吐哈盆地西南缘水西沟群沉积地球化学特征

对吐哈盆地西南缘区勘探孔不同层位的泥岩元素地球化学特征进行了研究。结果表明:不同沉积环境中形成的泥岩,其常量、微量元素质量分数及分布不同。利用泥质岩中常、微量元素质量分数及组合特征,采用聚类分析能很好地识别出不同的沉积环境,特别是10 0%识别出湖泊环境和河流环境;泥质岩中常、微量元素质量分数及组合特征,显示吐哈盆地西南缘水西沟群形成时古环境为温暖潮湿、富氧氧化的淡水湖泊环境。但是,从层序Ⅰ—层序Ⅲ,水体有从半咸水到淡水,古气候由半干热到温暖潮湿的变化特点。 

Characteristics of element geochemistry of Shuixigou Group in north-eastern Tu-Ha Basin

The characteristics of trace element in mudstone of three wells in the northeastern of Tu-Ha Basin are researched. The results show that the characteristics of trace elements are different in different mudstones formed in different environment. Therefore, the study results can be used to completely recognize the difference between river environment and lake environment. As a result of synthetic study, the palaeo-environment of the Early and Middle Jurassic Shuixigou Group was inferred to be the temperate rainy climate and oxygen-rich fresh water lake. But, from sequenceⅠto sequence Ⅲ, the water body has a trend from brackish water environment to fresh water environment, the palaeoclimate has a trend from semi-aridity climate to temperate rainy.