准东地区平地泉组微量元素地球化学特征及油气地质意义

Geochemical characteristics and petroleum geological significance of trace elements of Pingdiquan Formation in eastern Junggar Basin

李浩 徐怀民 王千军 肖雄飞

中国石油大学（北京）地球科学学院，北京 102249 中国石化胜利油田分公司勘探开发研究院，山东 东营 257015

文中在对准噶尔盆地东部（简称准东地区）平地泉组露头、钻井样品进行微量元素测试的基础上，分析了微量元素富集特征及相关关系。利用定量计算与元素比值法对研究区平地泉组古环境、古气候进行了重建，并分析其与有机质丰度分布的关系。结果表明：研究区基本处于弱氧化￣还原环境与干热气候下，水体深度从平一段至平三段表现为半深湖—深湖增至深湖为主、又减至浅湖—半深湖，水体盐度从平一段至平二段的半咸水—咸水环境转变为平三段淡水—半咸水环境；微量元素特征指示的高水深、高咸度环境有机质丰度也较高，微量元素演化对有机质富集具有良好的指示作用。

Based on the analysis and test of trace elements in the outcrops and drilling samples of Pingdiquan Formation in the eastern Junggar Basin, the enrichment characteristics and correlation of trace elements were analyzed. The paleoenvironment and paleoclimate of Pingdiquan Formation in the study area were reconstructed by using quantitative calculation and element ratio method, and the relationship between them and the abundance distribution of organic matter was analyzed. The results show that the study area is basically in a weak redox environment and dry-hot climate, and from Ping 1 member to Ping 3 member the water depth increases from semi-deep lake to deep lake and decreases to shallow lake and semi-deep lake. The salinity of the water body changed from the brackish-to-saline water environment of Ping 1 member to Ping 2 member to the fresh-to-brackish water environment of Ping 3 member. The abundance of organic matter in the environment with high water depth and high salinity indicated by the characteristics of trace elements is also high, and the evolution of trace elements plays a good role in indicating the enrichment of organic matter.

10.6056/dkyqt202302013