Artinskian

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,[2] though older versions of the ICS preferred a younger age range. It was preceded by the Sakmarian and followed by the Kungurian.

Artinskian
290.1 ± 0.26 – 283.5 ± 0.6 Ma
Chronology
Etymology
Name formalityFormal
Usage information
Celestial bodyEarth
Regional usageGlobal (ICS)
Time scale(s) usedICS Time Scale
Definition
Chronological unitAge
Stratigraphic unitStage
Time span formalityFormal
Lower boundary definitionNot formally defined
Lower boundary definition candidatesFAD of the Conodont Sweetognathus whitei
Lower boundary GSSP candidate section(s)Southern Ural mountains
Upper boundary definitionNot formally defined
Upper boundary definition candidatesNear FAD of the Conodont Neostreptognathodus pnevi
Upper boundary GSSP candidate section(s)Southern Ural mountains

StratigraphyEdit

 
Jimbacrinus bostocki Artinskian of Australia. (Found near Jimba Jimba Station )

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.[3]

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. 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.[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.[4] Earlier radiometric reported a much younger age of 280.3 Ma for the Sakmarian-Artinskian boundary.

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.[3]

ReferencesEdit

  1. ^ "Chart/Time Scale". www.stratigraphy.org. International Commission on Stratigraphy.
  2. ^ a b 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.
  3. ^ a b Gradstein, Felix M.; Ogg, James G.; Smith, Alan G. (2004). A Geologic Time Scale 2004. ISBN 9780521786737.
  4. ^ 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. Bibcode:2012GSAB..124..549S. doi:10.1130/B30385.1.

External linksEdit