Brittle-Plastic transition of continental crust and plastic Deformation of fine grained feldspar

为了了解细粒长石在地壳脆塑性转变过程中的变形行为，对天然断裂岩中的细粒长石进行了分析，并进行了钠长石烧结体实验。在自然变形的断层岩中，细粒斜长石的晶体取向几乎是随机的，位错亚结构发达，有应变诱导晶界迁移的证据。采用两种烧结钠长石压坯进行变形实验，一种是在夏季制备的，另一种是在冬季制备的。夏季制备的样品变形均匀，冬季制备的样品表现出明显的局部化变形。夏季试制的试件显微结构与实验后的天然断层岩中的试件相似。为了进一步了解长石的变形行为，有必要开发一种控制水含量的长石烧结技术。

Analyses of fine-grained feldspars within natural fault rocks and experiments using sintered albite compacts were carried out in order to understand the deformation behavior of the fine-grained feldspars at the brittle-plastic transition of the Earth's continental crust. In naturally deformed fault rocks, fine-grained plagioclase shows almost random crystallographic orientation, well developed dislocation substructure and evidence of strain induced grain boundary migration. Two kinds of sintered albite compacts were used in the deformation experiments, one was fabricated in summer and the other was fabricated in winter. The samples fabricated in summer were deformed homogeneously, while the samples fabricated in winter showed significantly localized deformation. The microstructure of the samples fabricated in summer is similar to that in natural fault rocks after the experiments. To understand the deformation behavior further, it is necessary to develop a technique to sinter feldspar in which water contents is controlled.