伸展作用过程中石英变形与重结晶的微观机制

Mechanisms of Deformation and Recrystallization of Quartz During Extension

在伸展作用过程中 ,石英的变形主要表现为三种不同类型变形石英的出现 :SGR -R型以中高温条件下的亚颗粒旋转与动态重结晶为主要特点 ;GBM -R型以中低温条件下的局部颗粒边界迁移与重结晶过程为主 ;FC型以低温条件下的破裂和碎裂作用为主要特点。三种石英变形类型及其变形机制主要受三方面的影响 :区域伸展环境的存在 ;伸展抬升作用过程中变化的p -T条件 ;变形岩石中微量流体的参与。

Three styles of deformed quartz developed during the extending processes, i.e.the SGR-R quartz (quartz grains deformed by subgrain rotation and dynamic recrystallization), GBM-R quartz (quartz grains deformed mainly by grain boundary migration and dynamic recrystallization) and FC quartz (quartz grains deformed by fracturing and cataclasis) are developed in the sheared quartz rocks. It is concluded that the occurrence of the above three different styles of quartz deformation and the variation of dominant deformation mechanisms are attributed to The existence of extension condition, the variation of p-T conditions during progressive uplifting, and the addition of minor amount of fluid into deforming rocks.