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GSSP for Sakmarian Stage

Definition:

The base of the Sakmarian Stage is defined in Bed 26/3 at 55.4m above the base of the Usolka Section, Southern Urals, Russia. It coincides with the first occurrence of conodont Mesogondolella monstra.

Location:

The Sakmarian GSSP section is located on the right side of the Usolka River near the Health Resort Kranousolsky (Republic of Bashkortostan, Russia) at a latitude of 53°55'28.86"N and a longitude of 56°31'43.38"E. 		GSSP for Sakmarian Stage


Sedimentology:

The GSSP level is located in an interval with continuous limestone and marl deposition 55.4m from the base of the section in Bed 26/3. Bed 26 in the Usolka Section consists of thin alternations of brownish-grey micritic limestone, marl and argillite.


Primary Markers:

First appearance of conodont Mesogondolella monstra within the evolutionary lineage from Mesogondolella uralensis ? Mesogondolella monstra ? Mesogondolella manifesta in Bed 26/3 in the Usolka Section.

Secondary Markers:

Conodonts:
   Sweetognathus binodosus first occurs close to the base of the Sakmarian.

Carbon 13:
A double negative shift in δ13 Ccarb is near the Asselian/Sakmarian boundary. The younger excursion nearly coincides with the first appearance of Mesogondolella monstra.

Correlation Events:

Conodont FAD Mesogondolella monstra

Other Locations around the World:

Mesogondolella monstra marks the base of the Sakmarian Stage in the Raanes Formation (latest Asselian to late Sakmarian) at the East Blind Fiord section in the Sverdrup Basin, Arctic Canada.

References:

Chernykh, V.V., Chuvashov, B.I., Shen, S.Z., Henderson, C.M., Yuan, D. X., and Stephenson, M.H., 2020. The Global Stratotype Section and Point (GSSP) for the base- Sakmarian Stage (Cisuralian, Lower Permian). Episodes 43/4, p. 961-979.

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