Bashkirian

The Bashkirian is in Earth's history, the lowest stratigraphic stage of Pennsylvaniums ( Carboniferous). The level corresponds in absolute terms ( geochronological ) the period from about 323.2 million to about 315.2 million years. The stage following the Serpukhovian and is detached from the Moscovian.

Naming and history

The stage is after the people of the Bashkirs and the Republic of Bashkortostan ( officially: Republic of Bashkortostan ) named in the southern Urals (Russia). And stage name was suggested in 1934 by Sofija Viktorovna Semichatowa.

Definition and GSSP

The lower limit of the stage and therefore the lower limit of the Pennsylvaniums is by the first appearance of the conodont species Declinognathodus nodiliferus sl defined. The stage ends with the first appearance of the conodont postsulcatus Type Declinognathodus donetzianus and / or Idiognathoides and fusulinids Type Aljutovella aljutovica. The official reference profile of the International Commission on Stratigraphy ("Global Stratotype Section and Point" ) for the Bashkirian is a profile in the Battleship Wash Formation in the Arrow Canyon ( Nevada, USA).

Subdivision

The Bashkirian is divided into six conodont biozones:

  • Neognathodus atokaensis zone
  • Declinognathodus marginodosus zone
  • Idiognathodus sinuosus zone
  • Neognathodus askynensis zone
  • Idiognathoides sinuatus zone
  • Declinognathodus noduliferus zone

Pictures of Bashkirian

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