阿尔金断裂东段断层滑动方式的研究

STUDY ON THE MODEL OF SLIPPING ALONG THE EASTERN SEGMENT OF ALTUN FAULT ZONE

采用宏观、微观相结合的方法 ,对阿尔金断裂东段断层滑动方式进行研究 ,结果表明 :(1)阿尔金断裂东段由多条羽列状次级断层所组成 ,相邻两次级断层间的夹角 :A段 <15°,B段 <12°,C段 <5°;(2 )断层物质具明显的组构现象 ,眼球状流动构造 ,较小的剪切破裂角等是阿尔金断裂东段断层蠕动的结果 ;(3)断层泥石英碎砾 SEM特征显示阿尔金断裂东段 Q3以来主要是蠕滑 ,但不同区段稍有不同。综上所述 ,阿尔金断裂东段断层活动主要是蠕滑 ,愈向东其蠕滑程度愈高。

The mode of slipping along the eastern segment of altun fault zone is analyzed through both macroscopic investigation and microscopic study. The results show that:(1) the eastern segment of Altun fault zone consists of en echelon subsidiary faults.It seems that creep slip will easily occur along the segment, where the angle between the subsidiary faults is less than 15°;(2) strong preferred orientation, augen structure, and small shear angle developed within the fault materials are the indications of creep slip along the eastern segment of Altun fault zone;(3) scanning electron micoscopic observation of quartz grains from the fault gouge has revealed that the recent movement along the eartern segment of the Altun fault since Q 3 is dominated by creep slip, but the intensity of slip is variable at different positions of the segment.The mode of movement along the eastern segment of the Altun fault zone was dominated mainly by creep slip, and the intensity of creep slip increases toward the east.