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重点报道了藏北双湖地区中侏罗统海相油页岩的生物标志化合物特征 ,首次在该层位油页岩中检出丰富的正烷烃、类异戊二烯烷烃、萜类化合物及甾类化合物。正烷烃图谱呈单峰形 ,nC15、nC16或nC17为主峰碳 ,轻烃组份占有绝对优势 ,OEP值 0 .93～ 1.0 1,无明显的奇偶碳数优势分布 ;Pr/Ph值为 0 .77～ 1.5 9,在剖面序列中呈波动分布 ,显示弱植烷优势或姥鲛烷优势 ;藿烷以C30 占优势 ,萜烷相对丰度五环三萜烷 >三环萜烷 >四环萜烷 ;规则甾烷∑ (C2 7+C2 8) >∑C2 9,∑C2 7/∑C2 9值为 0 .79～ 1.2 0 ,在剖面序列中下部C2 7甾烷略占优势 ,上部C2 9甾烷略占优势 ,重排甾烷C2 7/规则甾烷C2 7值为 0 .5 1～ 3 .6 3 ,在剖面序列中具有显著的波动性 ,同时检出了少量孕甾烷和 4 甲基甾烷。有机质母质构成中 ,既有丰富的藻类等低等水生生物 ,可能还有一定比例陆生高等植物输入混合的特点。油页岩处于成熟阶段 ,整个油页岩剖面序列具有一致的热演化程度。剖面中部油页岩具有极高的原始生产力 ,氧化—还原条件也是控制油页岩TOC和沥青“A”含量在剖面垂向变化的重要因素
The characteristics of biomarkers of the Middle Jurassic marine oil shale in Shuanghu area of northern Tibet are reported in detail. For the first time, abundant n-alkanes, isoprenoids, terpenoids and steroids are detected in this layer of oil shale Compound. NC15, nC16 or nC17 is the main peak carbon, the light hydrocarbon component has the absolute advantage, OEP value of 0.93 ~ 1.01, no obvious dominant distribution of odd and even carbon number; 77 ~ 1.59, showing a fluctuating distribution in the cross-section sequence, showing weak phytane or pristane advantages; hopane with C30 dominant, terpene relative abundance pentacyclic triterpene> tricyclic terpane> tetracyclic terpene Alkane; the regular sterane Σ (C2 7 + C2 8)> ΣC2 9 and the ΣC2 7 / ΣC2 9 value range from 0.79 to 1.2 0, with the C2 7 sterane slightly dominant in the cross-section sequence and the upper C2 9 Sterane slightly predominate, and the value of the rearrangement sterane C2 7 / regular sterane C2 7 is 0.51 ~ 3.63, showing significant fluctuation in the sequence of the cross sections. A small amount of gestatin and 4 Methyl sterane. Composition of organic matter parent material, both rich algae and other lower aquatic organisms, there may be a certain proportion of terrestrial plants mixed input characteristics. The oil shale is in a mature stage, and the entire oil shale profile sequence has a consistent degree of thermal evolution. Oil shale in the middle section of the profile has very high initial productivity. The oxidation-reduction conditions are also important factors controlling the vertical variation of TOC and bitumen “A” content in the profile