关键词: 大盈江断裂, 晚更新世, 左旋走滑, 活动

Abstract:

There are evident neotectonic characteristics along the Dayingjiang Fault,with fault landforms developed,such as fault facet,linear ridges,fault troughs etc. ,and clear linear features in satellite images.The Quaternary Basins of Lianghe,Yingjiang,Sanggang and Xipahe are obviously controlled by the fault.Based on field investigation results at home and abroad in recent years,the fault has displaced the Late Pleistocene or Holocene strata,as revealed by the outcrops at Dapingzi,Binghui,Laoxinzhai and Guangyun.At Binghui village,the age of the displaced stratum is(56.56±4.81)ka BP,and on the fault plane,loosely consolidated gouge is developed.The ages of the displaced strata at Laoxinzhai village are(24.80±2.11)ka BP and(28.80±2.45)ka BP.At Xipahe of Myanmar,there is a fault trench developed on T₂ terrace,with 500m in length,12～16m in width and 5～8m in depth,and the terrace formation age is(10.13±0.86)ka BP.It means that the latest active time of Dayingjiang Fault is late-Pleistocene to Holocene,and the fault has been dominated by left-lateral slip,with an average left-slip rate of 1.5～2.5mm/a along the northeastern segment and 1.2～1.6mm/a along the southwestern segment.

Key words: Dayingjiang Fault, late-Pleistocene, left-lateral strike-slip, activity