A palynological assemblage of the Qingshankou Formation from the Wudaogou Section, eastern margin of the Songliao Basin, and its implications of paleovegetation and paleoclimate

The pollen and spores found in the Qingshankou Formation at the Wudaogou Section, Bin County, Heilongjiang Province, northeastern China, were studied systematically, and a palynological assemblage was recognized and named Lygodioisporites – Pinuspollenites – Cedripites . According to palynological data, the strata in the Wudaogou Section are stratigraphically consistent with Member 1 of the Qingshankou Formation, and the geological time is constrained to the Turonian stage. On the basis of the palynological fossils, we can infer that during the depositional period of Member 1 of the Qingshankou Formation in Bin County, the paleovegetation was mainly dominated by coniferous forest, consisting primarily of Pinaceae, with rare Filicales growing on the forest floor; the paleoclimate was consistent with the subtropical zone of today, and the paleoenvironment was semi-humid. The results significantly provide biostratigraphic evidence for the division and correlation of the Qingshankou Formation and provide new insights for analyzing paleovegetation and paleoclimate in the Songliao Basin.