995), English physicist Arts, entertainment, and media Music * Series, the ordered sets used i ...

. The Artinskian likely lasted between and million years ago (Ma) according to the most recent revision of the

International Commission on Stratigraphy The International Commission on Stratigraphy (ICS), sometimes unofficially referred to as the International Stratigraphic Commission, is a daughter or major subcommittee grade scientific organization that concerns itself with stratigraphy, strati ...

(ICS) in 2022. It was preceded by the

Sakmarian In the geologic timescale, the Sakmarian is an age or stage of the Permian period. It is a subdivision of the Cisuralian Epoch or Series. The Sakmarian lasted between 293.52 and million years ago (Ma). It was preceded by the Asselian and fo ...

and followed by the

Kungurian In the geologic timescale, the Kungurian is an age or stage of the Permian. It is the latest or upper of four subdivisions of the Cisuralian Epoch or Series. The Kungurian lasted between and million years ago (Ma). It was preceded by the Arti ...

Stratigraphy

The Artinskian is named after the goniatite grits of Artinsk which was introduced by

Roderick Murchison Sir Roderick Impey Murchison, 1st Baronet (19 February 1792 – 22 October 1871) was a Scottish geologist who served as director-general of the British Geological Survey from 1855 until his death in 1871. He is noted for investigating and desc ...

, Édouard de Verneuil and count Alexander von Keyserling in their ''The Geology of Russia in Europe and the Ural Mountains'' (1845). The grits of Artinsk, in turn, get its name from the Artinsky District with center in the

Russia Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...

n smalltown of Arti (formerly ''Artinsk zavod''), situated in the middle

Urals The Ural Mountains ( ),; , ; , or simply the Urals, are a mountain range in Eurasia that runs north–south mostly through Russia, from the coast of the Arctic Ocean to the river Ural (river), Ural and northwestern Kazakhstan.

, about 170 km southwest of

Yekaterinburg Yekaterinburg (, ; ), alternatively Romanization of Russian, romanized as Ekaterinburg and formerly known as Sverdlovsk ( ; 1924–1991), is a city and the administrative centre of Sverdlovsk Oblast and the Ural Federal District, Russia. The ci ...

. The stage was introduced into scientific literature by Alexander Karpinsky in 1874.

Base of the Artinskian

The base of the Artinskian Stage is defined as the

first appearance datum First appearance datum (FAD) is a term used by geologists and paleontologists to designate the first appearance of a species in the geologic record. FADs are determined by identifying the geologically oldest fossil discovered, to date, of a partic ...

(FAD) of the

conodont Conodonts, are an extinct group of marine jawless vertebrates belonging to the class Conodonta (from Ancient Greek κῶνος (''kōnos''), meaning " cone", and ὀδούς (''odoús''), meaning "tooth"). They are primarily known from their hard ...

species '' Sweetognathus whitei'' 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 layers (strata) and layering (stratification). It is primarily used in the study of sedimentary and layered volcanic rocks. Stratigraphy has three related subfields: lithost ...

informally proposed a candidate

GSSP A Global Boundary Stratotype Section and Point (GSSP), sometimes referred to as a golden spike, is an internationally agreed upon reference point on a stratigraphic section which defines the lower boundary of a stage on the geologic time scale. ...

in 2002, later followed by a formal proposal in 2013. The proposed GSSP location — the Dal'ny Tulkas roadcut in the

Southern Ural Southern Ural (, ) encompasses the south, the widest part of the Ural Mountains, stretches from the river Ufa (near the village of Lower Ufaley) to the Ural River. From the west and east the Southern Ural is limited to the East European Plain, W ...

s, 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

-Artinskian boundary.

Top of the Artinskian

The top of the Artinskian (and the base of the

) is defined as the place in the stratigraphic record where fossils of conodonts '' Neostreptognathodus pnevi'' and ''Neostreptognathodus exculptus'' first appear. The proposed GSSP candidate — the Mechetlino section (Southern Urals).

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 Present-day climate change includes both global warming—the ongoing increase in global average temperature—and its wider effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes ...

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 A glacier (; or ) is a persistent body of dense ice, a form of rock, that is constantly moving downhill under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires ...

phase of the Late Palaeozoic Ice Age. In addition, it is also associated with significant global drying, 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 Brachiopods (), phylum (biology), phylum Brachiopoda, are a phylum of animals that have hard "valves" (shells) on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear e ...

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 ...

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

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

receded to refugia in the polar regions of

Gondwana Gondwana ( ; ) was a large landmass, sometimes referred to as a supercontinent. The remnants of Gondwana make up around two-thirds of today's continental area, including South America, Africa, Antarctica, Australia (continent), Australia, Zea ...

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 .