摘要
在差应力条件下出现柯石英的压力远小于静压条件下柯石英稳定存在的压力 ,这表明差应力对石英 -柯石英转化具有显著影响。根据柯石英形成条件 ,石英 -柯石英相变边界向低压方向迁移有两种不同物理机制 :发生在低温半脆性域的相变机制是差应力产生的剪切变形引起应力不稳定 。
Coesite was produced at certain differential stress conditions below its stability field under static pressure in laboratary, which shows that differential stress has obvious effect on the quartz-coesite transition pressure. According to the forming conditions of coesite, there are two different physical mechanisms for shifting quartz-coesite phase transition boundary to decreased forming pressure at differential stress conditions: the phase transition in semibrittle deformation region due to local shear deformation induced mechanical instability, and the phase transition in plastic flow region due to presence of high dislocation density within highly deformed quartz induced strain instability.
出处
《高校地质学报》
CAS
CSCD
2004年第4期523-527,共5页
Geological Journal of China Universities
基金
国家自然科学基金 (4 0 0 0 2 0 2 0 )
中国地震局地质研究所论著 (2 0 0 4B0 0 10 )
关键词
石英—柯石英转化
差应力
高温高压
quartz-coesite phase transition
differential stress
high temperature and high pressure