关键词: 走滑断层, 水平位移, 晚更新世, 滑动速率, 博罗可努断裂

Abstract: The Boluokenu fault is the boundary between the north and middle Tianshan, and has many periods of activity. Microgeomorphology related to fault activity, gully right-lateral displacement, fault scarp, pull apart basin occur along the fault in the southeast of Jinghe county town to Alashankou. Large gullies on the alluvial-pluvial fan are cut by the Boluokenu fault, the largest right-lateral displacement is about 500m, and its average is 400m. Some small gullies which only developed on the fault scarp have been cut by the fault. Its right lateral displacement can be divided into four groups in displacement values, i.e. 2.4～4.0m, 5.7m, 8.3m and 15.3m. The height of the fault scarp can be divided into three groups of which the value is 1.2m, 2.51m and 3.63m, respectively. In the southwest of Alashankou, right-lateral displacement for small gullies is 1～1.7m. The heights of the fault scarp on deferent geomorphic surface are 0.55m and 1.2～1.5m. All these didplacement values may indicate that the horizontal and vertical displacement of characteristic earthquakes on the segment is 3m and 1.2m, respectively. The age of the alluvial-pluvial fan in southeast Jinghe is about 70 ka old by geomorphic dating, and the right-lateral slip rate is 4.7mm/a.

Key words: Strike-slip fault, Horizontal displacement, Late Pleistocence, Slip rate, Boluokenu fault