Exhumation processes of the Sambagawa metamorphic rocks, as inferred from quartz microstructures and mineral radiometric ages

在这项研究中获得的结果已被概括如下。（1）我们已经建立了一个自动测量系统，用于改进的Quartz方向，并使用Zeiss petrographic microscope、数码相机和Macintosh个人计算机。这可能是由R. Heilbronner教授制作的，他于2003年在广岛大学工作了1个月，并在石英Schists从三叶川带和中央Shikoku使用这种方法进行了大量的微观结构研究。这些结果将被提交给一个特殊的纹理物理学卷。（2）桑巴加河和北部的奇奇布腰带之间的地形和边界的差异并不清楚。在这一研究中，我们发现，金泉构造线是两条构造带之间的边界错误，在文学和地质结构中完全不同。（3）我们已经对改进的石英学派进行了详细的地质调查和微观结构分析。作为一个结果，它很清楚，因为它是一个扩展的折叠和故障的模糊，并且存在良好的定义的石英C轴结构是由石英辅助的解决方案-重复处理由微故障在这个区域低温度下破坏的最终实验阶段。（4）我聘请N. Shigematsu博士担任2004年三个月的研究助理。他参加了一个K-feldspar单晶体的变形实验，并在广岛大学使用了一个经过修改的格里格设备。我们发现了K-feldspar单晶体通过机械双绞线和内衬滑动变形，但有时也因物理条件（T=800 ° C，应变率=10^<-5>/s）的故障而失败，建议实验条件可能与英国半导体过渡的那些相关。此外，这些实验性条件可能与ca.400 ° C的温度条件有关，如果自然应变率为400 ° C，那么解释如何在自然界周围融化这些温度的方法。

The results obtained in this research have been summarized below.(1)We have set up an automated measurement system of c-axis orientation of deformed quartz, using a Zeiss petrographic microscope, digital camera and Macintosh personal computer. This was made possible by Prof.R.Heilbronner, who stayed at Hiroshima University for 1 month in 2003, and investigated a lot of microstructures in quartz schists from the Sambagawa belt, central Shikoku with this method. The results will be submitted for a special volume of Tectonophysics.(2)The boundary and difference in the nature of terrane between the Sambagawa and Northern Chichibu belt have not been clear. In this study, we have found that the Kiyomizu Tectonic Line is the boundary fault between the two tectonic belts, which are completely different in both lithology and geologic structure.(3)We have conducted detailed geological survey and microstructural analyses of deformed quartz schist. As a result, it has become clear that an extensive folding and faulting occurred, and existing well-defined quartz c-axis fabrics were destroyed by solution-reprecipitation of quartz assisted by micro-faulting during the final exhumation stages under low temperatures in this area.(4)I hired Dr.N.Shigematsu as a research associate for three month in 2004. He was engaged in deformation experiments of K-feldspar single crystals, using a modified Griggs apparatus installed at Hiroshima University. We have found that K-feldspar single crystals deformed by mechanical twinning and intracrystalline slip, but also sometimes failed by faulting at the physical conditions (T=800゜C, strain rate=10^<-5>/s), suggesting that the experimental conditions can be correlated with those of the brittle-ductile transition. Also, these experimental conditions can be correlated with the temperature conditions of ca.400゜C at natural strain rate, which interprets that feldspars start to plastically deform around these temperatures in nature.