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

摘要: 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 …