川北寒武系碳酸盐岩压溶作用的影响因素  

Controlling Factors of Pressure Dissolution of Cambrian Carbonate in the Northern Sichuan

作　　者：胡力文 邹华耀[1,2] 杨伟强 黎霆 邓成昆 程忠贞 诸丹诚 陈星岳 HU Liwen;ZOU Huayao;YANG Weiqiang;LI Ting;DENG Chengkun;CHENG Zhongzhen;ZHU Dancheng;CHEN Xingyue(College of Geosciences,China University of Petroleum(Beijing),Beijing 102249,China;State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum(Beijing),Beijing 102249,China)

机构地区：[1]中国石油大学(北京)地球科学学院,北京102249 [2]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249

出　　处：《现代地质》2023年第5期1221-1231,共11页Geoscience

基　　金：国家自然科学基金项目(42172152)。

摘　　要：前人对缝合线的研究多倾向于定性描述,缺乏缝合线特征(密度和幅度)与矿物成分含量、结构组分和岩相的定量分析。本文明确缝合线密度和幅度与岩石不同矿物含量、不同结构组分和不同岩相之间的定量关系,阐明研究区缝合线的形成的控制因素。综合四川盆地北部寒武系碳酸盐岩野外露头、岩心及薄片等资料,对川北寒武系碳酸盐岩缝合线特征、矿物成分含量、结构组分和岩相进行定量统计。结果表明:(1)碳酸盐岩中混入陆源碎屑,导致岩石非均质性增强,陆源碎屑含量为10%~15%,有助于缝合线的形成;(2)当岩石不含基质,颗粒含量在50%~70%、胶结物含量在25%~30%时,具有较强的抗压溶能力;(3)同一井不同岩相的抗压溶的能力存在差异,颗粒白云岩、混积岩、晶粒白云岩和泥晶白云岩缝合线密度和幅度逐渐增加,表明它们的抗压溶能力逐渐减弱。Previous studies of the stylolites prefer qualitative analysis,lacking quantitative analysis of mineral composition,textures,lithofacies and their impacts on stylolites(density and amplitude).The paper clarifies the quantitative relationship between the density and amplitude of stylolites,mineral composition,rock textures and lithofacies,and expounds the controlling factors of stylolite formation in the study area.Based on the database of outcrops,cores and thin sections,the stylolite characteristics,mineral composition,textures and lithofacies of Cambrian carbonate in the northern Sichuan Basin are quantitatively evaluated.The results by the observations of cores and microscope show that:(1)The terrigenous clastics in carbonates leads to the enhancement of rock heterogeneity,which facilitates the formation of stylolite with a content of 10%-15%;(2)The carbonates are strongly resistant to pressure solution,with a content of 50%-70%grains,25%-30%cements,and no matrix;(3)Different lithofacies of one well could have different resistance to pressure dissolution.The density and amplitude of stylolites increase successively from granular dolostone,mixed siliciclastic-carbonate rocks,and crystalline dolostone through micrite dolostone in the same well,indicating that their resistance to pressure dissolution decreases gradually.

关 键 词：四川盆地 寒武系 碳酸盐岩 压溶作用 影响因素 

分 类 号：P534.41[天文地球—古生物学与地层学]