伦坡拉盆地渐新统丁青湖组油页岩特征及其地质意义

发布时间：2019-06-22 16:43

【摘要】：伦坡拉盆地丁青湖组油页岩呈北西—南东向断续分布,长约50 km,油页岩有18~22层,薄者0.10 m,厚者8.81 m,一般厚0.70~2.00 m。工业分析数据表明,油页岩属于高灰分、中低含油率、低发热量型。油页岩有机碳质量分数为2.40%~20.23%,平均值7.38%,丰度较高。干酪根镜检显示油页岩有机质类型为腐泥型(Ⅰ型),镜质体反射率(Ro)值为0.43%~0.71%,平均值为0.52%,说明油页岩有机质处于未成熟—低成熟阶段。油页岩样品检测出丰富的正构烷烃、类异戊二烯烷烃、萜烷化合物和甾烷化合物。饱和烃色谱/质谱特征表明伦坡拉油页岩有机母质来源以水生浮游植物为主。通过生物标志物特征及野外地质观察,揭示了油页岩形成于一定盐度的缺氧还原半深湖—深湖环境。湖盆内各种水生浮游植物、藻类等为油页岩的形成提供了主要的有机母质来源,稳定的构造条件和缺氧的环境有利于有机质的堆积和保存。
[Abstract]:The oil shale in the n-qing lake group in the Lunpo-La basin is distributed in the east to the east of the north-west, the length is about 50km, the oil shale is 18-22, the thinner is 0.10 m, the thickness is 8.81 m, and the average thickness is 0.70-2.00m. The industrial analysis data show that the oil shale belongs to the high ash, low oil content and low calorific value type. The mass fraction of the organic carbon in the oil shale is 2.40%-20.23%, the average value is 7.38%, and the abundance is high. The results showed that the organic matter type of oil shale was of the type (type I), the reflectance (Ro) of the vitrinite was 0.43% ~ 0.71%, and the average value was 0.52%, which indicated that the organic matter of oil shale was in the stage of low maturity and low maturity. The oil shale samples are rich in n-alkanes, isoprenoids, alkannane compounds and dioxane compounds. The characteristics of the saturated hydrocarbon chromatography/ mass spectrum show that the source of the organic parent material of the Lupa oil shale is dominated by the aquatic phytoplankton. Through the feature of the biomarkers and the field geological observation, the deep lake environment of the semi-deep lake, which is formed by the oxygen-deficient reduction of certain salinity, is revealed. The formation of various aquatic phytoplankton, algae and so on in the lake provides the main source of organic material for the formation of oil shale. The stable structure condition and the environment of the oxygen-deficient environment are favorable to the accumulation and preservation of the organic matter.
【作者单位】：中国地质调查局成都地质调查中心;西藏地勘局第六地质大队;
【基金】：国家科技重大专项(2011ZX05004001-006) 中国地质调查局地质矿产调查评价专项(12120115000301)~~
【分类号】：P618.12

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