压溶作用对脆塑性转化带强度影响的实验研究

There is a brittle-plastic transition zone between upper crust in brittle regime and lower crust in plastic regime, the pressure solution is one of most important deformation mechanism in brittle-plastic transition zone. There are a lot of field and experimental studies about pressure solution, but constitutive equation of rock strength in pressure solution regime is still scare. The project will perform creep tests and get the parameters of constitutive equation of pressure solution creep using quartzite and marble, which relatively easy to occur pressure solution, under high temperature and pressure conditions correspond to the brittle-plastic transition of crust and in the differential stress conditions. We also plan to study microscopic and deformation mechanism of deformed samples using optical and scan electron microscopy. Based on the experimental data, we try to set up the constitutive equation of pressure solution creep, and approximative correction the strength of brittle-plastic transition zone，and discuss the effect of pressure solution to strength of brittle-plastic transition zone. If the study achieves desired results, it is great significance to the crustal rheological strength and helping us to understanding the deformation mechanism of the brittle-plastic transition.

以脆性变形为主的浅部地壳和以塑性变形为主的深部地壳之间存在一个明显的脆塑性转化带，压溶作用是脆塑性转化带非常重要的变形机制之一。关于压溶研究的野外和实验结果很多，但以压溶为主导机制的岩石强度本构方程的研究比较少。本项目拟以相对容易发生压溶的石英岩和大理岩为研究对象，在脆塑性转化带的温压范围内，在差应力存在的条件下，进行压溶蠕变实验，获取实验样品压溶蠕变的力学参数；利用光学和扫描电镜研究实验样品的微观结构与变形机制；通过实验初步建立压溶蠕变本构方程；以此为基础修正脆塑性转化带的强度，探讨压溶作用对脆塑性转化带强度的影响。该项研究对认识地壳流变强度、理解脆塑性转化带变形机制具有重要意义。

以脆性变形为主的浅部地壳和以塑性变形为主的深部地壳之间存在一个明显的脆塑性转化带，压溶作用是脆塑性转化带非常重要的变形机制之一。关于压溶研究的野外和实验结果很多，但以天然岩石为样品，压溶为主导变形机制的脆塑性转化带强度的实验研究比较少。本项目以相对容易发生压溶的大理岩和石英岩为研究对象，获取实验样品压溶蠕变的力学参数，利用光学和扫描电镜研究实验样品的微观结构与变形机制，利用傅里叶变换红外光谱仪测试、分析样品的含水量，研究脆塑性转化带间震期压溶为主导变形机制的物理机制， 探讨压溶作用对脆塑性转化带强度的影响。该项研究对理解脆塑性转化带变形机制及强震孕育和发生具有重要意义。