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Lower-Middle Triassic conodont biostratigraphy of the Mingtang section, Nanpanjiang Basin, South China

Liang, Lei, Tong, Jinnan, Song, Haijun, Song, Ting, Tian, Li, Song, Huyue, Qiu, Haiou
Palaeogeography, palaeoclimatology, palaeoecology 2016 v.459 pp. 381-393
Retaria, algae, basins, extinction, fossils, China
The well-exposed stratigraphic sequences on the Great Bank of Guizhou (GBG) in South China provide important information for the understanding of various environmental settings during the Permian-Triassic mass extinction and the subsequent recovery, including one of the oldest Triassic marginal reef complexes, which is viewed as an important indicator of biotic recovery following the end-Permian mass extinction. Here we report a systematic conodont study on a newly exposed Lower-Middle Triassic section, the Mingtang section, at the margin of the GBG to provide more data for the time scale of the post-extinction recovery. Twenty-four species in 11 conodont genera are identified and assigned to Hindeodus parvus, Neoclarkina discreta, Neospathodus dieneri, Novispathodus waageni, Neospathodus triangularis-Triassospathodus homeri, Chiosella timorensis, Nicoraella germanica, and Nicoraella kockeli zones in ascending order. These zones correlate well with the conodont successions in South China and over the world. The Induan-Olenekian boundary can be well defined by the first occurrence of Novispathodus waageni in the lower-middle part of the Luolou Formation, while the Early-Middle Triassic boundary was placed at 0.2m below the top of the Luolou Formation according to the first occurrence of Chiosella timorensis. These conodont data suggest that the Tubiphytes-reef began to recover in the Bithynian (early Middle Triassic), later than benthonic organisms such as foraminifers and calcareous algae.