重庆白庙子下三叠统嘉陵江组第三、四段碳酸盐岩岩石学特征及成岩作用

发布时间：2018-04-04 07:26

本文选题：嘉陵江组　切入点：碳酸盐岩　出处：《成都理工大学》2015年硕士论文

【摘要】：下三叠统嘉陵江组作为四川盆地重要的含油气海相碳酸盐岩地层,前人针对其沉积相特征、储层特征及成岩作用进行了大量研究,但多局限于某个特定的构造或地区,而专门针对川东地区嘉陵江组碳酸盐岩岩石学特征及成岩作用的研究较少或不够系统深入,不能确切地反映区内的沉积特征,因此,有必要对川东地区嘉陵江组碳酸盐岩岩石学特征等进行深入研究。白庙子剖面位于四川盆地东部重庆市北碚区境内,构造位置上处于川东高陡构造带西侧,华蓥山帚状构造分支观音峡背斜轴部西翼,该区构造线多以北东向为主,沿嘉陵江有连续的三叠系地层出露地表。本文选取白庙子剖面嘉陵江组第三、四段地层作为研究对象,结合野外观察与室内分析,在沉积岩石学、碳酸盐岩沉积学等理论指导下,对该区嘉陵江组第三、四段碳酸盐岩岩石学特征、沉积相及成岩作用进行系统研究。白庙子剖面嘉陵江组第三、四段地层中岩石类型丰富,以碳酸盐岩为主,其次为盐溶角砾岩。嘉三段主要发育灰岩,包括亮晶颗粒灰岩,微晶颗粒灰岩,含颗粒微晶灰岩,微晶灰岩等;嘉四段主要发育白云岩和盐溶角砾岩,主要包括微晶白云岩,结晶白云岩及盐溶角砾岩,还含有微晶灰岩及结晶灰岩。通过室内及镜下观察与阴极发光分析等,详细阐述了各类岩石特征。在前人研究基础上,结合野外宏观现象、岩石学特征以及古生物特征,识别出研究区嘉陵江组第三、四段时期主要发育开阔台地、局限台地及台地蒸发岩三种沉积相,进一步划分为台内洼地、台内滩、泻湖、潮坪和蒸发坪等亚相类型。白庙子剖面嘉陵江组第三、四段碳酸盐岩经历了复杂的成岩过程,成岩作用类型较多,包括泥晶化作用,胶结作用,压实和压溶作用,溶解作用,白云石化作用,重结晶作用,破裂作用,去石膏化作用等主要成岩作用类型;根据各种成岩作用特征以及一些特殊的岩石组构,识别出研究区经历了准同生阶段的海水成岩环境、大气水成岩环境、成岩阶段的埋藏成岩环境及表生阶段的表生成岩环境。
[Abstract]:The Lower Triassic Jialingjiang formation is an important petroliferous marine carbonate formation in Sichuan Basin. Previous studies have been carried out on its sedimentary facies, reservoir characteristics and diagenesis, but most of them are confined to a particular structure or region.However, the study of carbonate petrology and diagenesis of Jialingjiang formation in eastern Sichuan is less or less systematic, which can not accurately reflect the sedimentary characteristics in the area.It is necessary to study the petrological characteristics of carbonate rocks of Jialing River formation in East Sichuan.The Baimaozi section is located in Beibei District of Chongqing City in the east of Sichuan Basin, located on the west side of the high-steep structural belt in eastern Sichuan, the west wing of Guanyin isthmus, a branch of Huayingshan broomlike structure, and the tectonic lines in this area are mostly northeastward.Along the Jialing River there are continuous Triassic strata exposed surface.In this paper, the third and fourth formation of Jialing River formation in Baimaozi section is selected as the research object, combined with field observation and laboratory analysis, under the guidance of sedimentary petrology, carbonate sedimentology and other theories, the third Jialing River formation in this area is studied.The petrological characteristics, sedimentary facies and diagenesis of the four-member carbonate rocks were systematically studied.The third and fourth member of Jialingjiang formation in Baimaozi section is rich in rock types, mainly carbonate rock, followed by salt solution breccia.Limestone is mainly developed in the third member of Jia-3, including granular-grained limestone, microgranular limestone, granular-grained limestone and microcrystalline limestone, while dolomite and salt-soluble breccia are mainly developed in the fourth member of Jia-4, which mainly includes microcrystalline dolomite.Crystalline dolomite and salt-soluble breccia, but also microcrystalline limestone and crystalline limestone.Through indoor and microscopic observation and cathodoluminescence analysis, all kinds of rock characteristics are described in detail.On the basis of previous studies, combined with field macroscopic phenomena, petrological characteristics and paleontological characteristics, three sedimentary facies, namely, open platform, limited platform and platform evaporite, were identified in the third and fourth member of Jialing River formation in the study area.The subfacies are further divided into subfacies such as subfacies such as depression, beach, lagoon, tidal flat and evaporation plateau.Carbonate rocks of the third and fourth member of Jialing River formation in Baimaozi section have experienced complex diagenetic processes, and there are many diagenesis types, including mud crystallization, cementation, compaction and pressure solution, dissolution, dolomitization, recrystallization, etc.According to the characteristics of diagenesis and some special rock fabric, the marine diagenetic environment and the atmospheric water diagenetic environment have been identified in the study area.Burial diagenetic environment in diagenetic stage and epigenetic environment in supergene stage.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.13

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