In order to discuss the relationship between sedimentary enviroment and organic matter accumulation in black shale of Middle Ordovician Shengping Formation,the Xishuiyuan Section in Wenqiao Town,Quanzhou County,northern Guangxi was chosen. The organic carbon content,kerogen carbon isotope,major and trace elements were analyzed to investigate paleo-redox,paleo-productivity,hydrothermal sedimentation,clastic influx and water limitation of the Middle Ordovician sedimentary environment in the northern Guangxi. The results show that the lower member of Shengping Formation is mainly composed of mud-rich siliceous shale with TOC of 1.45％-3.04％,and the upper member is mainly composed of siliceous shale with TOC of 0.63％-2.69％. The source of organic matter in the lower member of Shengping Formation is mainly type Ⅰ kerogen,while the source of organic matter in the upper member may be type Ⅱ kerogen in addition to type Ⅰ kerogen. The sedimentary period of Shengping Formation in northern Guangxi is a suboxic and anoxic deep-water shelf and basin facies environment. The organic matter accumulation of mud-rich siliceous shale is a dual control pattern of productivity and preservation conditions. The organic matter accumulation of siliceous shale is a preservation condition pattern.
关键词
黑色页岩/沉积环境/有机质富集/升坪组/桂北地区/石油地质
Key words
black shale/sedimentary environment/organic matter accumulation/Shengping Formation/northern Guangxi/petroleum geology
维普
万方数据