中文摘要：

钦-杭结合带南段发育一系列北东走向的韧性剪切带,防城—灵山断裂带是其中非常重要的一条。综合不同尺度地质构造特征和千糜岩绢云母单矿物40 Ar/39 Ar测年结果,表明钦-杭结合带南段防城—灵山韧性剪切带印支期可能存在两期活动,一期为早三叠世,另一期为晚三叠世,早期活动导致近E-W向变形,晚期形成NE向右旋韧性剪切带。根据千糜岩绢云母40Ar/39Ar年龄数据分析,认为防城—灵山断裂带在印支期发生右旋剪切活动的具体年龄接近于（203.9±1.7）Ma。

英文摘要：

A series of NE-trending ductile shear zones formed in southern segment of Qin-Hang combined belt, and Fangcheng- Lingshan fault zone is a very important one among them. Comprehensive geological features of different scales and the 4o Ar/39 Ar dating results of sericite in fault zone indicate that there may have been two periods of fault activity in Fangcheng- Lingshan fault zone during the Indosinian Movement. One is the Early Triassic when the early activity led to nearly EW-trending deformation; the other is the Late Triassic when the late activity led to the formation of NE-trending dextral ductile shear zone. According to the 4o At/ 39Ar dating results, the accurate age of late activity is close to 203.9±1.7 Ma.