中文摘要：

泥页岩的沉积环境控制了矿物、有机质特征和岩相类型。开展东营凹陷古近系沙河街组泥页岩薄片、X衍射、热解和微量元素等分析,研究各层段元素地球化学特征和岩相类型,探索沉积环境变化与岩相组合的响应关系。研究表明沙河街组沙三下-沙四上亚段泥页岩包含了均匀块状泥岩、细纹层状页岩、宽纹层状页岩、断续纹层状页岩和含石膏构造泥岩5种岩相类型。各层段沉积环境变化明显,沙四纯下次亚段沉积时期水体盐度最高,随着湖泊淡化,水体盐度降低,至沙三下亚段已演化为盐度较低且波动稳定的湖泊环境。岩石类型与沉积环境关系密切：沙四纯下次亚段浅水高盐度条件下沉积了石膏构造泥岩和少量均匀块状泥岩;沙四纯上底部高盐度水体加深的环境下沉积宽纹层页岩和少量细纹层页岩;沙四纯上次亚段上部盐度降低环境沉积均匀块状泥岩和少量宽纹层页岩;沙三下亚段深水安静且盐度较低的环境沉积细纹层页岩,充分展现了沉积环境对岩相的控制作用。因此,关注泥页岩沉积环境演变与岩相成因,探讨岩石与沉积环境响应关系,能够为非常规油气勘探提供新的思路。

英文摘要：

The features of mineralogy, organic matter and lithofacies of mudstones and shale are controlled by depositional environment. An amount of samples selected from the Shahejie Formation in the Dongying depression are studied by the authors by means of microscope, X-ray diffraction, pyrolytic analysis and chemical analysis. The results are used to establish the relationship between the element geochemistry and types of lithofacies, upon which the relationship between depositional environment and lithofacies is further revealed. The lithofacies of mudstone/shale includes thin laminated shale, discontinuous laminated shale, thick laminated shale, homogenous massive mudstone and the mudstone with anhydrite-relict. Their depositional environments are obviously different. During the time while the sub-member of Es4 cxEs3x was deposited, the lake evolved from deep to shallow and from saline to fresh, and was in an anoxic environment during the whole period. There is a close relationship between lithology and environment. In the early Es4c, it was a shallow and salty lake with deposition of anhydrite-relict mudstone and homogeneous massive mudstone; the upper Es4c is mainly consisting of laminated shale at the bottom and homogeneous massive mudstone on the top, as the lake changed from a salty to a brackish lake; the lower Esa represents a deep fresh lake, rich in laminated shale. In conclusion, both the rock types and their hydrocarbon potentials are controlled by depositional environment. In this regard, further research is suggested on the relationship between lithofacies of mudstone/shale and their depositional environment.