新甘交界北山地区大泉断裂走滑特征及ESR测年证据  

Electron Spin Resonance Dating and Strike-Slip Characteristics of the Daquan Fault in the Beishan Area on the Border between Xingjiang and Gansu Provinces

作　　者：张宇[1] 潘金花[1] 刘畅[1] 郭召杰[1] 

机构地区：[1]造山带与地壳演化教育部重点实验室北京大学地球与空间科学学院,北京100871

出　　处：《北京大学学报（自然科学版）》2009年第1期71-78,共8页Acta Scientiarum Naturalium Universitatis Pekinensis

基　　金：国家重点基础研究发展计划项目(2007CB411305)资助

摘　　要：卫星图片显示穿过大泉断裂的水系有被左行扭曲的特征，结合野外断层面上擦痕、断裂带中劈理观测统计和室内对断层岩显微构造的分析，确定了大泉断裂是以左行为主的走滑断裂带。对断层泥的ESR年代学测定，确定了大泉断裂开始活动时间为早更新世1．2～1．5Ma，其分支断层的活动时间在晚更新世300ka左右。大泉断裂活动时间与青藏高原在上新世末－早更新世初开始强烈隆升时间一致，表明大泉断裂的形成与青藏高原的隆升过程密切相关，是晚新生代印度和欧亚两大板块持续碰撞挤压和青藏高原隆升的远程效应。The left lateral characteristics of Daquan fault was confirmed by： 1 ） remote sense images of the left-distortional drainage system; 2） statistics of scratches on the fault plane and cleavages in the fault zone; 3） micro-characteristics of fault rocks. ESR age of fault gouge indicated the fault movement occurred in early Pleistocene （1.2-1.5 Ma）, whereas the branch faults movement occurred in ca. 300 ka. These data support that the formation of Daquan fault is closely related to the uplift process of Tibet, meanwhile it is also a long-distance effect of the continuous collision between Indian and Eurasia Plate and the uplift of Tibet during late Cenozoic.

关 键 词：北山地区 ESR测年 走滑活动 大泉断裂 

分 类 号：P542[天文地球—构造地质学]