塔藏断裂马家磨段晚第四纪以来活动性研究  

Late Quaternary Tectonic Activity on the Majiamo Segment of the Tazang Fault

作　　者：付国超 张军龙[1] 蔡瑶瑶 FU Guo chao ZHANG Jun-long CAI Yao-yao(Institute of Earthquake Science, CEA, Beijing 100036, China)

机构地区：[1]中国地震局地震预测研究所中国地震局地震预测重点实验室,北京100036

出　　处：《地震》2017年第3期51-60,共10页Earthquake

基　　金：国家自然基金项目(41372215);地震行业专项(201408023);山西省联合研究基金项目(2015012015;2012012003)

摘　　要：近NW向展布的塔藏断裂带位于巴颜喀拉块体东北缘,研究其东部活动性质对于探讨青藏高原东缘形成的动力学机制具有重要意义,也是判断断裂带地震危险性的基础。基于对塔藏断裂东部马家磨段卫星影像解译、地质地貌特征及地表破裂调查,对于其活动性得到以下认识:断裂空间几何展布总体呈NWW走向,倾向NE,起于漳扎镇西,止于沙尕里东南部,全长近60km。自西向东可以分为扎如沟段、唐寨段、勿角段3个次级段落,均为左旋右阶排列,阶区规模较小,最大阶区长约2km。广泛分布的构造地貌和古地震造成的破裂标志表明该段全新世仍有活动,断裂的最新活动时间为480±40aB.P.。该活动断裂为巴颜喀拉块体向东滑移提供了边界条件。The strike of Tazang fault zone which is located in the northeast edge of Bayan Hara block extends in the direction of NW. The research of the east extension and the east end point of the NW trending tectonics are of great impetus to explore the dynamic mechanism of the formation of the eastern margin of the Qinghai-Tibet plateau. It is the foundation of authenticating the danger of earthquake. Based on the interpretation of satellite im age, geological and geomorphological features and surface rupture of the Majiamo section of the Tazang fault, the tectonic activity of the fault is recognized as follows： The Majiamo section of the Tazang fault extends northward to the southeastern part of the Shagali area. The total length is nearly 60 km. The sub-division of Majiasha is Zharu, Tangzhai and Wujiao respectively. And they are all left-lateral. The largest order is about 2 km. The widely distributed tectonic landforms and the rupture signs caused by paleo-earthquake indicate that this section has experienced many tectonic activities, and the latest activity of fault occurred in 480±40 a BP. The active features of the Majiamo segment indicate that the Tazang fault is one of the major faults in the east extension of the East Kunlun fault zone, which is providing an evidence for the Bayan Hara block extending along the East Kunlun fault zone to the SEE ＂escape＂.

关 键 词：东昆仑断裂带 塔藏断裂 马家磨段 几何结构 晚第四纪 地震危险性 

分 类 号：P315.7[天文地球—地震学]