摘要
滑动速率是研究断裂运动学特征、地震活动性和区域应变分配的重要参数和依据。前人关于甘孜-玉树断裂带滑动速率的研究结果存在较大差异,因此,其晚第四纪滑动速率有待进一步调查研究。本文基于卫星影像解译和野外实地考察,对甘孜-玉树断裂带西段(玉树断裂)上典型断错地貌点进行测量分析,得到玉树断裂晚第四纪走滑速率为6.6±0.1—7.4±1.2mm/a。通过与前人对甘孜-玉树断裂带东段(甘孜断裂)滑动速率的研究结果进行对比,发现甘孜-玉树断裂带东、西段滑动速率不一致,其原因是甘孜断裂的左旋滑移在向西传递的过程中,一部分应变被分配到了巴塘盆地南缘断裂上。巴塘盆地南缘断裂的存在很好地解释了玉树断裂的走滑速率比甘孜断裂偏低的原因。但是,从区域变形来看,巴塘盆地南缘断裂分配的滑动速率恰好说明了甘孜-玉树断裂带东、西段及鲜水河断裂带的水平构造变形是协调一致的。
Slip rate is one of the most important parameters for studying kinematic and seismic activity of faults as well as deformation partitioning. Previous studies on slip rate along Garze-Yushu fault belt are of some controversy. It is necessary to do further research on the slip rate of Garze-Yushu fault belt. In this study we apply several methods such as satellite imageries interpretation, filed mapping, topographic measurement to study typical faulting sites along the western segment of Garze-Yushu fault belt, which is also named Yushu fault. The results show that the slip rate of Yushu fault is 6.6±0.1--7.4±1.2mm/a. Compared with the results of the eastern segment of Garze-Yushu fault belt （Garze fault） reported by Shifeng et al. in 2016, we find there is a discrepancy between the slip rate of Garzefault and Yushu fault. The reason for this discrepancy is that there exists a slip partitioning along Garze fault during its westward transfer process of deformation, which transfer partial deformation to Southern boundary fault of Batang basin. The existence of Southern boundary fault of Batang basin explains why the slip rate along Yushu fault is smaller than Garze fault. Considering the regional deformation, however, the tectonic deformation from eastern to western segment of Garze-Yushu is consistent since late Quaternary.
作者
吕丽星
李传友
魏占玉
董金元
谭锡斌
石峰
苏鹏
Lv Lixing Li Chuanyou Wei Zhanyu Dong Jinyuan Tan Xibin Shi Feng Su Peng(Key Laboratory of Active Tectonics and Volcano, Institution of Geology, China Earthquake Administration, Beijing 100029, China)
出处
《震灾防御技术》
CSCD
北大核心
2017年第3期456-468,共13页
Technology for Earthquake Disaster Prevention
基金
国家自然科学基金项目(41472200)资助
