天山南缘北轮台断裂东段构造变形样式  

STRUCTURAL DEFORMATION STYLE IN EASTERN SEGMENT OF BEILUNTAI FAULT AT SOUTH TIANSHAN IN XINJIANG

作　　者：姚远[1] 陈建波[1] 李帅[1] 宋和平[1] 谢江丽 

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》2017年第4期335-342,共8页Inland Earthquake

基　　金：新疆地震科学基金(201513);我国重点监视防御区"北轮台断裂1:5万填图"项目联合资助

摘　　要：北轮台断裂是一条全新世活动断裂,全长约130 km,构成天山南麓与山前冲洪积扇的界线。北轮台断裂东段(砖厂段)全长8 km,是一条低角度逆冲断层,晚第四纪以来有强烈的活动。通过对变形阶地进行微地貌测量,并选取2个典型变形位置开挖大型跨断层探槽,分析该段断裂的构造样式和演化模式。结果显示,北轮台断裂砖厂段的活动构造样式不是单一的以逆断层作为表现,而是伴随着褶皱挤压隆起,山体向S推挤形成逆冲断层断错地表,在受到来自盆地方向的阻挡,产生反向的挤压应力,沿断层一线构造挤压应力集中,但是在断层的上盘形成拉张区,应力释放的过程中形成了大量小规模的拉张型正断层。The Beiluntai fault is a holocene activity fault,about 130 km,which forms the boundary between the south of Tianshan and the front of the mountain alluvial. The Beiluntai fault east section( brick factory section) lies 8 km,a low angle thrust fault,has the intense activity since late Quaternary. By means of the micro-landform measurement of the deformation terrace and the excavation of the large-span fault trench in 2 typical deformation positions,the structural style and evolution mode of the fault are analyzed. The results show that the active tectonic style of the Beiluntai fault in brick plant is not single with the inverse fault,but along with the folds squeezing uplift,the mountain southward pushes to form the thrust fault surface,in the direction of the basin from the barrier,to produce a reverse extrusion stress,along the fault line structure to squeeze stress concentration,However,a large number of small-scale tensile faults are formed in the process of stress release in the upper disk of the fault.

关 键 词：天山 北轮台断裂 构造样式 

分 类 号：P315.2[天文地球—地震学]