【摘要】 乌什逆冲断褶带位于南天山库车前陆逆冲褶皱构造带的西段,对该地区晚新生代构造活动的研究有利于加深对南天山前陆逆冲构造带的认识。本文通过对卫星遥感影像和DEM数据的解译分析,并结合研究区野外考察及典型地震反射剖面的分析,表明乌什逆冲断褶带东部地貌演化受褶皱生长影响较为深刻,发育一系列由新到老的冲积扇和风口。台兰河中游河流阶地和冰碛物均被秋里塔格断层错断,阶地断距为3.1～6.7 m,台兰期冰碛物（M₂）断距约80 m。秋里塔格断裂第四纪以来水平缩短速率约为1.23～1.59 mm/a。西部地区发育一系列逆冲断层,并发育典型的活动断层陡坎。乌什凹陷地震活动也具有明显的西强东弱的特点,地震活动具有沿断层呈带状分布的特点。乌什逆冲断褶带位于南天山造山带东西构造的转换地带,地震活动西部明显强于东部,且具有呈带状沿南天山及其山前逆冲断裂带分布的特点。历史地震分析表明上个世纪以来该区域未有7级以上地震发生,但其西部地区6级以上地震频发,随着阿克苏地区区域经济的快速发展和人口的快速增长,乌什逆冲断褶带的地震活动性应该引起地质学家更加深入的关注和研究。更多还原

【Abstract】 The Wushi thrust-and-fold belt is an important structural transfer zone,which is located on the western segment of the Kuqa thrust-and-fold belt in the southern Tian Shan. Based on analysis of satellite images and DEM（digital elevation modal） data as well as field observations, our work suggest that the geomorphology evolution of the east part of the Wushi sag was strongly affected by folds propagation. A series of alluvial fans and wind gaps, which become younger from west to east, indicate that the Kumala River has diverted eastward with the uplifting and eastward growth of Tumuxiukexi anticline. The Qiulitage fault displaced fluvial terraces of the Tailan River with fault scarps from 3. 1 to 6. 7 m. Meanwhile, the vertical displacement of moraine deposits （ M₂ ） during Tailan glacial period reaches 80 m. The vertical displacement implies that the shortening rate of 1. 23 ～ 1. 59 mm/a on the Qiulitage fault. Earthquake activities are not uniformly distributed along the Wushi fault-and-fold belt, and the western part is stronger than that in the eastern part. Distribution of seismicities has a close relationship with active thrusting faults in the Wushi thrust-and-fold belt. Historical seismic events related to active thrust-and-fold belt are not larger than magnitude of 7 in the Wushi-Aksu region during the last century. However, large continental thrust events with magnitude ≥6 were frequently occurred in this region. Thus,we should pay a great attention to continental thrust events in the future with rapid growth of population in the Aksu area.更多还原