【摘要】 探讨差应力对熔体分布和成分演化的关系,利用细粒闪长岩进行高温高压条件下的岩石变形,主要包括静态熔融实验和有差应力参与的动态熔融2种类型。实验首先统计了熔体含量、确定了实验重要参数,然后分别描述了动、静态熔融实验后闪长岩的显微特征;并且通过对动、静态熔融实验结果熔体分布情况的对比,结合熔体成分电子探针数据进行分析。结果表明:在细粒闪长岩的部分熔融中,熔体在差应力的作用下沿一定的方向展布,并从差应力大的地方向差应力小的地方运移,差应力的作用使得高含水矿物(角闪石)先于熔点低的斜长石发生熔融,说明差应力促进了岩石的熔融,使得熔体成分向Si、Al等方向转化,即从基性向酸性转化。更多还原

【Abstract】 In order to investigate the relationships of differential stresses and melt distribution and component during partial melting of crustal rocks,we used fine-grained diorite samples to do the HT-HP experiments.Two types of experiment were carried out: static and dynamic experiments with differential stresses.After the experiments,we firstly estimated the volume and content of the melt and determined important experimental parameters.Then,we described microstructural characteristics of diorites under static and dynamic melting experiments.By contrasting melt distributions between static and dynamic experiments and combined with analyzing electron microprobe data of melt components,we found that the partial melt of fine-grained diorite is distributed along a certain direction under differential stress and migrates from place with strong stress to place with weak stress.The differential stress has resulted in the partial melting of hydrous mineral(amphibole) prior to low melting point mineral(plagioclase),suggesting that differential stress has caused partial melting of rocks,dri-ving the melt component changes from basic towards felsic(Si-and Al-rich).更多还原