海相泥页岩沉积过程研究进展  

A Review on Sedimentary Processes of Marine Mudstones and Shales

作　　者：李一凡[1] 魏小洁 樊太亮[1] LI YiFan;WEI XiaoJie;FAN TaiLiang(School of Energy Resources,China University of Geosciences(Beijing),Beijing,100083,China;Institute of Geomechanics,Chinese Academy of Geological Sciences,Beijing,100081,China)

机构地区：[1]中国地质大学(北京)能源学院,北京100083 [2]中国地质科学院地质力学研究所,北京100081

出　　处：《沉积学报》2021年第1期73-87,共15页Acta Sedimentologica Sinica

基　　金：国家自然科学基金青年基金项目(41702124,41802155);国家自然科学基金企业创新发展联合基金项目(U19B6003-01-02)。

摘　　要：随着全球页岩油气勘探开发的不断深入,海相泥页岩作为非常规油气沉积学的重要研究对象之一,其沉积特征及沉积过程日益引起学者们的关注,并在岩相分类、沉积过程解释及层序地层划分方面取得了显著进展。海相泥页岩的岩相划分已达到厘米—毫米尺度,其命名原则主要考虑结构(粒度)、层理及矿物成分等特征,结构方面着重参考砂级、粗泥级和细泥级的占比,层理描述注重纹层的连续性、形态和几何关系,矿物成分则比较黏土矿物、石英和碳酸盐岩矿物的相对含量。海相泥页岩的沉积过程多样,浅海陆棚环境下细粒沉积物(岩)的主要搬运与沉积过程包括风成输入、异轻流、重力流(前三角洲浊流、异重流和浪控沉积物重力流)及风暴流,而在平坦而广泛的陆表海则以季风或潮汐驱动下的远岸底流搬运沉积为主。重力流及风暴流沉积一般会形成特征相似但各具特色的粒序层理,而在远岸底流作用下则会形成纹层状泥页岩。沉积特征的精细描述推动了泥页岩层序地层格架的建立,三级层序界面的识别在于寻找可对比的主要侵蚀面,而层序内准层序的划分除了要寻找次要侵蚀面外,还需依靠对精细描述的沉积特征进行定量化统计与分析。上述研究表明,沉积特征的精细化描述与定量分析,并结合水槽模拟实验,是今后海相泥页岩沉积过程研究的主体发展方向。With the development of global unconventional resources,research on sedimentary features and processes have received more attention.Significant progresses have been achieved on classification of shale facies,interpretation of sedimentary processes,and reconstruction of sequence stratigraphy.Shale facies have been classified at centimeter to millimeter scale.Nomenclature of marine mudstones and shales should be based on their texture(grain size),bedding and composition.Regarding texture,proportion of sands,coarse muds and fine muds should be considered.Regarding bedding,geometry,continuity,and shape should be described.About mineral composition,components of clay minerals,quartz,and carbonate minerals would be compared.Sedimentary processes of marine mudstones and shales are various.Main transport and sedimentary processes of fine-grained sediments in in the marginal shelf sea include eolian input,hypopycnal plumes,gravity driven transport processes(prodelta turbidity currents,hyperpycnal flows,and wave and current enhanced sediment gravity flow),and storm induced currents.In the extensive,flat,and shallow epicontinental seas,bottom current driven by seasonal wind or tide is the dominated transport process.A few types of graded bed would be produced by gravity driven transport processes as well as storm driven bottom current,whereas offshore bottom current would result in laminated shale.Detailed description of sedimentary characteristics promotes establishment of sequence stratigraphy in fine-grained sedimentary rocks.Recognition of sequence boundaries is to find comparable main erosional surfaces,while division of parasequence in a depositional sequence depends on recognition of flooding surfaces(secondary erosional surfaces)and quantitative analysis of sedimentary features.Combining with flume experiments,detailed description of sedimentary features and quantitative analysis are main research directions for studies on sedimentary processes of marine mudstones and shales.

关 键 词：细粒沉积岩 沉积特征 水动力条件 层序地层 沉积环境 非常规油气沉积学 

分 类 号：TE122.2[石油与天然气工程—油气勘探]