差应力与石英组构关系的实验研究

Experimental Study on the Relationship Between Differential Stress and Quartz Fabrics

为了探讨柯石英的形成条件,利用河北省平山县西柏坡地区太古代阜平群中的黑云母片麻岩进行高温高压条件下的岩石变形实验。实验的温度为800℃,围压为0.2 GPa,应变量为10%,应变速率为10-5/s。实验结果表明,变形后样品中不同部位石英颗粒的激光拉曼光谱与标准的石英光谱相比较发生了明显的变化,具体表现为:挤压带中,石英颗粒的光谱出现了9个峰,而标准石英光谱为6个峰;在剪切带中,石英颗粒的谱线只有一个清晰的峰,在拉伸带中,石英颗粒的谱线无论峰的数目还是出现的位置都与标准石英光谱有着显著的区别,说明导致岩石变形的差应力对石英晶格结构的改造具有一定的影响。

In order to discuss the formation conditions of coesite, the authors use biotite gneiss from Archean Fuping Group in Xibaipo, Pingshan county, Hebei Province to conduct the deformation experiments under high temperatures and pressures. Under experimental temperature of 800 ℃ and confining pressure at 0.2 GPa, the stress degree is 10% and the stress rate is 10^-5/s. Experimental results indicate that the laser Raman spectra of quartz grains in different sites of the deformed sample show obvious changes compared with that of standard quartz, suggesting that differential stress may change crystal lattice of quartz.