上扬子区下寒武统海相页岩岩相类型及沉积模式

发布时间：2018-03-12 22:23

本文选题：海相页岩　切入点：岩相类型　出处：《现代地质》2017年06期 　论文类型：期刊论文

【摘要】：上扬子区下寒武统牛蹄塘组页岩是我国南方地区页岩气重要勘探层系之一。通过露头、岩心、薄片、实验测试等资料综合分析,识别了该套页岩岩相类型及相关沉积作用方式,在水体氧化还原条件演变规律分析基础上总结了其沉积演化模式。牛蹄塘组页岩共包含6类岩相:富有机质硅质页岩、含粉砂硅质页岩、粉砂质页岩、黏土质页岩、泥质钙质页岩及粉砂质钙质页岩,主要体现为5种沉积作用方式:砂质机械沉积、钙质化学沉积、硅质生物沉积、泥质絮凝沉积及底流改造沉积。从底到顶,该套页岩表现为一套水体变浅的进积型演化序列,水体还原程度减弱,有机质保存条件变差。牛蹄塘组下段沉积期,盆地相区和陆棚相区分别以硅质生物沉积和钙质化学沉积为主,主体岩相类型为硅质页岩和钙质页岩;上段沉积期,盆地相区和陆棚相区分别以泥质絮凝沉积和砂质机械沉积为主,主体岩相类型为黏土质页岩和粉砂质混合质页岩。提出的牛蹄塘组页岩岩相发育模式及沉积演化规律能为研究区优质页岩的分布预测及页岩气勘探选区评价提供理论依据。
[Abstract]:The Lower Cambrian Niutetang formation shale is one of the important exploration strata of shale gas in the southern part of China. Through comprehensive analysis of outcrop, core, thin slice and experimental test data, the shale facies type and related sedimentary modes are identified. Based on the analysis of the evolution law of water redox conditions, the sedimentary evolution model of Niulitang formation shale is summarized. There are six types of lithofacies: organic siliceous shale, silty silty shale, silty sand shale and clay shale. Shales and silty calcareous shales are mainly characterized by five types of sedimentary processes: mechanical deposition of sand, chemical deposition of calcium, deposition of siliceous organisms, flocculation of mud and redeposition of sediment from bottom to top, from bottom to top, from bottom to top, from bottom to top, from bottom to top, from bottom to top, from bottom to top, and from bottom to top. The shale shows a series of evolution series of shallow water bodies, the reduction degree of water body is weakened, the preservation conditions of organic matter become worse, and the depositional period of the lower member of Niutetang formation. The main lithofacies types are siliceous shale and calcareous shale. The basin facies and continental shelf facies are mainly composed of muddy flocculation deposition and sandy mechanical deposition respectively. The main lithofacies type is clay shale and silty sand mixed shale. The facies development model and sedimentary evolution law of Niulitang formation shale can provide theoretical basis for the distribution prediction of high quality shale and the evaluation of shale gas exploration area.
【作者单位】：中国石化石油勘探开发研究院;中国地质大学(北京)能源学院;中国石油辽河油田分公司;
【分类号】：P618.13

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