Sporopollen Assemblage And Evolution Of Palaeoclimate In Suqian City Area Since Late Pleistocene

This paper is on the basis of the major project of “Standard drill detection andquaternary standard profile” in “Project of seismic active fault detection and seismicrisk assessment in Suqian city” which lauched by Earthquake Administration ofJiangsu Province and Earthquake Administration of Suqian city. The main thesis is3standard drills for pollen analysis in Suqian city, division of pollen assemblage zones,according to the evolution of ancient vegetation, analysis of the ancient climate andevolution, comprehensive dating data, comprehensive analysis of workspacepalynological data and C14date, and obtained the following conclusions:(1) Use the analysis method of borehole lithology, color, sedimentary cycle,sedimentary facies, chronology, according to the3standard hole data, combined withthe results of previous studies, the work area of stratigraphic division and correlationscheme, which is divided into: Holocene Lianyungang group (QhL), Qi Zui group(Upper Pleistocene Qp3Q), Pleistocene middle berth hillock group (Qp2B),Pleistocene lower Douchong group (Qp1D). In addition, the Quaternary strataunderlying is Pliocene Suqian formation (N2S).(2) According to the pollen spectrum analysis, the Suqian BK2standard drill,since the late Pleistocene palynological assemblage is divided into5sporo-pollenzones. On the basis of sporopollen assemblage, lithology, dating data, determine thecombination Ⅰ,Ⅱ respectively represent the last interglacial and glacial stage;Ⅲ,Ⅳ,Ⅴ respectively represent postglacial early dry and cool, warm and moist andmiddle late cool and wet stage.(3) Palynological assemblages reflect the vegetation types and climate evolutionduring Quaternary period in Suqian city, BK2hole of Upper Pleistocene andHolocene5Palynological assemblages corresponding to the type of vegetation andclimate types:the earlier of Late Pleistocene (coniferous and mixed forest, warm andmoist) the later of Late Pleistocene (coniferous and mixed forestt-grassland, cool and moist.) the early Holocene (spare deciduous broad-leaved forest-grassland, cooland dry) the mid-Holocene (spare deciduous broad-leaved forest-grassland, warmand moist, coniferous and broad-leaved mixed grassland,) the late Holocene (sparedeciduous broad-leaved forest-grassland, cool and moist).