东昆仑断裂带东段玛曲断裂新活动特征及全新世滑动速率研究  

Study on characteristics of new activity and Holocene slip rate along Maqu fault of East Kunlun Active Fault

作　　者：何文贵[1] 袁道阳[1] 熊振[2] 葛伟鹏[1] 刘兴旺[1] 

机构地区：[1]中国地震局地震预测研究所兰州科技创新基地,甘肃兰州730000 [2]江苏省地震局,江苏南京210014

出　　处：《地震》2006年第4期67-75,共9页Earthquake

基　　金：中国地震局南北地震带中强地震短临跟踪项目;中国地震局地震联合基金项目(104073);国家自然科学基金项目(40372086);中国地震局兰州地震研究所论著编号:LC20060015

摘　　要：东昆仑活动断裂是青藏高原东北部一条重要的NWW向边界断裂。玛曲断裂位于东昆仑断裂带的最东段。根据野外考察结果认为玛曲断裂全新世以来活动强烈，主要表现为左旋走滑运动，并伴有正倾滑运动性质。断错地貌特征明显，断裂过玛曲县城以后，沿黑河南岸穿过若尔盖草地向东，直至岷山北端求吉附近。通过两处断错地貌的全站仪器实测和测年资料讨论了玛曲断裂新活动特征和全新世滑动速率，玛曲断裂全新世早期以来的平均水平滑动速率为6．29～5．71mm／a，全新世晚期以来的平均水平滑动速率为4．19～4．03mm／a。The East Kunlun active fault is an important NWW-trending boundary fault on the northeastern margin of the Qinghai-Tibet Plateau. Maqu Fault is the easternmost segment of the East Kunlun active fault. Based on the field investigation, the activity along the Maqu fault since Holocene has been characterized by left-lateral （sinistral） strike-slip and normal slide faulting. The characteristics of dislocation geomorphology are obvious. The fault runs through the Maqu County, and then extends to east along the southern side of Heihe River and through the Ruoergai Grassland, and the end of Maqu fault reaches Qiuji on northern sides of the Minshan Mountain. Moreover, based on measurement of geo- morphologic offset at the two sites by Total Station Instrument and the sample dating, the authors discussed new activity of Maqu fault and slip rate since Holocene. The average rate of horizontal displacement is calculated as 6.29-5.71 mm/a since early stage of Holocene and 4.19-4.03 mm/a since late stage of Holocene, respectively.

关 键 词：东昆仑断裂带 玛曲断裂 滑动速率 活动断裂 青藏高原 

分 类 号：P546[天文地球—构造地质学]