In order to study the distributions of the biomarker of the continental source rocks in the Sichuan Basin, 71 source rock samples were collected from the Upper Triassic-Lower Jurassic strata in different regions. The n-alkanes, isoprenoids, terpane, sterane, sesquiterpenes, caranes and aromatics in the extracts were analyzed in detail. GC-MS analysis has been conducted to analyze the biomarker of the continental source rocks. The results of GC-MS analysis indicate that the Upper Triassic source rocks are high in the content of extended tricyclic terpanes, pristane, phytane, gammacerane, C28 regular sterane and carotene. However, they are low in content of rearranged compounds. The ratio of Pr/Ph is less than 1, with the characteristics of tricyclic terpane C21 > C23. The Lower Jurassic source rocks are extremely low in content (even zero) of extended tricyclic terpanes, pristane, phytane, gammacerane, C28 regular sterane and carotene, and high in content of rearranged compounds. The ratio of Pr/Ph is more than 1, with tricyclic terpane C21 > C23. These characteristics are still preserved after maturation. Moreover, during the sedimentation of the source rocks of T3x2–T3x3 members, the supply of continental plants was low (TAR < 1, with regular sterane C27 > C29, 1-MP/9-MP < 1). The source rocks of T3x5 member were low in salinity (slightly low content of gammacerane and carotene), being different significantly from the other Upper Triassic source rocks. In addition, during the sedimentation of the source rocks of J1dn Member, the supply of continental plants was also low (regular sterane C27 > C29, 1-MP/9-MP < 1), being quite different from that of J1l member. Through analysis of the difference in biomarkers, it is indicated that the sedimentary environment had changed from anoxic and brackish water during the Late Triassic to oxygen-rich and freshwater during the Early Jurassic in the Sichuan Basin. During this process, the types of organic matters had changed for several times.

中文翻译：

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四川盆地陆相烃源岩生物标志物分布及沉积环境

为研究四川盆地陆相烃源岩生物标志物的分布情况，从不同地区的上三叠统—下侏罗统地层采集了71个烃源岩样品。详细分析了提取物中的正烷烃、类异戊二烯、萜烷、甾烷、倍半萜烯、卡拉烷和芳烃。已经进行了 GC-MS 分析来分析大陆烃源岩的生物标志物。GC-MS分析结果表明，上三叠统烃源岩中的扩展三环萜烷、原始烷烃、植烷、伽马蜡烷、C28正甾烷和胡萝卜素含量较高。然而，它们的重排化合物含量低。Pr/Ph比值小于1，具有三环萜烷C21>C23的特性。下侏罗统烃源岩中延伸三环萜烷、原始烷烃、植烷、伽马蜡烷、C28正甾烷和胡萝卜素含量极低（甚至为零），重排化合物含量高。Pr/Ph比大于1，三环萜烷C21>C23。这些特性在成熟后仍然保留。此外，在T3x2-T3x3段烃源岩沉积过程中，陆相植物供应量较低（TAR < 1，常规甾烷C27 > C29，1-MP/9-MP < 1）。T3x5段烃源岩盐度低（伽玛蜡素和胡萝卜素含量略低），与其他上三叠统烃源岩差异显着。此外，J1dn段烃源岩沉积过程中，陆相植物供应量也偏低（常规甾烷C27 > C29, 1-MP/9-MP < 1)，与J1l成员有很大不同。通过生物标志物差异分析，表明四川盆地沉积环境由晚三叠世的缺氧微咸水转变为早侏罗世的富氧淡水。在这个过程中，有机物的种类发生了多次变化。