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学者们在页岩层序划分与构成等方面还存在较大分歧;其次,现有研究中针对页岩非均质性在层序格架内的变化特征及成因规律方面亦有不足.五峰组-龙马溪组页岩是上扬子地区重要的页岩气勘探层位之一,通过钻井岩心、露头剖面、常规测井、能谱测井和地球化学参数等资料,对上奥陶统五峰组-下志留统龙马溪组黑色页岩层序地层学进行了定量分析.在五峰组-龙马溪组识别出3个三级层序,其中五峰组为一个三级层序,进一步划分出海侵体系域(五峰组下部黑色页岩)和高位体系域(五峰组上部观音桥段);龙马溪组一段作为一个三级层序,进一步划分出海侵体系域、早期高位和晚期高位体系域;龙马溪组二段和三段为一个三级层序,进一步划分出低位体系域、海侵体系域和高位体系域.以不同体系域为单元分析了五峰组-龙马溪组层序发育与沉积环境特征,揭示了各体系域内古生产力与水体氧化还原条件对有机质富集的控制机理,总结并提出了系统的五峰组-龙马溪组黑色页岩层序地层垂向演化模式.
Scholars still have big differences in shale sequence division and composition, etc. Secondly, there are still some shortcomings in the existing research on shale rock heterogeneity within the sequence framework and its genetic law.Wufeng Formation - The Longmaxi Formation shale is one of the important shale gas exploration beds in the Upper Yangtze region. Based on the data of drilling core, outcrop profile, conventional logging, energy spectrum logging and geochemical parameters, the Upper Ordovician Wufeng Formation- The Lower Shalom Longmaxi Formation black shale sequence stratigraphy was quantitatively analyzed. Three tertiary sequences were identified in the Wufeng Formation-Longmaxi Formation, in which the Wufeng Formation was a tertiary sequence and further divided into transgressive systems tract (Lower black shale in the Wufeng Formation) and highstand system tract (Guanyinqiao Member in the upper part of the Wufeng Formation). The first member of the Longmaxi Formation is a tertiary sequence that further divides the transgressive system tract, the early high level and the late high-level system tract. The Longmaxi Formation The second and the third sections are a tertiary sequence, and the lower system tract, the transgressive system tract and the upper system tract are further divided.The sequences of the Wufeng Formation-Longmaxi Formation sequence and sedimentary environment are analyzed by different system domains, Revealed the body Ancient productivity and reducing conditions within the oxidation of organic matter enriched water control mechanism, summarized and presented Wufeng system - Longmaxi black shale sequence stratigraphy vertical evolution mode.