THE APPLICATION OF SPORE-POLLEN INFORMATION FUNCTION FOR PALAEOENVIRONMENT ANALYSIS OF THE SHAHEJIE FORMATION IN THE WESTERN DEPRESSION,LIAOHE FAULT BASIN, NE CHINA
In order to strengthen the research of the palaeoenvironment and palaeoclimate in petroliferous basin, to search for a new method for palaeoenvironmental research, this study is to reconstruct the palaeoenvironment and palaeoclimate using spore-pollen information function. Spore-pollen is a sensitive information carrier of climate change. Suitable climate will result in a higher value of spore-pollen information function. And in the process of the deposition from the shore to the center of the basin, with the deepening of water, spore-pollen information function gradually decreased. Based on the spore-pollen information function, <2.0,2.02.1 or>2.1,the lake in the sedimentary period of the Shahejie Formation is divided into semi deep,shallow or shore shallow water lake environments in the western Depression, Liaohe Fault Basin. The rhythm change of spore-pollen information function values from the Member 4 to Member 1 of the Shahejie Formation shows low (1.97) high (2.12) low (1.88)high (2.28),implies a cycle of the palaeoclimate evolution was hot and dry-wet-hot and drywet. The result suggests that variation of spore-pollen information function of the Shahejie Formation in the western Depression has a good response to the palaeoclimate evolution, which is closely related with the palaeolandform and palaeoenvironment in different developmental stages of the basin. Therefore,the spore-pollen information function is one of the effective means to reconstruct the palaeoclimate and palaeoenvironment.