Palynological zonations and paleoecology of Carboniferous sequence from Zhongwei of Ningxia, Northwest China

Abstract

Six miospoe assemblage zones are established for Carboniferous strata (Namurian-Stephanian) in the Xiaheyan Section of Zhongwei, Ningxia, Northwest China. They correspond to the Early Namurian (goniatite E Zone and H Zone), Late namurian (goniatite R- G1Zone), Westphalian A-B, Westphalian C-D and Stephanian of West Europe, respectively. The general aspect of Carboniferous palynonora in Zhongwei is dominated by spore types with affinities of Filicopsida and Pteridospermospsida; Sphenopsid and Lycopsid spores occupy the subdominant position, while the gymnospermous pollen grains of Cordaitopsida and Confiferopsida make lesser contribution to the flora. Three miospore phases are recognized in ascending order as Lycospora-Crassispore phase, Laevigatosporites-Torispora Phase and Florinites-Pityosporites phase. The paleoecological considerations of each phase are also discussed.