中文摘要：

西秦岭北缘断裂是青藏高原东北缘的一条以左旋走滑运动为主的大型活动断裂。通过卫片解译和野外地质调查，认为断裂西端活动性仍很强烈，并发现切龙沟一带全新世活动特征明显。结果表明，全新世以来西秦岭北缘断裂西端至少有2次古地震事件，说明断裂经过土房村以后活动并没有停止，而是继续向西延伸，最后终止于甘加盆地。

英文摘要：

The northern margin of Western Qinling fault zone （NWQF） is one of the main left-lateral strike slip active faults in northeastern margin of Tibetan Plateau. Through field seismic and geological investigations, we opined that the west segment of this fault remain actively strong. Significant Holocene activity characteristics are found in Qielonggou. Trenches show that at least two Holocene paleoseismic events happened in wes＇t segment of NWQF, which shows that fault activities of NWQF still exist in the west of Tufang village, extend westward from Tufang village continually and finally terminate at the Ganjia basin.