Study On The Activity Of The Fault Zone In The Northern Margin Of Kuantan Mountain In The Late Quaternary

The Faults in the north margin in Kutantanshan lies in the north of the intersection region of the Altyn Tagh fault and the north margin of the qilian mountain,this area and the jiuxi basin,which is located at the western end of the hexi corridor,is divided by the Kuantanshan uplift.The fault of the north margin of the kuantanshan generally moves towards NE,its total length is 50 km.There are two faults in this zone,one is taerwan-chijiaciwo fault,the other one is ganxiashan-xiatianjinwei fault,the two fracture trends are almost identical,and the median distance is about 10km.The fault tends to the south west,and the south west plate is the ascending disk.The linear steepness along the fault zone is clear,indicating the vertical dislocation characteristics of the late quaternary.It was previously believed that the tarwan-chi jiagaiwo fault zone was a thrust fault with a vertical sliding speed of 0.04 to 0.06mm/a,three surface-dislocation-type earthquakes have been found in the past 35 thousand years.The fault zone of the north margin of the kuantan mountain is characterized by obvious linear characteristics,and the nearly parallel yinwa mountain fault and jiayuguan fault are characterized by right-lateral strike slip,It is not clear whether it is also slippery.It is of great significance to further understand the structural transformation relationship between the eastern section of aljin belt and the northern edge of qilian mountain.On west basin and wide beach area the latest tectonic deformation mechanism,a kind of view is that the east side of the altun fault sinistral strike-slip faulting and play a leading role,another is that thrust tectonic belt of qilian mountains was extended play a leading role in the direction of the north east.Of the former view to the end of the strike-slip fault effect,thus and altun sinistral strike-slip fault zone is 30-35 ° Angle of northern mountain fault zone should be characterized by thrust wide beach or thrust and sinistral strike-slip faulting and;The latter view is that the crust in the direction of south,west and north is shortened in the direction of south,north and east.Therefore,it is inferred that the fault zone in the northern margin of the kuantan mountain in the direction of north and west should be characterized by backwash or backwash and right-handed strike-slip dislocation.Paper fault features of satellite remote sensing image interpretation,on the basis of linear fault along the northern mountain fault zone wide beach landforms clear paragraph implemented a uav aerial survey,to obtain high resolution DEM river geomorphic interpretation and dislocation landform analysis,combined with the field geological landform survey and predecessors’ s testing,quantitative analysis of the fault zone late quaternary activity features.The following understandings are obtained from the study on the northern margin fault zone of the kuantan mountain:(1)The northern foothill of the kuantan mountain is generally developed in three physiognomy planes.The topography of the highest grade is bedrock platform or flood platform,and the topography of the lower grade is river terrace.Since the late quaternary period,the fault of taowan-chi jiajaiwo has been characterized by right-lateral strike-slip fault and right-lateral strike-slip fault.Since the 20ka fault of tarwan-chi jiaxi fossa,the right-lateral slip rate is about 0.56-0.91mm/a,and the vertical dislocation rate is about 0.11-0.15mm/a.(2)Along a stab tal bay-pool home nest fracture photography measurement results were analyzed,and received a total of 38 right-lateral dislocations,dislocation distribution performance of 4.5 m,8.0 m and 14.0 m three peak,the largest peak corresponding to the T2/T1 terrace scarp horizontal displacement of 14.0 +/-1.5 mm,instructs the T2 terrace incised since(19.8 +/0.7 ka ago),a total of three horizontal dislocation event happened,coseismic dislocation quantity from the old new,in turn,is 6.0 m,3.5 m and 4.5 m.(3)Qilian mountain thrust tectonic belt north north east extension is west basin and tectonic deformation of the main driving force,wide beach hill mountain north rim caused wide beach,dextral strike-slip fault zone and north west to fracture rupture,the north to the fracture of thrust faulting and left-lateral dislocation and nearly east-west fracture.