|Subdivision of the Permian system|
according to the ICS, as of 2017.
In the geologic timescale, the Artinskian is an age or stage of the Permian. It is a subdivision of the Cisuralian epoch or series. The Artinskian likely lasted between 290.1 and 283.5 million years ago (Ma) according to the most recent revision of the International Commission on Stratigraphy (ICS) in 2013, though older versions of the ICS preferred a younger age range. It was preceded by the Sakmarian and followed by the Kungurian.
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 in 1874.
Base of the ArtinskianEdit
The base of the Artinskian stage is defined as the first appearance datum (FAD) of the conodont species Sweetognathus whitei and Mesogondolella bisselli, i.e. the time when these species first appear in the geological record. In order to constrain this age, the ICS subcommission on Permian stratigraphy informally proposed a candidate GSSP in 2002, later followed by a formal proposal in 2013. This candidate GSSP is the Dal'ny Tulkas roadcut in the Southern Urals, near the town of Krasnousolsky.
U-Pb radiometric dating by Schmitz and Davydov (2012) 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 dating by Chuvashov et al. (1996) reported a much younger age of 280.3 Ma for the Sakmarian-Artinskian boundary, while Gradstein, Ogg, and Smith (2004) projected that the base of the Artinskian was ~283 Ma, though a widely cited 284.4 Ma age (used by the ICS until 2012) also originated in their publication.
Top of the ArtinskianEdit
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.
|Amphibians of the Artinskian|
|Boskovice Furrow, Czech Republic|
|Abo Formation, New Mexico and Seymour, Baylor County, Texas|
|Arthropods of the Artinskian|
|Kansas and Oklahoma|
|Synapsids of the Artinskian|
Kenilworth, Kenilworth Sandstone Formation, Warwickshire Group, Warwickshire, England; Autun, France, Cutler Formation, Arizona, Colorado, New Mexico and Utah; Fort riley, Chase Group, Kansas, Greene Formation, Dunkard Group, Ohio; Wellington Formation, Oklahoma; Clyde Formation, Texas and Oklahoma; Admiral Formation; Belle-Plains Formation; Wichita Group, all three in Texas,
|Wichita Group and Clear Fork Group, both in Texas, USA|
|Gzhelian-Artinskian||New Mexico; Utah-Arizona border region, both in USA; possibly England||The English specimen known as S?. brittanicus ) is now generally classified as Sphenacodontidae incertae sedis separate from the other Sphenacodon species so may need reassigning.|
- "Chart/Time Scale". www.stratigraphy.org. International Commission on Stratigraphy.
- Chuvashov, Boris I.; Chernykh, Valery V.; Shen, Shuzhong; Henderson, Charles M. (2013). "Proposal for the Global Stratotype Section and Point (GSSP) for the base-Artinskian Stage (Lower Permian)". Permophiles. 58: 26–34.
- Gradstein, Felix M.; Ogg, James G.; Smith, Alan G. (2004). A Geologic Time Scale 2004. ISBN 9780521786737.
- Schmitz, Mark D.; Davydov, Vladimir I. (March–April 2012). "Quantitative radiometric and biostratigraphic calibration of the Pennsylvanian–Early Permian (Cisuralian) time scale and pan-Euramerican chronostratigraphic correlation". Geological Society of America Bulletin. 124 (3/4): 549–577. doi:10.1130/B30385.1.CS1 maint: date format (link)