Terrestrial end-Guadalupian crisis constrained by mid-latitude Permian palynological data from Jimsar, Junggar Basin, China

Abstract

The end-Permian mass extinction and the end-Guadalupian crisis are the most remarkable events in the Permian terrestrial ecosystem. To better understand the end-Guadalupian event in mid-latitude of Pangea in the Northern Hemisphere, palynological investigations are conducted on the terrestrial Permian deposits in the Dalongkou profile of Jimsar, northern Xinjiang, China. Two palynological assemblages are recognized in stratigraphic ascending order, the Cordaitina subrotata–Striatoabieites lipidus–Protowelwitschiapollis exolescus assemblage from the uppermost Lucaogou, Hongyanchi and the lower Quanzijie formations, and the Kraeuselisporites spinulosus–Tuberculatosporites homotubercularis–Potonieisporites turpanensis assemblage from the upper Quanzijie and lowermost Wutonggou formations. Based on the palynological data, the uppermost Lucaogou and Hongyanchi formations are assigned to the Roadian stage, and the lower Quanzijie Formation to the Capitanian stage, and the upper Quanzijie and lowermost Wutonggou formations to the Wuchiapingian stage. Thus, a Wordian-age hiatus is confirmed between the lower Quanzijie Formation and the Hongyanchi Formation on the basis of palynological evidence. The palynofloral succession shows a smooth transition between the Guadalupian and Lopingian palynofloras in the Dalongkou profile of Jimsar, in the Junggar Basin. The end-Guadalupian crisis resulted in a 17% loss of pollen species, indicating that the extinction was on the background level.