The Global Stratotype Section and Point (GSSP) for the base of the Capitanian Stage (Guadalupian, Middle Permian)

The Global Stratotype Section and Point (GSSP) for the base of the Capitanian Stage was proposed in 1999 and defined by the first appearance datum (FAD) of the conodont Jinogondolella postserrata within the lineage J. aserrata -> J. postserrata -> J. shannoni at Nipple Hill in West Texas, USA. Despite its widespread recognition for more than two decades, the official GSSP paper was not published, nor have its index conodont fossils been properly documented. At Nipple Hill, only the uppermost 0.5 m of the Pinery Member belongs to the Capitanian Stage. J. postserrata first appears at 19.8 m above the base of the auxiliary Frijole section. Based on U-Pb CA-ID-TIMS geochronology of ash beds from the GSSP area, the base of the Capitanian Stage has been constrained at 264.28 +/- 0.16 Ma. Magnetostratigraphy suggests that the Illawarra Reversal is located slightly below the base of the Capitanian Stage. Strontium isotope chemostratigraphy generally shows a continuous decline in the Sr-87/Sr-86 ratio throughout the Capitanian in the GSSP area, but all ratios are higher than the Capitanian minimum of similar to 0.7068. delta(13)C(carb)profile shows no distinct excursion around the Wordian/Capitanian boundary interval. Detailed correlation suggests that the middle-upper part of the fusuline-based Midian Stage correlates with the Capitanian Stage.

Automated summary

The GSSP for the base of the Capitanian Stage was proposed in 1999 in West Texas, USA, but the official paper and index fossils have not been properly documented. Based on carbon isotope and magnetostratigraphic studies, the base and boundary of the Capitanian Stage have been constrained at 264.28+/- 0.16 Ma.