新疆北天山乌苏南断层晚第四纪活动特征及其构造意义  

LATE QUATERNARY ACTIVITY CHARACTERISTICS AND TECTONIC SIGNIFICANCE OF WUSUNAN FAULT IN NORTH TIANSHAN,XINJIANG

作　　者：陈建波[1] 罗福忠[1] 胡伟华[1] 常想德[1] 谭明[1] CHEN Jian-bo;LUO Fu-zhong;HU Wei-hua;CHANG Xiang-de;TAN Ming(Earthquake Agency of Xinjiang Uygur Autonomous Region,Urumqi 830011,Xinjiang,China)

机构地区：[1]新疆维吾尔自治区地震局,新疆乌鲁木齐830011

出　　处：《内陆地震》2021年第1期30-37,共8页Inland Earthquake

摘　　要：乌苏南断裂组发育于北天山山前的独山子逆断裂—背斜带(第3排)和西湖隆起(第4排)之间,在卫星影像显示为4~5排近平行断层陡坎组成,断层晚第四纪以来断层活动明显,沿断层断错山前冲洪积扇、冲沟和水系,形成断续分布的线性陡坎地貌,开挖地质探槽显示乌苏南断层组为高倾角逆走滑型断裂。依据断层断错地貌面年代,估算断层晚更新世以来的垂直活动速率约0.125 mm/a,右旋走滑活动速率为1.25±0.02 mm/a。根据乌苏南断层带所处的位置及构造特性,推断该断裂很可能是天山山前第3排背斜带与第4排背斜带之间的过度转换断层。Wusunan fault was originated between Dushanzi reverse fault(the third group)and west lake uplift(the fourth group)in front of Northern Tianshan,it was made up of 4~5 near parallel fault scarps according to satellite map.Since the late Quaternary,the fault activity has been obvious.Along the fault,the alluvial proluvial fan,gully and water system in front of the mountain have been staggered,forming a linear scarp landform with intermittent distribution.The excavation of geological trench shows that Wusunan fault group is a high dip reverse strike slip fault.In the age of fault dislocation geomorphic surface,it is estimated that the vertical activity rate of the fault since late Pleistocene is about 0.125 mm/a,and the dextral strike slip activity rate is 1.25±0.02 mm/a.According to the location and structural characteristics of Wusunan fault zone,it is inferred that the fault is probably an over conversion fault between the third and fourth anticlines in front of Tianshan Mountains.

关 键 词：乌苏南 西湖隆起 晚第四纪 转换断层 活动速率 

分 类 号：P315.9[天文地球—地震学]