微量、稀土元素和有机地球化学参数对于揭示油页岩沉积环境、古气候等沉积成矿作用、预测油气、油页岩资源潜力具有重要意义。对鄂尔多斯盆地南部延长组长7油页岩获得的地球化学参数进行研究，油页岩微量元素与地壳平均值及其他地区油页岩相比，W、Mo、As、Sb、U等元素明显富集，Sc、Cr、Ni、Cl等元素明显亏损。油页岩稀土元素总量较低，轻稀土元素富集，重稀土元素亏损，稀土元素较球粒陨石发生了明显分异，较北美页岩分异不明显。油页岩有机质类型为Ⅰ型和Ⅱ1型，以Ⅱ1型为主，有机质丰度达到最好级，成熟度为低成熟-成熟。通过对这些地球化学参数及特征的进一步分析，获得以下认识：①长7油页岩是在温暖潮湿的气候条件下，形成于陆相淡水深湖-半深湖还原环境中，这种沉积环境有利于油页岩有机质的富集和保存；②本区不具备形成油气田的潜力，具备形成中-高品级的特大型油页岩矿床的潜力。%Trace elements, rare earth elements and organic geochemical parameters are of important significance for revealing oil shale rock sedimentary environment, paleoclimate, prediction of oil and gas as well as oil shale resource potential. Based on geochemical pa⁃rameters obtained from the oil shale samples of Chang 7 reservoir in southern Ordos Basin, The authors have obtained the following results:Comparing with mean value of the earth's crust and other areas, W, Mo, As, Sb, U are obvious concentrated, and Sc, Cr, Ni, Cl show significant depletion;The oil shale exhibits lower total REE, enrichment of LREE, and depletion of HREE. The rare earth element is significantly different than that of chondrites, but the difference is not obvious in comparison with the North American shale; The types of organic matter in oil shale are of type Ⅰ and type Ⅱ1, dominated by Ⅱ1 type; organic matter abundance has reached the best level, maturity is low mature to mature. Through the further analysis of these geochemical parameters and characteris⁃tics, the following two aspects are obtained:First, the oil shale of Chang 7 oil reservoir was formed under the condition of warm and humid climate and in a deep-semideep lake reducing environment, which is conducive to the enrichment and preservation of organ⁃ic matter in oil shale;Second, this area does not have the potential of formation of oil and gas, but has potential of forming high grade and large oil shale deposits.
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