泥质岩成岩作用中的黏土矿物研究

文章通过对泥质岩的黏土质矿物组分、成岩作用中黏土质矿物变化综合研究,认为泥质岩中存在大量黏土矿物,且泥质沉积物由松散到固结成岩实质上是黏土矿物组成的变化。泥质岩中主要黏土矿物包括高岭石、蒙皂石、绿泥石、伊利石以及其组成的混层型矿物伊利石/蒙皂石、绿泥石/蒙皂石,其成岩过程可划分为成岩早期的压实阶段、成岩晚期的黏土矿物转化阶段。压实阶段的泥质沉积物中黏土矿物具有物源的继承性、沉积水体古环境指示意义;受压实作用孔隙水、层间水被排出,原生絮凝团被压破,使片状质点趋于平行排列,黏土矿物与孔隙水发生反应,亦形成少量的新生作用矿物,因而黏土矿物具继承源和新生作用源特性。成岩晚期阶段发生层间水释放及层间阳离子交换,从而使得矿物晶体结构与成分发生变化,主要表现为一元黏土矿物向二元混层型转化,最后再到一元型黏土矿物的转化,最终形成转变源黏土矿物。

Research on clay minerals during diagenesis of argillaceous rock

According to the research on clayey mineral composition of argillaceous rock and change of clayey minerals in diagenesis stage a large number of clay minerals occur in argillaceous rock and consolidation of loose sediment is essentially changes of clay minerals. The clay minerals are mainly kaolinite, smectite, chorite and their mixed-layering mineras (illite/smectite, chlorite/smectite). The diagenesis could be divided into early compaction and late transformation of clay minerals. During compaction the clay mineral could be of the source provenance and implication of paleo-environment of the sediment-precipitated water body or new generation provenance. The pore and interlayer water are expelled, primary flocculate mass is broken and the flaky particle tend to be parallel. A few new minerals are formed from reaction of the pore water and the original clay minerals thus the clay mineral is characterized by the source provenance and new generation provenance. During transformation the interlayer water released and interlayer cations exchanged leading to change of clay crystal structure and composition. The unitary clay mineral becomes dual mixed layer clay mineral.