东天山碱泉子-巴里坤断裂带晚第四纪活动习性及其强震行为研究

东天山地区位于天山东段，其最新构造活动是天山复活型造山带的重要体现，对其开展相关研究是完整理解陆内新生代构造变形的必然需求。同时，由于该地区处于构造活动强烈的天山造山带，具有大震孕育和发生的条件与背景。而东天山又恰是国家对外经济战略“丝绸之路经济带”的重要通道，其地震安全性成为当前社会关注的问题。然而，东天山地区的活动构造一直缺乏系统研究。本项目拟选择该地区最重要的活动断裂---碱泉子-巴里坤断裂带为切入点，通过野外追踪调查、关键段落详细考察、探槽开挖等手段，结合高精度遥感资料解译，无人机航拍、LIDAR等先进技术的高精度地貌测量，以及10Be、OSL和14C等多方法联合的年代测定，确定其晚第四纪几何学和运动学特征，分析其活动习性、变形机制和强震活动规律。以此为基础，认识东天山最新构造变形和运动转换方式，探讨其在天山新生代构造变形中的作用；揭示该断裂带的强震行为，评估其未来强震危险性。

The eastern Tianshan is an important part of a major intracontinental mountain range of the Tianshan that is thought to reflect remote effect of the northward motion resulted from the collision of the India with Eurasia, and thus a natural laboratory for studying the fault architecture affected by a kinematic transition. However, work on active faulting in this region has been absent because most attention is drawn by the western Tianshan whose deformation looks more intense. Study of the late Quaternary activity of the faults in this area can help understand the kinematic transition from thrust faulting deformation to left-lateral and thrust faulting deformation in the eastern Tianshan. This project proposal targets the Jianquanzi-Balikun fault, one major active fault in the eastern Tianshan, to study its late Pleistocene behavior that represents deformation of the eastern part of this mountain belt. On the other hand, this area covers the populous part of the Silk Road Economic Belt and historical records show earthquakes of M>7 that occurred along this fault and destroyed the region and caused death. So, we also propose to study the present-day crustal deformation of this fault with the purpose of evaluating seismic hazards. One of our objectives is to quantify the slip rate on the Jianquanzi-Balikun fault. Using detailed geological and geomorphic field investigations combined with analysis of high-resolution satellite images, and Quaternary dating techniques, we will determine cumulative offsets and Holocene slip rates on the fault. Then we will discuss the implications of the data for the role of the Jianquanzi-Balikun fault in the recent deformation in the eastern Tianshan. Our another main objective is to make an earthquake risk assessment for the region by combining historical earthquake rupture and paleo earthquake observations. Such assessments aid our understanding of repeated fault behavior and help us to predict the likely location and magnitude of future rupture events on the fault. These objectives will give a greatly improved understanding of the late Pleistocene activity of active faults and seismic hazard in the area on which this project focuses, and so provide data for dynamical understanding of the whole Tianshan orogenic belt and seismic risk assessment of the fault.