Deformation mechanism of rocks of the Ryoke metamorphic belt as deep process of the inland earthquakes

为了阐明内陆地震的深部过程，我们研究了中地壳深部岩石变形的机制。通过对古变质增生杂岩-辽岳变质带岩石的构造岩石学分析，揭示了石英岩的主要变形机制可能是扩散蠕变或粒度敏感蠕变，而不是位错蠕变。由于扩散蠕变变形岩石的粘度比位错蠕变变形岩石的粘度小三个数量级，因此本文提出的新地壳模型的地壳强度比位错蠕变变形地壳的经典模型的地壳强度弱。研究结果为孕震过程和地壳流变学研究提供了新的思路。

To clarify the deep process of inland earthquakes, we studied the deformation mechanism of rocks that had deformed at the middle crustal depth. Based on results of the structural petrological analysis on rocks of the Ryoke metamorphic belt, an ancient metamorphosed accretionary complex, we revealed that the dominant deformation mechanism of quartzose rocks could be diffusion creep or grain-size-sensitive creep instead of dislocation creep. Since viscosity of rocks deformed by diffusion creep would be three orders magnitude smaller than by dislocation creep, crustal strength for the new crustal model proposed by this study would be weaker than that for the classical model with the crust deformed by dislocation creep. The results of the study provided the new insight on studies for seismogenic process and crustal rheology.