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.aser...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±0.16Ma.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 87Sr/86Sr ratio throughout the Capitanian in the GSSP area,but all ratios are higher than the Capitanian minimum of~0.7068.δ^(13)Ccarb 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.展开更多
基金supported by an international collaborative project of NSFC(Grant no.41420104003)the Strategic Priority Research Programs of the Chinese Academy of Sciences(Grant no.XDB26000000)the NSERC Discovery Grant to CMH.
文摘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±0.16Ma.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 87Sr/86Sr ratio throughout the Capitanian in the GSSP area,but all ratios are higher than the Capitanian minimum of~0.7068.δ^(13)Ccarb 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.
