桂北中奥陶统升坪组黑色页岩沉积环境与有机质富集  

Sedimentary Environment and Organic Matter Accumulation of Black Shale in Middle Ordovician Shengping Formation,Northern Guangxi

作　　者：余烨[1,2] 蔡灵慧 王莉 吴海东 Yu Ye;Cai Linghui;Wang Li;Wu Haidong(School of Earth Sciences and Spatial Information Engineering,Hunan University of Science and Technology,Xiangtan 411201,China;Hunan Provincial Key Laboratory of Shale Gas Resource Utilization,Hunan University of Science and Technology,Xiangtan 411201,China)

机构地区：[1]湖南科技大学地球科学与空间信息工程学院,湖南湘潭411201 [2]湖南科技大学页岩气资源利用湖南省重点实验室,湖南湘潭411201

出　　处：《地球科学》2024年第7期2315-2329,共15页Earth Science

基　　金：湖南省自然科学基金项目(No.2023JJ30239);湖南省教育厅资助科研项目(No.23B0467)。

摘　　要：为了探讨桂北中奥陶统升坪组黑色页岩沉积环境与有机质富集的关系,利用有机碳、主量元素、微量元素及碳同位素等地球化学方法,分析了广西北部全州县文桥镇溪水源剖面中奥陶统升坪组黑色页岩的古氧化还原条件、古生产力、热水沉积作用、碎屑注入及水体局限程度等古沉积环境.结果表明:升坪组下段以富泥硅质页岩为主,TOC含量为1.45%~3.04%;上段以硅质页岩为主,TOC含量为0.63%~2.69%.升坪组下段有机质来源为Ⅰ型干酪根,上段有机质来源除了Ⅰ型干酪根外,可能还有Ⅱ型干酪根的参与.升坪组沉积时期总体为贫氧-厌氧的深水陆棚-盆地相环境.下段富泥硅质页岩中有机质富集为“生产力”和“保存条件”的双控模式;上段硅质页岩中有机质富集为“保存条件”模式.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 

分 类 号：P595[天文地球—地球化学]