鲁西汶东凹陷Qk203钻孔黏土矿物特征及其古环境OA

By using X-ray diffraction(XRD),clay mineralogy characteristics and paleoclimate indicators of sediments in borehole Qk203 of Wendong Depression in western Shandong province have been studied.It is showed that clay minerals in the sediments are mainly montmorillonite,kaolinite and illite.Based on AMS 14C dating results of borehole Qk203,lithologic association characteristics,relative content changes of clay minerals and Ⅴ(Ch+I)/Ⅴ(Kao+S)ratio,paleoclimatic environment evolution since late Pleisto-cene in Wendong depression can be divided into five stages.It has successively experienced cold drying—warm-humid—dry and cool—warm and humid—further warm and humid cycle.Stage Ⅰ(2.15～0m)is Holocene,corresponding to deep sea oxygen isotope MIS1(postglacial period);stage Ⅴ～Ⅱ(33.00～2.15m)is late Pleistocene,corresponding to deep-sea oxygen isotope MIS2(last glacial maximum).It is showed that the climate change since the last glacial maximum is global,but it will be different in different regions.It is in response to the changes in the global paleoclimate and the paleoclimate in eastern China to a certain extent.The global climate change has played a certain role in controlling the evolution of the cli-mate in Quaternary in China,while unique tectonic movement in China will also affects local climate evolu-tion process to a certain extent.