福建泰宁白垩纪红层植物及孢粉化石组合特征

泰宁白垩纪红层盆地由朱口、梅口、龙安3个盆地组成,盆地内出露的岩石地层为沙县组和崇安组。近期工作,首次在龙安盆地沙县组采获植物化石和孢粉化石,梅口盆地崇安组采获孢粉化石。根据植物化石及孢粉组合特征,沙县组地质时代为晚白垩世早、中期,相当于赛诺曼期-土仑期(Cenomanian-Turonian);崇安组为晚白垩世晚期,相当于康尼亚克期-马斯特里赫特期(Coniacian-Maastrichtian)。依据泰宁梅口盆地崇安组孢粉组合特征,建立晚白垩世晚期Pinuspollenites-Ulmipollenites minor组合,以代表福建白垩纪第Ⅵ孢粉组合。

The Assemblage and Characters of Floras and Sporo-pollen Fossils in the Cretaceous Red-bed Basin of Taining County, Fujian Province

The Cretaceous red-bed basin in Taining County is made up of three basins:Zhoukou Basin,Meikou Basin and Longan Basin.The lithostratigraphy distributed in the basins is Shaxian Formation(K_2s) and Chongan Formation(K_2c) of Upper Cretaceous.Because no palaeontological fossils which can be used to determine the stratigraphic time are discovered in the red-bed basin,the stratigraphic time of the red-bed basin has been considered as Late Cretaceous epoch for a long time only on the basis of the comparison with other red-bed basins in Fujian Province.In the recent fieldwork,plant remains and sporo-pollen fossils are discovered in the strata of Shaxian Formation in the Longan Basin of Taining County and sporo-pollen fossils in the strata of Chongan Formation in the Meikou Basin,which provide with reliable palaeontological evidences of determinating the stratigraphic time.Based on the characteristics of plant remains and sporo-pollen assemblages,it is inferred that geologic time of the strata Shaxian Formation of the Cretaceous red-bed basin in Taining County is early-mid stages of Late Cretaceous epoch,which is equivalent to the Cenomanian-Turonian Stage and that geologic time of the strata Chongan Formation is the late stage of Late Cretaceous epoch,which is equal to the Coniacian-Maastrichtian Stage.According to the characteristics of sporo-pollen assemblage from the strata Chongan Formation of the Meikou Basin,the sporo-pollen assemblage Pinuspollenites-Ulmipollenites minor is established,which can stand for the sporo-pollen assemblage of the late stage of Late Cretaceous epoch in Fujian Province.