【摘要】 上奥陶统五峰组观音桥段一直存在着深水和浅水成因的争论。据此本文通过岩心、露头、岩矿测试、有机地化和元素分析等资料，对观音桥段基本的地质特征和沉积古环境进行分析，并与上、下围岩进行对比，探讨其成因模式及页岩气地质意义。结果表明：赫南特冰期全球海平面骤降，鄂西地区具有陆源输入量低、上升洋流活跃、滞留程度中等和海洋生产力高的特点，而水体氧化还原条件在不同地区差异明显，这种差异受海平面变化和沉积前古地貌共同控制，进而影响着观音桥段的岩性展布；在隆后凹陷区，底水氧化还原状态受海平面下降影响相对较弱，以贫氧环境为主，有机质和浮游生物的保存条件较好，岩性以富有机质深水硅质页岩沉积为主，与上、下围岩岩性基本一致，体积压裂可以穿越该段同时对两套富气页岩进行产层改造，为勘探开发有利区域；而在隆起区周缘，海平面下降导致水体变浅明显，底水以富氧环境为主，保存条件变差，岩性以贫有机质的浅水介壳灰岩或泥质灰岩沉积为主，对上、下围岩产生明显的隔断，体积压裂难以穿越该段，产层改造效果差，为次级有利区。更多还原

【Abstract】 There has always debated whether the Guanyinqiao interval of the Upper Ordovician Wufeng Formation is of deep or shallow water origin. Based on data such as core, outcrop, rock, mineral tests, organic geochemistry, and elemental analysis, this study analyzed the basic geological characteristics and sedimentary paleo-environment of the Guanyinqiao interval, and compared them with those of the upper and lower surrounding rocks to discuss the genetic model and geological significance of shale gas. The results show that the global sea level dropped sharply during the Hirnantian glaciation. The western Hubei region has the characteristics of low terrigenous input, active upwelling currents, moderate retention and high marine productivity. The redox conditions of water column in the western Hubei are obviously different in different regions, which is controlled by sea level changes and paleo-geomorphology, and further affects the lithology of the Guanyinqiao interval. The depositional environment of the bottom water is mainly reductive environment in the depression, and its redox state has a relatively weak relationship with the declining sea level. The preservation conditions of organic matter and plankton are better. The lithology of the Guanyinqiao interval was mainly organic rich deep-water siliceous shale, which is basically consistent with the lithology of the upper and lower surrounding rocks. Volume fracturing can simultaneously transform two sets of gas-rich shale through the Guanyinqiao interval, which is a favorable area for exploration and development. In the uplift, the drop of sea level leads to the obvious shallower water, and the bottom water is dominated by oxygen-rich environment, with poor preservation condition. The lithology of the Guanyinqiao interval was mainly composed of the shallow-water shell limestone and argillaceous limestone deposits with poor organic matter, which produces obvious partition to the upper and lower surrounding rocks. It is difficult to cross the Guanyinqiao interval by volume fracturing in the uplift, and the production zone reconstruction effect is poor, so the uplift area is a secondary favorable area.更多还原