Global Stratotype Section and Point (GSSP) for the base-Artinskian Stage (Lower Permian)

The base-Artinskian Stage GSSP is defined at 0.6 m above the base of bed 4b at the Dal’ny Tulkas section in the southern Urals of Russia (53.88847N and 056.51615E). This point corresponds to the First Appearance Datum of the conodont Sweetognathus asymmetricus, which is part of a well-defined and widely distributed lineage. Additional markers for correlation include a radioisotopic age interpolated between 290.1 and 290.5 Ma, a strontium isotopic ratio of .70767, and many additional fossils groups, particularly ammonoids and fusulines, but also including small foraminiferans, radiolarians, and palynomorphs. Finally, the boundary occurs within a transgressive succession, near, or at a maximum flooding surface in many sections, thereby forming a distinctive sequence stratigraphic signature in the field. The Artinskian Stage is the third stage of the Lower Permian or Cisuralian Series.