岩石中纳米粒子层的观察厘定及其地质意义

OBSERVATION AND DETERMINATION OF THE NANO-SIZED PARTICLE LAYER IN ROCKS AND ITS GEOLOGICAL SIGNIFICANCE

纳米粒子具有个体极小(≤100nm),大小均一,多元物质和功能繁多的特点。岩石剪切滑移面纳米粒子层最早发现于美国圣安德列斯断裂带的花岗质糜棱岩中,后相继在国内外一些地区的不同岩类中观察到。在剪切滑动作用下,具有圆度和球度的纳米粒子可被变异,并形成层状结构和各种构造型式。对岩石中纳米粒子层的成因有着不同的观点,我们倾向于剪切摩擦的主导作用,纳米粒子层可称谓摩擦-粘性薄层带。纳米级尺度粒子的力学、物理和化学效应是多种的、新奇的,因此,岩石纳米粒子层的研究有着重要的理论和实践意义。目前有关方面的研究工作,国内外都处在起步阶段。

Nano-sized particles are extremely tiny （≤ 100 nm） and homogeneous in size, consist of polybasic materials and have multiple functions. The nano-sized particle layer of shear slip plane in rocks was firstly discovered in granitic mylonite of the San Andreas Fault Zone, United States, and later this phenomenon was found in different rock types in some areas both at home and abroad. Under actions of shear slip, nano-sized particles with roundness and sphericity can become alien ones, and those alien particles may form layered textures and various structural types. There are different views about the genesis of nano-sized particle layers in rocks, and we incline to the view that shear friction plays a dominant role and that the nano-sized particle layer may be called a frictional-viscous thin layer. The mechanical, physical and chemical effects of nano-sized particles are multiple and novel and the study of nano-sized particle layers of rocks has great theoretical and practical significance without doubt. At present the study has just started both at home and abroad.