通过对川西坳陷上三叠统中段,包括鸭子河、金马、马井、孝泉、合新场地区须二-须五段有机质生物标志化合物的特征研究,发现烃源岩普遍具有微弱的奇数碳优势,异戊二烯烃含量低;Pr/Ph比值及低含量γ蜡烷说明沉积环境受淡湖水沉积影响,主要为还原环境;C27、C28、C29甾烷分布显示,烃源岩有机质以水生生物和陆源有机质混源输入为主,陆源有机质略占优势;甾烷和萜烷的异构化指数表明烃源岩有机质处于成熟阶段。 Based on the study of the characteristics of organic matter biomarkers in the second, second and fifth member of the Upper Triassic, including Duzihe, Jinma, Majing, Xiaoquan and Hexindian areas in the western Sichuan depression, it is found that the source rocks generally have weak odd numbers Carbon and low isoprenoids. Pr / Ph ratio and low content of γ-wax indicate that sedimentary environment is affected by sediment deposition in the lake, mainly in the reducing environment. The distribution of C27, C28 and C29 steranes shows that the organic matter of the source rocks is mainly composed of aquatic The mixed input of biological and terrigenous organic matter is dominant, and the terrigenous organic matter is slightly dominant. The isomerization index of sterane and terpane indicates that the organic matter of source rock is in mature stage.