Recent advance in study of K-Pg boundary in Jiayin of Heilongjiang, China and its adjacent area

摘要

The non-marine Cretaceous-Paleogene boundary(KPgB)in Jiayin of Heilongjiang was first defined and reported in China by the authors research team in 2011.Thereafter the continuous research on the KPgB and its related Late Cretaceous biota in Jiayin has been made by the authors in 2012-2020.The achievements of the research are mainly reflected as follows:(1)a new drilling borehole with 60 m in depth carried out in the Xiaoheyan of Jiayin in 2016,supplemented new palynological evidence for the KPgB definition in 2011;(2)some radiometric dating newly made on the strata related to the KPgB in Jiayin and its neighboring Russian area,provided the supplemental evidence for the KPgB definition in Jiayin;(3)many new fossils found by the authors,represented by the angiosperms Dalembia and Nelumbo,refresh understanding the Late Cretaceous environment of Jiayin;and(4)the TEM method is applied in the study of pollen exine ultrastructure of Pseudointegricorpus,Wodehouseia,and Aquilapollenites,promoting the late Maastrichtian ecological study in Jiayin,related to the KPgB.