大春河—一朵云断裂断层泥中石英表面 SEM 特征的分析研究

大春河—一朵云断裂位于昆明市的东南侧,沿断层线断错水系、土林地貌发育,河流的最大左旋扭动距离达两公里。断层泥中石英碎砾的SEM研究表明:断层的强烈活动时期为早更新世晚期和晚更新世,全新世断层的活动有所减弱;晚更新世以来断裂的活动方式以蠕滑为主。

SEM FEATURE OF SURFACE TEXTURE OF QUARTZ GRAIN IN GOUGE OF DACHUHE-YIDUOYUN FAULT

The Dachuhe-Yiduoyun fault lies to the southeast of Kunming City. Along the fault line there are a lot of dislocation river systems and earth forests. The maximum left-handed torsion distance of the systems is as long as two kilometres. Having studied the SEM feature of the quartz fragment contained in the fault gouge, the authors have concluded that the intensely-active period of the fault contains the late early-pleistocene epoch and the late pleistocene epoch. The activity of the fault was weak during Recent epoch. Since the late Pleistocene epoch the activity mode of the fault has mainly been creep-slippage.