关于岷江断裂若干问题的讨论

Discussions on the Minjiang Fault

本文在野外观察的基础上，结合年代学样品测定资料，讨论了岷江断裂的几何特征、晚第四纪活动性以及潜在地震能力。笔者认为，岷江断裂并不是一条单一的南北向断裂，而是由多条北东—北北东向次级断层左阶羽列而成。由于岷江断裂总体延伸方向的差异，可以把它分为南、北、中三段。中段控制第四纪盆地，并具有晚第四纪活动性。进一步的研究认为，断裂几何特征导致的断层分段对断裂的潜在地震能力具有控制作用。

On the basis of field observation and data about dating, this paper discussed the geometrical feature, late Quaternary activity and potential seismicity of the Minjinag fault.We are inclined to consider that the Minjiang fault is not a single fracture in South-North striking but composed by a series of sub-faults with northeast or north-northeast trending which arranged in left step en echelon. Because of the variations in the general trending,the Minjiang fault can be devided into three segments, the north, the middle and the south. The middle segment controls Quaternary basins and shows activity in late Quaternary. We also believe that the segmentation caused by geometry of the fault may contruethe potential earthquakes along the Minjiang fault.