Abstract: The Bolokenu-Aqikekuduke Fault extends over 700km and obliquely cuts the North Tian Shan. The fault is quantitatively studied in this paper based on remote sensing data, field observation, and the analyses of the relationship between the morphology and the climate change. The fault is composed of two portions, the NW-striking western portion and the NWW-striking eastern portion. The western portion is right lateral strike-slip with a rate of 5mm/a, having a length of about 250km and extending northwestward into the Kazakhstan. Along the fault 3～4 rupture zones produced by Paleoearthquakes or historic earthquakes were found. It has the potential for generating strong earthquakes of Magnitude around 7.5. The NWW-striking fault of east portions is dominated by right lateral slip with a rate of 1～1.4mm/a. Relatively small rupture zones, no more than 10km long, were found along this fault. It has the potential for generating strong earthquake of magnitude around 7. The western section of the Bolokenu Aqikekuduke Fault is one of the major NW-striking right lateral strike-slip faults in central Asia, and it is the result of the regional clockwise shearing. It accommodates the different deformations between western and eastern Tianshan and transforms the tectonic deformation among different compressive area. The NWW-striking fault of eastern section was developed from the NWW-striking suture zone in Northern Tianshan. It is accompanied by the E-W-striking thrust system in the front of the mountains and makes up a typical strain partitioning style of the oblique compressive belt. The strain in the oblique compressive belt is partitioned into pediment thrust belt and intermontane strike-slip fault. They transform the deformation laterally along the mountains and directly toward the foreland basin.

Key words: strike-slip fault, Bolokenu-Aqikekuduke Fault, strain partitioning, earthquake deformation zone, active fault, Tian Shan

摘要： 利用遥感资料,通过野外实地考察并结合气候地貌事件的分析,对斜切北天山、长逾700km的博阿断裂(博罗科努-阿齐克库都克断裂)的右旋走滑运动进行了定量研究。该断裂分为西部NW向断裂和东部NWW向断裂。西部NW向断裂长近250km,向西北延伸进入哈萨克斯坦,右旋走滑速率可达5mm/a;由4～5个断裂段组成,其上发育3～4条古地震或历史地震形变带,显示具有发生7.5级地震的能力。东部NWW向断裂右旋走滑速率1～1.4mm/a;其上发现小规模古地震形变带,显示具备发生7级左右地震的能力。该断裂与山前的逆冲推覆构造之间构成典型的挤压区应变分配形式,即在斜向挤压作用下,变形分配为山前的逆冲推覆构造和山内的走滑断裂。

关键词: 走滑断裂, 博阿断裂, 应变分配, 活动构造, 地震形变带, 天山