松辽盆地滨北地区白垩系源岩有机质演化程度低(Ro值为0.33%～0.70%),可溶有机质酸性非烃主要由正构一元酸、正构二元酸、姥鲛烷酸、植烷酸、藿烷酸和甾烷酸等化合物组成。其中正构一元酸含量占绝对优势并呈两种分布形态(一为单峰型,以C₁₆为主峰,C₁₈、C₁₄丰度较高,生源母质主要为藻类等水生生物;二为双峰型,前峰群以C₁₆为主峰,后峰群为次主峰,以C₂₄为主,前峰群表征水生生物输入,后峰群表征有陆源高等植物输入),各形态均呈现偶奇优势(与生物脂肪酸合成酶合成双碳乙酰单元有关);正构二元酸含量较低;藿烷酸含量高于甾烷酸。随着埋藏深度的增加,多数样品的姥鲛烷酸/植烷酸的比值及甾烷酸/藿烷酸的比值均减小,表明沉积环境逐渐向还原环境转化。认为由于酸性含氧化合物尤其是正构烷基脂肪酸的脱羧反应,故在形成正构烷烃的同时形成CO₂,不仅为产甲烷菌提供了大量营养能源,而且也提供了呼吸代谢的基质;在青山口组和嫩江组时期,湖盆面积扩大,水体加深,区域内出现滨浅湖―半深湖相沉积,因此滨北地区局部时空范围内可形成商业性生物气田。

The immature or lower-mature sourc e rock was collected from the Cretaceous of Binbei area in Songliao Basin, with  low vitrinite reflectance of 0.33%~0.70%. Acid bearing-oxygen compounds in non-hydrocarbon consisted of normal-monocarboxylic acid, normal-binarycarboxylic  acid, pristane acid, phytane acid, hopanoid acid and steroid acid. Normal monoa cid had a higher content and occurred two modeles of peak distribtuion, the one  was single peak group with C₁₆   dominant position and C ₁₈  , C ₁₄    higher aboundance, which indicated the input of algae, the other had two peak gr oups, the fromer with C₁₆   main peak characterized by aquatic organisms sou rce matirials, the latter group was secondary, with C₂₄   higher peak, this  suggests the input of terrestrial higher plants transformed by bacteria. Those a cid non-hydrocarbon was dominated by even carbon number, due to the fatty acid  synzyme of organisms synthetized acetyl unit with two carbon atom. Normal binary acid had a lower content and the amount of hopanoid acid was more than steroid a cid. In the most of samples, those ratios of Pr/Ph acid and ster/hopan acid decr eased with increasing of depth,this suggests that depositional envirenment chan ges to reducing conditon. ;
As de-carboxyl reaction taked place, acid bearing-oxygen compounds, in particu lar nonmal alkyl fatty acid was formed into hydrocarbon and CO -2, not only supp lied for the large amount of nutritive energy-carbon origin, also supplied for  the largest substrate of respiratory metabolism to methanogenic bacteria During  Qingshankou and Nenjiang periods of Cretaceous, water system changed to deep wit h expanding of lake area, shallow and mid-deep lacustrine facies deposit occurr ed at parts of Binbei area, leading to biogas field was formed.