Sporopollen Assemblage And Evolution Of Palaeoclimate In Qinhuangdao City And Surrounding Areas Since Late Pleistocene

Quaternary pollen studies for the current urbans relatively weak, this paper based on the major project of China Earthquake Administration and Earthquake Administration of Hebei Province " Projects of cities in Hebei Province seismic active fault detection and seismic risk assessment (Qinhuangdao)". Based on the sporopollen sampled analysis of controlled standard hole in Qinhuangdao, we could divide sporopollen assemblage and derived the corresponding ancient climate and its evolution according to the evolution of ancient vegetation. In addition, based on the chronological datas ,we made comparative analysis of sporopollen datas.So we drewn some conclusion as follows:1.The sporopollen assemblage in controlled standard Qinhuangdao hole could be divided into three sporopollen zone, six sporopollen sub-zone, the upper Pleistocene series (7.8m-31.5m), corresponding to sporopollen assemblageⅠ-Ⅱ, sub-zoneⅠa mirrored cold and humid climate, sub-zoneⅠb mirrored cold and dry climate, sub-zoneⅡa mirrored cold and humid climate, sub-zoneⅡb mirrored cold and dry climate; generally reflected a period of cold climate. Holocene series (0-7.8m), corresponding to sporopollen assemblage III, sub-zone IIIa mirrored warm and cool climate partial dry, sub-zone IIIb with humid and warm climate. The climate in Holocene reflects the volatility of climate warming from the cold, sub-band IIIa belonged to the early Holocene climatic characteristics, sub-zone IIIb belonged to middle and late Holocene climatic characteristics.2. Based on the comparative analysis of sporopollen assemblage in controlled standard Qinhuangdao hole, Handan, Ningjinbo and Caofeidian, summed up the features of sporopollen assemblage and climate evolution in North China Plain since the late Pleistocene, which had reflected a climate change characteristics of alternating of warm and cold.They experienced the changes of warm period - cold period - warm period, which is equivalent to the climate cycles of the last interglacial of Pleistocene - the last glacial– postglacial of Holocene.3.Compared with deep-sea oxygen isotope and the Antarctic ice core, vegetation types and climate in Qinhuangdao affected by glacial - interglacial period were more significant. Deep-sea oxygen isotope stage 1 corresponds to the sporopollen assemblageⅢ, corresponding to Holocene interglacia period climate characteristics. Deep-sea oxygen isotope stage 2 corresponds to the sporopollen assemblageⅡ, corresponding to the late Pleistocene glacial climatic characteristics of the ice class. Deep-sea oxygen isotope stage 3 corresponds to the sporopollen assemblageⅠb, correspond to the late Pleistocene glacial climatic characteristics of the inter-ice bands. Deep-sea oxygen isotope stage 4 corresponds to the sporopollen assemblageⅠa, corresponding to the late Pleistocene glacial climatic characteristics of the ice class.