The Aptian Palynoflora Of Razdolnaya (Suifen) River Coal Basin

The Cretaceous Razdolnaya(Suifen)River Coal Basin located in the eastern border area between Russia(South Primorye)and China(eastern Heilongjiang).The Early Cretaceous flora and strata of the Basin has been studied for nearly 80 years in Russia,however,there is no any complete work on the whole basin’s palynoflora and strata carried out,mainly due to the previous work was short of the study of the western edge area of the Basin.Thus,this dissertation is the first complete and synthetic work on the Aptian(late Early Cretaceous)palynoflora of the Basin spanning the Russian and Chinese both sides.Main achievements of the dissertation are mainly in the follows.1.There are 217 palynological samples from five coal mine areas of this Basin both from Russia and China,were collected and analyzed by the author.The four sites,coal mines in Russian side,and the Dongning coal mine(Dongning)in China’s side,are new and for the first time.2.A synthetic study of the taxonomics of the palynological assemblage of the Lipovtsy Formation of Razdolnaya Basin with stratigraphic and paleoecological analyses in detail are conducted in this dissertation.About 88 species of 55 genera of the palynological spectra of the Lipovtsy and Dongning formations recognized and synthetically reported by the author.In these palynological spectra,the spores have 54 species of 32 genera(occupied ca.60%);gymnosperm pollen have 25 species of 18genera(ca.35-40%);and angiosperm pollen have 8 species of 5 genera(ca.1-3%).3.Clarifying further the age of the palynofloras of the Lipovtsy and Dongning formations as the Aptian,based on the main index taxa in this palynofloras,the comparisons of the palynological spectra and the stratigraphic correlation with some typical Aptian palynofloras and strata in the Far East Russian region were documented in age by direct or indirect evidences with marine fossils.4.By palynological evidence,the author further confirmed the cyatheaceous,gleicheniaceous and dicksoniaceous fern trees were the main coal-forming plants for the humic and liptobiolithic coals in the northwestern Razdolnaya Basin.Besides,it is considered also that some conifers and the Cycadophtes-Ginkgoalean trees,paying possible roles also for the coal-forming in the Lipovtsy and Dongning formations,during the Aptian time.5.The angiosperm pollen are found,including monosulcate and tricolpate in type,which is significant for the study of early evolution of flowering plants in Primorye even in the East Asia during the Early Cretaceous time.6.With the reconstruction of paleoclimate and paleoenvironment of the palynofloras,the author further proposed the palynofloras of the Lipovtsy and Dongning formations were probably a swamp plant communities and living in a swampy river valley environment,and the warm or warm-temparate and humid climate was also favorable for coal-forming.During the time,volcanic ash repeatedly covered this area.