黑龙江宁安盆地古近系油页岩沉积环境分析

Analysis of sedimentary environment of palaeogene oil shale in Heilongjiang Ning'an basin

分析宁安盆地古近系化石类型和含量特征，以及油页岩中岩石矿物组成含量特征及各种元素的地球化学特征，阐述研究区油页岩形成时的古气候条件及沉积环境．结果表明：古植物类型以温带、亚热带的草本植物、落叶阔叶林为主，矿物组成含量体现富含高岭石、伊蒙混层较少的特点；微量元素质量比m（Mn）／m（Ti）值介于0．02～0．11之间，m（Sr）／m（Ba）值介于0．48～0．68之间，Ⅲ（Ni）／m（Co）值介于1．97～3．02之间，m（Ni）／m（v）值介于0．10～0．39之间，m（V）／m（V＋Ni）值介于0．72～0．91之间；稀土元素中ace值分布在0．76～0．87之间．研究区内油页岩形成时的气候主要为温带一亚热带半湿润、湿润、多雨的气候条件；形成于近岸、陆相淡水浅湖～沼泽，贫氧的还原性沉积环境中．该研究对明确研究区油页岩形成时的沉积环境及其勘探潜力具有一定意义．

The types and characteristics of paleontological fossil and minerals composition of the oil shale of palaeogene in Ning'an basin have been analyzed;the geochemical characteristics of various elements in the oil shale have been analyzed and compared.The paleoclimate condition and the sedimentary environments of Paleogene oil shale in Ning'an basin were discussed.Results show that the paleontological type in oil shale is mainly the herbaceous plant and deciduous broad-leaved forest in temperate and subtropical zone;the ratios of m(Mn)/m(Ti)is between 0.02 and 0.11,the ratios of m(Sr)/m(Ba)is between 0.48 and 0.68,the ratios of m(Ni)/m(Co)is between 0.02 and 0.11,the ratios of m(Ni)/m(V)is between 0.48 and 0.68,the ratios of m(V)/m(V+Ni)is between 0.48 and 0.68,theδCe value is between 0.76 and 0.87.The oil shale was formed in freshwater lake-swamp facies of inshore,reduction sedimentary environment.So it is very important to develop the research for confirming the sedimentary environments of Paleogene oil shale and the potential of the oil shale exploration.