中文摘要：

形成于早更新世的湛江组地层广泛分布于雷州半岛地区,其最为典型的灰色黏土因具有强结构性,在实际工程中出现了一系列岩土工程问题,为众多学者所关注。根据地层学研究结果,雷州半岛各区域的湛江组灰色黏土具有不同沉积环境。由于地质成因的差异,灰色黏土在不同区域表现出不同的工程特性。工程实际中,灰色黏土工程特性的区域性,使得工程界及研究者对于该土层的工程力学效益更是难以掌握。利用X射线衍射试验及电镜扫描试验,研究了不同区域灰色黏土的矿物成分及含量、微结构等微观结构特性。结果表明：不同沉积环境灰色黏土矿物成分及含量存在区域性差异,各矿物成分按照不同比例组合,形成的土体微结构区域特性明显。灰色黏土具有强结构性微观机制的揭示及区域差异性的分析,有利于对该层黏土的全面认知和利用。

英文摘要：

Zhanjiang formation formed in early Pleistocene is widely distributed in Leizhou peninsula in China.The most typical gray clay of Zhanjiang formation is known as its strong structural performance and had produced a series of geotechnical engineering problems in actual engineering.According to the stratigraphic research,this typical gray clay of Zhanjiang formation has different sedimentary environments and compositions in different areas of Leizhou peninsula.Thus,the differences of geologic origin make the engineering properties of gray clay changing with the area.In the actual projects,it is difficult for engineers and researchers to master the engineering mechanics effect of gray clay due to its regional characteristics.Some tests by X-ray diffraction and scanning electron microscope（SEM） are carried out to study the microstructure characteristics of gray clay such as mineral composition and its content,and microstructure in different areas.The results show that there are differences of mineral composition and its content.Different proportions of mineral composition compose different microstructures of gray clay which have obviously regional characteristics.The revelations of micromechanism of gray clay which lead to its strong structural performance and the analysis of its regional characteristics make for cognition and use of this clay.