Lower-Middle Triassic Strata in Qingyan, Guizhou Province, South China
CHEN Jing
TONG Jin-nan
NIU Zhi-jun
ZHOU Shi-qin
SONG Hai-jun
YI Fei
Abstract：The Lower-Middle Triassic strata in Qingyan, Guizhou are well exposed and have abundant fossils. In particular, the Qingyan fauna in Middle Triassic shows biota radiation. The stratigraphical sequence has been studied extensively for a better understanding of the course and pattern of the biotic recovery and radiation following the End-Permian mass extinction. Five co-nodont zones, including Neospathodus dieneri zone, Neospathodus waageni zone, Neospathodus pingdingshanensis zone,Neospathodus homeri zone, and Chiosella timorensis zone, 2 foraminifer assemblages and 6 bivalve assemblages are recognized.The boudaries of Induan-Olenekian and Olenekian-Anisian have been defined by the conodonts. Various fossils and their ecolog-ic assemblages indicate that the first episode of recovery-radiation after the End-Permian extinction happened in the early Aini-sian, and the fossil assemblages in Leidapo Member (Middle Anisian) reveal a typical prosperous biotic ecosystem after radia-tion. The brachiopod assemblages, Madoia sp. assemblage and Rhaetina angustaeformis assemblage, from the Middle Anisian Qingyan Formation represent the first radiation of brachiopod faunas from the recovery. In addition, the sedimentary evidence indicates two up-shallowing cycles of paleoenvironmental setting, basin-slope-platform-hasin-slope-shelf.
Keywords：Lower-Middle Triassicbiostratigraphyrecovery and radiationQingyan of Guizhou.
Publication Date：2010-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：11( 51-61 )