阿尔金山前中下侏罗统泥页岩元素地球化学特征及其地质含义

Shale Elements Geochemical Charactristics of Middle and Lower Jurassic Strata in the Frontal Areas of Altun Mountains and Their Geochemical Implications

柴达木盆地西部阿尔金山前中下侏罗统暗色泥页岩地层发育,依据对月牙山剖面的野外地质调查,结合野外样品元素地化资料分析,对该区中下侏罗统泥页岩的沉积特征及环境进行了较为详细的研究。其结果表明:阿尔金山前月牙山泥页岩发育,主要为湖相沉积;沉积环境主要为还原环境;水体较深;有机质类型以Ⅱ2型为主,烃源岩处于生排烃高峰期,具备一定的生烃能力,为中等烃源岩。本研究内容对于今后有利勘探区的划分具有指示重要作用。

A set of middle and lower Jurassic shale formation developed in the frontal areas of AltunMountains in the western Qaidam Basin.According to geology and geochemical signatures of the samples from Yueya Mountains,the sedimentary charactristics and environments of the Middle and Lower Jurassic strata are systemic discussed.For the middle and lower Jurassic strata in the frontal areas of AltunMountains,the results show a series of information as follows：①Shale from Yueya Mountains are mainly lacustrine dark shale.②Sedimentary environments are mainly in reducing environments.③Deep water in the sedimentary period.④The organic matter type is type Ⅱ2,its rock is in hydrocarbon generation and expulsion peaks,which are moderate source rocks and having the ability to generate hydrocarbon.Our research has a good effect for oil-gas exploration.