关键词: 断裂构造特征; 活动断裂; 水平走滑运动; 龙蟠-乔后断裂带; 桃源水库;

Abstract: During the preliminary geological survey of the Taoyuan Reservoir, through detailed field geological mapping, and by means of drilling, geophysical exploration and cave exploration, three new fault structures with fracture width of 200～350 m and depth of more than 600 m were discovered in the lower dam site project area, and the three faults developed in parallel with the known Longpan-Qiaohou fault.Through comprehensive analysis and research, it found that the four faults had large development scale, obvious characteristics and complex properties.They were all late quaternary active faults with medium activity and close relationship with each other.They belonged to the same series of fault structures and jointly constituted a fault structural belt with width of 3.5～4 km.The distribution, development scale and activity of fault structure in the project area greatly affected the project design of Taoyuan Reservoir, especially the choice of dam site.

Key words: fault structure feature; active fault; horizontal strike-slip motion; Longpan-Qiaohou fault; Taoyuan Reservoir;