论泥晶套与次生白云岩原岩结构特征的恢复及意义  

On the micrite envelope to restoration of primary texture character of secondary dolomites and its significance.

作　　者：毕义泉[1] 田海芹[2] 赵勇生[2] 马玉新[2] 于文芹[2] 胡书毅[2] 

机构地区：[1]胜利石油管理局纯梁采油厂,山东东营256504 [2]石油大学资源系油气勘探开发综合研究所,山东东营257062

出　　处：《岩石学报》2001年第3期491-496,T001-T004,共10页Acta Petrologica Sinica

基　　金：中国石油化工集团公司资助项目 (编号 :9910 0 8-0 1)

摘　　要：本文以偏光显微镜岩石薄片、扫描电镜、阴极发光等岩石学研究成果为基础资料 ,结合矿物学、岩石学、沉积学及物理化学等基础理论 ,对白云岩中的残余结构、碳酸盐岩颗粒泥晶套的矿物成分、成岩变化及其在白云化等成岩作用过程中对颗粒结构及形态的保护作用进行了较为深入和系统的研究 ,认为泥晶套及其精细的鉴别对次生白云岩原岩结构特征及沉积环境的恢复既有重要的鉴定意义也是重要的研究方法。本文首先根据碳酸盐岩结构组分的类型、交代强度及可识别性把次生白云岩的残余结构分为交代残余结构、交代影像结构及交代晶粒结构三大类 ;每一大类还可根据具体的结构组分类型等进一步细分和命名。同时认为在研究次生白云岩残余结构 (构造 )的过程中 ,可通过寻找和鉴别受泥晶套保护的颗粒结构或轮廓 ,进而分析判别原始颗粒的结构和类型 ,达到恢复白云岩原岩 (结构特征 )的目的。在上述实际资料研究的基础上 ,又通过理论研究认为碳酸盐岩颗粒的泥晶套具有保护颗粒结构及形态免遭白云化作用等成岩作用彻底破坏的作用。这是因为泥晶套的原始矿物组成主要是文石、方解石及有机质等 ,且可在沉积期及成岩过程中吸附一定量的粘土矿物。泥晶套矿物晶体细小 ,特别是粘土矿物具有笼形结构 ,可以有选择地吸附一定大小的分?The remainder texture of the secondary dolomites and the processes and significances of the Micrite Envelope (ME) that could protect the texture and outline of the gains not subjecting deformation by diagenesis are systematically studied in this paper, based on the data of the thin section, SEM, cathodluminescence thin section etc., and combined with the theories of the mineralogy, petrology, sedimentology and chemistry. According to the texture components of carbonate rocks, the intension of replacement and the identifiability of the texture and the ME, the remainder textures can be classified into 3 types: replacement remainder texture, replacement image texture and replacement crystalline grain texture; and every type of remainder texture can also be divided and named by variety components. It is very important that finding and identifying the remainder texture and the image or outline of the grain in the research process, thus the primary texture and the grain type can be reconstructed, and the primary rock type too. Based on the studies above and combined with theory analysis, it is pointed out that the micrite envelopes not only are not damaged thoroughly, but also play a protection role to the outline of the grains, and increase the velocity in the earlier processes of dolomitization, because the envelops are mainly constituted by aragonites, microcrystalline calcites, organic matters and some of clays that have effects of molecular sieve and permeable membrane, especially to those limestone bearing some of grains. Therefore, the author considered that the investigations of the remainder textures, especially the ME, are very important to restoration of the sedimentary environment, the palaeoclimate, ancient oceanography, stratigraphy, tectonics and the carbonate primary type basin.

关 键 词：泥晶套 分子筛 渗透膜 次生白云岩 结构特征 白云化作用 碳酸盐岩 

分 类 号：P588.245[天文地球—岩石学]